[ElJamoquio]

Numbers are one thing, but I have a hard time telling my K-5 and 5DM2 apart in blind tests, at similar equivalent focal lengths, and not pixel peeping.

Well that's because it's a Canon. Duh.

The K-5 saves my back.

No doubt.

How much smaller and lighter is a 7D compared to a 5DII?

When Pentax brings out it's FF camera, I have no doubt it will be small(ish) and quite light.

I fail to see how PP factors into lens reach, unless you are cropping? The extra reach a FF lens gives APS-C is very real and to me, makes that format superior in a lot of ways if you are into bird photography, etc as you get more mm for the buck with camera lenses.

Yup, I crop. I crop *now* with APS-C. A FF camera like the D800 makes cropping completely lossless vs. APS-C and makes tracking sports + wildlife "infinitely" (300%) easier... so I fail to see a practical reason (other than initial cost) someone would choose a D7000 over a D800 for birding.

[normhead]

But if you assume that an APS-c sensor is somehow different than an FF sensor, instead of just smaller... you might have a problem. SImple fact... same pixel pitch, same lens, same distance from subject... same I Q. The only question is, is the APS-c image big enough, and can you stand the softer image on the edges of the FF lens if you need the larger image.

"

but the difference between 'regular' lenses and the LImiteds (in IQ) is less than he difference you see changing formats

"... if you start with a faulty premise it's hard to explain it simply.

[jsherman999]

But if you assume that an APS-c sensor is somehow different than an FF sensor, instead of just smaller... you might have a problem. SImple fact... same pixel pitch, same lens, same distance from subject... same I Q.

And different image, unless you crop the FF image to the same FOV, in which case it would be the 'same' image with the same IQ (if you kept the pixel pitch and sensor QE the same.)

Put a different focal length on the FF body, though, one that brings the same FOV from the same position, and things can change quite a bit with regard to IQ. Of course I've tried to explain this to you dozens of times, and it's never stuck, so I don't know why I'm bothering now other than I have a spare moment and I'm bored.

" "... if you start with a faulty premise it's hard to explain it simply.

Oh, it's not a faulty premise, Norm. However I've found that if you try to explain something like this to someone who refuses to acknowledge simple points about equivalence, everything and anything can be 'faulty' in their eyes.

.

[Edvinas]

i really don't think FF "thrashes" or "destroys" the K-5 in IQ. FF is marginally better in my experience but it really boils down to whether you want the additional coverage, larger VF, and thin DOF, extra cropping ability, or you want to make massive prints. If you want better AF, you don't need to go to FF; there is the 7D or probably even the D7000.

I've referred to K-5 + DA* 16-50 combination. Nikon FF with 24-70mm destroys it. I've used both and this is my personal impressions. Thrashed, destroyed, etc. Sad, but true.

[Marc Sabatella]

I've referred to K-5 + DA* 16-50 combination. Nikon FF with 24-70mm destroys it. I've used both and this is my personal impressions. Thrashed, destroyed, etc. Sad, but true.

Obviously you can't post a print* that would allow anyone to judge this more objectively, but would be interesting to post digital images of various sizes to see just how much much larger than a computer screen you'd have to display it in order for anyone to be able to reliably tell difference. I'm guessing it wouldn't show until you were at about 4X the dimensions of the typical computer monitor, and would require a print of at least 12x18". But those are just guesses.

*Actually, you could post scans of portions similar-sized prints.

[Marc Sabatella]

This sort of speaks to a point I always try to make - folks talk about the vast differences between, say, regular FA or DA lenses and the Limiteds, but the difference between 'regular' lenses and the LImiteds (in IQ) is less than he difference you see changing formats - and yet some of the same folks maintain that there's no significant difference available when changing formats.

In other words, If you claim to see the difference in the 43ltd over the F 50 1.7, or the 31ltd over the DA 35 f/2.4, then you can't claim that FF would hold no value for you - because it would hold more difference than those lenses would on aps-c.

(I'm also still struggling about how to really clearly articulate that point...)

I think you did fine. It is indeed a somewhat "inconvenient truth" for some. Luckily, I hold no pretensions that the difference in sharpness between two lenses is particularly significant. I suspect it takes a larger print than I care to make, viewed from a closer distance than I like to view large prints, in order for me to see *any* of these differences. I can of course see a difference in 100% crops, but in the real world, not so much. It's that way for lenses, and I have no doubt it's that way for formats.