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Old April 27th 12, 03:08 PM posted to rec.photo.equipment.35mm
Chloe
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Posts: 35
Default frankencamera...

Dearest Noons...
Dear Alan Browne...

And Anyone else interested in this fascinating subject... Depth of
field. DOF for short. The first and most critical subject for Portrait
specialists to comprehend and understand. Well maybe understanding light
and shade might be so I'll call it equal to light and shade...

All of you are entirely correct and completely wrong at the same time,
depending on the application of the subject. Precision in wording is
missing from all your posts. Specific detail lost in your rush to best
your opponent. What a shame and complete waste of effort. Still I guess
if you no longer have a darkroom to while away your idle hours...

As a general rule, small sensors WILL produce a greater depth of field
than larger ones IF the picture is the same compositional size. A quick
and dirty example is comparing an iPhone to my pride and joy- a Phase
One (actually an updated Mamiya 645AFDII). The same photo at the same
screen composition size will have a seriously deep DOF on the iPhone but
barely hold focus for a few inches with the P1 at the same aperture and
compositional size. --Take note I said nothing about the lens focal length.

The reason for this DOF conundrum is in the focal length of a lens
needed to achieve the same compositional size wrongly referred to by the
gorgeous Alan Browne as "Enlargement Ratio"... An entirely different
subject.

85mm (I call this the useless size once supplied as a standard lens I.E.
equal to 50mm with 35mm frame size) on my P1 it is a "standard" lens but
I only ever use it for shooting art prior to making LE prints.

The iPhone "Standard" lens has a 3.9 mm focal length although you can
digitally zoom it to about 12mm FL if you feel adventurous. And here
lies the conundrum ladies... Forget all about the size of the
composition, it's the focal length and aperture of a lens that dictates
how much or how little DOF a camera will have.

TO see why you are all right and wrong at the same time, look up some
DOF specs of various focal length lenses. There is a canyon of distance
between what will stay in focus with a 4mm focal length lens and an 85mm
FL lens. In fact many phone cameras use such a wide angle lens,
everything past 3 feet is in focus all the time.

What you have as a DOF with a "full frame" DSLR using a 50mm lens at
f2.8 (almost nothing useful for sharpness) will be measured in feet,
even meters with a 4mm lens at the same aperture.

But when you start swapping and assuming, picking up and interposing
snips of relevant and irrelevant information you've picked up as you
surf through the plethora of bull**** written on the subject... You'll
all be right and wrong at the same time and as this thread demonstrates
so eloquently, end up not knowing when to apply what piece of
information about what subject. all you've done is try (but fail
miserably) to demonstrate that bull**** beats brains. Well it might in
newsgroups but not when your income depends of the brains.

TO Noons... Pull you head in Sweetheart. Be specific if you intend to
use this sort of information in an argument or to start one. That way
you'll be right from the start and not have to learn as your combatants
make similar mistakes.

TO Alan Browne... When you get cold, go inside and light a fire, don't
try to start one here with flaming people. Your cut and paste knowledge
starts to show up. So until you are prepared to do what you so often
expect others to do... Be specific... Shut up!

Enlargement ratio has SFA to do with depth of field. It's all about
focal length and aperture. Nothing more or less. Trying to display your
technical ineptitude by posting stuff you once read and (wrongly)
thought was correct only shows up your true self... Someone who thinks
photographing snow flakes in a winter storm with Ektachrome E100G is
artistic creativity.

Chloe
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chloe(underline


On 21/04/2012 6:30 PM, Noons wrote:
Alan Browne wrote,on my timestamp of 21/04/2012 6:06 AM:

Yep. Enlargement ratio (negative size to print) is actually the most
important
aspect of DOF presentation. I'm surprised that Noonsie doesdn't know
that.


And what'that got to do with size of sensor, moron?
DOF doesn't change ONE bit with size of sensor.
And you know that perfectly well.


f/0.7 Zeiss designs for NASA (Apollo program) and then further
modified. It's
not clear to me if Kubric borrowed/rented/bought/stole the lenses from
NASA or
if they were new lenses made for him.


And of course those were frankemcameras with large sensors?
In fact, I'm quite sure that sensor size is defined in "fn.n" units.
And that "negative size to print" had a lot to do with it, of course...