My previous post on this generated many response/questions/issues etc. Some of which were not really relevant to my original post. If that is due to my brevity or lack of explanation or testing procedure then I apologise.
Here is the rationale of this comparison:
My longest lens is a 300mm f/4L IS.
I have access to a 5D2 and a 7D.
I want to know what "reach" or image quality the 5D2 can give me compared to the 7D with my longest lens, in a real world example.
I will not be changing focal length.
I will not be moving toward or away from the subject.
I will not be shooting charts or different ISOs/apertures.
This comparison is for those photographers who are interested in how the FF 5D2 compares with the crop 7D when you can't move or change lenses.
To get the subject sizes the same (and again, without changing lenses/focal length or foot zooming!) The 5D2 image needs to be increased 150%
The shots were @300mm, f/4, 1/4000s, ISO400, tripod, 10x live view manually focused on the same point, processed exactly the same in DPP with no NR and with Sharpening 1.
Here is the scene as seen by each camera:
7D:
http://i46./316l1dz.jpg
vontom wrote:
This comparison is for those photographers who are interested in how the FF 5D2 compares with the crop 7D when you can't move or change lenses.
?
Talk about limiting your test group! Most photographers who select one format or the other will select lens most appropriate for use with that system. (An exception perhaps being those who shoot certain subjects with the very longest focal lengths.)
I guess that the question you are trying to "answer" is one that has been asked and (maybe or maybe not) answered many times, namely: If you use the lens that is right on a cropped sensor body, what is the image quality going to be if you use the wrong focal length on a full frame camera and try to compensate by cropping.
The lens limitation arises from the fact I don't have a longer lens and I don't want to buy a longer one. I wanted to see what both cameras can do with that lens. There are plenty of tests of crop vs FF when the subject distance/aperture/focal length are changed to "match". This is not one of those comparisons.
The EF 300/4L IS really starts getting sharp around f/5.6. Performance at f/4 is not optimal, especially in the corners. You may find the 7D's advantage to be greater once you stop down. I know this because I use the 5D2 + 300/4L IS regularly, and if I can see the difference between 300/4 and 300/5.6 on a 5D2, then it should be very evident on a 7D.
Thanks for the test. Being a birder myself, this IS THE test.
My personal experience match with your results here. If I limited myself to birds only, i think
1. 7d doesn't offer any extra reach over 5d2. ( on 300/2.8LIS, 400/5.6, and 600/4LIS)
2. 5d2's pixels are better, 7d files has to be re-sized to match 5d2's pixel quality. In other words, same location and same lens, 7d crop has to be downsized to match the size of 5d2's to get similar image quality.
3. 5d2's center AF point is under-stated and 7d's AF is over-stated.
4. 5d2 take TCs much better than 7d
5. 7d's BIGGEST advantage over 5d2 is the fps - i can easily get perfectly focused BIF shots with 5d2, but it is pretty hard to get the wings at exact position! This is THE reason i get 7d, and is the reason to KEEP it.
jxsq wrote:
My personal experience match with your results here. If I limited myself to birds only, i think
1. 7d doesn't offer any extra reach over 5d2. ( on 300/2.8LIS, 400/5.6, and 600/4LIS)
Thanks again.
That's somewhat surprising results with those lenses. I believe your observations are correct, yet I will provide some other observations I have done, to fill into the total picture:
On the 500D camera, I have tested the 400/5.6 with 1.4 TC to resolve more detail than the bare lens.
On the 7D, I haven't done controlled testing with the 300/2.8, but using it with the 2x TC gave very good results when stopped down one stop.
With the EF-S 60 macro, I have found the 7D camera to resolve slightly more detail than the 500D.
vontom, the re-test and extended introduction was a good thing
For those interested, here is a 100% crop of the original 5D2 image and a 100% crop of the 7D image that was downsized 150% in DPP. Same processing as before - no sharpening.
vontom wrote:
For those interested, here is a 100% crop of the original 5D2 image and a 100% crop of the 7D image that was downsized 150% in DPP. Same processing as before - no sharpening.
I like these better. The 5D family uses a weaker AA filter and does not require much sharpening. I rarely go beyond 60% in CS4. Much higher and halos and other PP artifacts cause image degradation.
