Full Frame and Bigger Pixels vs. APS-C and Smaller Pixels - The Reach War

[RustyTheGeek]

Lots of stuff to digest on this thread. I have to admit that I eventually started skimming a bit.

Fortunately, I think the general consensus supports what I have always thought about this subject.

At the end of the day, the fact that I don't have to put forth the effort to crop images in post when I use a APS-C sensor camera is well worth owning that body, IMHO. After all, when shooting hundreds of swimming pictures, I already have enough work to do with the lighting issues.

 

[Dylan777]

I recently picked up 2x TC III for more reach with my 400mm f2.8 IS II. IQ drops 20-30%. FF body has larger pixel plus cropping will make it worst.

I'm not sure how you are measuring or quantifying your "IQ drops 20-30%" but if I was you I would be looking hard at what is wrong. I use a 2X TC III with a 300mm f2.8 IS II and I have used it with an equivalent 400. I'd like to see anyone reliably tell if a TC has been used or not.

20-30% is my own est. IQ drops. No scientific data.

With 1.4x TC III, IQ still good(not good as bare). The IQ drops dramatically with x2 TC III, especially in Ai servo.

IQ will drop when use with TC, on any lenses. I don't care how good the 300mm f2.8 IS II is. If you don't see IQ drops on your 300 when use with 2x TC, then you might want to check your 300 as bare.

 

[Steve]

I think the 7D can do even better than your example. Here is a bird photographed with a 500mm f/4 L II:

Very low noise. Here is another:

Also very low noise. The 7D, when used properly, can be a truly superb camera. I think people get caught up in the noise levels when they first use it, then make a decision early on that the 7D simply cannot produce low noise results.

Whats the EXIF on these? They both look like they were shot with flash so I'm guessing they are low ISO shots.

There seems to be this idea that there are a lot of people who think the 7D (or crop sensor cameras in general) is useless or bad when I don't think that's the case at all. The 7D can be used to make really excellent pictures, no doubt about it. It's a fantastic camera and it clearly has some advantages in some very, very specific situations. But there is a reason that pros use full frame camera bodies and there is a reason that Canon and Nikon have made their highest end, action specific, pro level cameras full frame. Its just plainly more useful in more shooting situations to have the better noise handling and IQ of the FF sensor. I mean, the 7D might have the advantage for low ISO moonshots but those are going to make up a tiny percentage of shooting situations compared to, say, early morning/late evening wildlife or indoor/night sports shooting. You can literally get useful shots at 12k ISO on a 5DIII/1DX while the 7D starts falling apart at 1600. There's also the matter of the AF systems and the whole "who cares how many pixels you can put on a blurry subject?" thing Hopefully the 7DII will eliminate that difference but for the time being its also a legit concern.

 

[Skulker]

............
I've long held the opinion that crop sensor cameras, like the 7D, do have value in certain circumstances. The most significant use case where a camera like the 7D really shows it's edge over full frame cameras is in reach-limited situations.

............

I'd like to prove my case

................

Both images were initially scaled to approximately 1/4 their original size (770x770 pixels, to be exact).

The 5D III image was then layered onto the 7D image, and upsampled in Photoshop by a scale factor of exactly 161.32359522807342533660887502944%.

While I agree with you that a 7D (or any so called crop sensor) can have advantages over a so called full frame sensor. I think you need to review your work if your objective is to reach a valid conclusion.

1) you start off with a strong opinion. (its better to have an open mind)
2) Then you try to "prove my point". (it might be better to try to test your opinion)
3) Then you do something that is going to be very detrimental to one of the images.

You may claim that you would have to upsample the 5D3 image to get the same size as the 7D. But you have already down sampled it - so you have lost detail in the 5D3 file.

To demonstrate I made a simple file in Photoshop. 770 pixies ;D wide, copied it, scaled it to 481 wide, then upscaled it to 770 wide. Hardly by chance my file had two types of detail. A sharp line and a not so sharp line. The result can be seen below.

I think I have just proved that photoshop is better than photoshop.

Don't get me wrong I'm a fan of the 7D and think its a great camera. I also think there is a place for "crop sensors". I'm waiting for the 7D2, I don't think it will be for me, but I definitely see a crop sensor shaped hole in my kit.

and finally whats with 30 odd decimal places!


EDIT: Just in case anyone wonders ;D the down sampling and up sampling were done with default PS settings

 

[candc]

Which has greater noise? An APS-C sensor or a full frame sensor cropped to APS-C size? Bare in mind our hypothetical situation is you're still reach limited, so the bigger sensor in itself conveys no advantage, and the only arguable difference is pixel size. For roughly comparable sensor generations I'd argue they're practically the same. Outside of lab tests, it probably isn't significant.

At ISO6400, I'd happily use either of my 600D or a 5D mk2 (as secondary body to 7D), but when reach limited the 600D would be my preference of the two. To me noise isn't the limiting factor in this scenario.

Below are a pair of images shown at 100%. One is from an 18 MP APS-C camera at ISO 3200. The other is from an 18 MP FF camera at ISO 6400, a full stop higher than the APS-C image.

I'm having trouble telling which is which, the noise levels are so similar. : :

I think the 7D can do even better than your example. Here is a bird photographed with a 500mm f/4 L II:

Very low noise. Here is another:

Also very low noise. The 7D, when used properly, can be a truly superb camera. I think people get caught up in the noise levels when they first use it, then make a decision early on that the 7D simply cannot produce low noise results.

I'm a very well versed guy when it comes to photography. I do not have pro-level skill and my images don't exhibit pro-level quality, but that is simply a matter of practice. I still have to work, and I work my butt off to pay for the kind of equipment I buy. I know what the difference between the 5D III and 7D is. I've had more than enough time with the 5D III, between playing with other peoples out in the field, to having had mine for several months now. Things are what they are...6.25µm pixels vs. 4.3µm pixels. Smaller pixels mean more detail. Greater sensor area on subject means more light. Normally, a full frame sensor is capable of putting MORE sensor area on subject...however that is not the case in a reach-limited scenario. In a reach limited scenario, the same sensor area is on subject. That means the only significant difference is pixel size.

I've said it so many times, I know others have also said it. Noise is relative to the area, not the pixel. If two cameras use the exact same area of sensor to resolve a subject, then there is no difference in noise. Not when the image from the sensor with smaller pixels is downsampled to the same dimensions as the image from the sensor with bigger pixels.

Very nice bird photos.I know this has been hotly debated here but I am pretty sure its the pixel size and not the sensor area that affects noise the most. My reasoning is that I have looked at images from the d800 which has aps-c size pixels and exhibits aps-c levels of noise when viewed on a per pixel basis. That tells me that pixels of a similar size in the same generation show similar noise levels?

 

[Skulker]

I recently picked up 2x TC III for more reach with my 400mm f2.8 IS II. IQ drops 20-30%. FF body has larger pixel plus cropping will make it worst.

I'm not sure how you are measuring or quantifying your "IQ drops 20-30%" but if I was you I would be looking hard at what is wrong. I use a 2X TC III with a 300mm f2.8 IS II and I have used it with an equivalent 400. I'd like to see anyone reliably tell if a TC has been used or not.

20-30% is my own est. IQ drops. No scientific data.

With 1.4x TC III, IQ still good(not good as bare). The IQ drops dramatically with x2 TC III, especially in Ai servo.

IQ will drop when use with TC, on any lenses. I don't care how good the 300mm f2.8 IS II is. If you don't see IQ drops on your 300 when use with 2x TC, then you might want to check your 300 as bare.

LOL well put ;D

I'm quite happy with the quality of the 300 bare. and I'd agree there is a drop in IQ with both converters. I certainly wouldn't say it was anything like 20-30%. When I had the 7D I seldom used the 2x with the 300, but now I have the 1Dx its my favorite lens. I mean I use the 300 with 2x more than any other lens or combination. Maybe its something to do with the improved focusing on the latest cameras getting the best out of the lens and TC combination.

 

[DominoDude]

You guys are never boring! As long as you reason with logic and use mathematical formula, then I don't care too much if you're wright or rong - we get to know how you are thinking to get to your results. I love it! It makes me think a bit too.
So keep 'em coming.

 

[jrista]

Very nice bird photos.I know this has been hotly debated here but I am pretty sure its the pixel size and not the sensor area that affects noise the most. My reasoning is that I have looked at images from the d800 which has aps-c size pixels and exhibits aps-c levels of noise when viewed on a per pixel basis. That tells me that pixels of a similar size in the same generation show similar noise levels?

Your talking about on a per-pixel basis. On a per-pixel basis, that is true. However I'm talking about on a whole-image basis, or as it's called, on a "normalized" basis. When you compare images as a whole at the same size, assuming the same absolute area of sensor was used, then there won't be any difference in noise regardless of pixel size. There will, however, be a difference in detail.

This all assumes same pixel generation. The 5D III does have an advantage in upsampling due to it's newer pixel generation. It has higher quantum efficiency and overall a better pixel architecture, than the 7D pixels. That means less noise per pixel. I actually wish I had a 70D. That would make for a better comparison, as then both cameras would use sensors of similar generation, instead of being separated by over three years of technology. That's unlikely to happen unless I meet someone with a 70D who will let me borrow it for a night, though...as I have no intention of buying a 70D.

 

[SiliconVoid]

Commendations on the in-depth research and comparison of the 7D and 5DmkIII.

Although the example used could be a little misleading as your results do not exactly show how APS-C sensors 'will' have a reach advantage over 35mm frame sensors - but exactly how they 'could' such as a 7D at 18mp over something like the 5Dmkx at 22mp when using the same lens for the same subject at the same distance. As APS-C sensors with less than half the pixel resolution of 35mm sensors still exist, and will likely be the case as long as the same technology is applied in both sensor designs, the ideology that APS-C will provide an advantage depends entirely on the mp/mm ratio of both sensors - not simply APS-C over full frame.

For example in Canon world (1.6 multiplier) something like the 7D would only provide the reach advantage you show as long as the smaller sensor provides at least 40% of the pixel count of the larger sensor. In other words, an 18mp APS-C sensor would have no reach advantage over a full frame 45mp sensor, because they would both produce the same resolution/data of the subject to crop for final output. Further, if the smaller sensor provided less than half the pixel count (less than 40% in the case of Canon) it would have no advantage at all as the larger sensor would have more pixels across the subject - both before and after cropping.

For some the mathematics may be difficult to follow as Canon does not have anything even close to 45mp (not even half that currently) so we can use another brand like Nikon. The 12mp APS-C sensor of say the D300s, or the 16mp APS-C sensor of the D7000, provide no reach advantage over their 36mp FX bodies because even with the subject only covering a ~50% region of the sensor it is still resolved by more mp than the APS-C sensors.

Still a very informative research project within the offerings of one manufacturer where a photographer has the choice of an APS-C body providing more than 40-50% of the pixel count of full frame.

 

[jrista]

............
I've long held the opinion that crop sensor cameras, like the 7D, do have value in certain circumstances. The most significant use case where a camera like the 7D really shows it's edge over full frame cameras is in reach-limited situations.

............

I'd like to prove my case

................

Both images were initially scaled to approximately 1/4 their original size (770x770 pixels, to be exact).

The 5D III image was then layered onto the 7D image, and upsampled in Photoshop by a scale factor of exactly 161.32359522807342533660887502944%.

While I agree with you that a 7D (or any so called crop sensor) can have advantages over a so called full frame sensor. I think you need to review your work if your objective is to reach a valid conclusion.

1) you start off with a strong opinion. (its better to have an open mind)
2) Then you try to "prove my point". (it might be better to try to test your opinion)
3) Then you do something that is going to be very detrimental to one of the images.

You may claim that you would have to upsample the 5D3 image to get the same size as the 7D. But you have already down sampled it - so you have lost detail in the 5D3 file.

To demonstrate I made a simple file in Photoshop. 770 pixies ;D wide, copied it, scaled it to 481 wide, then upscaled it to 770 wide. Hardly by chance my file had two types of detail. A sharp line and a not so sharp line. The result can be seen below.

I think I have just proved that photoshop is better than photoshop.

Don't get me wrong I'm a fan of the 7D and think its a great camera. I also think there is a place for "crop sensors". I'm waiting for the 7D2, I don't think it will be for me, but I definitely see a crop sensor shaped hole in my kit.

and finally whats with 30 odd decimal places!


EDIT: Just in case anyone wonders ;D the down sampling and up sampling were done with default PS settings

You are correct. However, the image below was actually done a bit differently. In this case, both samples were downscaled to fit in the 770x770 pixel image...the 5D III image was not first downsampled then upsampled again.

Your right, certainly not as stark a difference as my first example. Maybe that one is invalid. This example, however, does show that the 7D is still picking up more subtle details and nuances of color. The differences are not stark, but they do exist. Also note, both of these images were denoised. They were both denoised to the point where they both exhibited about the same noise levels...where noise was pretty much not visible. Obviously, there was quite a bit less noise reduction applied to the 5D III image.. That actually costs the 7D a little bit of it's detail as well...but it is on a level playing field with the 5D III as far as noise goes, so I still think it's a fair example.

 

[jrista]

Commendations on the in-depth research and comparison of the 7D and 5DmkIII.

Although the title could be a little misleading as your results do not exactly show how APS-C sensors have a reach advantage over 35mm frame sensors - but exactly how a 7D at 18mp can have a reach advantage over something like the 5Dmkx at 22mp when using the same lens for the same subject at the same distance. As APS-C sensors with less than half the pixel resolution of 35mm sensors still exist, and will likely be the case as long as the same technology is applied in both sensor designs, the ideology that APS-C will provide an advantage depends entirely on the mp/mm ratio of both sensors - not simply APS-C over full frame.

For example in Canon world (1.6 multiplier) something like the 7D would only provide the reach advantage you show as long as the smaller sensor provides at least 40% of the pixel count of the larger sensor. In other words, an 18mp APS-C sensor would have no reach advantage over a full frame 45mp sensor, because they would both produce the same resolution/data of the subject to crop for final output. Further, if the smaller sensor provided less than half the pixel count (less than 40% in the case of Canon) it would have no advantage at all as the larger sensor would have more pixels across the subject - both before and after cropping.

For some the mathematics may be difficult to follow as Canon does not have anything even close to 45mp (not even half that currently) so we can use another brand like Nikon. The 12mp APS-C sensor of say the D300s, or the 16mp APS-C sensor of the D7000, provide no reach advantage over their 36mp FX bodies because even with the subject only covering a ~50% region of the sensor it is still resolved by more mp than the APS-C sensors.

Still a very informative research project within the offerings of one manufacturer.

You are correct, this is really less of APS-C vs. FF as it is small pixels vs. large pixels. It really doesn't matter if the small pixels are in an APS-C sensor or a full frame sensor...they could all be in an MFD sensor. The actual size of the frame really doesn't matter. What matters is the size of the pixel. It just so happens that smaller sensors tend to have smaller pixels...so it still holds true that APS-C sensors have reach advantages over FF sensors.

The exact advantage is indeed relative to the specific sensors involved. The 7D probably wouldn't show any advantage over a D800 if they were compared like the image in my last post. The D800 has vastly superior sensor technology, so even though it's pixels are slightly larger, all that technology is going to trounce the 7D. The difference between the 7D and 1D X is going to be more significant than the difference demonstrated here between the 5D III and the 7D. That's a given, I think everyone understands that.

I'd just been asked in the past to prove my case with actual images, instead of just theory and math, as I've often argued that the smaller pixels will always have a resolving power advantage over larger pixels. I am simply trying to fulfill my promise here, and provide some actual images to back up my claims. The advantage isn't wildly huge...I've never claimed that. It's a nuanced advantage, for sure. But the advantage exists, nevertheless.

BTW, you brought up some differences between some older Nikon cameras and the new 36mp FF cameras. I'd like to point out that you failed to account for Nikon's newer APS-C parts. Nikon has several 24mp APS-C cameras that maintain the balance, and preserve the reach advantage of the smaller sensors over larger sensors. A 24mp Nikon APS-C is going to have a similar reach advantage over a 36.3mp D800 or D810. Both the smaller and larger sensors use the same technology, same generation of sensor...so the only key difference is pixel size. Assuming the subject fills the same absolute sensor area...on a normalized basis, the differences in noise will be minor but the differences in detail will be measurable.

 

[candc]

Very nice bird photos.I know this has been hotly debated here but I am pretty sure its the pixel size and not the sensor area that affects noise the most. My reasoning is that I have looked at images from the d800 which has aps-c size pixels and exhibits aps-c levels of noise when viewed on a per pixel basis. That tells me that pixels of a similar size in the same generation show similar noise levels?

Your talking about on a per-pixel basis. On a per-pixel basis, that is true. However I'm talking about on a whole-image basis, or as it's called, on a "normalized" basis. When you compare images as a whole at the same size, assuming the same absolute area of sensor was used, then there won't be any difference in noise regardless of pixel size. There will, however, be a difference in detail.

This all assumes same pixel generation. The 5D III does have an advantage in upsampling due to it's newer pixel generation. It has higher quantum efficiency and overall a better pixel architecture, than the 7D pixels. That means less noise per pixel. I actually wish I had a 70D. That would make for a better comparison, as then both cameras would use sensors of similar generation, instead of being separated by over three years of technology. That's unlikely to happen unless I meet someone with a 70D who will let me borrow it for a night, though...as I have no intention of buying a 70D.

seems reasonable.

your moon photos are always a pleasure to view. it is going to be passing a bit closer than usual so hopefully the the air is clear and dry so you can get some good shots.

 

[jrista]

Very nice bird photos.I know this has been hotly debated here but I am pretty sure its the pixel size and not the sensor area that affects noise the most. My reasoning is that I have looked at images from the d800 which has aps-c size pixels and exhibits aps-c levels of noise when viewed on a per pixel basis. That tells me that pixels of a similar size in the same generation show similar noise levels?

Your talking about on a per-pixel basis. On a per-pixel basis, that is true. However I'm talking about on a whole-image basis, or as it's called, on a "normalized" basis. When you compare images as a whole at the same size, assuming the same absolute area of sensor was used, then there won't be any difference in noise regardless of pixel size. There will, however, be a difference in detail.

This all assumes same pixel generation. The 5D III does have an advantage in upsampling due to it's newer pixel generation. It has higher quantum efficiency and overall a better pixel architecture, than the 7D pixels. That means less noise per pixel. I actually wish I had a 70D. That would make for a better comparison, as then both cameras would use sensors of similar generation, instead of being separated by over three years of technology. That's unlikely to happen unless I meet someone with a 70D who will let me borrow it for a night, though...as I have no intention of buying a 70D.

seems reasonable.

your moon photos are always a pleasure to view. it is going to be passing a bit closer than usual so hopefully the the air is clear and dry so you can get some good shots.

I probably won't be imaging the moon this weekend. I think it will be cloudy, but even if it was not...the full moon just doesn't have the same kind of interesting detail as non-full moons do. There is no shadow playing across it's surface, so a LOT of small details are invisible.

That's actually a problem with my current set of images here...you can only see detail right around the limb, and there still isn't that much there. A waxing moon is actually better, as there are a lot of interesting features when it's going from the waxing crescent phase to just about where waxing gibbous begins. I am going to start imaging the moon regularly with the 5D III and 7D at 840mm and 1200mm (and maybe even 1680mm, as I still have my Kenko TC), and maybe I'll catch it on a good night with very good seeing, so atmospheric turbulence won't be as much of a problem as it was in this set of images.

 

[SiliconVoid]

That is a good point, regarding current tech versus older tech, though my reference to the same 'technology' being used was in the context of technology limitations. In that at some point we will reach the boundaries of our technology where we are limited to xx number of pixels per mm. At which point APS-C sensors will not have any more than half the pixel count (40% for Canon) of full frame sensors and cropping becomes nothing more than an output/framing preference.

You and I will likely not see that day, but someone will..

 

[Loswr]

...certainly not as stark a difference as my first example. Maybe that one is invalid. This example, however, does show that the 7D is still picking up more subtle details and nuances of color. The differences are not stark, but they do exist.

Thanks. This revision addresses the issue about which dak723 and I were commenting (namely, a method biased in favor of the 7D). The difference you're showing here aligns more closely with what I've seen under similar conditions, i.e., at low ISO. I wonder what you'd find empirically at ISO 1600 or ISO 6400...

 

[candc]

Very nice bird photos.I know this has been hotly debated here but I am pretty sure its the pixel size and not the sensor area that affects noise the most. My reasoning is that I have looked at images from the d800 which has aps-c size pixels and exhibits aps-c levels of noise when viewed on a per pixel basis. That tells me that pixels of a similar size in the same generation show similar noise levels?

Your talking about on a per-pixel basis. On a per-pixel basis, that is true. However I'm talking about on a whole-image basis, or as it's called, on a "normalized" basis. When you compare images as a whole at the same size, assuming the same absolute area of sensor was used, then there won't be any difference in noise regardless of pixel size. There will, however, be a difference in detail.

This all assumes same pixel generation. The 5D III does have an advantage in upsampling due to it's newer pixel generation. It has higher quantum efficiency and overall a better pixel architecture, than the 7D pixels. That means less noise per pixel. I actually wish I had a 70D. That would make for a better comparison, as then both cameras would use sensors of similar generation, instead of being separated by over three years of technology. That's unlikely to happen unless I meet someone with a 70D who will let me borrow it for a night, though...as I have no intention of buying a 70D.

seems reasonable.

your moon photos are always a pleasure to view. it is going to be passing a bit closer than usual so hopefully the the air is clear and dry so you can get some good shots.

I probably won't be imaging the moon this weekend. I think it will be cloudy, but even if it was not...the full moon just doesn't have the same kind of interesting detail as non-full moons do. There is no shadow playing across it's surface, so a LOT of small details are invisible.

That's actually a problem with my current set of images here...you can only see detail right around the limb, and there still isn't that much there. A waxing moon is actually better, as there are a lot of interesting features when it's going from the waxing crescent phase to just about where waxing gibbous begins. I am going to start imaging the moon regularly with the 5D III and 7D at 840mm and 1200mm (and maybe even 1680mm, as I still have my Kenko TC), and maybe I'll catch it on a good night with very good seeing, so atmospheric turbulence won't be as much of a problem as it was in this set of images.

i know what you mean. its been hazy here and not very clear at night lately. the full moon is flat looking to begin with. the 2 shots below are 70d on the left and 6d on the right. the 6d one looks better but that is because i jacked up the contrast more on it. if they were processed the same i think the 70d one would look better. both were handheld with a sigma 120-300 and canon 2xiii taken a few minutes apart. i am going to keep an eye on the sky and see if i can get some better ones.

 

[jrista]

...certainly not as stark a difference as my first example. Maybe that one is invalid. This example, however, does show that the 7D is still picking up more subtle details and nuances of color. The differences are not stark, but they do exist.

Thanks. This revision addresses the issue about which dak723 and I were commenting (namely, a method biased in favor of the 7D). The difference you're showing here aligns more closely with what I've seen under similar conditions, i.e., at low ISO. I wonder what you'd find empirically at ISO 1600 or ISO 6400...

I dunno, I guess I can try. The moon has a LOT of dynamic range. In general, a hell of a lot more dynamic range than is possible to capture even with 14 stops of DR. So I try to shoot at as low an ISO as possible. On a Canon camera, ISO 100-400 are roughly the same, there is only a fraction of a stop difference in DR between them. I chose ISO 200 in this case, as I noticed that banding was occurring at ISO 400 on the 7D.

At ISO 1600 and 6400, the biggest single problem would simply be not having enough dynamic range to differentiate fine nuances of detail, due to quantization noise. That is one area where bigger pixels do help...they reduce quantization noise, so shadow detail is better at higher ISO.

You can't think of photographing the moon as photographing something in the dark, though. It's reflecting the sun. It is an EXTREMELY bright subject, and it has massive dynamic range. (I mean, think about it...how many stops of DR do you think you would need to resolve clean, crisp detail on the dark side while simultaneously resolving clean, crisp detail in the brightest crater hotspots on the light side? At least 20 stops...although, I've tried merging a bunch of moon frames together into a 32-bit float HDR for processing in ACR...and the shadowed site was STILL too noisy...)

 

[RustyTheGeek]

I think this thread has a lot of DR! So much that my head is starting to hurt!

 

[mackguyver]

Jon, thank you for the comparison and I'm not too surprised by the results. I found it to be that way when I shot with the 7D & 5DIII side-by-side, but as soon as you hit ISO 1600 (maybe even 800) or above, the reach advantage fell apart. Also, I found the Zone AF on the 7D to work well with AI Servo, but it wasn't nearly as good as the 5DIII. I kept them both for a while, but like many others, sold it, keeping the 5DII and 5DIII, at least until the 1D X replaced the 5DII earlier this year.

 

[jrista]

So, I thought I'd throw in a bit of a "reference image". One way to image more detail, even when seeing is bad, is to take a lot of frames at high shutter speeds, and integrate the best 10-20%. It's called Lucky Imaging (lucky, in that in some of the frames you image, you'll be "lucky" enough to have very good to perfect seeing, where the turbulence clears and everything resolves at high resolution. The exposure duration can range anywhere from a few hundred milliseconds to microseconds. In my case, I kept my exposure settings, so my exposure duration was 10ms.

I took a couple of videos of the shadowed limb of the moon at 1000 frames at 5x zoom, and integrated the best 10% (100 frames) with AutoStakkert! 2. I used the 3x Drizzle option, which is actually a superresolution algorithm, then downsampled to 50% (1.5x original resolution), so the final image is actually showing detail beyond the diffraction and aberration limits of the optics. This is the result:


(Click for full size)

I want to give this a try with the 600mm, 2x TC, and 1.4x Kenko (1680mm) on the 7D. I bet I could resolve some pretty amazing detail by resolving a few thousand frames and integrating the best 10%.