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Messages - jrista

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Landscape / Re: Deep Sky Astrophotography
« on: April 04, 2014, 02:28:47 AM »
Hi Reinz. When it comes to astrophotography, the mount is pretty much the most important thing. Most astrophotographers who have even moderately diverse goals (i.e. just galaxies and nebula) are going to need to use multiple telescopes with different focal lengths, or at least one telescope with barlows and focal reduces, to get a field of view wide enough or narrow enough to frame their subjects properly. A good mount can last you for many, many years, where as telescopes (or, for that matter, camera lenses) usually come and go until you hit the real high end (i.e. 20" RCOS or PlaneWave telescopes).

For $1000, you can get yourself an entry-level mount. Something like the Orion Sirius, which is the little sibling of the Orion Atlas. The Sirius has a capacity of 30lb, which for visual is generally fine, but that pretty much equates to 15lb for astrography (the Sirius doesn't have the most sturdy tripod, so you REALLY have to stick to the 50% capacity limit for imaging work). That is practically nothing in terms of capacity, but if you just stick to your DSLR and lenses, it'll at least get you started.

The Orion Atlas is a much more capable mount, it's capacity is 40lb, however imagers have been putting on 60-70% of the capacity and getting excellent results. Visual observers have put over 50lb on this mount when using sturdier tripods or full blown piers. The Orion Atlas is $1499, however it's fairly frequently on sale for $1399, and at times has been as low as $1200. Given how important the mount is, especially if you think you might want to move up from your lenses to a real telescope at some point in the future (and entry cost for telescopes can actually be pretty low...for example, the Astro-Tech AT6RC, a 6" Ritchey-Chretien telescope, is only $399 and it's designed specifically as an astrograph.) If you can muster it, I highly recommend getting the Orion Atlas mount, even though it's more than your $1000 budget. It will give you LOTS of room to grow in the future if you find that you like astrophotography (it could even be "the" mount you use for the next ten or twenty years....many people used the predecessor to the Atlas/EQ6 class mounts for about that long.)

From your existing equipment, the 5DIII hands down. Don't use a Nikon for astrophotography...their nickname in our community is "Star Eaters", since they clip to the black point, rather than using a bias offset (one of the many ways Nikon "cheats" their way towards cleaner shadows :P.) Canon's use of a bias offset is the reason there is a lot of banding in their shadows, which isn't good for regular photography. However since in astrophotography we use bias frames to remove the bias from the signal, Canon DSLRs are actually a lot better...they preserve more stars and deep nebula detail. So definitely use the 5D III.

You have a good range of lenses as well for "wide field" work. The 40/2.8 @ f/4 and 50/1.4 @ f/3.5 are both excellent for "whole constellation" images (for example, you could image the entirety of the core Orion constellation, as well as most of his club and kill: The 100mm Macro @ f/4 is a great lens for imaging entire small constellations, or for imaging parts of larger constellations (for example, it would neatly encompass the core of Orion, but not his club or kill: The 70-200 at 200mm @ f/4 is great for narrower regions, small constellations (for example, 200mm would encompass Orion's Belt and Sword, and the small reflection nebula M78: The 100-400 at 400mm @ f/8, while a bit slower and probably requiring more equipment (such as a guider, which itself would probably require a number of additional accessories to properly mount next to your camera), is good for imaging nebula themselves (for example, it would encompass just Orion's sword, which includes Orion Nebula (M42/M43) and Running Man Nebula:; or it would encompass just Orion's Belt, which includes Horse Head and Flame Nebulas, IC434, and a number of small reflection nebula:

If you go with just the mount, you will be able to attach your DSLR and a lens. The 100-400mm is probably not quite going to work, as you would need pretty steady tracking to image at f/8...that's pretty slow. Were talking 1" (" means arcsecond, ' means arcminute, 60 arc minutes per degree) tracking, which is not easy to achieve. So your probably going to be stuck at 200mm and less until you decide to upgrade. Thing is, that is really the best place to start anyway, as at those focal lengths, tracking error is really forgiving, so you should be able to track for several minutes, maybe as much as five minutes, without appreciable star elongation or trailing, allowing deep exposures of wide regions of the sky (which, during the two times of year when the milky way is up, are PACKED with IMMENSE swaths of nebula).

Unguided imaging is basically the domain if the wide and ultra wide field. If you want to see the kinds of images you can get at those scales, you should check out AstroBin. Plenty of good examples there (better than anything I've done as of yet.)

If you get an Orion Sirius mount, which is $1000, then that will suffice for DSLR with 200mm and less. You'll need to get a better mount than that if you want to do more. There are a lot of small APO refractors on the market, ranging in price from around $500 to as high as $10,000 or more, however most of the smaller, lighter ones that would work on a Sirius fall into the same general focal range that you already have with your Canon lenses (200mm to ~800mm). The logical upgrade for you would be to eventually move to a Cassegrain type OTA (Optical Telescope Assembly). Cassegrains include your standard SCT (Schmidt-Cassegrain Telescope), the Celestron EdgeHD (an Aplantic SCT, designed specifically to support a wide and flat field, right into the corners, for imaging), and the Ritchey-Chretien cassegrains (primarily those from Astro-Tech.) Meade also makes some Aplantic SCTs like Celestrons, however they tend to be more expensive, despite not really offering anything more, and there is one special benefit to the Celestron EdgeHD OTAs: They support Hyperstar, a special conversion mod that allows you to do ultra wide field imaging (~200-400mm) at f/2 (REALLY could get really deeply exposed images in a couple minutes at that aperture.)

Generally speaking, the best upgrade from DSLR+Camera Lens imaging is to move to something like the Celestron EdgeHD 8" SCT, or the Astro-Tech AT8RC 8" Ritchey-Chretein. Both are reasonably priced, although Astro-Tech's prices are really hard to beat for the quality, optical design, and overall capabilities for imaging. For either of these, you would really want at leas the Orion Atlas (or the equivalent from Celestron, the CGEM or CGEM DX, however the Atlas is really the better option due to the rich community, EQMOD, and the option for installing belt mods to improve tracking and guiding accuracy down the road.)

My recommendation is pick up the Orion Atlas EQ-G, and use your 5D III and 50mm, 100mm, and 70-200mm lenses. You should be able to just bolt your camera to the included Vixen dovetail that comes with the mount, and not bother with purchasing any additional accessories initially. You will need to learn how to polar align the mount (the Atlas comes with a built-in polar finder scope, which once properly centered (the most annoying thing you will ever do, but thankfully you only have to do it once! :P), is highly accurate and easy), and you will need to either learn how to use the hand controller to "Align GOTOs", or purchase a $40 EQDIR cable, use EQMOD, and completely computerize your process (HIGHLY recommended, you can buy BackyardEOS ($50) to greatly simplify your imaging sequences, and gain a lot of powerful features, such as highly precise live view focusing on your laptop or a windows 8 tablet, to get the best results.)

Landscape / Re: Deep Sky Astrophotography
« on: April 04, 2014, 12:26:44 AM »
Interesting, and I do like the color detail of the nebula, but overall it just looks softer than I'd like. 

It's a nebula...they generally tend to be "soft", what with being a bunch of whispy gas and all. ;P As for the stars, I purposely "decrispified" them and made them rounder/softer because otherwise they completely dominated the image, making it difficult to actually see the nebula. Part of the reason my stars end up too bright and crisp is the centroids are getting just a touch clipped during my exposures (necessary, to expose the nebula properly), and during processing the centroids get enlarged. So the star reduction routine is really just restoring the proper look to the stars anyway.

simply fantastic!  it feels like i'm looking at it through an ultra powerful telescope.

Thanks! Rosette is actually a fairly large nebula. It's larger than the Orion Nebula, which you can sort of see with your naked eye, too large even to fully fit in my 600mm FoV. The entire region is probably a bit bigger than your thumb  if you held it out about a foot and a half from your face over the sky...just to give you an idea of how large this region of space actually is. ;) Sadly, Rosette is so dim that unless you had a really garganguan telescope with  multi-foot sized aperture, you probably could never observe it visually.

Actually the stars in this image appear does really the entire image.  Just calling it like I see it.

Indeed, soft exactly as they are supposed to be. ;) No one wants HARD stars in their astrophotos...they are overbearing and dominating, and distract from the rest of the image, from the more interesting aspects of the image.

EOS Bodies / Re: Canon's Medium Format
« on: April 04, 2014, 12:25:14 AM »
The first generation foveon sensor was available in the early or mid 2000's, it was before 2008.

Your post is insulting and I'm reporting it for abuse.  I am not a small, weak man.  You are the small weak man, who attempts to compensate for your shortcomings by posting lengthy forum posts.

Please, report away. There is a very healthy trail on these forums that clearly demonstrates who the antagonist is, in EVERY case. You, Carl, are a very antagonistic individual. It isn't just me you antagonize, you poke and prod and insult otherwise antagonize anyone who seems to disagree with you, the only difference between me and them is I'm tired of letting you get away with it.


Let's see if we can get to the bottom of your mental disorder, and figure out a way to help you LEAVE IT BEHIND when you decide to come onto these forums and participate in a public community. I'm tired of having you insult and berate everyone you dislike because they have disagreed with you, or proven you wrong, or called you out. I'm HAPPY to be friendly and cordial with you on these forums. There is evidence all over these forums that clearly demonstrate you as being the instigator, and me regularly ignoring your antagonism, and in every case I've always only ever RESPONDED to your insults, never instigated them myself. So go ahead, report away.

It does sound as though the 70D has similar AF jitter issues as the 7D. If you have a 5D III now, then I have to say, you will probably be disappointed in the consistency of the 70D AF. When it locks, it's pretty accurate, but it doesn't maintain the lock well...AF constantly shifts around, and it can result in soft detail. I've had this problem with my 7D, it happens with a lot of 7D's, and it's the biggest problem with these cameras.

My AF jitter is the reason I'll be getting a 5D III this year.

I honestly cannot fathom why you would sell off the 1D IV (unless you were seriously strapped for cash, which if that's the case, well then I understand ;P).

For as good as the 70D may be, it is good "within it's class". The 70D doesn't hold a stick to the 1D IV. The 1D IV may be "older", but it is still a vastly superior device. It has better noise  handling, better color, higher frame rate, more features, better features, and (at least IMHO) has the wonderful APS-H sensor size with larger pixels than the 70D (so better dynamic range.)

Outside of the "strapped for cash" situation, there is no way in good conscience that I could recommend you trade the 1D IV for the 70D. From a functionality, capability, and IQ standpoint, your trading DOWN, WAY DOWN, and I truly think you would regret the decision.

Lenses / Re: Philosophical question about Sigma Lenses - Why?
« on: April 03, 2014, 04:01:35 PM »
Just out of curiosity thanks to a conversation in Marketing 101 - why would a company like Sigma create products for other brands, specifically lenses for Canon? I'm curious about the thought process that went into a decision by such a company to create accessories and devices for someone else's products since they already have their own line of camera bodies...

There have been a bunch of good answers from other people, so I'll take a different tack.

I'm not sure the question needs to be "philosophical"...I think it really just boils down to a question of mere survival. If it wasn't for the fact that Sigma made lenses for other brands, there probably wouldn't be a Sigma! ;-P I mean, when you get right down to it, Sigma's cameras have basically "nil" for market share. Of the total camera market, Canon, Nikon, and Sony command some 87-92% (depending on which years data you reference, from the last 10 years). On average, there has been about 11.5% "other" market share, and from that 11.5%, Sigma doesn't even come up in any searches, graphs, charts, or tables, indicating it's share of that share is only a few percent.

Without lenses, Sigma's ~1-2% market share in cameras wouldn't be enough to keep them alive. They wouldn't have any money for R&D of any kind, let alone for lenses. Sigma is a lens company first and foremost, and they have become a good lens company. They are a camera or general photography company a distant second.

So, why does Sigma make lenses for other brands? Because THAT is their business: Lenses. :) (Just to be clear, I'm not bashing Sigma for this. I applaud Sigma for moving beyond their prior status as an "Decent" lens manufacturer in years past, and have moved into the realm of "Great" lens manufacturer. It's just that, quite simply, that's what Sigma is...a lens manufacturer. They aren't really a full blown imaging company like Canon or Nikon...who's core businesses involve several lucrative divisions and large, broad R&D departments spanning multiple markets from medical to industrial to cinematography to photography. Sigma's primary business is lens design and it's no surprise they produce lenses for third parties as well as their own cameras.)

Third Party Manufacturers / Re: How to Annoy a Photography Snob
« on: April 03, 2014, 03:52:44 PM »
Last weekend, I went out to the desert with the local natural history group and saw a huge guy with muscles on muscles, shooting with a big Nikon D4 + 800mm lens, holding them with just one hand ... obviously he was showing off to some of the ladies there,

One hand, as in the shutter button hand (gripping the camera, and letting the lens "hang off" the front)? That guy is crazy!! I'd be worried about the stress on the mount by such a huge lens... People HAVE sheared off their supertelephoto lenses right at the lens mount, and it doesn't seem to take as much force as you would expect.

EOS Bodies / Re: Canon's Medium Format
« on: April 03, 2014, 02:39:28 PM »
You can clearly see that the D800E has at least twice the real-world "resolution" (read that as spatial resolution or resolving power, not width and height image dimensions) as the SD1.

The only thing I clearly see, are the both corners you mentioned. Yepp, the line is smaller and more accurate, but that's the only sweet spots for the Nikon, the 98% percent of the (for me) important picture is in the center, where the D800E just compounds every wire with each other into a heap-meshup . Try to find the one diagonal wire in the lower center. It's not visible and it's not visible in the Pentax 645D (!) eighter.

The Sigma shows it clearly... for me the results are by far better than the Nikon. Maybe we talk at cross-purposes, but if that's not resolution or sharpness or spatial whatever than may it be. Whatever it is, I like it. I want it. I want it THAT way.

You CAN see the diagonal threads in the D800 image. I can see them fine, it's just that those threads are dark, rather than light...but at the same time, they are dark and much more finely delineated than the SD1 image. I'm not sure if you guys just don't have that great of eyesight, or if you are just subconsiously not seeing what you don't want to see here, but those "diagonal wires" (it's thread, btw, since were talking about a fabric swatch) are MOST DEFINITELY visible on both the D800 and 645D images. They are far sharper and clearer in both the D800 and 645D as well...the only difference is their contrast with the rest of the threads.

Again, that could EASILY be due to how they illuminated the scene when taking the SD1 sample shots. I've seen plenty of other samples of that same scene for other cameras where those diagonal threads were more or less visible, and the vast majority of them are from bayer sensors. Because of that, I'm suspecting even more that how well those diagonal threads show up is due to lighting, and possibly color balance (the color balance of the SD1 image is quite different than the D800 and 645D images...that affects color contrast, and if one was to change the color balance of the D800 and 645D images, they could probably enhance those diagonal red threads of the foreground mesh vs. the background blue fabric). DPR doesn't maintain that sample scene to perfection...there are LOTs of little changes that occur from camera review to camera review...slight changes in the orientation of the feathers, slight changes in lighting or light angle, etc.

I truly think you are latching onto a facet of those images that really has nothing to do with the sensor, and more to do with the scene. That's the danger with custom test setups, especially ones that have the potential to change or that aren't performed with the utmost care with EXACTITUDE in all the details (like lighting). You don't get directly comparable results, or at least results that can lead to the kind of confusion you guys are having now.

The only thing I could admit is that the lense of the nikon was limited, as not even the Zeiss OTUS is able to serve the Nikon to the fullest (29MP was counted @DXO). I think you don't want to see, what I see  (or vice versa) ::)     But let me say, those Sigma FoveOn Pictures are available with my Pocket DP3M, too. You just don't need the ultra-highpriced lenses, you can do this with the Kitzoom (17-55 2.8) of a SD1 or with a 50mm 2.8 @DP3M.

It's nothing to do with me no wanting to see something. I'm talking about something very specific and measurable: spatial resolution. You are talking about something more ephemeral, more subjective: aesthetics. It's different things, but your conflating a particular aesthetic result (from the SD1) with a technical fact (spatial resolution or resolving power). The Foveon sensors that exist today have considerably less "resolution" (spatial resolution/resolving power) than bayer sensors that exist today. The math, the science, the physics, the facts, even visual examples all confirm that.

You and Carl are talking about the much more subjective qualities of the Foveon. You, personally, like the color contrast, color balance, color tone, whatever it is that the SD1 produces. Thats perfectly fine, everyone has their personal preferences for OOC color and sharpness. The SD1 certainly has a unique color, given it's design, and is definitely sharper as far as OOC results go. Subjectively, as far as personal preferences go, the SD1 has a lot going for it, obviously, as it definitely has it's fans.

My problem with Foveon (and rather, not so much Foveon as with how Sigma sells Foveon) is the way they use very missleading marketing that clearly seems to be brainwashing potential customers into thinking they are getting more than just better color fidelity and better OOC sharpness. Foveon is what it is, it has it's strengths, but it has it's weaknesses as well. Foveon's weakness is spatial resolution. Bayer has it's strengths, and it has it's weaknesses. Bayer definitely has far higher resolution these days, but suffers a bit in terms of color fidelity and color noise and color moire (unless an OLPF is used, which eats away a tiny bit at maximum resolving power.)

I rarely use my DP3M, I'm mostly a Canon 5D kind of guy (yes, the first one, on purpose)... and the other time I often use my Zenza Bronica ETRSi (645 mediumformat, analoque). But if I decide to go out with a tripod and shoot landscapes, nothing came close to the foveon. They can't match the pictures and the tests were with the Sigma 35mm 1.4 ART. So this shouldn't be the weak point of the system.

Well, we'll just have to agree to disagree here. I've had my Foveon phase, and I've seen all the wonderful images those cameras can take. That said, I'd take a D800E or, for that matter, even a Sony A7r, over a Foveon for landscapes these days. I am not a resolution junkie myself...most of my work is action, and I appreciate different attributes of DSLRs more than resolution...namely AF system and performance, frame rate, buffer depth, and high ISO noise and high ISO DR. In the past, I think Foveon was a great choice for landscapes, given its sharpness and blues. However...that was, things have changed.

When it comes to landscapes, that is the one area where I'll take all the resolution you can possibly give me. I think that is the general consensus among landscape photographers as well. Resolution, and even more importantly dynamic range, are truly KING when it comes to landscapes. In that respect, the D800E trounces all, hands down, no question, even the SD1 Merrill doesn't hold a stick to what the D800 can do. I'd also offer that, among DSLRs with bayer sensors, the D800 offers the best color fidelity around, and can rival the Foveon itself at ISO 100 (which is mostly thanks to it's dynamic range...Foveon just doesn't have the kind of DR that the D800E does, and despite it's superior design for color, it's noisier, and that hurts it at ISO 100 vs. the D800E (which has the cleanest color and lowest noise of any camera I've ever seen to date...I don't think even the A7r is better, although it might be more convenient)).

I'd be happy to produce a demonstration of this fact, if I could find a place to rent the SD1 Merrill (I honestly don't know of any rental places that offer Sigma cameras.) There really is no contest here, the D800E will pretty much stomp all over any other camera from a landscape perspective, with the possible exception of the A7r, in terms of resolution, dynamic range, color fidelity, sharpness, etc. Since it's twice the megapixel count of the SD1, I could also downsample, and the gap between the two would only increase. If anyone is willing to let me borrow their SD1, if anyone has one, I'll rend a D800E, because I have absolutely no question in my mind that I can prove this case beyond any shadow of a doubt. ;-) Sorry to be so forceful about it, but I really want to debunk the notion that for landscapes especially, the Foveon is in any way "the best" or "unbeatable".

Landscape / Re: Waterscapes
« on: April 03, 2014, 01:34:22 PM »
Really wonderful images lately, everyone! WildlifeAndMore, that Jackson Lake photo is amazing. That is such a beautiful region, one of my favorite (and I only get to it every few years! :o)

EOS Bodies / Re: Canon's Medium Format
« on: April 03, 2014, 01:07:08 PM »
Sure. As I've said, I have nothing against the concept, at all.

I truly, honestly believe that does Foveon a disservice. Not everything is about megapixel count.

Sigma should be marketing their DP series of cameras on the STRENGTHS of Foveon, instead of fabricating fanciful "megapixel equivalency" numbers and the like. They are undermining Foveon that way, when it IS such amazing technology.

If you were being honest here, you would own one yourself.

If a camera with a Foveon sensor was available in late 2008/early 2009, I very probably would. However, Foveon was a mythical beast back then...the sensor was designed, but Sigma did not own it at the time. There WAS no Foveon camera. So I ended up with Canon. I'm now bought into the Canon system. I own tens of thousands of dollars worth of Canon lenses. Canon cameras are better for astrophotography. I have no reason to switch now.

You obviously are trying to have it both ways, trying to appear unbiased.  You frankly have everything against this concept, when it comes to this manufacturer. Admit it, you don't like Sigma as a company, you would not buy any of their lenses or cameras. 

I have absolutely no qualms about admitting I am biased against Sigma's handling of Foveon. I think they are doing it an injustice. I haven't NOT admitted that, as a matter of fact, I've been pretty up front about it! Beyond that, please don't try and put words or opinions in my mouth. As I've told you many times in the past, you really do not know me, Carl. You are a small, weak man who has to poke and jab from the sidelines, because you are too afraid to just stand up and be strait with anyone. So you poke and to prod and you bait, just like your doing here now. I'll be strait up and honest again: I find that to be pathetic and distasteful. Especially on a public forum like this.

So here's the truth. I'm not against Sigma in general, I think their recent lenses are EXCELLENT, and I applaud them for providing some competition on that front for Canon and Nikon. I GREATLY appreciate the fact that Sigma exists and is continuing to produce quality lenses, especially for short focal lengths/wide angles. I've had my eye on the Sigms 35mm for a while, and I may buy one of their wide angle zooms. I'm not against buying Sigma, so long at it meets my own personal quality standards. I hope they stick around, too, for the long run. I truly do not care for their cameras. I have absolutely no problem admitting that. It's my opinion. Everyone is entitled to their opinion, and I have no reason to hide mine. I think they have potential, but Sigma just doesn't put the right kind of effort into their cameras. I've found their firmware to be very lacking, to be more specific, and I am definitely not the only one. They have made strides over the years, but their progress on the ergonomics, functionality, and firmware front is too slow. They would have to rival Canon's ergonomics and firmware for me to take much interest in them. I'll be quite frank here, it wouldn't matter if Sigma used a bayer type sensor or the Foveon in their cameras...that isn't the reason I wouldn't buy one.

But The difference between you and me is, I've owned a foveon camera, the one with the sensor you deride most (and I currently own 2 Sigma lenses at the moment).  It simply had more resolution than its native 4.6 MP dimensions...I'm sorry but it just did.  You can rely on math all you like, but the proof is in the using, and viewing.  To say that it only had 4.6 MP of resolution is utter nonsense.  Plenty of reviews have backed me up on this.

Take a look at my recent reply to VSCD. I used his own sample images to prove, visually, the difference in resolution between the SD1 and the D800. The difference is very obvious. If there was a tiny difference, it wouldn't be obvious. From a pixel size standpoint, the SD1, which has no AA filter AND requires no interpolation, has at least 2.5 pixels for the fiber widths of the finest strands of thread in the upper right corner (in some cases it seems to be close to 3px). The D800 has about 1.25 pixels for the fiber widths of the finest strands of thread in the upper right corner. That is a spatial resolution difference of at least 200%!! That sounds about right...15mp vs. 36.3mp. From a SPATIAL resolution standpoint, Foveon sensors cannot be measured by their photodiode count. They have to be measured from their literal pixel count on the sensor (each Foveon pixel has three photodiodes). So yes, your camera has 4.6mp of "resolution"...spatial resolution, or resolving power. There is nothing you can do about it.

As for the Quattro sensor, I have no idea why it has fewer photodiodes for the other color channels...but frankly, if they are making the camera produce a 39 MP jpeg, then logic would dictate that it is resolving at least somewhat more than 10 MP.

You can create a 39mp JPEG simply by upscaling. However again, I have provided a demonstration of how upscaling does not increase resolution by using VSCD's own images. Go see for yourself. Sigma can upscale to their hearts content, it doesn't change the fundamental laws of physics that govern how much real resolution you have.

With a bayer array, you don't have 18 MP of all three colors of photodiode in your 7D.  You have far less than that.  And yet you're happy with the results you get.

Your right in that I don't get 18mp of "colors". I get 18mp of "luminance", I get less than 18mp of "chrominance". Again, I haven't been trying to hide that fact. I've been very explicit in my answers as to the terms I use. Again, refer to the SD1 vs. D800 GIF I posted. LUMINANCE resolution in a bayer sensor is "full" get 18mp, or 20mp, or 22.3mp or 36.3mp, whatever it is. Your CHROMINANCE (color) resolution is LESS than full, because of the interpolation. That causes a loss in color fidelity (color accuracy, natural vibrancy, color contrast), but it does NOT cause a loss of spatial resolution.

I really don't know how many times I'll have to say that before it sinks in. I'm not obfuscating the facts here, I'm trying to expose them. I guess you guys will have to remove the scales from your eyes first, though, because the message really doesn't seem to be sinking in.

Again, the proof is in the using, and the images, and less so the math.  Math can be used to predict things like a rise of 10 feet in sea level over the next 20 years due to that nasty old capitalism, but how accurate, honest, and complete is that math?

Sure, the proof is in the images. I think I proved with the little GIF I posted that the D800 has about twice the spatial resolution as the upscaled SD1 image. Math and theory simply model reality, physics. Use and sample images cannot violate the laws of physics here, there is no magic bullet that will somehow make a 15mp Foveon have the same spatial resolution as a 36.3mp D800E, or even a 36.3mp D800 with AA filter. It just can't happen.

I'm not exactly sure how the bit about rising sea levels has anything to do with the debate here. That is less based on math and more based on speculation and assumption...the prediction about how much sea levels might rise is indeed mathematical, based on the volume and density of ice found at the poles, however whether the prediction comes true or not is not based on math, it's based on the (probably mistaken) assumption that global temperatures will continue to rise. Since August 2013, global temperatures have taken a deep dive...when Arctic sea ice was supposed to disappear entirely in August, instead it was at it's greatest extent in decades. Where the winter this year was supposed to be mild, it's been record-breaking cold.

Don't conflate speculation with math. I'm not speculating about Foveon...Foveon is no longer some mythical sensor that is predicted to materialize at some future date. Foveon is a concrete thing that actually exists, has explicit specifications, and HAS BEEN measured with enough accuracy to prove that math and reality, a far as it pertains to Foveon, DO correlate.

EOS Bodies / Re: Canon's Medium Format
« on: April 03, 2014, 12:44:46 PM »
I really like to interchange information with you on this objective way, but I think you're to bent to think on your decisions, you once made. I know what you're talking about and I mostly agree, but there is more than just theory... there is practice use. Even if we get out the AA-Filter of the formula, which we always did (because we choosed the D800E to compare) and we think of an optimal lense (which are rarely seen!) to serve a D800E... the result is something you have to explain after all. So I took the time, went to and got both RAW-Files, from the Nikon D800E ( and from the SD1M (

Your misunderstanding. Every bayer pixel may have only one color, but regardless of color, every pixel receives "light". This is why the spatial resolution of a bayer sensor is so high, and why a D800 is capable of resolving so much detail. If you convert a bayer sensor's data to monochrome, you effectively have just the full detail luminance.

I take you literally, ok? I converted the NikonFile with CaptureOne7 to a stock b/w TIFF and the SigmaFile with SigmaPhotoPro5.5 to a b/w TIFF, too. So, here are the results (as png, to loose no pixelinformation):


Sigma SD1:

Sigma SD1, (normal) resized to fit the Nikonsize:

There are no tricks, no JPG Artefacts, no Color, no catch. You can repeat this by your own. Now, if you speak scientifically (as you apparently like), your theory has to get prooved. One counter evidence prooves a theory wrong, you know... this is my try. Explain the results as we speak from a 15MP against a 38MP. In my humble opinion the Sigma clearly outperforms the Nikon, and this is not just a pixelpeeping Testchart, this is my daily experience. I don't speak about the disadvantages (AF, HighISO, Accu...), they are all clear and bespoken.

You and I clearly see different things. You seem to be seeing the LARGE SCALE contrast between certain threads in the upscaled sigma image as an indication that it has more detail. That is not resolution, that is just a form of contrast. Probably due to the way the Foveon deals with color, or possibly the exact nature of the illumination used. I'll use your own sample data to demonstrate the difference in SPATIAL RESOLUTION, for which the advantage clearly goes to the D800E:

I've enlarged your samples by 200% using nearest neighbor filtering, so as to preserve the exact details on a per-pixel basis (Bilinear or Bicubic filtering would have changed the pixels). I've aligned the two images to be as close to exactly on top of each other as possible. I've highlighted the most obvious regions where very fine detail can be seen with orange arrows. You can clearly see that the D800E has at least twice the real-world "resolution" (read that as spatial resolution or resolving power, not width and height image dimensions) as the SD1.

Your looking at the wrong bits of "detail". Your seeing the bright higher contrast threads in the red swatch as an indication of "more detail". That's not more detail, it's just a difference in contrast. That could be caused by the lighting that was used when the SD1 image samples were taken, it could be due to nuances in the way the Foveon sensor works and deals with color, it could be any number of things. But that's the wrong thing to look at. The best example of the D800's spatial resolution advantage is seen in the very fine dark strands of threads in the upper right the D800 they are VERY fine and VERY crisp, however in the SD1 upscaled image they are quite soft. Where at their finest those strands are about 1 1/4 pixels thick in the D800, they are at least 2-4 pixels thick in the SD1. That would roughly equate to a FACTOR OF TWO difference in real-world resolution between these two cameras, probably more than that.

I'm not trying to dash anyones hopes and dreams, here, honestly. I'm not trying to bring up math and theory just to be "more complicated" and confuse you guys. I'm just trying to be objective and accurate. Foveon's advantage is not, has never been, and will never be in terms of resolving power. It just plain and simply does not and can not resolve as much detail as a bayer sensor. The facts are staring you in the face right up there in that little animated GIF.

Foveon's advantages lie native sharpness and native color fidelity.

Landscape / Re: Deep Sky Astrophotography
« on: April 03, 2014, 12:07:11 PM »
Interesting, and I do like the color detail of the nebula, but overall it just looks softer than I'd like. 

It's a nebula...they generally tend to be "soft", what with being a bunch of whispy gas and all. ;P As for the stars, I purposely "decrispified" them and made them rounder/softer because otherwise they completely dominated the image, making it difficult to actually see the nebula. Part of the reason my stars end up too bright and crisp is the centroids are getting just a touch clipped during my exposures (necessary, to expose the nebula properly), and during processing the centroids get enlarged. So the star reduction routine is really just restoring the proper look to the stars anyway.

simply fantastic!  it feels like i'm looking at it through an ultra powerful telescope.

Thanks! Rosette is actually a fairly large nebula. It's larger than the Orion Nebula, which you can sort of see with your naked eye, too large even to fully fit in my 600mm FoV. The entire region is probably a bit bigger than your thumb  if you held it out about a foot and a half from your face over the sky...just to give you an idea of how large this region of space actually is. ;) Sadly, Rosette is so dim that unless you had a really garganguan telescope with  multi-foot sized aperture, you probably could never observe it visually.

EOS Bodies / Re: Canon's Medium Format
« on: April 03, 2014, 12:00:02 AM »
It's not "my own" website. 

I know it wasn't your own...but it was the one "you" linked.

If you calculate the RAW image dimensions, it is 5424 x 3616 = 19.61 MP.  Obviously there is some processing and/or interpolation involved to arrive at this image size, but there it is.

That would only be the dimensions of the blue channel. The red and green channels are 4.9mp. When you actually render the RAW to screen, your effective resolution is going to be much closer to the average of those three channels, which is ~10mp.

I never claimed it would outresolve a D800 "spatially", I just asked if he had seen it, and that it looked interesting...especially considering it's a crop sensor.  The fair comparison would be, what is the resolving power of this camera, compared to the 70D and the Exmor 24 MP 1.5x crop sensor's best output, with its best lens mounted.  To compare it to a full frame, is not a fair comparison, for various obvious reasons.

True, you personally did not. I was kind of trying to respond to the whole group of you stating that the DP2 had an effective resolution of "39mp" and that the DPR sample images somehow proved that. I wasn't exactly trying to single you out like that. That said, I do think the "evidence" that has been put forward so far by everyone defending Foveon is grossly misinterpreting the information they have at their fingertips, especially the DPR sample images. One need not up or down sample anything to know, from those same images, that the D800 and 645D TROUNCE the DP2 when it comes to spatial resolution. UTTERLY TROUNCE. Splat!

You're claiming that this new Sigma camera and sensor, could not resolve more than 10 MP worth of (equivalent "bayer"?) spatial information.  I submit that you are jumping to conclusions, and they are quite possibly in error.  Let's wait and see how it does when tested, rather than approaching a new product with a closed mind, and conclusions drawn...because of an unapologetic bias against the design, and the manufacturer.

It isn't closed minded, it's just how the math and the theory works out. Same as the fact that the D800 gets more DR than the 5D III at ISO 100, but that the differences are negligible above ISO 400, and meaningless (either way) above ISO 800. You don't need to compare results to know that, because it's all based on the concrete, theoretical LIMITS imposed by physics.

It's not as if Canon have not explored their own foveon-type sensor ideas, all mockery aside.

Sure. As I've said, I have nothing against the concept, at all. I've said as much in several of my prior posts. I've loved the general idea of Foveon since I first read about it in one of the first couple of books I purchased on photography...years and years ago, I think before I even purchased a DSLR. My problem is really less with Foveon and the whole concept of layered photodiodes, and more with Sigma's execution and missleading statements about resolution. I understand WHY Sigma has taken the advertising route they have taken, they think it's the only way to compete with the high megapixel counts of bayer sensors, so they count each photodiode as a "pixel" (which is arguably a mendacious), in order to jack up their "megapixel" counts to comparable numeric levels.

I truly, honestly believe that does Foveon a disservice. Not everything is about megapixel count. That has clearly been demonstrated by the 1D X, which produces STELLAR results with a "mere" 18 megapixels. I really think Foveon, if marketed properly, could stand on it's own despite it's lower spatial resolution. The color fidelity benefit is nothing to shake a stick at, it's really Foveon's greatest strength, and Sigma's current advertising hardly does it justice. High resolution photography isn't even what everyone wants these days. Too many pros came out of the woodwork during the 1D III/5D II days to COMPLAIN about "too many megapixels", which is the very reason why the 1D X has a reduction in megapixel count compared to the 1Ds III.

Sigma should be marketing their DP series of cameras on the STRENGTHS of Foveon, instead of fabricating fanciful "megapixel equivalency" numbers and the like. They are undermining Foveon that way, when it IS such amazing technology. It doesn't matter that it can't produce the same kind of spatial resolution as a D800 or 645D, or even a 5D III. It has color fidelity and native sharpness our the ass, and strait out of the camera, Foveon images are better than any DSLRs with similar megapixel counts. On a same-megapixels basis, Foveon wins, and THAT is what I think is the important fact. All this trying to make it sound like Foveon is "as good as" much higher resolution bayer cameras is glossing over those strengths.

IF, someday, a Foveon with 35 real megapixels (spatially) does hit the streets, it would produce better images than a D800. Granted, by the time that day arrives, we'll probably all be using 70 megapixel bayer sensors, so Foveon still wouldn't be winning the resolution contest. But by that time, it wouldn't matter, either, as 70mp is really getting up there, and fewer people actually need that kind of resolution (maybe landscape and architectural photographers).

Landscape / Re: Deep Sky Astrophotography
« on: April 02, 2014, 11:36:07 PM »
I reworked my Rosette Nebula image with a new software package called PixInsight. A VASTLY superior product for astrophotography, it gives me so much more control over everything, and allows me to tweak specific layers and scales of detail independently without messing with my color balance. This version of Rosette is much more color accurate than the nearly monochrome-red version that I posted before...and it has a bit more color contrast, so certain details should be easier to see than before:

Landscape / Re: jrista et al, Why Astrophotography?
« on: April 02, 2014, 11:33:38 PM »
Sorry for the late reply...I did not see this thread till now.

Don pretty much summed up the core of it: I've ALWAYS been fascinated by the night sky, by the cosmos in general, ever since I was a very young kid (I think I got my first telescope for Christmas when I was 6.) Astrophotography lets you, personally, "see" deeper than is usually possible, and in more vibrance and brilliance, than you can visually. That's definitely a big part of the draw...and extension of that childhood fascination with the sky that needed an active outlet.

Visual observation, even with some fairly hefty equipment (i.e. say a 12-14" cassegrain type OTA) is usually largely "gray"...color is very hard to discern until you get into the really gargantuan apertures. A lot of visual-only amateur astronomers build their own "Dobs", or Dobsonian-type truss-design telescopes, with apertures up to several feet. They are usually pretty basic in construction, have wood mounts and secondary mirror supports, use basic metal piping for the truss structure, and they grid their own mirrors (there are actually several mirror grinding parties combined with star parties that occur a couple times a year in the US, on where a guy will actually teach you how to grind your own mirrors). I've heard of some personal project dobsonians being up to 60" of aperture, there are even a couple here in Colorado that are around 40" of aperture. At those sizes, you can visually observe the universe in colorful glory, although it still isn't as detailed as what you can get with astrophotography.

When it comes to the repetition and "it's been done before" aspect, I think Soulless nailed it. This is nothing new in photography. Were all part of a VERY saturated population of people, and repetition is common with any kind of fixed subject photography. Particularly landscapes, I've seen the same scenes, image pretty much identically, from dozens if not hundreds of photographers. Monument Park? Horseshoe Bend? Zion National Park? Etc. etc. Being "unique" in the realm of landscape photography is extremely have to set yourself apart with technique and vision, rather than subject, because every subject has already been photographed countless times over the last century.

I've noticed that architectural photography, and increasingly "stairwell" photography, are also beginning to suffer from this problem. (I love photos of stairwells and the like...especially some of the subway escalators of some of those really cool new European....but I'm beginning to see the same escalators photographed pretty much the same way over and over now...) So, I don't think that is a "detractor" to be assigned only to astrophotograph. Other forms of photography have the same issue. Were just part of a very saturated have to move into the realm of action and maybe macro photography to get more unique images, however even then...once you've seen a couple dozen "Fly Eye" macro photos, you've effectively seen them all. Repetition, there isn't much getting away from it, and the only way to truly set yourself apart is with your technique and vision...don't just photograph a fly eye...photograph it with flare, do something unique with it, make it stand out and do it with the utmost precision and exquisite aesthetic....and you have yourself a wonderfully unique, interesting, likable photo that people will gravitate to. Despite the fact that it really ISN'T unique. ;)

Soulless covered the other reason I gravitate towards astrophotography: It's a great technical challenge! It's a challenge, period. Astrophotography is probably the most difficult form of photography, and certainly one of the most expensive if you really want to do it right. It's not just about pointing a camera, composing, and pressing the shutter. There is an extensive base of knowledge, about imagers, optics, telescopes, mounts, electronics, and a slough of software packages, that is necessary to start creating truly beautiful, detailed night sky images. This holds true for pretty much anything that requires an equatorial tracking mount.

Creating the base sub frames that are ultimately integrated into a final image is meticulous, detailed, and very interactive work. When you really get into astrophotography, it isn't just about pointing at some DSO, telling your camera to take X number of frames at Y exposure time and Z ISO setting. For the best detail, color, contrast, and depth, you use a monochrome sensor with individual color filters. You image "clear" luminance, red, green, blue for broad-band color channels. You can also image in narrow-band color, filtering out all but one emission line at a time for nebula, such as Hydrogen-Alpha, Sulfur-II, and Oxygen-III. If you really want to go all out, you also image in infrared, as IR produces more "translucent" images that allow distant background objects, such as galaxies, that are normally obscured by nebula or foreground milky way dust lanes, to be seen. For EACH of these individual color channels, you have to create multiple "sub frames", so you might expose 20x1200s Lum, 15x600s Red, 15x600s Green, 15x600s Blue, 20x1200s Ha, 12x1200s SII, 12x1200s OIII, and 20x1200s IR. That's a total of over 35 SOLID hours of exposure time. That does not include any of the additional time before you start imaging to set up, polar align, drift align, inter-exposure dithering and cooldown times, etc. Some subjects might require fewer exposures, some require considerably more...depends on exactly how dim they are. Some of the worlds top astrophotographers have put 60-80 hours of exposure time into ONE single region of the sky. And that is just getting the initial light-frames themselves! There is still more work to integrate them into a full-color image.

Astrophotography is a highly technical, very meticulous, and very detailed form of art. You aren't just pointing a camera, framing, focusing, and opening the shutter. Astrophotography is more like painting than have to have your final goal entirely planned out in your head ahead of time, you have to prep, you have to be meticulous about each and every color.

You mention that astrophotography is just "visual impression being more or less filter-effect digital artwork." That is the farthest thing from the truth. Good astrophotography does not apply a bunch of filter-effects in post to create some hyper-saturated image full of colors. That's cheap, it's a cop-out, and it isn't astrophotography. A properly done astronomical photograph won't have any effect filters applied at all. Everything you see is real. Most astro images are done in visible light, so most of it is what these deep space objects would look like to the naked eye. In many cases, saturation is a choice left up to the one doing the processing, and a lot of astro images are generally oversaturated, but very rarely is it "effect-filter fakery". Many astro images these days are what we call "narrow band mapped color", where imaging was done only in Ha, SII, and OIII. Those three narrow bands of light are then mapped to red, green, and blue to produce the kind of images you normally think of as Hubble images, or "false color" images (as while these narrow bands of color do exist in the overall spectrum coming from deep sky objects, they are too narrow to be represented accurately with just R,G, and B channels in an image). There is even a form of NB mapping called "Hubble Mapped Color", but one need not use the exact blending method as Hubble. Some imagers use Ha for red and SII for green, some use SII for red and Ha for Green. Some will perform a more complex blend that uses various mixes of Ha, SII, and OII for the red, green, and blue channels to create more unique results. In general, narrow-band images produce much higher contrast, especially between dark dusty nebula and brighter emission and reflection nebula, where as visible light images are less contrasty, but often a bit more vibrant. Finally, the most advanced imagers will often blend all seven of these different color layers together to produce some rather wild results. Some, as I noted before, will even bring in an IR layer to add a whole new measure of depth and transparency to visible and/or narrow band base image.

The incredible colors you see in astro images is rarely ever from effect filters. It's all detail and color that's there in the objects themselves, and different techniques to blend various color layers together bring out different colors and aspects of detail. None of that detail is is EXTRACTED. You might be surprised to find out that most astro images, after calibration and stacking, usually appear as almost pitch black. For all the dozens of hours you may spend exposing, all that exposure time does is produce images where all the color is packed DEEPLY into the utter depths of the lowest levels of your image. A properly calibrated and integrated stack has at least 20 stops of dynamic range, and when you stack enough, you can end up with more than that. It is becoming pretty common these days with the more advanced tools at our disposal to save our integrations as 64-bit IEEE floating point FITS images. A 32-bit IEEE floating point TIFF can store well more than 24 stops of dynamic range...a 64-bit floating point image is, for all intents and purposes, capable of storing an infinite amount of dynamic range (more than capable of storing enough DR that, if one figured out how, they could represent a dim, distant galaxy about to be occluded near the edge of the sun, while concurrently storing enough information to resolve details on the surface of the sun itself). The very vast bulk of astrophotography post processing is geared towards "stretching" those really deep shadows to lift all the detail up into a level range that is visible to the human eye. The rest of astrophotography processing is geared towards reducing noise (because when you lift an image by 20 stops, even if you stack dozens of frames to reduce noise and improve SNR, you STILL have lots of noise), and towards enhancing the detail that exists within the stretched image. You would be surprised at how often very fine structure that you actually capture in your images appears to be flat takes some careful, meticulous, and often highly mathematical processing to separate the various levels of that detail to make it visible...but not separate them so much that the results look over-processed in the end.

So, is there a massive imbalanced trade-off in "effort vs. results" when it comes to astrophotography? It depends on how you look at it. Is there a massive imbalanced trade-off in "effort vs. results" when it comes to oil painting? Sculpting? How about architecture? All of these endeavors, which are undoubtedly great forms of art, require a far more considerable investment up front, and throughout the entire process, in order to produce one single artistic creation in the end. Astrophotography is also, without question, a form of art. As much as it is called photography, I think it may be more appropriate to compare it to painting than photography, as when you get down to the foresight and vision, the preparation, and the very manual process of stretching and detail extraction, astrophotography feels more like painting to me than photography. Just like painting, you often have to spend hours focusing one one small area of your image, figuring out the various algorithms that will enhance that detail in just the right way. And, similarly, the kind of satisfaction you get in the end, after putting in all that effort, all that dedicated, meticulous care and attention into your artistic's wonderfully satisfying.

The only real drawback with astrophotography is the cost. People balk at the $6800 price tag of a 1D X, or teh $12,000 price tag of an EF 600mm f/4 L II lens. When you get right down to it, to do astrophotography well, $6800 is down right cheap! For me, my ultimate goal is to be able to produce images that approach the kind of quality you might see from Robert Gendler or Russel Croman. To achieve that level of imagery, you not only need skill, but you need the right equipment. Were talking $20,000-$40,000 mounts, $40,000 telescopes, $30,000 thermoelectrically cooled scientific grade CCD monochromatic image sensors, and robotic equipment like filter wheels, image rotators, and focusers (each of which can cost thousands of dollars each.) Were talking about $115,000 in equipment, and were still not done. This kind of equipment isn't portable, the mount weighs a few hundred pounds, the telescope (such as a 20" RCOS or PlaneWave) weighs a good hundred pounds or so, and all the other accessories pile on another couple dozen pounds. You need a permanent observatory, complete with remote operation capabilities, power, internet, etc., built under permanently dark skies, in order to use this kind of equipment. That's probably another $35,000 to $50,000. Throw in another grand or so in software, for good measure.

Without this kind of equipment, then in large part, some of what you've said, Larry, about astrophotography just being repetition, is kind of true. With the kind of equipment and setup above, you have the ability to image narrow regions of the sky very deeply, very precisely, and so long as it's all set up out under consistently, persistently dark skies away from light pollution, you can use it every time the sky is clear, from the comfort of your own home. The ability to image very narrow regions of the sky very deeply means you can, if you wish, find regions of the sky that are often only a few pixels of "most" astrophotography, and image them in extreme detail. A 20" RCOS or PlaneWave telescope is usually going to be around 3500-4000mm in focal length, and you can throw on a 2x barlow to make that 7000-8000mm. You can also use focal reducers to get a wider field (say 2700mm), image at a lesser magnification, and even do mosaic imaging to expose gigantic regions of the sky in exceptional detail.

Most of the astrophotography you'll see on the internet is usually what we call "wide field", where large multi-arc minute or even arc-hour swaths of sky are imaged all at once with a short focal length...200mm, 350mm, 400mm, 600mm. At these levels, the large scale structures are easily recognizable, their locations in the sky are well known, and you don't need as much total integration time to get decent results. And the brighter the structures are, such as Orion Nebula or Andromeda Galaxy, the more frequently they will be imaged by novice and moderately skilled amateur astrophotographers.

So there is a certain amount of "repetition" when it comes to astrophotography, more so due to a barrier to entry due to the excessive high cost of getting high quality, precise equipment that allows astrophotographers to pursue more unique targets. I doubt I'll ever be spending a hundred grand on astrophotography equipment, at least not all at once, however over the next few years, I don't think it's out of the realm of possibility to spend $35,000 to $50,000 on better equipment. I doubt I'll ever be able to afford a 20" RC Optical Systems (RCOS) Ritchey-Chretine ion-milled telescope. I also doubt I'd ever be able to afford a 20" PlaneWave CDK, which are a bit cheaper, different design, just as high even that still costs over twenty grand just for the OTA. To get serious at all, though, you have to purchase a mount that is capable of high precision, absolutely encoded, precision modeled, and permanent tracking. Such mounts are expensive, around $20,000. Once you have a mount like that, however, then your pretty much free to put any kind of OTA you want on it, and you can slowly upgrade to better and better OTAs over the years. By the time I retire, I might finally have a 20" PlaneWave CDK with a nice FLI ProLine 37x37mm 4096x4096 cooled CCD imager sitting on a nice 10Micron 2000HPS mount, and be capable of creating some of those unique images of narrow regions of the sky that most people just think of as "That little group of 50 pixels over there" in their images.

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