Re: 4x5 field camera considerations - Reply

[boblong@xxxxxxxxxxx (Robert Long)]

On Sat, 14 Dec 1996 19:36:50 +0000 (GMT), Willem-Jan Markerink wrote:

|On 14 Dec 96 at 15:32, francisco sandoval wrote:
|
|> What difference will it make if you take your picture to the higher
|> F-stop that your lens allows you, so you will get higher details, is
|> that correct or not, am I wrong??????   (I must be)... explain to me,
|> excuse my ignorance........ :).......  Francisco
|
|With 35mm camera's the golden rule is to close aperture 2-3 stops
|from the highest opening (best performance of the lens), but for

While I'm not sure I understand the original question, I suspect that
we have a classic problem here: Confusion about whether a "high"
f/stop means a large opening or a large number.  However it was meant
in the question, I guess the answer makes plain what the situation is.

|My German literature on the other hand also suggest *not* to stop=20
|down too far, since diffraction ('bending' of light around the=20
|aperture blades) is twice as bad with IR than with visible light, and=20
|diffraction is one of the 'errors' that increase with small=20
|apertures.=20

Also, if maximum sharpness is required, most lenses (certainly for
35mm work, and I assume this is true in larger formats as well) tend
to be measurably sharpest at medium apertures and to lose some
sharpness at both minimum and maximum settings.  Whether the loss of
sharpness when you closed down the smallest available opening will
actually be visible in the print is another question, however.

Bob Long
(boblong@xxxxxxxxxxx)

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Topic No. 2