Resolution of a 24-70 2.8L MKI on a Canon 6D

Is the resolution of the 24-70 2.8L MKI sufficient on a 6D body or is it too low and how does this result in the picture quality when it would be too low ?
How does it compare to Sigma 35 Art's resolution ? (I don't mean any comparison with the prime sharpness/IQ as primes are always better), but purely the resolution comparison.
Can you see this on the pictures, maybe less dynamic range, a difference in dark/bright zones ?

Please don't take this wrong, but if resolution is making a difference in your photographs, you really need to work on one or more of the following: subject selection, lighting, composition, framing, lens choice, ISO choice, aperture choice, shutter speed choice, and the entire slew of post-processing options. All of them have much more impact on your photo than any minor difference in resolving power between two relatively modern, top-shelf lenses.

Just found it, it's just enough for a 6D 20mpix: https://www.slrlounge.​com …s-mk2-portrait-comparison
I was just curious as there still is some old secondhand glass with low resolution sold....

What Canon is doing is designing these high-end lenses to work with the future generations of high-resolution, 40-50+ megapixel full-frame DSLR’s. While the current generation of mk1 lenses can decently resolve 18-20 megapixels on full-frame, they are beginning to reach their limits towards the edges of full-frame sensors.

If you’re planning on sticking with 12-20 megapixel cameras for example for the foreseeable future, you might even be wasting part of your money by getting a mk2 lens. A mk1 lens plus a little sharpening and clarity might do the trick, especially if you’re on a budget. However if you truly push your equipment to the limits, and plan on upgrading to higher resolution bodies as they become available, you’ll probably have to invest in mk2 lenses sooner or later.

For me it will be more the question : do I miss the clarity / sharpness / colours / bokeh of the 35 Art vs my current 24-70 2.8L I, as i'm used to work with fast primes...

It is already possible to make nice looking 20"x30" prints from crop cameras with consumer lenses. I imagine that if I really wanted to push my 6D and a good L-lens, I could make nice 30"x45" prints, possibly even 40"x60". Advertisers and billboards already team up to print lesser (20MP?) images the size of small houses. What impact will 50MP+ cameras and/or lenses make?

CanonYouCan wrote in post #18075476
For me it will be more the question : do I miss the clarity / sharpness / colours / bokeh of the 35 Art vs my current 24-70 2.8L I, as i'm used to work with fast primes...

I don't know if you will, but in my opinion clarity / sharpness / colors / bokeh are better on modern primes.
That said, the 24-70 is a great lens if you need the flexibility of a zoom.
It was sharp enough for me on a 20-ish MP sensor, but I sold it to get a 35/1.4.

Bassat wrote in post #18075492
It is already possible to make nice looking 20"x30" prints from crop cameras with consumer lenses. I imagine that if I really wanted to push my 6D and a good L-lens, I could make nice 30"x45" prints, possibly even 40"x60". Advertisers and billboards already team up to print lesser (20MP?) images the size of small houses. What impact will 50MP+ cameras and/or lenses make?

You seem to be missing the point of cropping an image to get a longer equivalent focal lenght and yet a good resolution.
OP's worries are totally legit, as he want a lens that at least matches his camera.
And just in case he wants to re-sell the lens in a few years, I think no one will will want a lens able to resolve only 20 MP. My 24-70 v1 is gone for good.

CheshireCat wrote in post #18075538
You seem to be missing the point of cropping an image to get a longer equivalent focal lenght and yet a good resolution.
OP's worries are totally legit, as he want a lens that at least matches his camera.
And just in case he wants to re-sell the lens in a few years, I think no one will will want a lens able to resolve only 20 MP. My 24-70 v1 is gone for good.

My guess is that it is not. Someone else is using it to make perfectly acceptable photos.

Bassat wrote in post #18075551
My guess is that it is not. Someone else is using it to make perfectly acceptable photos.

It is not what ?
Yes, a lot of good people are using it to make great photos, but this is not a good reason to dismiss the OP's argument.

CheshireCat wrote in post #18075566
It is not what ?
Yes, a lot of good people are using it to make great photos, but this is not a good reason to dismiss the OP's argument.

Nope. That lens is not a good reason to dismiss the OP's argument. Adequate knowledge of physics and 50 years of experience behind the viewfinder are. Ultimate resolution makes or breaks in infinitesimally small number of photographs. It is not relevant unless one is pushing the boundaries of photography.

Perhaps you've heard of Matthew Brady, or Ansel Adams. Both produced some very nice work with very limited equipment. Gear does not make the photograph.

Just like money doesn't make you happy BUT it helps!

Bassat wrote in post #18075576
Gear does not make the photograph.

CanonYouCan wrote in post #18075587
Just like money doesn't make you happy BUT it helps!

Oh, we totally agree on that one! All I've ever wanted is a chance prove that ($1M / 70-200 II) won't make me happy. Anyone care to loan me either?

Bassat wrote in post #18075576
Perhaps you've heard of Matthew Brady, or Ansel Adams. Both produced some very nice work with very limited equipment. Gear does not make the photograph.

I wish Brady and Adams had the gear we have nowadays. We'd be enjoying many more amazing photos.

I use my mk I on my 6D and it seems to have entirely adequate resolution for real world objects. If you look at the res test charts for a large number of the mk I and mk II you'll see that a really good mk I can be better than a really poor mk II. That's just the reality of unit-to-unit variability. But resolution isn't the primary reason Canon designed the new lens. It has less field curvature and a more robust zoom/focus system design as well as various technology improvements which have been adopted since the original lens was designed.

I seem to remember someone doing a test with several modern lenses on the new 5Ds and concluding that lens resolution wasn't the limiting factor. It turned out that camera shake caused far more degradation of the image than a typical lens. There, incidentally, is a situation where Brady and Adams had a huge advantage with their large negatives. Less magnification-> less motion blur.

For full resolution colour detail the Nyquist limit for both the 7DII and the 5DS are around 65 LP/mm, for the 5DSr anything above that level is likely to induce colour moire effects from aliasing. Admittedly because you can play tricks with the fact that for colour you are having to use the RGGB sensel quartets, you can get away with a bit higher resolution from the lens for full colour detail. I would still not want to provide more than about 80 LP/mm of colour signal to the sensor. In almost all other situations where you are converting from an analogue to a digital signal it is considered bad form to to closely approach the Nyquist limit, much better to have some buffer room. Although you don't get aliasing if you keep under Nyquist, you can still get some serious distortions of the signal if you run close. For example if you are sampling a signal at the Nyquist frequency, although you can recover the frequency correctly, the recorded amplitude will be dependent on the phase relationship between the signal and the sampling point. You could actually record the signal with an amplitude varying between 0 and 100% of the actual signal level.

When you look at older cameras their resolution is even lower, a 300D has a Nyquist frequency that is about half that of the modern cameras. It is only the inclusion of the analogue anti aliasing filter on these sensors that stops us from suffering moire from aliasing, be that colour, or simply grayscale, even with relatively cheap lenses. IMO we really need to get to at least 40 Megapixels on APS-C, and 100 MP on 35mm before removing the AA filter really becomes viable, with the current best lenses, which seem to be capable of resolutions between 120 and 130 LP/mm. For full colour resolution on a lens resolving 120 LP/mm you need to be using a 91.3 MP APS-C sensor, if utilising a RGGB Bayer Colour Filter Array. That jumps to 234 MP for the 35mm format.

The other big problem with digital imaging seems to be the constant desire to display the resultant image data on a digital output device*, at a relatively low fixed output resolution. Not only do we do this, but we look at only a generally small area of the image, and a stupidly close viewing distances. The vast majority of computer screens run at around 100 PPI, so your current generation cameras with sensors that contain in excess of 5500 pixels on the long side are effectively being displayed at over 55" wide. For a camera with a 35mm format sensor that is an enlargement factor of at least 39× and on APS-C it is a 62× enlargement. If you take say a 6 Megapixel camera like the 300D with only 3072 pixels on the long edge, your 100 PPI monitor is displaying the image as if it were only 30" wide, or for APS-C an enlargement factor of only 31×.

To make a proper comparison of the images it should be done at a fixed output size, with a variable output resolution to match the physical sizes. So if we pick 30"×20" as our output size your 7DII is going to have about twice the resolution of your 300D. Size matched like this with unsharpened images, the newer sensor will show almost twice as much detail, i.e. resolution, while the apparent sharpness of incontinuous signals, such as edges between large areas of differing tone/colour will actually look the same. As long as you are comparing output at the same physical size, and are using the same sized sensor, the effects on image quality from things like lens aberrations, where you use the same lens; and camera shake, where the amplitude stays constant, will also appear to be the same, regardless of sensor resolution.

*Computer screens are still digital devices when considering the spatial domain, even CRT screens are digital in the spatial domain. When we view a computer or TV screen it is actually our eyes that integrate the digital spatial domain signal to an analogue signal that our brains can interpret.

Alan

... so your answer to the OP's question is ?