On 2/3/2025 11:16 PM, Ken Norton wrote:
I don't know what I should feel about the digital lens correction. The
amount of correction applied to the 20-70/4 is staggering. The
70-200/4 is moderate. The 200-600 is minimal. The 70-200/2.8 GM is
minimal.
That seems to be the rule: The wider and/or cheaper, the greater the
correction. Makes good common sense.
From that perspective the 20-70/4 should be a very hated
lens. But here is the deal. The correction algorithms are so good now
(I'm using Lightroom) that it's pretty much a moot point.
What MikeG is saying is that it does make a difference, blurring the corners,
in his experience.
I tend to agree with you that it's not much of an issue most of the time. I suspect that's less about how good the
algorithms have become than that there is so seldom in-focus detail that we pay much attention to in the outer reaches
of the frame.
While I
would prefer that the lens be "perfect" I am NOW much more accepting
of the fact that the lens is just a part of the "imaging system."
If I think about the raw lens quality, there is no way that I should
keep the 70-200/4 and instead use the 2.8 GM. I'll need to make that
choice at some point soon. But the GM also needs to go into SONY for a
repair before I can put it back in use.
I did some skyline photography last night and used all three lenses,
but mostly the 70-200/4. I did notice a point where I did absolutely
run into the limits of the lens. Not just in distortion correction,
but sharpness.
Digital rejiggering of images decreases sharpness. That's just the way it is. MikeG can do the math; me, not so much.
Ctein contends that Bayer array color loses about as much fine detail as halving resolution, because of the interpolation.
Simple illustration: Take the exact same shot, tripod, full of fine detail, using Oly's HR mode and ordinary mode. Now,
downsample the HR to the same pixel size and compare. There's more clear, fine detail in the downsampled version. The
reason's simple, HR moves the sensor so that each location is recorded with each color sensel, so no interpolation of
color channels is needed.
So . . . moving the pixels around, interpolating expansion and contraction, in a digital image, simply softens. Color
and brightness for each pixel is an imperfect guess. In my post processing, I almost always lightly (re)sharpen, to at
least partially correct for resampling losses.
The 70-200/4 is a great lens, but the 2.8 is a
more-better great lens. It was pixel sharp-ish but didn't quite want
to focus exactly as well as the other lenses. There is a nuance there
that I can't quite put my finger on.
Whatever. I'm happy to have this lens for this trip.
That's the best measure! My 12-200 is imperfect — and I'm happy using it and with the results I'm getting, esp after
post. No word from Oly repair for a couple of days, since it went into actual repair
Pixelated Moose
--
What if the Hokey Pokey *IS* what it's all about?
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|