swhiggins wrote in post #15224693
Actually, I looked up the tests for both in Popular Photography... the T4i came out on top from a noise standpoint, not too surprising since it's sensor is bigger. But I think they create TIF files from Camera Raw files for their analysis, so the jpeg processing in the Oly may be better... were you looking at jpegs?
Yes. Popphoto's tests are flawed from certain aspects. They take the RAW and process it in the manufacturer's RAW software, in this case DPP at the default NR settings. DPP applies the prescribed NR for each ISO. These NR settings are really cranked up for the T4i.
I also have a T3i and a 7D, and have owned the 60D and T2i as well, so basically all 18mp sensor Canons. When I open RAW files from all of them, the NR in the same ISO RAW images varies by camera. For example let's say ISO 1600 has luma 4 chroma 8 for 7D Raw while the same 1600 is luma 6 chroma 10 for the T4i. These aren't accurate numbers, I can't check them now but you get the point. The T4i RAW files have about 30-40% more NR applied by default in DPP than any of those other 18mp Canon bodies at the same ISO. And the same is true for Jpegs. However, the sharpening algorithms are able to handle it well I think.
So I actually took very very controlled tests with all 3 of my 18mp bodies. Same scene, same lights, manual settings, timer, tripod, etc.
I compared out-of-camera jpegs and the T4i's jpeg processing is pretty good, significantly cleaner than the 7D, and certain ways better than the T3i, but it's mostly a wash.
As for RAW comparisons, it's interesting. My 7D and my T4i expose exactly the same, same brightness at identical settings. My T3i is a tiny bit darker.
As for RAW noise levels, the T4i has a little more chroma noise than the other 2, but only by a tiny bit. Chroma noise is easly curable, so no big deal there. It has perhaps a tiny bit more luminance noise than the 7D. As for the T3i vs T4i RAW noise levels I found that if I equalize the exposure differences (-1/3 EV for the T4i) the noise level is about the same. There is really no winner there.
It is interesting since the early tests on the internet (DPreview, TDP, etc.) found that the T4i slightly but visibly noisier at higher ISOs than the other Canon 18mp bodies. I downloaded full RAW files from DPreview taken with T3i, T4i, 7D and confirmed the findings.
But when I compare my own images I mentioned above, I don't see that difference they saw.
Another interesting phenomenon - which TDP also pointed out - is that images from the T4i are processed differently in DPP than the other 18mp Canon images, namely they are sharper for some reason. I also confirmed that. T4i images at sharpness setting 0 are as sharp or slightly sharper than T3i and 7D at sharpness 1. The funny thing is that in Adobe Camera Raw, there isn't such a difference, they look roughly the same sharpness-wise.
This sharpening also can contribute to more noise if someone uses DPP and processes T4i images without the default NR settings.
I looked at T4i samples at various sites, RAWs, JPegs etc till my eyes were bleeding... I wanted to buy this camera due to the upgraded features over the T3i, but for a few days the supposed step back in noise performance kept me from pulling the trigger.
Then I pretty much put my concerns to rest and bought one. And like I said the noise performance - at least in my case - is a wash; it's such a non-factor compared to the other more important features (5fps, 60D's AF system, BETTER shutter sound etc.) that it didn't keep me from buying one.
that's my 2 cents
Now, I've seen a bunch of test images from the Oly and they are very impressive, they look awesome.