Is Full Frame sharper than APS-C? My answer here

[rs]

Right, sensor sizes, output resolutions and print sizes aside; any sensor with a higher pixel density (smaller pixels) with resolve finer details, commonly measured in Line-Pairs per mm (or how many lines you can squeeze into a millimeter). 

So an equal pixel APS-C sensor has the potential of resolving finer details but the lens needs to be sharper, many of todays lenses, even EF-s lenses, are made for 135 (Full Frame 35mm) sharpness but APS-C needs sharper than that because it's trying to resolve finer details.  So blowing up to 100% (pixel level) on the APS-C image will look softer than a 100% 135 image because by going to "pixel level" you are actually magnifying the APS-C image about 50% larger than the 135 image.

This is also one of the reasons why the GH2 with a 4/3 sensor can resolve near 1000 lines in 1080p video vs the 5D2 resolving about 700 lines in 1080p and the older 2/3 HD camcorders did 1000 lines easy.  Now of course there is still diffraction to worry about, 5D2 starts to limit around f/11 while the 7D starts at f/6.3, go too small (pixel size that is) and you'll start out limited wide open!  APS-C has a deeper DoF so it about evens out; but this is why I think the high megapixel full frames like the D800 isn't a practical camera, you get a low f-stop diffraction limit with a shallow DoF, which is only really usable at f/4-f/5.6. 

The best setup to test this is with a 135 and an APS-C with the same output resolution (D3x and NEX7 maybe), get the sharpest glass you can find (a Leica Summicron or maybe that Ziess 35/2. shoot and compare.

But no matter what you find it doesn't change the fact that some things are better with 135 and some better with APS-C.  If you need shallow DoF, higher dynamic range or low light shots than APS-C will not work but if you need the extra reach but can't afford an exotic telephoto, need finer details and have the lenes that can resolve them or need a deeper DoF without sacrificing light than grab your APS-C.  There is a reason why the 1Dx, 1Dc and Nikon Full Frame DSLRs have an APS-C mode...

All makes sense, except the smaller pixels of an equal MP crop sensor means each pixel is detecting less light. As a result, there is a weaker electrical signal which requires more amplification to reach the same industry standard ISO settings. Which is why the older the tech/the higher the pixel density, the more NR (software or even built into the sensor) is applied to further soften the image.

Also, Canon don't offer an APS-C mode on any of their FF cameras. Nikon offer it on all of theirs, but that's only because their APS-C lenses can be physically mounted on FF cameras, the rear element clears the FF mirrors, and they took the decision to allow people to shoot with such lenses without having to crop later.

Crop sensors initially existed due to cost constraints - in the early days of DSLR's, FF was just a pipe dream. In 2002 it became a reality, but a very expensive one. It was only in 2007 that Nikon eventually offered FF, and now we have budget FF offerings from both Canon and Nikon, and FF SLT's and compacts from Sony. FF sensors are becoming more cost effective, their advantages are real, but their is a trade off - lenses - their size, weight and price. However we've already got that disadvantage compared to compact cameras anyway.

[TrumpetPower!]

Right, sensor sizes, output resolutions and print sizes aside

Squeeze me?

What, exactly, do you think people are using cameras for if not to output images and make prints?

It's incredible.

I post clear, indisputable, incontrovertible evidence that a full-frame camera with a decidedly "meh" lens with a pinhole aperture at high ISO absolutely blows away a P&S camera with a state-of-the-art lens at ideal aperture and base ISO...and all people can do is go on and on about how there's a theoretical possibility that a smaller camera maybe possibly could perform equally to a larger one if the DeLorean hits the wire at exactly 88 mph at the stroke of midnight when the moon is ascending Uranus.

All this strum und drang about sensors that violate the laws of physics and lenses that require materials and manufacturing processes that don't exist, just to argue that somebody could theoretically make a small-sensor camera almost as good as a large-sensor camera if only there were flying unicorn ponies to deliver them down chimneys at Thanksgiving.

I'm sorry, people, but this is just nuts. Common wisdom says that bigger is better. Commercial photographers say that bigger is better. Clients say that bigger is better. Editors say that bigger is better. Critics say that bigger is better. Customers say that bigger is better. Manufacturers say that bigger is better. The back of the envelope says that bigger is better. Basic geometry says that bigger is better. Empirical testing says that bigger is better.

So where on Earth does all this religious passion come from that smaller can be just as good as big, if you just stack the deck in its favor sufficiently?

Look, the smaller formats not only have their place, they're actually wonderful. They still produce superlative results, more than enough, outperform the 80/20 rule, and they do so while being lighter and cheaper and easier to fit in your pocket. What's not to love?

But they do not, and never will, beat the larger formats in any measure of image quality.

But so what? That's not their purpose. That's not why you buy them. That's not what you use them for.

When sheer image quality is the primary concern, go with the larger format. When there are other considerations in addition to image quality, such as handling or price, the smaller formats will likely win out.

No P&S is ever going to have anywhere near the image quality of an 8x10 view camera -- but nobody's ever going to stash an 8x10 view camera in a purse and snap a picture of a friend in a nightclub, either!

Horses for courses, guys. Horses for courses.

Cheers,

b&

[AprilForever]

Full frame is not sharper than APS-C. It has shallower depth of field when framed the same, requiring a higher f-stop to get more in focus. Why did Ansel belong to the f64 club? Because much less than f64, even with tilts, and not much is in focus. Full Frame has the grim problem of using the bad part of lenses too, making corners truly grim on all but the most fine of lenses.

But, mainly, a pixel is a pixel, and it really doesn't matter what size the sensor was. Full Frame can deliver a better image sometimes, but there is a reason Canon's lead Action camera was a crop body (APS-H). Most likely, tachnology has progressed to the point where the 7D MK II will have better IQ at 1.6 crop than the old 1d MK IV had at its 1.3 crop.

APS-C has some serious advantages. Google "7D bird photography". You will see some amazing things...

The reason the Canon 1D line of cameras had a 1.3x crop is when it was introduced in 2001, it was the largest sensor Canon could source - as far as I know, it was the largest in a production camera at the time. FF sensors didn't hit the market until the Contax N Digital was introduced in 2002. That same year, Canon introduced the much more successful FF 1Ds. Due to the limits of the technology it had much slower read out, so it was nowhere near as fast as the 1.3x crop sensor 1D. They continued as two lines of bodies - FF for the highest image quality, 1.3x crop for speed. Nikon managed to combine FF and speed with the D3 (although it was slightly slower than 1D mk III and much lower res than 1Ds mk III). The D4 was their successor, and Canon's rather elaborate answer to it was to combine the two 1 series lines with the 1D X.

Granted, sometime lots in focus is desired. But that's why lenses can be stopped down, and why tilt and shift lenses exist. To get as large a depth of field on FF as on 1.6x, simply use an aperture 1.6x smaller. You will need an ISO just over a stop higher if you want the same shutter speed, but the advantage of FF is still there. And TS-E lenses take things to another level. When you don't want a huge DoF, try a lens like the 70-200 II or the 100L. What's in focus is capable of being so detailed even at the edges of the frame that you'll no doubt be immediately aware of the difference FF makes.

I have shot full frame. I even have a full frame camera. Actually, I have three full frame camera, if you count my Spotmatic and Kiowa. I even have two large format cameras, Crown Graphics.... What I am saying is that full frame is not the all end all. There are times and places and needs for smaller sensors, which will in their case well out perform a larger sensor.

[AlanF]

Right, sensor sizes, output resolutions and print sizes aside

I post clear, indisputable, incontrovertible evidence that a full-frame camera with a decidedly "meh" lens with a pinhole aperture at high ISO absolutely blows away a P&S camera with a state-of-the-art lens at ideal aperture and base ISO...

Your evidence was disputed by me and you did not bother to answer. Until you answer satisfactorily, your "proof" is not a proof and is certainly not indisputable. I am happy for my arguments to be disproved in a logical manner but will not take you seriously if you fail to consider them.

[TrumpetPower!]

Right, sensor sizes, output resolutions and print sizes aside

I post clear, indisputable, incontrovertible evidence that a full-frame camera with a decidedly "meh" lens with a pinhole aperture at high ISO absolutely blows away a P&S camera with a state-of-the-art lens at ideal aperture and base ISO...

Your evidence was disputed by me and you did not bother to answer. Until you answer satisfactorily, your "proof" is not a proof and is certainly not indisputable. I am happy for my arguments to be disproved in a logical manner but will not take you seriously if you fail to consider them.

Alan, I was being gracious in ignoring your complaint, as it indicates that you really don't understand even the simplest fact about what a crop sensor camera actually is. Specifically:

It seems to me that all that "experiment" has shown is that if you use a low quality telephoto lens to take a photo of, say, a small bird sitting in the middle of a tree you get a better image of it than taking a photo of the whole landscape with a wide angle lens and blowing up the teeny weeny central section.

That is exactly what all crop format cameras do -- except, of course, that they don't have all the rest of the sensor to crop from, just the teeny weeny central section.

The Wikipedia article is not bad:

http://en.wikipedia.org/wiki/Image_sensor_format

But have a look at any P&S camera. Look at the focal length of the lens. Not the "35mm equivalent focal length," but the actual focal length, usually printed on the lens and always included in the specs. They're all ludicrously wide, if the were full-frame cameras. Something like a 4mm - 24mm zoom is not unusual; it would work out to a 24-135 "equivalent." So, if you were to take such a P&S camera and zoom all the way in to its most telephoto setting of "135mm equivalent," you would, indeed, be using a wide-angle lens and be blowing up a teeny weeny sensor, exactly what I did in that experiment.

And, yes, those P&S cameras take better pictures than just cropping away all but the teeny weeny central section of a full-frame camera, but only because they have sensors with insane pixel densities. Build a full-frame camera with the same pixel density and you'll wind up with a 150, 200 megapickle monster...and then, yes, cropping away all but the teeny weeny central section of a wide-angle image shot with that monster full-frame camera would result in the exact same picture as taken with the P&S camera.

Think back to the early days of digital photography, when even small cameras didn't have a single megapickle in their sensors. (Kodak was the first to reach the megapickle mark in '86.) Imagine you had a camera with a 4mm x 6mm sensor and a whopping 0.7 megapickles of resolution. Slap a 24mm lens on it, and you'd get the exact image on the right in my experiment -- pixel for pixel. That's the actual raw dump of the image, no post-processing, nothing. And that's as good as that camera can do.

Now, use the exact same tech to build a full-frame sensor...and you've got the 5DIII. Now, take another step, and imagine a full-frame sensor built using the same tech in today's megapickle P&S cameras.

That's the whole point of this illustration: that sensor size really does matter.

Is it the whole story? Of course not. I've already pointed out that, though an 8x10 view camera will mop the floor with a full-frame camera, you can't exactly go clubbing with it. But it is the whole story when it comes to image quality: all else being equal, bigger is always better.

Cheers,

b&

[TrumpetPower!]

bigger is always better if you talk about the same sensor tech

<sigh />

Have I even once indicated otherwise? I don't know how many times I've typed, "all else being equal" in this thread -- I can't count that high.

And your chart just proves that smaller is cheaper, nothing more. We already know that. Spend the money, and you'll get a full-frame sensor with the electronics of the P&S. Hell, the NSA probably has medium- or even large-format sensors with the electronics of a P&S, plus insanely long lenses better than anything you can buy from Canon, plus they're in orbit.

So what?

The question was whether or not sensor size matters. It does.

It really does boggle my mind that anybody would even think to dispute that, let alone argue for all the ways in which some other variable can compensate.

You know what else could make a small sensor outperform a bigger one than using newer and more expensive technology in the small sensor and older and cheaper technology in the big one?

Here's a short list.

You could put one of the world's greatest lenses in front of the small sensor but put a dirty, chipped Coke bottle in front of the big one. (Hey, that's not far off from what I did, and still the big sensor won!)

You could smear vaseline all over the big sensor but not over the small one.

Or, lastly, you could put the small sensor in a camera in the hands of a real photographer and put the big sensor in the hands of an Internet measurebator troll.

Cheers,

b&

[bdunbar79]

Full frame is not sharper than APS-C. It has shallower depth of field when framed the same, requiring a higher f-stop to get more in focus. Why did Ansel belong to the f64 club? Because much less than f64, even with tilts, and not much is in focus. Full Frame has the grim problem of using the bad part of lenses too, making corners truly grim on all but the most fine of lenses.

But, mainly, a pixel is a pixel, and it really doesn't matter what size the sensor was. Full Frame can deliver a better image sometimes, but there is a reason Canon's lead Action camera was a crop body (APS-H). Most likely, tachnology has progressed to the point where the 7D MK II will have better IQ at 1.6 crop than the old 1d MK IV had at its 1.3 crop.

APS-C has some serious advantages. Google "7D bird photography". You will see some amazing things...

The reason the Canon 1D line of cameras had a 1.3x crop is when it was introduced in 2001, it was the largest sensor Canon could source - as far as I know, it was the largest in a production camera at the time. FF sensors didn't hit the market until the Contax N Digital was introduced in 2002. That same year, Canon introduced the much more successful FF 1Ds. Due to the limits of the technology it had much slower read out, so it was nowhere near as fast as the 1.3x crop sensor 1D. They continued as two lines of bodies - FF for the highest image quality, 1.3x crop for speed. Nikon managed to combine FF and speed with the D3 (although it was slightly slower than 1D mk III and much lower res than 1Ds mk III). The D4 was their successor, and Canon's rather elaborate answer to it was to combine the two 1 series lines with the 1D X.

Granted, sometime lots in focus is desired. But that's why lenses can be stopped down, and why tilt and shift lenses exist. To get as large a depth of field on FF as on 1.6x, simply use an aperture 1.6x smaller. You will need an ISO just over a stop higher if you want the same shutter speed, but the advantage of FF is still there. And TS-E lenses take things to another level. When you don't want a huge DoF, try a lens like the 70-200 II or the 100L. What's in focus is capable of being so detailed even at the edges of the frame that you'll no doubt be immediately aware of the difference FF makes.

I have shot full frame. I even have a full frame camera. Actually, I have three full frame camera, if you count my Spotmatic and Kiowa. I even have two large format cameras, Crown Graphics.... What I am saying is that full frame is not the all end all. There are times and places and needs for smaller sensors, which will in their case well out perform a larger sensor.

Can you please give us an example of when a smaller sensor would OUTPERFORM a larger sensor?  And I just mean the sensor.  Thanks.

[TrumpetPower!]

YOU wrote
Build a full-frame camera with the same pixel density and you'll wind up with a 150, 200 megapickle monster...and then, yes, cropping away all but the teeny weeny central section of a wide-angle image shot with that monster full-frame camera would result in the exact same picture as taken with the P&S camera.

and I say NO

Well, thanks for so clearly demonstrating to all that you fail at introductory-level geometry (which is all this is really about).

Sorry. First your misinformation on ISO in that other thread, and now your misinformation on sensors. If you really are a professional photographer, if I were you I'd be deleting all these posts lest your clients discover your technical incompetence.

Even if it's all a giant misunderstanding due to a language barrier, it still demonstrates an inability on your part to understand the limits of your communication skills -- and communication is key with clients.

Cheers,

b&

[RLPhoto]

The Great Picture > LF > MF > 35mm > APS-C > M4/3 > Compact Sensors

This shows that if your film is big enough, a Hanger door could be a lens. 
http://en.wikipedia.org/wiki/The_Great_Picture

[neuroanatomist]

Nikon 5200 blow 5d of the road, if you have enough good lens on the Nikon

Technically true in terms of sensor performance.  Of course, comparing a camera from last year to a camera from 8 years ago isn't exactly an apples-to-apples comparison. 

[AlanF]

Alan, I was being gracious in ignoring your complaint, as it indicates that you really don't understand even the simplest fact about what a crop sensor camera actually is. Specifically:

It seems to me that all that "experiment" has shown is that if you use a low quality telephoto lens to take a photo of, say, a small bird sitting in the middle of a tree you get a better image of it than taking a photo of the whole landscape with a wide angle lens and blowing up the teeny weeny central section.

Gracious is not a word that most people would apply to your style. And belittling your questioners does not refute arguments. It is perfectly obvious that a large format with a long focal length lens beats out a small format with the same number of megapixels with a short focal length lens, all things being equal, if they have the same field of view. But your "experiment" did not do that. Your set up had the long focal length lens with a narrow field of view and compared it with a short focal length with a wide field of view and then lost resolution from the small format by cropping.

[TrumpetPower!]

It is perfectly obvious that a large format with a long focal length lens beats out a small format with the same number of megapixels with a short focal length lens, all things being equal, if they have the same field of view. But your "experiment" did not do that. Your set up had the long focal length lens with a narrow field of view and compared it with a short focal length with a wide field of view and then lost resolution from the small format by cropping.

Alan, are you serious?

Scenario a: two cameras, one with a 4.27mm x 6.4mm sensor and a 24mm lens, the other with a 24mm x 36mm sensor and a 135mm lens. Both sensors have 6.25µ pixels.

Scenario b: one camera with a 24mm x 36mm sensor with 6.25µ pixels. One image is made with a 24mm lens and cropped to only use the 4.27mm x 6.4mm central portion of the sensor; the other image is made with a 135mm lens and the full sensor.

Educate us: what, exactly, is the difference between those two scenarios?

Or are you somehow under the misimpression that lens focal length is a function of format size? Is that it? Do you think that a 24mm lens on a 4.27mm x 6.4mm sensor is still a wide-angle lens? If so, you need to brush up on your introductory optics. That small sensor would need a 4.27mm lens to produce the same field of view as a 24mm lens does on a 24mm x 36mm "full frame" sensor. That's why a 50mm lens is still a 50mm lens whether it's on a Rebel or a 5D, but it's a normal lens on the 5D and a telephoto on the Rebel. The lens hasn't changed, and it's still the exact same focal length as always, regardless of what camera you attach it to.

b&

[Sporgon]

I'm getting really confused on this thread.

With regard to Mikael's post on 5D and D5200, I thought the value of read noise was derived from the amount of photons that have not been converted to electrical charge. As 5Dc has whopping great pixels compared with D5200 when are able to receive far more photons and so the amount of non converted with be much higher number, and so the read noise will be much higher even if the efficiency of light conversion in the 5Dc and D5200 was the same.

So you'd expect 5D to have much higher read noise, or is my understanding of how read noise values are reached wrong ?

[TrumpetPower!]

Nikon 5200 blow 5d of the road, if you have enough good lens on the Nikon

Technically true in terms of sensor performance.  Of course, comparing a camera from last year to a camera from 8 years ago isn't exactly an apples-to-apples comparison.

So, he's comparing Nikon's just-released high megapickle APC camera not to the 5DIII, but to the classic 5D?

Whoopee.

Maybe he can follow it up by racing a 2013 Accord against a Ferrari 125 S....

b&

[dtaylor]

Nah, the differences cut against the WA shot.

Seriously?

There is no way to quantify and compensate for the many variables which are different. Your test, however much you think it proves the point, is simply invalid.

As for your argument about the lenses, it's pointless because the crop-n-scale trumps everything else. Even the f-stop selection in this case. You didn't have any where near as many pixels on target, and then you let a computer algorithm (which one? what settings?) fill in the missing data. This bears no analogy or relevance to having an actual APS-C sensor, of the same MP resolution, take the shot with the same lens and aperture positioned for the same FoV. (Side note: the soft filter argument was silly. That does not come into play on that lens unless you select it.)

Again, I agree in principle because the principles are well established and understood. But the test you posted was horribly flawed.

If you don't think that this test demonstrated the importance of format size over pixel dimensions...well...all sorts of unflattering adjectives come to mind, with "hopeless" being the one best suited for a family-friendly forum.

Nobody can tell what your test demonstrated because of all the confounding variables.

I've compared FF and APS-C a number of times...all other factors being equal...and I've always found the same thing: FF is sharper out of camera, but the range is small enough to be closed by bumping up sharpening in camera or post. When the sensors are otherwise comparable of course.