Enlarger f-stop sweet spot
 

I recently asked the question about sweet spots for Cameras and Enlarger on the
MF site. I received so very good information on camera lens and learned about
diffraction. My question is "are the problems the same with enlarger lens?"
Since the projection is on to a two dimensional field does this change the
quality of the print.
Is there an optiimum f-stop?
Thanks.

Enlarger f-stop sweet spot
 

The problem is the same with enlarger lens, there's a sweet spot.
Usually, 2 stops less than maximum aperture.

Jorge

ojunk (ATIPPETT) wrote in
:

I recently asked the question about sweet spots for Cameras and
Enlarger on the MF site. I received so very good information on
camera lens and learned about diffraction. My question is "are the
problems the same with enlarger lens?" Since the projection is on to a
two dimensional field does this change the quality of the print.
Is there an optiimum f-stop?
Thanks.

Enlarger f-stop sweet spot
 

I've read a number of times that, in general, APO's are at their
sharpest one stop from wide open and others at 2 stops. This has been
true in my own experience and with my own equipment. Naturally,
alignments and focus accuracy become extra critical at these settings
as you lose the forgiveness of expanded depth of field at these wider
settings. I've also found that until you get into 11X14 and up
(medium format) and 8X10 (35mm), these differences are extremely hard
to discern. This assumes good, solid, high grade equipment that is in
proper adjustment.

On 12 Jun 2004 18:46:36 GMT, ojunk (ATIPPETT) wrote:

I recently asked the question about sweet spots for Cameras and Enlarger on the
MF site. I received so very good information on camera lens and learned about
diffraction. My question is "are the problems the same with enlarger lens?"
Since the projection is on to a two dimensional field does this change the
quality of the print.
Is there an optiimum f-stop?
Thanks.

Enlarger f-stop sweet spot
 

"ATIPPETT" wrote in message
...
I recently asked the question about sweet spots for Cameras and Enlarger
on the
MF site. I received so very good information on camera lens and learned
about
diffraction. My question is "are the problems the same with enlarger
lens?"
Since the projection is on to a two dimensional field does this change the
quality of the print.
Is there an optiimum f-stop?
Thanks.

If you go to the Schneider web site I provided on the MF newsgroup, you will
see the MTF charts for each enlarging lens and see where the sweet spot is.
Not all apertures are tested, but you can get the idea.

Note that there are multiple factors to consider such center sharpness, edge
sharpness, light fall-off, distortion (probably not important unless your
photos have a lot of straight lines near the edge).

Also note that measurements differ according to the enlargement factor in
addition to the aperture. This is because enlarging lenses are optimized for
a certain enlarging factor (just like camera lenses are optimized for
distances close to infinity).

Enlarger f-stop sweet spot
 

Enlarger f-stop sweet spot
 

"ATIPPETT" wrote in message
...
I recently asked the question about sweet spots for Cameras and Enlarger
on the
MF site. I received so very good information on camera lens and learned
about
diffraction. My question is "are the problems the same with enlarger
lens?"
Since the projection is on to a two dimensional field does this change the
quality of the print.
Is there an optiimum f-stop?
Thanks.

Yes. Around f/5.6 or f/8 for faster or slower lenses respectively.

Enlarger f-stop sweet spot
 

Yes. Around f/5.6 or f/8 for faster or slower lenses respectively.



To get reasonable printing times of 8s or so, I have to print at f11 or f16.
Anybody know if they sell ND filters for enlargers?

Enlarger f-stop sweet spot
 

"Mike" wrote in message
m...

Yes. Around f/5.6 or f/8 for faster or slower lenses respectively.



To get reasonable printing times of 8s or so, I have to print at f11 or
f16.
Anybody know if they sell ND filters for enlargers?

Despite what some have said, f/11 has just as good resolution (even with
diffraction limitation) as f8 on many lenses.

But check with B&H Photo. You should be able to find a large unmounted
filter that you can cut down to size.

Enlarger f-stop sweet spot
 

Mike wrote:

Yes. Around f/5.6 or f/8 for faster or slower lenses respectively.



To get reasonable printing times of 8s or so, I have to print at f11 or f16.
Anybody know if they sell ND filters for enlargers?


Check your lens it might have filter threads. Or you could stick ND
filters in the filter drawer. OTOH you might want to figure out why you need
such short times. Small enlargements? Bulb too bright?

Nick

Enlarger f-stop sweet spot
 

"Mike" wrote

Yes. Around f/5.6 or f/8 for faster or slower lenses respectively.

To get reasonable printing times of 8s or so, I have to print at f11 or f16.
Anybody know if they sell ND filters for enlargers?

From the department of shameless self promotion: You might try

rec.photo.marketplace.darkroom

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/