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DavidWEGS
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 p.4 #9 · FX vs. DX throwdown... | |
Sam,
So, your point regarding FX vs. DX was what then? Can you state it more clearly, as in the original post you say it was to show how the DX does something where FX does not, or vice versa. I am just a bit unclear about the point of the test when using the same body in crop mode and using different glass and using different apertures. So many things changed but none of them include showing anything whatsoever between an FX and a DX sensor as the same sensor was used in the experiment.
Why not do this experiment using an FX sensor, then using the same setup (glass, FL, aperture, lighting, SS, distance to subject, etc.) on a real DX body shoot it again. Then you have a throwdown that means something as a true comparison. This test does not.
Using the same optics on the different sensors would have, and does produce similar results. In fact, I tested this and found that if you don't change anything other than the body (you keep the same piece of glass, same aperture, same distance to subject and same FL if using a zoom), the resulting DOF is LESS on the DX sensor. Odd but there it is, and if you test this yourself using a ruler or some way to reasonably measure the DOF, that is what you too will find. I will see if I can dig that test up when I next get to my office where I have those images.
I guess what I am saying here is that what I see, is an attempt to show the benefit of one sensor over the other. Unfortunately, even though there are definite benefits to each, this test does not show those strengths/weaknesses as the same sensor was used for both shots, and a different piece of glass, different FL, distance to subject and different aperture was used. I don't think it gives a real comparison or impression of how the two behave differently, which is what I understand your original point to be.
The thing is, the pixel density of the DX sensor yields better detail than that of the FX sensor WHEN used with the exact same FOV and everything else on both bodies.
However, when you adjust the FL on the DX to replicate the FX FOV, you have a more level playing field. Where that becomes less useful is when you up the iso's to the 800+ range as the FX sensor can actually gather more light per pixel and therefore holds detail/contrast/color better than the DX can.
It's all kind of an apples to oranges thing anyhow IMO.
I use both sensors for their relative strengths. DX is not inferior to FX at the same MP's when shot at low ISO's, in fact it looks better in some cases. Additionally, FX is of no advantage when they become equal in the size of the photo site either. IOW, if we get a 24mp FF cam and use it in DX mode, you will have a direct comparison and in that case the FF looses its high ISO advantage, or any other perceived advantage except for more MP's mean better printed product.
Anyhow, food for thought, and its fun to discuss the veritable benefits of one and the other.
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| Nov 12, 2008 at 11:41 AM |
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