October 01, 2014, 11:13:49 PM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - jrista

Pages: 1 ... 87 88 [89] 90 91 ... 316
1321
EOS Bodies - For Stills / Re: Advice on a upgrade from the Rebel XS
« on: May 11, 2014, 12:56:54 PM »
7D or 70D: these are fast enough, but do they do well enough in low light?  I'll define "well enough" as having at least the same image quality at ISO 3200 as the Rebel does at 800.

6D: fixes the low-light issues, but is the frame rate fast enough to have a decent shot at capturing action?

I'd appreciate any advice on this.  Should I go for one of the above options, or just bide my time and save up for the 5D III?

Fundamentally, ISO/noise performance is a factor of two things: Real sensitivity (quantum efficiency) and total sensor area. Assuming you frame your subject the same, the only way to really reduce noise is to use a larger sensor. Pixel size does not really play a role unless your only putting the same number of pixels on the subject (which means you are not necessarily framing the same). With the same number of pixels on subject, then pixel size matters, and larger pixels do better.

Given these facts, it's highly unlikely that you will ever see an APS-C camera that has ISO 800-level performance at ISO 3200. Even if Q.E. reached 100%, your still not going to see that much of an improvement. I think the XS had around 25-30% Q.E. The 7D has 41% and the 70D has 45%. That is not even a factor of two improvement over the XS, let alone a factor of four improvement. You will see an improvement in high ISO IQ, but no where near enough that ISO 3200 looked like ISO 800. ISO 1600 will look a lot better, almost as good as ISO 800 on your XS, but still not quite as good.

The only real way you are going to get a significant improvement in high ISO performance is to move up to a full-frame camera. The 6D has about 50% Q.E., so just from a real sensitivity standpoint, it's about twice as sensitive as your XS. On top of that, it's got 2.6 times the sensor area. So you'll gain almost two stops of improvement in high ISO performance...indeed, ISO 3200 would look a lot like ISO 800 on your XS. Because of the greater pixel count, if you frame the same, ISO 3200 should look quite a bit better than ISO 800 on your XS for a given output size. These same fundamental facts apply to the 5D III as well. It has 49% Q.E. and the same total sensor area.

Whether you choose the 6D or 5D III is really up to you. The AF performance is indeed much superior on the 5D III, and for action, that will certainly be better. The 6D's 11pt AF system is not bad, though, and at least for kids  and for some lower action wildlife, it should suffice quite nicely. The 5D III's AF system is going to be able to lock onto active subjects, like kids running around or wildlife in action, a lot better than the 6D's. For action, frame rate is pretty important as well, and I'm not sure the 4.5fps of the 6D is really quite up to snuff. Personally, my limit, having used 3.4fps, 3.7fps, 6fps and 8fps cameras, is about 6fps. Anything lower than that, and I really feel I'm missing the right moments. At 8fps the frame rate feels really good, and you definitely see an improvement in small changes in subject pose and orientation that give you the option of picking a really ideal frame. The 7D, which I own, has an AF jitter problem that causes some frames to become very slightly out of focus, which basically negates some frames for all but the smallest reproduction ratio online. My average "keeper rate" is about 5-6fps at best, which is part of the reason I feel the 6fps of the 5D III, with it's much better AF system, is acceptable for action. I say acceptable, however ideally I'd say 8-20fps is probably where the sweet spot is, and I think 10-12fps, maybe 15fps is really quite ideal (assuming the AF system can keep up.)

At the very least, given that you've stated high ISO performance is one of your biggest concerns, that you should really move up to a full frame camera. The 6D is a very nice camera, and for certain applications, like landscapes, low light photography, and still scenes (like floral macros), and even astrophotography, it is a very, very good camera. For action, it's maybe middle ground at best. The AF system is capable enough, but the 4.5fps frame rate may just not quite be up to snuff. Whether you choose the 5D III or not would really have to be up to you. If you do choose the 6D, I honestly think you will find it to be a truly MASSIVE improvement over your XS...despite the shortcomings of the 6D vs. the 5D III, it really is a vastly superior device compared to your XS, and once you get it in your hands, you'll understand what I mean.

1322
Animal Kingdom / Re: Show your Bird Portraits
« on: May 11, 2014, 11:21:52 AM »
Northstar, looks like Sandhill Cranes. Beautiful birds! I had originally planned to go photograph them in Nebraska during the migration, but something came up and I wasn't able to go. :( Second year in a row that's happened. I am hoping I get another chance this fall, would love to photograph these beauties.

1323
Lenses / Re: New Canon Tilt-Shift Lenses at Photokina [CR1]
« on: May 11, 2014, 10:02:01 AM »
The fly actually was a rather large one. I took those shots late last year, weather was cold, and it was just before sunset, so the inset was very sluggish. I coaxed it into a stick, and it just hung there. I clamped it into a gorilla holder, stuck it on a tripod, and then started shooting.

Like I mentioned before, if your dedicated, you find a way of getting things to work the way you want them to. Some macro photographers regularly resort to bait, which often gets insects to stop and sit still for a minute. Others resort to setups, where they generally know where the insect will be in a few minutes span of time, so chasing it down isn't nearly as tough a job. The other way is to find insect subjects in the mornings (usually) when it's cold, and they are lethargic. They they can be quite cooperative subjects.

The image is cropped about 50%, so the fly isn't 35mm in size. I'd also say magnification was probably closer to 1:1.1 or so than 1:1...it was shot hand held, after all, which makes it extremely difficult to nail focus right exactly at 1:1. The largest subject size in a 1.6x crop at 0.9x mag is ~17mm, so the size of the fly's head is less than that. If I run the numbers through Cambridge in Color's calc, I get a DoF around 0.5mm. Now, CiC assumes a CoC of 0.032mm. Given my crop and the fact that the image I shared here is pretty much exactly a 3x downsample, I've calculated my CoC at 0.02mm, and when I run the math on that, I get a DoF of 1.03mm.

If I run the numbers through DofMaster, I get a DoF of 3.3mm. I figure subject distance was probably about 33cm, 330mm, or around 13 inches.

A DOF of around 1-2mm sounds about right, given what I know about the actual subject size and imaging distance.




Regarding the effectiveness of tilt in macro. I honestly can't say what it would be like with a design like Canon's old TS-E lenses. They are much more complex designs. The Novoflex Bellows T/S design, however, for all intents and purposes, uses a "simple" lens design attached only to the front of the bellows. Focus is achieved by moving the lens on the bellows or the whole bellows assembly forward/backward...there are no additional optical elements behind the Schneider APO Digitar lens. In which case the math works much more like it does on the Wikipedia page for Schiempflug, in which case my original diagram of a 20mm ball would apply much more readily. If I could gain almost 6mm of additional DOF with tilt on a 20mm ball, I figure another half a millimeter shouldn't be out of the question with the Novoflex and a 3-4mm fly head. If I assume an effective aperture of f/21 (i.e. if I had stopped down to f/11 instead of f/5.6), and a CoC of 0.02mm, then the DoF is 2mm (according to 2Nc((m + 1)/m^2))...if tilt gets me even a mere half millimeter of increased focus along the back of the fly's head, then I think I'd have achieved my goal. And at a significantly less diffraction limited aperture than a real f/22.

1324
Lenses / Re: New Canon Tilt-Shift Lenses at Photokina [CR1]
« on: May 11, 2014, 01:40:19 AM »
I do not disagree, there is indeed value in both experience and theory. I'm not trying to dismiss experience, honestly. However I do believe that if tilt is of no value at macro scale, it should be easy to prove, especially for someone who has ready access to a wide variety of tilt/shift lenses with a range of capabilities and designs. I'm also not above admitting I could be 100% wrong here, but I honestly do not believe I am.

PrivateByDesign and I have a long history. He has his way, and he thinks it is 100% purely objective, and in many cases he very much is, however there have been cases where I believe he is blind to his bias, and his bias is very persistent. Hence my reason to doubt him until I get some kind of concrete proof. You came on pretty strong, immediately claiming a superior position then also immediately and subsequently trouncing any possibility that you would provide any evidence to back up your position. I'm happy that your happy and confident in your position...but that doesn't change anything. :P

You have still made claims I have no reason to believe just on your word alone, or even the combined word of you and private, and given that there is apparently quite a number of T/S bellows systems explicitly designed for macro photography, some with magnifications up to 2:1 and tilts from 10° to 25°, that only gives me further cause to doubt your strong assertions, based on your own personal experience, that tilt is of no practical value for macro photography. Experience is well and good, but how different, really, is photographing a carpet of moss with a tiny mushroom in the middle different from photographing a ring on a slate in a whitebox? I don't see any fundamental difference in the subject distances, angles, or viability of T/S between these two things. In the case of the fly, it's head as a whole is indeed a largely round object like a ball...but from the standpoint of what's visible within the field of view and what really needs to be in focus, the top of the eye and front part of the fly's head that is within view ALSO make for a relatively flat subject at a slight incline, which is again not all that different from a carpet of moss with a mushroom in the middle or a ring on a slate in a product photography box.

If T/S can be useful for product photography at macro distances, it can be useful for nature photography at the same distances. Insects, being ever-mobile subjects, are certainly rather arbitrary subjects...your not always going to have them cooperating and giving you the opportunity to get a good composition with a good angle on the interesting parts to fully maximize the potential of a flexible T/S macro system. But the same core argument could be made about insect macro in general...that you can't really get the most out of macro photography with insects, for the very same reasons. And yet...thousands of photographers have found a way, not only to make their subjects cooperate, but even photograph them, sometimes hand-held, at magnifications up to 5:1, even in natural lighting.

So, epistêmê or technê, theory and/or experience... I'm not speaking from a purely theoretical standpoint myself. While I have not actually used a macro t/s bellows before (hopefully something that I'll rectify before too long, I actually really want to get some actual evidence that demonstrates what, if any, and how much of a difference tilt could actually affect focus at macro scale now...I'm about ready to DIY myself a little bellows system and use my 50mm and 100mm lenses to test the theory out in the short term), I am not without experience with macro or T/S photography. The assertion that I am simply an ignorant, hopeful idiot doomed to be disappointed, well, it's certainly your right to have an opinion, but it also certainly doesn't give me any reason to trust what you say at face value any more than I had reason to before. :P

Well, good night.

1325
Landscape / Re: jrista et al, Why Astrophotography?
« on: May 11, 2014, 01:12:56 AM »
Here is an example of how sharp you can get the moon with BYEOS:





This is effectively perfect focus. The fine-grained controls in BYEOS allowed me to find the exact focal plane where the moon sharpened up to maximum. One tiny step forward or back, and things got visibly less sharp and atmospheric turbulence was visibly worse. IMO, even if all you do is shoot the moon, BYEOS is totally worth the money. :P

It also has a planetary imaging mode that will take video clips, automatically string them together, and offers a few other features (such as 10x zoom video, which when the planet only fills a tiny area of the sensor, can be quite useful).

1326
Lenses / Re: New Canon Tilt-Shift Lenses at Photokina [CR1]
« on: May 11, 2014, 01:07:27 AM »
Here is a full-blown T/S bellows kit with focusing rail and lens, designed specifically for macro, that allows up to 1.2x magnification on FF sensors and up to 1.8x on APS-C sensors. Allows up to 25° of tilt freedom. Adaptable to a very wide range of camera types and mounts.


The fact that this exists does not proove it will work for your purposes around 1:1. It might not even live up to the purposes by which the device is marketed. Just be aware of that possibility. This set-up is certainly useful for product-photography but also more clumsy than many others on the market with regards to plain tilt-movements.

Perhaps, however I haven't seen any other system that allows 25° of tilt freedom either. I've seen some that go up to 15°, but they also had a similar focusing/tilt rail setup.

Also, I think this system would still be considerably easier to use than my 100mm macro lens on a ball head. Trying to focus and compose that way is a major PITA, especially if your subject tends to be on the move. A bellows on a shiftable focus rail is a lot easier to work with for composition and focusing. For macro photography of other natural, but otherwise immobile subjects (like flora), a setup like this would be ideal, allowing not only for improvements in the utilization of the focal plane, but also creative focus uses that have nothing to do with maximizing focus or dof.

1327
Lenses / Re: New Canon Tilt-Shift Lenses at Photokina [CR1]
« on: May 11, 2014, 12:06:01 AM »
Here is a full-blown T/S bellows kit with focusing rail and lens, designed specifically for macro, that allows up to 1.2x magnification on FF sensors and up to 1.8x on APS-C sensors. Allows up to 25° of tilt freedom. Adaptable to a very wide range of camera types and mounts.

http://www.novoflex.com/en/products/macro-accessories/bellows-systems/bellows-attachment-castbal-ts/

This is even better than the LensBaby gizmos if you really want a highly flexible macro system. For anyone who is actually interested in a flexible macro setup, you can buy all the parts on B&H:

http://www.bhphotovideo.com/c/search?Ntt=novoflex+castbal&N=0&InitialSearch=yes&sts=ma&Top+Nav-Search=

Pricey at $1904 for the bellows/focuser, lens, and adapter, but probably still less costly than any potential new Canon TS Macro lens that might be announced this year.

1328
Landscape / Re: jrista et al, Why Astrophotography?
« on: May 10, 2014, 11:31:26 PM »
How are you focusing? Live view 10x? You should be able to get pretty accurate in-camera, especially with the short focal length of 105mm. Trying to focus through the viewfinder is pretty much impossible. I can't even do that with my 600mm lens. I either use live view at 10x zoom, or I use BackyardEOS in it's focusing mode while tethered to the camera.

I used 10x live fiew and manual focusing, turning the ring as slowly as possible.

Well, that's the right technique. Are you having trouble because the camera is shaking? Sometimes it actually helps to pretty much grab the whole rig, and balance it against yourself with as much surface area as possible. When the camera just kind of hangs free, it is sometimes actually more susceptible to wild shake than if it is being actively balanced by you. You'll still have some shake, but it should be slower and less problematic for your focusing.

BackyardEOS is a program that runs on a laptop or Windows 8 tablet that has a focusing mode that can control the lens' focus group directly. It has fast, medium, and slow controls, and it's actually the best way to focus DSLRs. The program costs about $50, but I've found it to be completely invaluable, especially for focusing my DSLR for astrophotography. If you can't get your focusing figured out using live view and 10x zoom, and are serious enough to spend the fifty bucks, BYEOS will definitely do the trick.

Shake wasn't an issue, as I said before, the Sigma's focusing ring is just not good enough for slow/steady turning. I have already looked at Backyard EOS before and it is a very nice program. The 2 shots I have were just quick/rushed ones I did a few hours ago, just step up the tripod, kept it stable, point at object, focus and take the images.

If it really is the manual focus ring, then BYEOS might just do the trick. It focuses electronically, so the build quality of the manual focus ring really doesn't matter. If the lens focuses well when using AF, then you would have very fine grained control with BYEOS. You should be able to get things tack sharp.

1329
Landscape / Re: jrista et al, Why Astrophotography?
« on: May 10, 2014, 11:26:25 PM »
How are you focusing? Live view 10x? You should be able to get pretty accurate in-camera, especially with the short focal length of 105mm. Trying to focus through the viewfinder is pretty much impossible. I can't even do that with my 600mm lens. I either use live view at 10x zoom, or I use BackyardEOS in it's focusing mode while tethered to the camera.

I used 10x live fiew and manual focusing, turning the ring as slowly as possible.

Well, that's the right technique. Are you having trouble because the camera is shaking? Sometimes it actually helps to pretty much grab the whole rig, and balance it against yourself with as much surface area as possible. When the camera just kind of hangs free, it is sometimes actually more susceptible to wild shake than if it is being actively balanced by you. You'll still have some shake, but it should be slower and less problematic for your focusing.

BackyardEOS is a program that runs on a laptop or Windows 8 tablet that has a focusing mode that can control the lens' focus group directly. It has fast, medium, and slow controls, and it's actually the best way to focus DSLRs. The program costs about $50, but I've found it to be completely invaluable, especially for focusing my DSLR for astrophotography. If you can't get your focusing figured out using live view and 10x zoom, and are serious enough to spend the fifty bucks, BYEOS will definitely do the trick.

1330
Landscape / Re: jrista et al, Why Astrophotography?
« on: May 10, 2014, 11:02:44 PM »
You know, there is 1 main advantage I noticed with inexpensive telescopes/mounts, they're usually a lot lighter and smaller.

Very true. I guess that's one of the biggest pros of going inexpensive. If you need portability, then high end stuff just isn't viable. That's one of the reasons I got the Orion Atlas...I do take it out to dark sites about 40 miles away or so. The 10Micron GM2000HPS has an ultra portable version, where the head disassembles into two lighter weight parts, plus the control box. But it's still heavier than the Atlas...

I do love using my 600mm lens as a telescope. It's relatively short, so good for wider field work. Optically, it's as good as the $12,000 Officina Stellare HiPer API 152, and faster. Once I get a mono CCD camera, it will make for a superb wide field setup. I also like using my 100mm and 50mm lenses with my DSLR mounted to a Vixen dovetail for really wide field stuff. I haven't had many opportunities to do that...but the first clear night in almost four weeks is supposed to happen on the 13th...I plan to take the Atlas, my DSLR and those two lenses out to a dark site and see if I can get some wide field shots of the milky way core, scorpius, and a few of the Ha nebulas near the galactic core. :) I've been waiting for the 13th for so long, I'm kind of chomping at the bit. :P

Luckily, it won't be Friday on the 13th but anyway, I tried using my Sigma 105mm on the 7D, and I found near impossible to get near accurate focusing, especially on the moon. I also have an image of Jupiter and it's moons.
(deep sky stacker was used)

How are you focusing? Live view 10x? You should be able to get pretty accurate in-camera, especially with the short focal length of 105mm. Trying to focus through the viewfinder is pretty much impossible. I can't even do that with my 600mm lens. I either use live view at 10x zoom, or I use BackyardEOS in it's focusing mode while tethered to the camera.

1331
Lenses / Re: New Canon Tilt-Shift Lenses at Photokina [CR1]
« on: May 10, 2014, 10:44:56 PM »
Here is an actual example of tilt at macro distances and scales:



Your getting a whole lot more personal and insulting here.

Perhaps. Ignorance paired with loudness makes me aggressive at times.

Further, I am decidedly not an anonymous computer and prefer not to be treated as such. I took you by your words and they demanded retribution with regards to contents AND demeanor.

I agree we disagree. But only I am in the comfortable position to know what I know in the aristotelian manner of the craftsman (techne). You instead can only hope you might be right but wish to proof that in a lenghty scientific manner.

I never said you were an anonymous computer. You are, however, an anonymous person. I have no reason to believe you are as intelligent as your incredible arrogance might otherwise make you seem, therefor I have no reason to take you at your word that your supposed experience give you some insight that cannot be demonstrated in a "lengthy scientific manner."

Angry, arrogant, and insulting words have no meaning in the original context of this thread. Which means we have another derailed thread. Guess that isn't surprising, seems to be the M.O. around CR these days...

1332
Lenses / Re: Waiting for 35 1.4L II
« on: May 10, 2014, 10:04:00 PM »
If you need it this summer, consider the Sigma 35 f/1.4 ART

I second this option. Sigma Art lenses are pretty nice these days. Definitely viable options to Canon branded lenses, especially of the Mark II version you really want hasn't been created yet. :P

1333
Landscape / Re: jrista et al, Why Astrophotography?
« on: May 10, 2014, 10:02:06 PM »
You know, there is 1 main advantage I noticed with inexpensive telescopes/mounts, they're usually a lot lighter and smaller.

Very true. I guess that's one of the biggest pros of going inexpensive. If you need portability, then high end stuff just isn't viable. That's one of the reasons I got the Orion Atlas...I do take it out to dark sites about 40 miles away or so. The 10Micron GM2000HPS has an ultra portable version, where the head disassembles into two lighter weight parts, plus the control box. But it's still heavier than the Atlas...

I do love using my 600mm lens as a telescope. It's relatively short, so good for wider field work. Optically, it's as good as the $12,000 Officina Stellare HiPer API 152, and faster. Once I get a mono CCD camera, it will make for a superb wide field setup. I also like using my 100mm and 50mm lenses with my DSLR mounted to a Vixen dovetail for really wide field stuff. I haven't had many opportunities to do that...but the first clear night in almost four weeks is supposed to happen on the 13th...I plan to take the Atlas, my DSLR and those two lenses out to a dark site and see if I can get some wide field shots of the milky way core, scorpius, and a few of the Ha nebulas near the galactic core. :) I've been waiting for the 13th for so long, I'm kind of chomping at the bit. :P

1334
Landscape / Re: jrista et al, Why Astrophotography?
« on: May 10, 2014, 09:10:28 PM »
To he honest, post processing is my least favourite part, until I finished the image ,

I hear that! :) I haven't had many of those moments lately...I tried to do galaxy imaging with my wide field 600mm lens...wasn't nearly as successful as I originally thought it would be. It's pretty hard to do galaxy imaging in a wide field under polluted skies.

and good luck to getting that mount! c:

I'm actually really hoping the price on the absolute encoders these mounts use drops in the next couple of years, so that by the time I'm finally ready to invest in one, they'll be cheaper. Astro-Physics just started adding encoders to their mounts (they don't seem to be doing it as well as 10Micron). Their lower-end mounts (which are still all ultra high end in general) cost around $8000 or so without the encoders. Just adding the encoders pushes the price up to $15,000 or more. That's almost double the cost. If the cost of these high resolution, absolute encoders comes down in the future, these nice high end mounts should come down in cost as well, and I intend to be all ready to pounce the moment they do. :P

1335
I use my Microsoft Surface Pro out in the field. It's a full blown computer, weighs about a pound, and runs Lightroom 5 and Photoshop CS6/CC quite nicely. The battery life is the biggest problem, but that's largely been solved with the Surface Pro 2.

The screen is pretty good, I think my photos look quite nice on it, although just ever so slightly less saturated than on my desktop screen. I haven't tried to calibrate the Surface Pro yet...but I bet some calibration would probably fix the saturation problem.

You can even shoot tethered with the Surface Pro and Lightroom. You can plug in either a high capacity memory card or a USB drive, and write images to that. I've also set it up using an "offline files" folder that automatically syncs up to my NAS at home when the tablet connects back up to my home WiFi, but there is limited space on the SSD drive.

Anyway, if you want a nice way of showing your work to racers at the track, I really don't think you could go wrong with a Surface Pro 2 tablet. You could shoot tethered, immediately apply some basic processing in Lightroom, and it's a touch-based device, so sliding through a gallery of your shots for a race car driver would be not only easy, but full screen and beautiful. ;)

Pages: 1 ... 87 88 [89] 90 91 ... 316