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

[LesC]

I would think the 24-70 would be very nice on a crop sensor IQ-wise considering it's only using the middle portion of the lens, well, not the edges anyway.

Really depends on what focal length you're happy with too - I'd find the 24 end not wide enough on a crop sensor - I used the 17-40 as my walkabout lens for several years on a crop sensor body (EFL of 27-64) but now use a 24-70 F2.8 on full-frame.

 

[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.

Could anybody guess which one -7DII or 24-70 4.0- would be the "bottleneck" in this combo, resolution-wise??
The sensor in this example is very demanding, but the lens, corresponding, offers high image quality.

 

[Loswr]

Could anybody guess which one -7DII or 24-70 4.0- would be the "bottleneck" in this combo, resolution-wise??
The sensor in this example is very demanding, but the lens, corresponding, offers high image quality.

To what 'bottleneck' are you referring? Bottleneck suggests you're not getting what you'd expect. System resolution is a combination of the effects of multiple components, not just lens and sensor, but also the AA filter, the demosaicing algorithm used for the RAW images, etc.

 

[gruhl28]

The sharpness on a crop camera with smaller pixels is going to look worse than on a FF with a similar number of larger pixels, so it's no surprise that the lens (or any lens) doesn't look as good on the 7DII as on the 1Ds. But that doesn't explain why the 18-55 II would look sharper than the 24-70 f/4. I know the kit lens is supposed to be reasonably good optically, but I would not expect it to be better than the 24-70 f/4.

 

[picturefan]

But that doesn't explain why the 18-55 II would look sharper than the 24-70 f/4. I know the kit lens is supposed to be reasonably good optically, but I would not expect it to be better than the 24-70 f/4.

Let's say it must be sample variation of the lens at the TDP test, as I also guess that 24-70 must look sharper than the kit-lens. That's the point. The kit-lens is quite good, but 24-70 should be even better.
On all other cameras the 24-70 performs very good ("as expected") at TDP, but not so on 7DII. One of both must be the "bottleneck" (or sample variation).

My real life experience is that 24-70 4.0 is a good performer on crop, on 7DII the lens is nearly close to the 24-70 2.8II, in terms of resolution.
In no point I can proof the results of TDP with the combo 7DII and 24-70 4.0. I want to understand that (because in all other ways, I find TDP very useful and with reliable results).
Of course, I can post it on TDP, maybe they can do another testing.

But here I'm interested in user's opinions about that combo. Are you satisfied with resolution? Is someone doing portraiture or events with that combo?

 

[AlanF]

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.

TDP has not tested the 18-55 II on the 7D II - it's tested on the 30D only. The 18-55 STM has been tested on the 60D, where it is sharper than the 24-70. The 18-55 STM is a remarkably sharp little lens, getting a 4 star rating on Photozone - http://www.photozone.de/canon-eos/831-canon_1855_3556stmis

One of the great virtues of the Canon APS-C cameras is that there are excellent and cheap lightweight lenses designed by Canon for them (as well as Sigma and Tamron to some extent) and you don't have to lug around heavy lenses designed for FF.

 

[Loswr]

TDP has not tested the 18-55 II on the 7D II - it's tested on the 30D only.

In fact, they did. The EF-S 18-55mm f/3.5-5.6 IS II...but not the STM version. It does get a bit confusing with so many versions of that lens.

 

[AlanF]

Oops! I got my first 18-55 with the 300D (the first Rebel) in 2003/2004, which set me on an expensive road.

 

[Mt Spokane Photography]

Oops! I got my first 18-55 with the 300D (the first Rebel) in 2003/2004, which set me on an expensive road.

Pretty close to when I bought mine, I spotted a DPR announcement and picked one up at our local camera store. I was familiar with film SLR's and had a Nikon CP-990, so I expected that the rear LCD would have a live view, and was disappointed when it did not, since I used it for product photography and wanted to make sure of focus and composition as well as brightness before capturing the image.

When the 40D came out with Live View, I sold my 6 month old 30D and bought one. It paid for itself in time saved taking multiple shots until everything was how I wanted it.