n 10/12/2019 8:01 PM, Wayne Shumaker wrote:
I found an interesting site related to ISO and various cameras.
And it all supports what Moosexpert has been saying all along, duh.
WHEW!
On 10/13/2019 10:27 AM, Wayne Shumaker wrote:
. . .
So what Moose has been saying is that you get more dynamic range by
setting the ISO low and setting the EV compensation to -2/3.
Well, no, I didn't mean to say that. I don't have the raw file for the example I posted with me on the road, so I don't
know in what context I took it. It does look like I did a typical thing for me, skipping the EV comp dial in favor of
half pressing the shutter button while aiming at a highlight area (or, in other cases, shadow area.)
I'd guess the actual exposure for mid tones was closer to -3 EV. -2/3 is my default; has been for many cameras over many
years.
Then pull back in the shadows in post processing - Because the Shadow
Improvement
with ISO is nearly flat but the overall dynamic range decreases with ISO.
Just so, but with much more negative EV comp. than you assumed from my sample.
-3 EV is a pretty good starting point.
. . .
I have not thought about what the implications are for using auto-ISO,
other than you can probably shoot at -3EV and be able to pull back in
the shadows in post processing.
I think a lot depends on how a particular camera combines EV comp. and auto-ISO. My Pannys seem to understand that I am
intentionally underexposing, and do not increase ISO to stymie that.
On 10/13/2019 10:41 AM, Wayne Shumaker wrote:
PS
So a better definition of ISO Invariance is not what the DPR article
describes, rather it is the flatness of the Shadow Improvement with ISO curve.
Hence, A flat Shadow Improvement vs ISO curve implies ISO invariance.
I suggest everyone check out their camera curves.
If I were to push this to extreme with my A7iii, I would have to go into the
menu and set the EV to -5 as the dial only goes to -3EV.
I read reviews, tests and analyses, but at heart am an empiricist. -3 EV works well for my gear, subjects, technique and
post.
The downside of the menu EV setting, for a7iii, a7riii, is that if the dial
changes
from zero, the menu setting is overridden. Some people have suggest
putting slick tap around the knob to make it less likely to get bumped.
Equipment flaw, eh?
Now I'm wondering when to actually set the ISO higher?
Test/try it.
==============
{FF-rant: Comparing a dynamic range of FF sensor to u43, for example, a7r3 (or
a73) is 11.64 at ISO 100 compared to GX9 is 9.75 at ISO 100, almost 2 stops.}
----------------------------------
Anti FF-rant:
Most subjects don't require that much DR.
A camera with infinite DR that can't take the photo I want to take is useless.
FF cameras and their lenses are heavy enough that I simply can't use them in
the field
With µ4/3, I can have an 800 mm eq, hand holdable lens. That doesn't exist for
FF.
I use a FL range of 14-800 mm eq. (Horiz. AoV of ~150° to 2.5°) and often
switch FL a great deal from one shot to the next.
A fair amount of what I shoot moves, so it's zoom or miss the shot.
Using FF for my kind of field photography would be like using an 8x10 view
camera for flutterby photography.
----------------------------
I DO have a FF A7 for other sorts of photography, but would no more use it for my general photography than I'd use a
howitzer for hunting cheetahs.
Moose D'Opinion
--
What if the Hokey Pokey *IS* what it's all about?
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