Question: Performance of 24-70 4.0 on 7DII (based on tdp and real world)

[picturefan]

Dear all,

sometimes I check the lens comparison tool of tdp, which gives me good advice about sharpness of lenses.
Always thougt I understand the findings.

Now there is one thing not quite clear, the comparison of Canons 24-70 2.8II vs. 4.0., which is showing a bigger than expected difference between the two lenses, as you can see here:
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=787&Camera=963&FLI=0&API=0&LensComp=823&Sample=0&SampleComp=0&CameraComp=963&FLIComp=0&APIComp=0

Sure, most people find the 2.8II the sharper lens (to a certain degree) than the 4.0. So, of course, there is only a small difference in sharpness between the two lenses on 1DsIII or 5Dr. See here.
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=787&Camera=453&FLI=0&API=0&LensComp=823&Sample=0&CameraComp=453&FLIComp=0&APIComp=0

But when tested on 7DII the difference gets much more significant, the 4.0 is getting " kind of bad" in comparison.
All tests on tdp with 7DII and 24-70 4.0 are showing not really sharp results with that combo (even 18-55 II is sharper on 7DII than 24-70 4.0).
Can anybody please explain why that is?
Anybody got some experience with that combo?

Thanx.

 

[Mt Spokane Photography]

Re: Question: Understanding TDP

TDP has a forum, why not ask there? This site is not knowledgable about how TDP works, some members may be, like Neuro who knows Brian.

 

[picturefan]

Re: Question: Understanding performance of 24-70 lens, based on TDP

TDP has a forum, why not ask there? This site is not knowledgable about how TDP works, some members may be, like Neuro who knows Brian.

Yes, maybe need to be more precise in the question, already changed the topic´s name.

Why not ask here? The question is not about TDP in general, it is about lens performance and experience with Canon 24-70 4.0 on 7DII.

 

[Mt Spokane Photography]

Re: Question: Understanding performance of 24-70 lens, based on TDP

It is true that lenses act differently with different camera bodies, so its always a good idea to see what multiple lens testers reveal and pick lenses that perform well with your body.

Generally, lenses will do much better on FF than on crop, at least as far as sharpness numbers. There are other things to consider, but a person can usually see a huge improvement by going to a FF body of about the same MP. Not always though, there are a few exceptions.

 

[sedwards]

Re: Question: Understanding performance of 24-70 lens, based on TDP

Here is a little info about the tests . You are seeing 100% crops so it seem worse than it really is . Read this and you will understand the tests a bit better ---- http://www.the-digital-picture.com/Help/ISO-12233.aspx

 

[picturefan]

Re: Question: Understanding performance of 24-70 lens, based on TDP

Thanks for the link. Different testings, different results. That's how it is.
But it's not about the testing technologies, lots of people here seem to love them. Me not . It's about "real life" experiences, because I like to spend more time outside, close to my subjects...

So, is someone in this forum using a 7DII in combination with the 24-70 4.0??
I hardly can imagine that the results won't differ to EF18-55II...

a) Do you see any real world differences in your pictures (compared to the cheapo kit-lens)?
b) Do you miss the 70-105 extra range (compared to 24-105)?


Can anyone tell me about his experiences, please?

Thanks, in advance, for some practical answers and happy holidays all!

 

[Sharlin]

Number of (mega)pixels being equal, a FF sensor has physically bigger pixels (photosites). This means that beyond a certain point, sensor resolution is a bottleneck and lens differences become less relevant. The smaller and denser pixels of a crop sensor demand more resolution from the lens as well, the lens becomes the bottleneck. The same holds for high-resolution FF cameras like the 5Ds which has pixel density roughly equal to that of the 7D2.

 

[picturefan]

In that way I tried to understand the results from tdp.

Does that means that the 24-70 4.0 might be the better performer on 5DIII (21MP, bigger pixelsize) than on 7DII (smaller pixelsize, higher density, more lateral ca's).? (Probably yes!)
And if you look at the tdp-site (5Dr, similar pixel-dens like 7DII), the 24-70 4.0 is, again, performing better on 5Dr. (OK, because of bigger sensor and more pix).

But, I still don't understand which one here (7DII or 24-70 4.0) is the "bottelneck"?

 

[Loswr]

An APS-C sensor is smaller than a FF sensor, and the testing workflow uses a fixed output size. Therefore, the APS-C image must be enlarged more than the FF image. That's why the FF image looks better.

 

[picturefan]

An APS-C sensor is smaller than a FF sensor, and the testing workflow uses a fixed output size. Therefore, the APS-C image must be enlarged more than the FF image. That's why the FF image looks better.

I see, that's cropping on sensor level. And cropping (e.g. in post-processing) from an given image, that was already made with an crop-cam, also leads to worse results than cropping an image from an FF-image (because it is cropped 2 times).

 

[picturefan]

An APS-C sensor is smaller than a FF sensor, and the testing workflow uses a fixed output size. Therefore, the APS-C image must be enlarged more than the FF image. That's why the FF image looks better.

Does that mean (simplified, of course), that comparing 5DIII and 7DII (both ~ 22MP, crop-factor 1,6) leads, resolution-wise, to 1,6x less resolution with the same lens on the crop-body?

Would it mean that only a 35MP crop-cam can have similiar resolution or quality as the 5DIII (35 = 22*1,6)?

Hope for all experts out there this seems not be too simple a question...

(if it is so simple, than there wouldn't always been discussions about that topic!)

 

[picturefan]

Number of (mega)pixels being equal, a FF sensor has physically bigger pixels (photosites). This means that beyond a certain point, sensor resolution is a bottleneck and lens differences become less relevant. The smaller and denser pixels of a crop sensor demand more resolution from the lens as well, the lens becomes the bottleneck. The same holds for high-resolution FF cameras like the 5Ds which has pixel density roughly equal to that of the 7D2.

But, still, my main question is about quality of 7DII with 24-70 4.0.

Which one (7DII or 24-70 4.0) is the "bottelneck"?

 

[Arty]

Test shots on a chart are going to be at pretty close distances. While I don't have the 24-70F4, it has been reviewed extensively. Take a look at LensTip or other sites. It has some spherical aberration, which means focus shift as you stop down at close distances. This is more of a problem at the longer focal lengths and close to what you are photographing.
Lenses can perform differently close up and at a distance.
I have used version 1 of the 24-105L on full frame and crop. The lens works great on a crop camera, as long as you are fine with the range. I find the long end very useful. If you decide on the 24-70, you need to compensate for focus shift close up. I often use a zoom for portraits and like the longer focal lengths (70-105). While the 24-70F4 can be sharp, it does have some limitations. People seem to like it, but I won't trade in my 24-105F4IS, no way.

 

[Busted Knuckles]

An APS-C sensor is smaller than a FF sensor, and the testing workflow uses a fixed output size. Therefore, the APS-C image must be enlarged more than the FF image. That's why the FF image looks better.

Does that mean (simplified, of course), that comparing 5DIII and 7DII (both ~ 22MP, crop-factor 1,6) leads, resolution-wise, to 1,6x less resolution with the same lens on the crop-body?

Would it mean that only a 35MP crop-cam can have similiar resolution or quality as the 5DIII (35 = 22*1,6)?

Hope for all experts out there this seems not be too simple a question...

(if it is so simple, than there wouldn't always been discussions about that topic!)

inside out and upside down - a 35mp Full Frame would have the same pixel size as the 7dII. What is being attempted is a comparison between Crop and Full Frame. Putting more pixels into the crop would only help if the AA filter and lense could resolve the yet smaller photosites.

No one has brought up the AA filter.

I have the v1 24-105 and up to 70 like it very much after that, it is a snap shot lens as it gets soft. If I am doing anything "important" - I don't do weddings so typicall time is not that crushed - I switch to the 70-200. I might be switching to an 85 1.4 if my GAS flairs up.

 

[StudentOfLight]

1) Different portion of image circle is used for creating APS-C image vs full frame image
2) Finer pixel pitch of APS-C will more easily resolve optical imperfections in lenses
3) Some sample variation is possible

 

[picturefan]

An APS-C sensor is smaller than a FF sensor, and the testing workflow uses a fixed output size. Therefore, the APS-C image must be enlarged more than the FF image. That's why the FF image looks better.

Does that mean (simplified, of course), that comparing 5DIII and 7DII (both ~ 22MP, crop-factor 1,6) leads, resolution-wise, to 1,6x less resolution with the same lens on the crop-body?

Would it mean that only a 35MP crop-cam can have similiar resolution or quality as the 5DIII (35 = 22*1,6)?

Hope for all experts out there this seems not be too simple a question...

(if it is so simple, than there wouldn't always been discussions about that topic!)

inside out and upside down - a 35mp Full Frame would have the same pixel size as the 7dII. What is being attempted is a comparison between Crop and Full Frame. Putting more pixels into the crop would only help if the AA filter and lense could resolve the yet smaller photosites.

No one has brought up the AA filter.

I have the v1 24-105 and up to 70 like it very much after that, it is a snap shot lens as it gets soft. If I am doing anything "important" - I don't do weddings so typicall time is not that crushed - I switch to the 70-200. I might be switching to an 85 1.4 if my GAS flairs up.

Back in film days, switching lenses around the 70mm was very annoying, mostly when shooting portraits.
So I think with a cropcam one can be fine with 70mm, as it is 110mm.
I don´t know what your subjects are, but with a 70-200 lens also in your pocket, would you think 24-70 on crop is also good to manage?

 

[slclick]

24-70 on a 1.6 was always awkward for me, the 70-200 was great. But what do I know, now the 50-100 is a hot item for crop bodies.

 

[picturefan]

24-70 on a 1.6 was always awkward for me, the 70-200 was great. But what do I know, now the 50-100 is a hot item for crop bodies.

This lens would be pretty amazing, if it would be possible for FF also!
With ww-zoom, 50-100 and tele you would be ready for everything!

 

[Loswr]

24-70 on a 1.6 was always awkward for me, the 70-200 was great.

I found the 70-200 /2.8 to be 'awkward' on APS-C - often too long for indoor use (where the f/2.8 is useful), often too short for birds/wildlife (but I did have the 100-400 at the time). I found it most useful for outdoor event shooting. However, once I added a 5DII to my kit, the 70-200mm focal length became a lot more useful,

 

[Deleted member 7828]

24-70 on a 1.6 was always awkward for me, the 70-200 was great.

I found the 70-200 /2.8 to be 'awkward' on APS-C - often too long for indoor use (where the f/2.8 is useful), often too short for birds/wildlife (but I did have the 100-400 at the time). I found it most useful for outdoor event shooting. However, once I added a 5DII to my kit, the 70-200mm focal length became a lot more useful,

I tend to agree to a certain extent - particularly indoors, 70mm proved to be too tight on crop for even mid-range shots. However, I did like the reach of 200mm particularly at signings which enabled me to sit farther back and be less of a "distraction". With FF I have to be in the first couple of rows to get similar coverage - that part I miss about crop, but in general with FF the 70-200 range makes more sense and is more useful for a greater variety of situations.

And the 24-70 range made NO sense at all to me on crop sensor cameras. 24 not wide enough, 70 not long enough...24-105 at least had some reach, and I bought that lens originally to use with my T2i (although I still own the 24-105, this one's a different copy).