Is the Sinar depth of field calculator the final answer?

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nobody - 22 Oct 2005 19:29 GMT

Is it as good as it sounds? No fiddling with focus tweaking tilts etc.? Or
is it too good to be true?

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Nicholas O. Lindan - 22 Oct 2005 23:07 GMT

"nobody" <nobody@nowhere.com.re>

> Is it as good as it sounds? No fiddling with focus tweaking tilts etc.? Or
> is it too good to be true?

Works just the same as one on any other camera. You can make
one yourself: just measure the distance the back travels to
focus from near to far -- somewhere on the web is a
distance -> fstop chart.

Sinar assumes a maximum enlargement of 2x - it is a commercial/
professional camera and 8x10 or so is as big as photos get in
catalogs and magazines.

I find stopping down one stop from the Sinar's reading is
prudent.

Signature

Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
Fstop timer - http://www.nolindan.com/da/fstop/index.htm

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Leonard Evens - 23 Oct 2005 04:13 GMT

> Is it as good as it sounds? No fiddling with focus tweaking tilts etc.? Or
> is it too good to be true?

It just uses well known principles and does the calculations for you.
But it ignores diffraction and makes an assumption about what the
maximum allowable circle of confusion is. If you want to be more
demanding or if you think diffractions may be an issue, you should stop
down one or more additional stops. Of you could study the methods
based on focus spread discussed at www.largeformatphotography.info.

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nobody - 23 Oct 2005 10:49 GMT

Thank you very much indeed.
nobody

On 23/10/05 04:13, in article qK6dnYNgn9huYsfeRVn-tA@comcast.com, "Leonard
Evens" <len@math.northwestern.edu> wrote:

>> Is it as good as it sounds? No fiddling with focus tweaking tilts etc.? Or
>> is it too good to be true?
[quoted text clipped - 5 lines]
> down one or more additional stops. Of you could study the methods
> based on focus spread discussed at www.largeformatphotography.info.

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Mark Westling - 23 Oct 2005 22:49 GMT

Where is this Sinar DOF calculator?

>> Is it as good as it sounds? No fiddling with focus tweaking tilts etc.?
>> Or
[quoted text clipped - 6 lines]
> additional stops. Of you could study the methods based on focus spread
> discussed at www.largeformatphotography.info.

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nobody - 23 Oct 2005 23:42 GMT

On the Sinar itself, more particularly on the rear focusing knob, and
another knob (for calculating tilt) (you make me feel like an expert...

:-)). Do a Google search on Sinar, and you will also become an expert like

me...

On 23/10/05 22:49, in article %yT6f.57673$WR2.13331@fed1read03, "Mark
Westling" <MarkWestling@cox.net> wrote:

> Where is this Sinar DOF calculator?
>
[quoted text clipped - 8 lines]
>> additional stops. Of you could study the methods based on focus spread
>> discussed at www.largeformatphotography.info.

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Bandicoot - 24 Oct 2005 00:28 GMT

> Is it as good as it sounds? No fiddling with focus tweaking tilts etc.? Or
> is it too good to be true?

Rodenstock makes a little calculator device that you can dial various info.
into and it will give you the aperture needed for a given DoF at the CoC
they recommend for a given film format - just change the format choice to
get a different CoC. You can work out what it is using for its CoC by
dialing in some known numbers. This thing also calculates tilt for
Scheimpflug adjustments.

Peter

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