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

[ajfotofilmagem]

Thank you for your test. He shows that APS-C may give better results in situations of limited reach and low ISO. For me it was not a surprise, because I've thought that way. I also know that if the comparison was made ​​in ISO6400, the result would be different. But this does not invalidate the test result in ISO200.

Another reason to love APS-C is price and weight of the lenses. Those who have held in their hands 7D + 300mm F4L and also 1Dx + 500mm F4L (angle of view equivalent), know that the weight and price are very different. Yes, I know I have high noise in 7D ISO6400, but we hope that 7D Mark ii will close this gap.

 

[MichaelHodges]

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. : :

One of those crops smells like a 7D.

I shoot wildlife all over the country. Most of the big animals come out in crepuscular conditions. At this point, noise will determine which camera you use. Going from 420mm to 300mm doesn't matter because you won't get the shot with APS-C.

 

[ScottyP]

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'm not convinced. I'd need to see the squirrels on the moon to be sure.

 

[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.

 

[LetTheRightLensIn]

Thanks for the comparison!

As I've often stated, APS-C does have a 'reach advantage'...if you're FL limited AND at low ISO (~800 or less) AND printing larger than 16x24"/A2.

First, I don't think it makes sense to mention printing size. If you are very reach limited you might only have enough left to fill 2MP. It really depends. Maybe you have 1MP or maybe 15MP, it depends shot to shot. And 16x24" is pretty large, even a complete frame from a 5D3 only fills 13x19" at 300PPI!

Second, you can go above ISO800 and still get a reach advantage from the 7D. In fact, with a high contrast subject in a well lit portion of the frame, the advantage is actually still clear even at ISO6400. In fact, compared to the 5D2, the 7D does the same, or almost always better, in any circumstance at any ISO, if reach limited (as the 7D has higher pixel density, is more efficient per area of sensor and has better high iso banding characteristics). Compared to the 5D3 it is a bit trickier, but I have shots of Hairy Woodpeckers (granted that is a high contrast target), so-called real world, where the 7D does better IMO and they were ISO1600-2500, better with ease. Of course if you have a low contrast main subject and it's dark in coloration and in a dark part of the frame, in that case, the 7D may fall back to the 5D3 or even fall behind it at higher ISOs since the 5D3 is a little bit more efficient per sensor area and has good high iso banding characteristics.

 

[scyrene]

Well, I said for a long time that once I got a 5D III, I'd do some comparison shots. 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. A reach limited situation is one in which you cannot get physically closer to your subject, and your subject does not fill the frame. The likely case is that you are using your longest lens, and will likely crop in post.

In the past, others have made the argument that a camera like the 5D III or 1D X has so much more image quality than a camera like the 7D that the 7D could never compare. The argument was made that an upsampled 5D III or 1D X image (or even, for that matter, D800/E, D600, etc. image) would be just as good.

I'd like to prove my case. I've taken the most reach-limited scenario possible...photographing the moon, with a 1200mm lens (Canon EF 600mm f/4 L II w/ Canon EF 2x TC III). I used a Canon EOS 7D and a Canon EOS 5D Mark III for imaging. The lens and camera were attached to an Orion Atlas EQ-G equatorial tracking mount, operating in Lunar tracking mode, to minimize any other factors that might affect image quality. Seeing (atmospheric turbulence measure) was average.

Above is a GIF image of the 7D and 5D III images scaled to the same size, overlaid directly on top of each other using Photoshop's layer difference blending mode for best possible alignment. Both images were created exactly the same way, by initially focusing with BackyardEOS' focus module for optimum focus (BYEOS is like having a 2560x1600 live view screen...it's awesome!) The image exposures for both cameras are 1/100s f/8 ISO 200. Five images for both cameras were taken, the best frame from each set was chosen for comparison. Both images were maximally cropped simply by choosing 1:1 in Lightroom. Both images had identical processing applied in Lightroom (one image was processed, it's settings were copied and pasted onto the other.) 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%. This scale factor was derived by computing the sensor diagonals of both cameras:

ffDiag = SQRT(36^2 + 24^2) = 43.266615305567871517430655209646
apscDiag = SQRT(22.3^2 + 14.9^2) = 26.819768828235637870277777227866

Then dividing the FF diagonal over the APS-C diagonal:

43.266615305567871517430655209646/26.819768828235637870277777227866 = 1.6132359522807342533660887502944x

Then finally multiplying by 100% (to get a relative scale factor that I could directly apply with Photoshop's layer scaling tool.)

I believe the GIF above speaks for itself. The larger pixel size of the 5D III clearly does not resolve as much detail as the 7D does. Not only is the 7D image sharper, but there is a significant increase in fine details, small craters, nuances of color, etc. Here is another GIF, this time the images are only 1/2 original size (any larger, and the effects of seeing diminish any real benefit...I've had days where seeing is excellent, and more detail can be resolved, but sadly tonight was not one of those days):

The 7D's smaller pixels, despite being a generation prior to the 5D III's, are still resolving more detail, especially fine edges to crater rims (some of which don't even show up at all in the FF image), and are extracting a finer and more nuanced level of color. Many smaller craters, especially those that are inside larger craters, as well as the central mounds of many craters, are either difficult to make out or simply don't appear in the 5D III image, where as they show up clearly in the 7D image.

A common reach-limited use case is bird photography. Similar to the moon, it can be difficult to get close to and fully extract all the detail from a small songbird, shorebirds, and shy waders or waterfowl. One either needs a significantly longer lens on the full frame (I am still experimenting with the 5D III, but I'll probably be using 840mm and 1200mm a lot more than 600mm), or you need the skill to get much closer to your subjects, in order to fully take advantage of the benefits the larger frame has to offer.

Anyway, there you have it. The 5D III is an excellent camera, and when you have the option of framing identically (i.e. filling the frame with your subject), the larger frame trounces the 7D in terms of image quality. It gathers 2.6002949408613476991603214253469x more light:

(36 * 24) / (22.3 * 14.9) = 864 / 332.27 =  2.6002949408613476991603214253469

With more than two and a half times more light, it's two and a half times better. Like using two and a half stops lower ISO on the cropped sensor. However if you don't have the option of either getting closer to your subject, or using a super long lens (not everyone has the option of spending $13,800 ($12,800+$500+$500) on a 600mm f/4 II and both of Canon's Mark III TCs), then there is no question that a camera like the 7D, or currently the better option the 70D, is going to give you the option of creating more detailed photos.

Very effective presentation. I did the same thing when I got my 5DIII - although in that case, I was comparing it to the 50D (see https://flic.kr/p/cHKKfQ). Still, I gave the crop sensor the edge. I didn't think to overlay them, but instead (if I recall correctly) compared the size of the smallest visible features each could resolve.

Can the full frame camera regain some ground through image stacking? It certainly seems to produce much crisper images.

 

[johnhenry]

Its really great to see someone has done a really good comparison between the two big players from Canons two formats

 

[Sella174]

Well, if the lens is up to the job, obviously any high megapixel count sensor at a low ISO setting will provide more image detail than a bigger sensor with a lower megapixel count at the same ISO setting with the same lens.

 

[jrista]

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%. This scale factor was derived by computing the sensor diagonals of both cameras:

That would give an unfair advantage to the 5D III. You have to do exactly the same things to both images to keep both results consistent. Even if I did not crop at all, the 5D III image would still have to be upscaled by the same amount.

I performed every action identically, for both the 1/4 scale and 1/2 scale images, then added the one extra step of upscaling the 5D III moon to the size of the 7D moon. That was simply to normalize subject size.

I can do it again, and leave everything at 100% scale. The moon in the 5D III shot is MUCH smaller than the moon in the 7D shot, so it really doesn't matter if I scale first or not. Here is another example...these are cropped and scaled to 770px, but the 5D III image was not upscaled...it's at it's native size:

For reference, these are full size crops...the full height of the sensor is used...I only cropped out empty black space to the left and right. For all intents and purposes, these are downsampled 1:1's. I'll get some more images of them at 100% size, without any noise reduction.

 

[Loswr]

Thanks for the comparison!

As I've often stated, APS-C does have a 'reach advantage'...if you're FL limited AND at low ISO (~800 or less) AND printing larger than 16x24"/A2.

First, I don't think it makes sense to mention printing size. If you are very reach limited you might only have enough left to fill 2MP. It really depends. Maybe you have 1MP or maybe 15MP, it depends shot to shot. And 16x24" is pretty large, even a complete frame from a 5D3 only fills 13x19" at 300PPI!

Second, you can go above ISO800 and still get a reach advantage from the 7D. In fact, with a high contrast subject in a well lit portion of the frame, the advantage is actually still clear even at ISO6400. In fact, compared to the 5D2, the 7D does the same, or almost always better, in any circumstance at any ISO, if reach limited (as the 7D has higher pixel density, is more efficient per area of sensor and has better high iso banding characteristics). Compared to the 5D3 it is a bit trickier, but I have shots of Hairy Woodpeckers (granted that is a high contrast target), so-called real world, where the 7D does better IMO and they were ISO1600-2500, better with ease. Of course if you have a low contrast main subject and it's dark in coloration and in a dark part of the frame, in that case, the 7D may fall back to the 5D3 or even fall behind it at higher ISOs since the 5D3 is a little bit more efficient per sensor area and has good high iso banding characteristics.

To your first point, as I stated originally, if I would need to crop so severely that I would be left with a 1-2 MP image, I wouldn't bother pressing the shutter button.

To your second point, the squirrels above tell a different story. Granted, I've not done a head to head of 7D vs. 5DIII, but the 1D X cropped down to match framing is clearly superior to the 7D at higher ISO settings.

 

[jrista]

Jrista,

Do you think you could post the unprocessed RAW files? I'd like to see these with no noise reduction. It almost looks like the 5DIII had too much applied or was out of focus.

I'll post some 100% size crops (no scaling) so you guys can see the noise.

Regarding the foucs...that is actually the impact of seeing. As I described in my original post, with a longer focal length, you can kind of "cut through" that a bit more. Maybe that is skewing the results a little...but remember that both images are suffering from the effects of seeing, not just the 5D III. The 5D III suffers a little more from seeing, however I did choose the best out of five of both the 5D III and 7D images.

The thing about seeing is there are moments when the turbulence "flattens", and things get really clear. There is actually an astrophotography technique, used even by professional observatories, called "Lucky Imaging". Described in 1978 by David L. Fried, the technique involves taking many (sometimes many thousands) of exposures of the same celestial subject in sequence. Over the span of those exposures, many will have near-perfect seeing, and the subject will show up clearly. Professional observatories might use highly sensitive imagers to take tens of thousands of short exposures of a single subject, then pick the best 500 and integrate those to get extremely clear results that rival Hubble images (which does not suffer from seeing at all, given it's in space). Now, I did not take thousands of exposures.

Something I can certainly try is to set up on a better night with better moon features, and take several hundred each with both cameras, and pick the best out of those frames. That is a much more significant task, however I'm happy to do it if it would help further prove the point. I do not believe it will change the results. There are 2.6x more pixels in the area of the moon for the 7D than the 5D III. If we have 3 million pixels on subject with the 5D III, we are going to have 7.8 million pixels on subject with the 7D.

It really doesn't matter either way...the 7D is ultimately going to win the detail battle when your reach is limited. I'll share more images, and I'll see if I can get the RAWs uploaded somewhere so you guys can experiment yourself.

 

[LetTheRightLensIn]

I'm not surprised. It's been shown again and again before, but some just don't want to believe. I did careful tests and posted them, Romy has done the same, but some still insisted the 7D just can't compare, even when reach limited, not even to the 5D2. In fact, on FM right now, there is a group still insisting that the 7D isn't as good even when reach limited, considering that, it's welcome to have yet another demonstration.

Here is a quick shot I dug up from my low ISO, high-contrast target test, pretty darn clear to me the 7D has better reach. It goes 7D on top, then 5D2, then 5D3, then the 7D again. I've posted this here a few times in the past, but it never hurts to post it again, since no matter how many times such tests get posted, you constantly see threads pop up where people claim the 5D2/5D3 easily do better than the 7D even when reach limited:

Make sure to click the image to get the 100% view!

 

[jrista]

Nice comparison. Thanks for posting.
They were both shot with the same settings and the same processing in Lightroom and I wonder what happens if you use the best settings and most optimal processing for each camera/image.

With more than two and a half times more light, it's two and a half times better. Like using two and a half stops lower ISO on the cropped sensor.

Double the light is one stop so 2.6 times the light is about one and a quarter stops.

You are correct about the number of stops. My mistake.

As for settings...what would be better settings? I mean, exposure is exposure...and technically speaking, using the same ISO means the 5D III has the advantage, no? I used ISO 200 for both shots...the larger pixels of the 5D III should mean that much more light is gathered per pixel at ISO 200 (which is indeed the case, noise comparison coming.)

So, I honestly don't think I could have used any better settings on the 5D III. And exposure is exposure...it's light over time...for a given subject of given brightness, you have to use the same exposure.

 

[LetTheRightLensIn]

I shoot wildlife all over the country. Most of the big animals come out in crepuscular conditions. At this point, noise will determine which camera you use. .... you won't get the shot with APS-C.

You won't?? Even if you use say a 7D and a 5D2 and the 7D sensor is more efficient at collecting and converting photons per area of surface than the 5D2?? With the 7D you can chose to get either: more detail (unless conditions are super bad) and more noise OR slightly better detail with less de-bayer and other artifacts and slightly better noise (if you view or convert to same scale as the 5D2).

 

[unfocused]

Thanks for the disciplined comparison.

This is one reason why I think the 7DII will be Canon's "high megapixel" camera (probably at about 24 mp).

It makes sense to me that Canon will optimize its top of the line APS-C camera to emphasize the strengths of its format -- which is resolution. They will then have full frame bodies optimized for noise and crop frames optimized for resolution and reach.

It's also why I can't imagine a 7DII with less megapixels than the current 7D or 70D – people who want lower noise at higher ISOs, have the 6D. Which will be in the same price bracket as the 7DII (or possibly even slightly less.)

Fits in nicely with Canon's two-body marketing strategy.

 

[jrista]

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.

 

[LetTheRightLensIn]

Thanks for the comparison!

As I've often stated, APS-C does have a 'reach advantage'...if you're FL limited AND at low ISO (~800 or less) AND printing larger than 16x24"/A2.

First, I don't think it makes sense to mention printing size. If you are very reach limited you might only have enough left to fill 2MP. It really depends. Maybe you have 1MP or maybe 15MP, it depends shot to shot. And 16x24" is pretty large, even a complete frame from a 5D3 only fills 13x19" at 300PPI!

Second, you can go above ISO800 and still get a reach advantage from the 7D. In fact, with a high contrast subject in a well lit portion of the frame, the advantage is actually still clear even at ISO6400. In fact, compared to the 5D2, the 7D does the same, or almost always better, in any circumstance at any ISO, if reach limited (as the 7D has higher pixel density, is more efficient per area of sensor and has better high iso banding characteristics). Compared to the 5D3 it is a bit trickier, but I have shots of Hairy Woodpeckers (granted that is a high contrast target), so-called real world, where the 7D does better IMO and they were ISO1600-2500, better with ease. Of course if you have a low contrast main subject and it's dark in coloration and in a dark part of the frame, in that case, the 7D may fall back to the 5D3 or even fall behind it at higher ISOs since the 5D3 is a little bit more efficient per sensor area and has good high iso banding characteristics.

To your first point, as I stated originally, if I would need to crop so severely that I would be left with a 1-2 MP image, I wouldn't bother pressing the shutter button.

Hey 2MP still looks nice shared on the web, plus it doesn't have to be 2MP, it could be 6MP or 8MP or whatnot and, as I said, even 23MP still doesn't make 16x24" hit 300PPI!

To your second point, the squirrels above tell a different story. Granted, I've not done a head to head of 7D vs. 5DIII, but the 1D X cropped down to match framing is clearly superior to the 7D at higher ISO settings.

The squirrels tell me no story.

1. the processing is pretty terrible IMO. NR city, no way to tell what is going on, all smeary and waxy looking, looks almost OOF for both and yet still with some nasty pepper noise. I can't compare noise or detail there the processing is so weird and who knows if applied evenly either.

2. If it gets to the point that someone finds the noise too bothersome to care about the reach advantage then you normalize and compare at the same scale and since the 7D average de-bayer mistakes and so on over more pixels and you get effectively downsampled res those aspects come out at least a trace in the 7D's favor and then as for noise, it depends upon the bodies, as I said the 7D has better noise per sensor area than many FF cameras (although it's a bit worse than the 5D3 and a bit more so still compared to the 1DX) and better high iso banding characteristics than any Canon FF other than 6D/5D3/1DX, all the 1Ds3,1Ds2,1Ds,5D2,5D have worse.

 

[jrista]

Alrighty. I've updated the original post with more examples. I've added full 1:1 crop comparisons between the 7D and 5D III, WITHOUT scaling the 5D III. That should clearly show how much smaller in the frame the moon is with the 5D III, at exactly the same focal length.

I've also added a noise comparison example, which shows both images at native size, then downsamples a 7D of the same region to 5D III dimensions.

 

[LetTheRightLensIn]

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.

So then why do you keep questioning DxO sensor normalization? What you just described above is exactly the same thing. So why do you get it in one context, but not in the DxO context?

 

[jrista]

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.

So then why do you keep questioning DxO sensor normalization? What you just described above is exactly the same thing. So why do you get it in one context, but not in the DxO context?

We've had this argument. We've had it countless times. You know the answer. I've been extremely detailed and clear about my opinions, and exactly what my opinions are. I'm NOT going to let you ruin this thread by diving into another pointless discussion of DXO. You want to have that debate, please, don't ruin my thread...start another thread. PLEASE.

Everyone, let's keep DXO out of this discussion. This thread has nothing to do with comparing Canon and Nikon cameras or anything like that. It has to do with the reach advantage of smaller pixels. That's it. I don't want this thread to be derailed by another useless debate that we've all had ten thousand times.