Hi Mike -
I hope I'm not picking nits here, but I think we are further confusing
the situation.
All DOF is "perceived." The gradient from what looks sharp in the
final medium to what doesn't is a continuum that is very dependent
upon magnification, print size, contrast, subject and a number of
other factors.
I'm going to stick with the idea that only aperture controls DOF. Back
and/or lens movements can shift the PLANE of focus in useful ways, but
it does not increase DOF.
Eric Goldstein
On Fri, May 4, 2018 at 11:33 AM, Mike Bischof
<dmarc-noreply@xxxxxxxxxxxxx> wrote:
Let me rephrase this -- let's call it "perceived DOF," which I think is what---
the OP meant. How can you achieve maximum perceived DOF - i.e. in the final
image/print both the little flower in the foreground and the big mountain in
the background "look" sharp / in focus. Under that assumption, my comments
below stand :)
I'm aware of the laws of physics and true DF and true CoC, but I don't think
that is what the OP meant...
Cheers,
Mike
________________________________
Mike Bischof
Phoenix, AZ
________________________________
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From: Eric Goldstein <egoldste@xxxxxxxxx>
Date: Wed, 2 May 2018 11:06:02 -0400
Subject: [rollei_list] Re: DOF solutions - Rollei or otherwise
There's a bit of a misnomer here... It's been mentioned but bears
repeating...
DOF is purely a function of aperture. Some would say magnification is also
a factor but if you control that, you see that it really isn't.
With movement, you can choose a more optimal plane of focus, but you are
not truly increasing the DOF
Eric Goldstein
On Wed, May 2, 2018 at 10:51 AM, Mike Bischof <dmarc-noreply@xxxxxxxxxxxxx>
wrote:
If you want "maximum" DOF, then a large-format field camera or monorail is
really the only option. With T/S lenses in 135 cameras or even the
bellows/Schleifpflug solution of the Rollei 66, you just don't have the
space on either groundglass or viewfinder to accurately adjust perspective
enough to be truly accurate. You can stop waaay down to offset that, but
the you affect ultimate image quality due to diffraction.
Years ago, when I was about to pull the trigger on a used Rollei 66, the
guy in the store convinced me to look into LF instead, and I am very glad
he did.
I now have a Arca Swiss Field camera (yes, they can still be purchased
new), which gives me the best of both LF worlds (portability of a Field
Camera, but capabilities of a monorail). I use it whenever I want to do
"serious" photography (mind you, I am not a professional, just a hobbyist
who aspires to do fine art photography).
For B&W photography, the equipment is all a bit bigger, but the workflow
is the same. Load filmholders and tanks in a changing tent, and develop in
broad daylight. JOBO made/makes a tank for 6 4x5 sheets, including a
loading ramp. And when you hand-develop with that tank, you get a free
workout (tank needs 45 oz. of soup).
Cheers,
Mike
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Mike Bischof
Phoenix, AZ
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