7d Review- when?

[EdN]

Brian


Great Review! It gives me a lot to think about for getting one for wild life and action to complement a 5D Mk II.

[Jon Ruyle]

Thanks, Daniel, for another detailed answer.


I guess part of my problem is that I was using the word "aliasing" wrong... I thought it referred only to specific types of artifacts caused by box-like sampling. The wikipedia article helped.

the general
formula is (sin(pi*a*f))/(pi*a*f)

This shows you need a *lot* more sampling to reduce aliasing. Much more than I would have thought.

So you are right that we can use a low pass filter in software, but only over the frequencies that are *already* in the image file itself.

Yeah I figured that after I wrote it and felt silly [:$]

If you use a point filter and downsample to 3.6 MP, you keep the 40 lp/mm details

I guess this is why people use a point filter to down sample. I always thought they did it because they were stupid. But, as you say, some people *want* to see aliasing.


I recall an article by Ken Rockwell in which he compares the 5DII to the D3x and concludes that the 5DII sucks because it isn't as sharp. Aside from a few obvious issues with this comparison (like the fact that he only compared jpegs), it seems also that he does not consider sharpness vs aliasing a trade-off... maybe it is time for a myth-busting thread about "per-pixel sharpness" (except, I suppose, that Ken Rockwell probably doesn't read this forum [])