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Messages - jrista

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1321
Landscape / Re: hide and seek with the moon
« on: May 05, 2014, 11:16:12 AM »
Thanks for the pointers. I already ordered the reducer/field flattener that goes with this scope.  I think that should help the vignetting I'm seeing right now with my 2" to 1.25" adapter + t-mount adapter + t-mount to EOS adapter.

Reducers/flatteners definitely help with corner performance. They do reduce focal length, though...so, if you have an f/7.5 scope, and use a 0.85x reducer, your going to end up with a 765mm scope. Wider scopes are great for nebula and imaging larger regions of the sky, they are a lot harder to use for galaxies, clusters, planetary work, etc. For those, you want something much longer, at least 1600mm, and for planetary, it's really best to have as much focal length as you can muster (regardless of the f-ratio...3000mm, 5000mm, even 9000mm is best for planetary work.)

I'm looking to get the Celestron Advanced VX mount to go with this. Any thoughts on that? Any accessories I should also pick up in one shipment? I heard the GPS unit is nifty, as is a polar axis scope. Anything else I should look into?

Celestron is not really my first choice for mounts. They make some excellent scopes, and are they only source of hyperstar capable scopes, but their mounts are generally a bit wanting, and you pretty much always have to go to Celestron for any support. The EQ5/EQ6 range of mounts are actually better mounts, and the support community for them is truly vast. The Orion Sirius is an EQ5 type mount, where as the Orion Atlas is an EQ6 type mount. The Sirius is a step above the Celestron AVX, but closer to it in price. The Atlas is one of the most popular and best supported lower end mounts in the world. It's $1400, vs. the $1000 for the Sirius, but it is really the lowest entry mount you probably want to go with for astrophotography.

Mounts like the AVX are just too low end to really do a good job for astrophotography. Mount capacity is a critical factor, as is the intrinsic periodic error. The AVX has a max capacity of 30lb, and it's periodic error (PE) is around 30-50" peak-to-peak (P2P). The Orion Atlas, on the other hand, has a capacity of 40lb and a (PE) of around 15" P2P. The periodic error is what is going to determine the minimum size of your stars as you track across the sky for long exposures. At 30" or more, the AVX is just not going to handle exposures of more than about a minute or so without really good guiding. The Atlas can handle unguided exposures of a few minutes, and is easier to guide than the AVX.

Capacity is the next most important point. It's best not to load up a mount with more than about half it's capacity if you are doing astrophotography, unless your using a real high end mount. At 30lb, your 23lb scope is already over 2/3rds the weight capacity, where as it is barely over half for the Atlas. At 2/3rds capacity (and even more, once you throw on a camera, and even more once you throw on a guide scope and guide camera, which are really going to be essential for tight stars with any lower end mount), the AVX is going to be extremely difficult to control and guide out errors for. For the size and weight of your scope, especially with a camera and guider setup, you want a mount that is at the very least capable of handling 40lb. A mount capable of handling 60lb would be best...but that gets you into the territory of midrange mounts, which cost around $2500-3500.

So, I very highly recommend the Orion Atlas. It's a very capable mount, with a phenomenal support community. It also works with EQMOD, which is a full open source, free total replacement software driver package that lets you ditch the hand controller and control your mount entirely from a laptop (once you really get into imaging, you'll learn you also need computer control software, such as BackyardEOS if your using a Canon DSLR for imaging, PHD2 for guiding, etc.) EQMOD is more capable and more flexible than the SynScan hand controller that comes with EQ5/EQ6 type mounts. The use of EQMOD also opens up the door for improving the Atlas, which is another somewhat unique feature...there is a hypertuning mod available (which cleans up the mount and gets rid of manufacturing crap left behind in the gears, which makes the PE worse, and regreases everything with high quality synthetic grease), as well as a number of belt and worm mods. Belt and worm mods can eliminate gears, reduce backlash issues, and otherwise greatly improve the performance of your mount to midrange levels for far less cost. (NOTE: To use EQMOD, you will need to get an EQDIR cable. They are about $45, but a standard USB to Serial cable costs almost that much anyway, so it is a very worth while investment.)

You really can't go wrong with the Orion Atlas (or any other EQ6 mount, like the SkyWatcher EQ6 SynScan, which is basically the same thing, just different seller.) Either way, the Atlas/EQ6 is a much better fit given that your scope already weighs 23lb, and that you are guaranteed to need to do guiding. You can pick up the Orion 50mm mini guidescope and SSAG guider for relatively cheap, and the weight of that setup is about as small as you can get for guiding. Without guiding, even with an Atlas, the 15" p2p periodic error is going to kill your chances for doing exposures longer than a couple minutes. Average seeing is 2-3", average star size is 1.5-1.8"...without guiding, your stars will eventually be around 10-15" in size...far too large.

1322
Landscape / Re: hide and seek with the moon
« on: May 05, 2014, 02:06:54 AM »
After mulling about for a bit, I finally decided to bite the bullet and get a telescope. After much thinking and searching I decided to get a Sky-Watcher ProED 120mm Doublet APO Refractor. I saw it as a poor man's EF 800mm. Sure, it doesn't have AF, or sharpest of corners... but, I now have a 900mm lens ;D.

I have only started this new part of my habit hobby. There's no equatorial mount... no GOTO tracker... they'll (likely) appear in due time. I just got the scope last Thursday and am struggling with the Astrophotographer's curse, 30 days and 30 nights of rain (living in the Pacific NW isn't helping). Today was the first night I had any opportunity and for a 5 minute window, I had a break in the clouds!

I present to you a "moonscape". Image taken with a Canon EF 2x Tele + EOS 5D3 mounted on a Arca-Swiss Z1 + Gitzo 2541 at 1/320 sec & ISO 6400.  The photo has been touched up but uncropped in Lightroom 5.

For the seasoned astrophotographers lurking around, any advice? I know the ISO is a tad high for this, but I didn't have a lot of time and had to make sure I got the shot in less than 5 photos.

First, congrats on the purchase. Good to see others getting into astrophotography. :) Once you get an equatorial mount, a very wide new world will open up to you. Just make sure you get s good mount...they are the most important piece of any astrophotographers kit.

As for advice...best bit is to definitely use a lower ISO. I pretty much always use ISO 100 or 200 for the moon. It moves, but not fast enough that a 1/4 second exposure will cause blurring. You REALLY want the DR that a lower ISO offers when shooting the moon...it's an exceptionally high DR subject.

I have lots more advice to offer...but I'll let you settle in first. ;P

1323
Animal Kingdom / Re: Show your Bird Portraits
« on: May 04, 2014, 10:37:44 PM »
Great shots, everyone! Some really good work is showing up on here these days. Alan, love that last shot with the Greenfinch...the way his head is cocked is great!

Click, thanks! I like that first Killdeer shot, too. Hopefully I'll be able to get some better ones as spring rolls on...those were my first shorebird shots of the year, and killdeer...well, sometimes they kinda make you wanna kill a deer...just because you gotta kill something...with their antics. :P

1324
Software & Accessories / Re: Gimbal Head: Wimberley Vs Jobu
« on: May 04, 2014, 10:35:38 PM »
Thanks jrista.
I saw some youtube clips about Jobu II, I'm impressed. The price is slightly more than Wimberley II, therefore, I settled with Wimberley II. This is my 1st gimbal head, so far, I like the feel of wimberley II.

I'm putting extra money toward decent tripod instead ;)

There is really very little difference between the Jobu 2 and Wimberley II. Someone mentioned the Wimberley didn't have ball bearings. I guess that might be one of the reasons I ended up choosing the Jobu 2 (it is WICKED SMOOTH), but I don't really think it matters all that much in the end. The Wimberley felt just as solid to me...the main reason I got the Jobu Pro 2 was because it was on sale on Amazon, and I had a bunch of amazon points to throw at it (I actually got it really cheap). It's really hard to go wrong with either of them.

1325
Software & Accessories / Re: Microfibre Cloths for Lens Cleaning
« on: May 04, 2014, 06:13:26 PM »
The point about the lens cap is key!! Also, if you can avoid it...never put a,kens cap in your pocket...that is just a transfer nightmare.

1326
F*ck focus peaking and all that video-style sh*t. All I want is a kick-butt, precise and fast af system. To hell with manual focus rings. I am done with that since the 1970s.

I want an oculus rift grade evf instead of those laggard mickey mouse vga evfs. Along with a good af-system with af fields all over the place all the way out to the corners.

 ???

1327
Software & Accessories / Re: Microfibre Cloths for Lens Cleaning
« on: May 04, 2014, 03:54:43 PM »
Seriously, it's just not that big of a deal.  If I shot thousand dollar pictures for million dollar clients in an expensive studio I would be more fastidious I guess but when you're outdoors in dust, dirt, sweat, etc then what's the point?

I guess I think of it exactly the opposite. If your shooting thousand dollar pictures for million dollar clients in an expensive, CLEAN studio, you probably don't have all that much dust and grime to worry about in the first place.

Out in the field, where there is dust, dirt, sweat, and other crap, you have to be that much more careful to avoid scratching your lens when you clean it. I wouldn't ever even remotely dream of using a napkin to clean my lens...those things are incredibly rough with nasty scratchy fibers. Just because you get dust on your lens more often doesn't mean you should trash your lens. As much as there are demonstrations on the net that show how you can still use a scratched up or even cracked lens, those defects DO impact image quality.

Just because your studio is the big, bad, dirty outdoors world doesn't mean you should not be diligent about keeping your gear clean and in pristine condition. If for no other reason than to preserve resale value.

1328
EOS Bodies / Re: New Sensor Technology Coming From Canon? [CR1]
« on: May 04, 2014, 03:02:34 PM »
Why do the etchings always have to go in the same direction?
I guess it's how are they cut out? what do they use, a saw  ;D

Well, there is no specific reason why they couldn't etch some additional sensors in the perpendicular direction, but it would be costly. The way sensor fabrication works is by etching the silicon with extreme UV light via a template. The template is oriented in a single direction. The wafer is moved underneath the light beam so that multiple sensors can be etched. Etching of a single sensor is a multi-step process, with various steps involving masking, etching, dissolution of masks, more etching, doping and layering of new materials, masking, etching, etc. This stuff has to be precise to the level of a few nanometers at most, so it is entirely automated. Rotating the wafer to etch additional sensors in a different direction introduces a source of error that could hurt yield.

Fascinating, must be very impressive to watch, though I guess not actually viewable. Thanks for the enlightenment!

Regards

As far as I know the systems used to fabricate silicon devices are not sealed. The wavers are open and accessible in most of the pictures I've seen. These things have to be done in sealed clean rooms where not even one speck of dust exists (as one speck of dust on a wafer means whatever is etched in that area of the wafer is useless). If you could find a way to get into a cleanroom at Canon, you could probably watch sensor fabrication in action. It isn't a particularly fast process, from what I understand, though.

1329
EOS Bodies / Re: New Full Frame Camera in 2014? [CR1]
« on: May 04, 2014, 02:59:26 PM »
What about a 4D? It's just a matter of time :)

No then all the Physicists would get confused they might think it were referring to advanced hypothetical spacial relationships beyond the current acknowledged 3 Dimensions...  :-*

Why do you think they went from 1D and then straight to 5D?
Bypassing 2D, 3D and 4D... then 7D.... whoops we missed the 6D so lets fill that space too...
I don't think they would ever do a 2D, 3D or 4D... simply because its a pun waiting to happen...

The number 4 in Japan is an unlucky number, same as with the number 9. I generally would not expect to see any products with those numbers from Japanese companies...but then Nikon went and made the D4...so you never know. :P

I think the 2D and 3D are definitely puns waiting to happen, or at the very least confusing names for a DSLR that is very likely to have video capabilities. The 3D just sounds too much like a camera capable of taking three-dimensional video.

I'd kind of like to see a 4D though...something above the 5D line in specs, but not as costly as the 1D line.

1330
Software & Accessories / Re: Microfibre Cloths for Lens Cleaning
« on: May 04, 2014, 02:28:45 PM »
I have never used the carbon end of my lens pen - chicken I guess - but I really should try it!

Everyone fears the carbon end. :P It's because if you touch it, your fingers get black...but that just means it's working. The carbon bonds with oils, which is why it works. Your fingers get black because they are oily, but on a lens, the carbon lifts the oils off. You really do have to make sure there is no grit, though...you do need some pressure for the carbon tip to work, and if there is any grit, your lens is going to get scratch. But, that's pretty much the same as when using wipes or anything else...grit is death.

1331
Software & Accessories / Re: Gimbal Head: Wimberley Vs Jobu
« on: May 04, 2014, 01:07:01 PM »
Personally I chose the Jobu Pro 2 as the gimbal for my 600mm f/4 L II. I looked at the Wimberley, Mongoose and RRS Pano. There really isn't much difference between the Wimberley and Jobu, same basic thing, same weight. The Jobu is a bit beefier, and has a nice lock for the inner arm, but otherwise, they are the same thing. I got the Jobu because I got it a little cheaper thanks to a sale on Amazon.

I tried out the Mongoose, which seems to function the same as the RRS Pano. These are side-mount heads...you attach the lens to the joint where the wimberley/jobu attach the inner arm. They don't quite work the same as a true gimbal, and for whatever reason, the Mongoose felt more restrictive. I guess I just like having my lens return to base balance due to gravity.

I've shot thousands of bird and wildlife photos with the Jobu Pro 2, and I haven't got a single complaint about it.  LensCoat had a specially designed coat for the Jobu, so I was able to camo my whole setup with lenscoat (tropod legs, gimbal, and lens), which was also ideal. I believe there is a lenscoat for the mongoose, however I couldn't find anything other than a camo carrying bag for the RRS Pano.

If you picked up the Wimberley, then you shouldn't ever have any problems.

1332
EOS Bodies / Re: More Sensor Technology Talk [CR1]
« on: May 04, 2014, 12:38:26 PM »
Are you using telescopes for astro or the 600?

Currently using the 600, however this baby is at the top of my list:

Astro-Tech 10" f/8 truss tube Ritchey-Chrétien optical tube

Telescopes are kind of like lenses, though. You usually need a few. The 600 is ideal for wider field work. I think the 200mm f/2 L would be an excellent one for very wide field work, but I think when I get the 300/2.8 L II that will be the last Canon supertele for a long while. The 300 is still excellent for wide field work. The 10" RC is a longer focal length, which is better for galaxies and clusters, and for close-up work of parts of nebula.


1333
EOS Bodies / Re: More Sensor Technology Talk [CR1]
« on: May 04, 2014, 11:56:42 AM »
Glancing at his gear wish list, it looks like he's more into action than astro. An A7R is 2500 less in the budget (camera + EF adapter). Personally I would love one for portrait and landscape work, but I can not justify the expense. I suspect I'd get more use from that tamron 150-600 and a new tripod.

I'm actually pretty into astrophotography. It splits my budgets now. The A7r, along with pretty much any Sony camera, Nikon camera (with the exception of a couple that use different sensors), and a lot of other cameras that use Sony sensors (i.e. Pentax) are all pretty poor choices for astrophotography. Those manufacturers all mess with the image signal pretty heavily.

They clip the black point, rather than using a bias offset (Canon uses a bias offset). That causes two problems for astrophotography: By clipping to the black point, you simply eliminate a lot of the dimmer background stars entirely, they are gone from the signal, unable to be retrieved; They make it difficult to use standard bias frame calibration techniques to remove any noise caused by sensor bias and recover those dim stars (which IS possible with Canon cameras.)

Sony/Nikon/Pentax/etc. also tend to apply noise reduction to the RAW signal in hardware...an unconfigurable noise reduction, that's just always applied. Having total control over noise is a pretty critical facet of astrophotography...the vast majority of images you create for astrophotography have image data only in the lowest echelons of the signal, stars are the only things that have levels throughout the signal. While you can do some pretty amazing things with the D800 at ISO 100 when it comes to lifting shadows, that's nothing compared to the kind of lifting you do in astrophotography. The D800 can be lifted about six stops. In astrophotography, your often lifting by a lot more than that...to really pull out dust lane detail and dark nebula detail and things like that, it's common to lift things by an equivalent of 10-15 stops! Not even the great D800 or any other Exmor DSLR camera can handle that, in part because of the black point clipping, which is throwing away a couple/few stops of potentially recoverable information in the first place.

A proper astro CCD camera has at least 18-19 stops of dynamic range, and usually well over 20 stops. They are thermally regulated (anywhere from -40°C to -80°C Delta-T from ambient), which nearly eliminates dark current noise, generally have relatively low read noise, usually have much higher Q.E., and usually have larger pixels (smaller astro CCD sensors usually have around 5-6µm pixels, larger astro CCD sensors usually have 9-24µm pixels; FF DSLRs tend to have pixels in the 6-7µm range, and APS-C DSLRs are now around 3.5-4.5µm). Since astro CCD sensors are also most often monochrome, and you usually image in LRGB (luminance + RGB), you can produce images with much stronger signals than you can with bayer-filtered DSLRs.

So, while I'd like an A7r for my landscape photography, it is actually one of the worst possible choices for astrophotography. I do landscapes sometimes, wildlife and birds most of the time, and astrophotography every time there is a clear night. Since Canon cameras don't mess with the image signal nearly to the degree that other manufacturers to (they do some response curve tweaks at certain higher ISO settings, but I usually image at ISO 400, which Canon pretty much leaves alone), and since the 5D III can be used for landscapes (it has a very respectable pixel count and frame size for that), wildlife and birds (it meets my minimum expectations for rate at 6fps), AND can be used for astrophotography, it's a far better investment in the interim (especially with prices hitting $2700 pretty regularly now.) It may not have the DR of the A7r, but it is a vastly more versatile device.

If it wasn't for the astrophotography, I'd get a 1D X. By getting a 5D III, that leaves me plenty of cash to invest in a proper astro CCD, a filter wheel and filter system, and a few other accessories.

So...given how versatile Canon's DSLRs already are...do they really need to become a Sony clone with their new sensors?  ;D :P

1334
Only because I'm feeling particularly argumentative :)

Canon has never chased anyone. They never chased anyone in the past, and they are not chasing anyone now.
Canon were pretty quick to chase Sony's camera division (previously known as Minolta) when they introduced auto focusing SLRs.  The Minolta Maxxum 7000 came out in February 1985.  By the end of 1986, Auto focus SLR's accounted for more than 50% of SLR sales and was dominated by Minolta and Nikon.  And where was Canon? (hint: The T80 doesn't count...)

Well, if you want to get right down to business. In the late 70's, Konika released a camera with a passive AF system. Everyone else followed suit, and released cameras with the same kind of AF system. Canon? Instead of simply "responding" with a "me too" product, they innovated...and created the first active AF system capable of focusing in the dark.

The T-80, which does count, as it was well into development and just about ready for release when the Minolta AF cameras were released (I mean, it was less than two months later that the T80 hit), was Canon's first modern-ish DSLR AF system and was obviously in development for some time before it's release. That was 1985.

Canon released the first EOS in 1987, two years later, with a completely new CAMERA SYSTEM designed from the ground up. We aren't just talking AF, were talking about the platform that Canon launched to fuel their camera systems for decades, the same system that their current modern cameras are based on. Were talking about a mount system, a flash system, a camera system that spawned Canon's entire photography ecosystem. It takes more than two years to plan and develop such a huge thing, so one has to assume they were already working on it by the time the T-80, a-7000, etc. hit the streets.

So, did Canon "respond" with EOS, an entirely new camera system, just because of the a-7000's AF system? Or did Canon innovate their way into total dominance with a camera system built for a new era from the ground up to support the things their customers demanded? Personally, I think there was a little bit of both "response" and a lot of "lets build something kickass and new that will triple our bottom line". It just takes too much time to R&D up an entirely new camera system from scratch for it to just be purely in response to the AF dslrs that hit in '86. The plan had to have already been in motion before hand.

1335
Animal Kingdom / Re: Show your Bird Portraits
« on: May 04, 2014, 03:04:44 AM »
Blue-Winged Teal Headshot

Another headshot. This time of a blue-winged teal. Really just love the mottled golden feathers these beauties have. This shot came out a bit darker than the rest, but the angle of the light on it's head just brought out the iridescent feathers and it's eye so much better.

This is one of those shots that brings out the worst of the 7D. It's a moderately heavy crop, definitely not the heaviest by a long shot, but heavier than I generally prefer. It's sharp, but it's also noisy. That's especially evident in the background...I even used a 0.8 radius for sharpening in LR (which helps reduce the graininess of noise), and the OOF background is still too noisy. I wasn't exactly reach limited here (the bird was quite large in the frame overall, this is a heavier crop for the head), so a full-frame camera with a 1.4x TC would have done a lot better...more total light, bigger pixels, more DR...so less noise. Really can't wait to get my hands on a 5D III.

Blue-Winged Teal, Male
Cottonwood Creek Wetland
Colorado

Canon EOS 7D
Canon EF 600mm f/4 L II
Gitzo GT3532LS + Jobu Pro 2


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