SEL20F28 impresses and puzzles at the same time

Started Apr 10, 2013 | Discussions thread
wb2trf Veteran Member • Posts: 3,038
Please stop shouting

007peter's comments are way too harsh.  For openers, stop shouting, get rid of the underlining, all caps and bold.  We can read.  Your emphasis doesn't improve your argument.

If there is an interaction between the lens and the AF that causes problem, why wouldn't we want to know that?  Maybe, like most people, we want to use the lens with AF and JPEG, not raw and MF.  If it doesn't work well when used as AF JPEG, that's important.

Secondly why do I care if "in camera corner sharpening" is at work or not?  "Lens optics" is a vanishing idea in a world of software correction, af and IS.  It isn't as though someone is going to mount this lens on a 1970's slr.

007peter wrote:

blue_skies wrote:

I I have a shot where the E20 focuses very sharp at the left edge, but not at the foreground, whereas the S19 focuses sharp on the foreground, but not at the (very) left edge.

Sound like wrongly focal point between each lens swap

DOF does not explain this. Camera (tripod?) and possibly decentering perhaps, but for now, I am betting on in-camera lens corrections that may have a hand in this (straightening of lines), and are caused by the different optical formulas of both lenses.

You should have DISABLE IN CAMERA CORRECTION to reduced outside factor (cpu/in camera software corner sharpening) that is ruining your test results

Let the chips fall where they may. Don't HIDE or MAKE EXCUSE for Sony.  Please show each lens "raw & uncorrected" image.  This is the only way we can compare a lens optics.

Otherwise, we never know if Sony is sharper due to in-camera-corner-sharping as part of its software corrections, or as your own result show, make it worst and produce mushy corners.

Either way, your test is ruin by enabling the in-camera-correction

Aside from this strange quirk, I find the E20 and S19 fairly comparable. The E20 does seem a tad softer at the corners, but it seems sharper in the center.

I cannot say which is lens is sharper because as you indicated, CDAF shoot different AF points after each lens swap.  The only valid way to compare lens is to MANUAL FOCUS with peaking.  This way, you take the "AF ERROR" out of the testing equation

I'll look forward to your re-shoot.  The current results are invalidated and I cannot form any conclusion when I doubt the test results itself.

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