Return of Interesting article on DxO about 5D III and D800...

Started Apr 10, 2013 | Discussions thread
qianp2k
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Re: resolution
In reply to MAC, Apr 15, 2013

MAC wrote:

qianp2k wrote:

MAC wrote:

Just another Canon shooter wrote:

schmegg wrote:

When you shoot with equivalent FL's, you do shoot from the same distance.

"Equivalent lenses" is a bit of an oxymoron when you think about it. I can't think of a single pair of 'equivalent' lenses that would be suitable for determining the resolving power of a sensor.

We are not talking about that, whatever that means. The question was why similar lenses perform better in the DXO tests on FF bodies - which they do. The explanation is - DXO measures basically medium contrast, and then FF wins due to less enlargement. The extinct resolution of the sensor plays very little role for that specific metric.

dxo is measuring sharpness, not resolution.

DXOMark sharpness is not regular "sharpness" that you can achieve thru software sharpening.  It's based on MTF resolution but translate with a factor that human eyes can perceive that likely around 20% MTF.  DXOMark uses two words interchangeably sometime.

To do any kind of comparison across formats, one must keep the distance the same.

This is a disputable part.  All those labs test by framing the test subjects (such as resolution chart or test subjects) into the same AOV either by eq FL (such as zoom) or by adjusting distance (such as prime).  It represents in real world how we use the camera-lens system.  Such as we use the same 85mm lens on FF or on crop to shoot half-body portraiture, so 7D/60D shooter need to move 1.6x away.  If shoot from the same distance, you will end with half body on FF vs shoulder above on APS-C crop.  Such as we use 24mm on FF or 15mm on APS-C for the same AOV in landscape photos, otherwise the same 15mm or 24mm on two different crop formats will end with two different AOV scenes.  What you compare, apple to orange?  You could setup a website to promote your test by shooting from the same distance and the same FL in your own lab  But I know which lab tests I will follow, hehe.

One needs a better optic, the farther away from the subject.

It's crop cameras need much better lens and much more pixels to overcome more crop penalties when frame subject into the same AOV.

yeah right, the crop blows away the 5d3 "at the same distance with the same lens, thereby measuring resolution

http://www.dpreview.com/forums/post/51145798

LOL. I don't take 5D photos from the same FL lens from the same distance then crop out to match to my 60D's AOV in landscape, studio or portraiture I guess nobody else doing in that way

1) In reality what lens on your T4i or 60D that you can achieve FF eq 24mm AOV to match my 24-70L II on my 5D3 in landscape photos?   From 15-85 at 15mm?

2) In reality what lens on your T4i or 60D that you can achieve FF eq 85mm AOV to match 85L on 5D3 in portraiture? Hehe.

3) In NFL sport and Olympic venues, now professional PJs use 400L/2.8 II, or 500L/4.0 IS II or rarely 600L/4.0 IS II on 1DX/5D3 that absolutely beat 7D with 300L or 400L as with those tele lenses, PJs can frame players into sport fields without cropping. No chances 7D or 2.0x crop E-5 could win.  It's the reality in sport fields these days.  Actually it's also one of reasons why Canon was forced to move to FF sport cameras as its 1.3x crop 1D lines cannot compete to Nikon FF D3/D4 lines in IQ especially in high ISOs.

Sure, you can quote in birding case.  But don't forget 1DX owners can use 1.4x or 2.0x TC on 800L that usually have enough reach most times.  Or 1D4 owners (1.3x crop is much close to FF in IQ than APS-C) have the best balance of IQ and reach in birding.  7D is unable to AF at F8.0 with TC.

That simply reflected in reality of photography world.

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