Extra lenses with enlarger - why?

Okay - this might sound like a dumb question - the "new" enlarger I just
picked up (1960s vintage Opemus III) has two lenses, with the numbers 4.5/55
and 4.5/75 on them. 4.5 is the maximum aperture, of course, and I presume
the 55 and 75 refer to focal lengths. Why would I want this choice of
lenses, and under what circumstances might I prefer one over the other?


Thanks,

Gabriel

On 2006-03-19, Gabriel wrote:

Okay - this might sound like a dumb question - the "new" enlarger I just
picked up (1960s vintage Opemus III) has two lenses, with the numbers 4.5/55
and 4.5/75 on them. 4.5 is the maximum aperture, of course, and I presume
the 55 and 75 refer to focal lengths. Why would I want this choice of
lenses, and under what circumstances might I prefer one over the other?


Thanks,

Gabriel



55mm for 35mm negs, and 75mm for medium format negs.

hth
--
Jon
____________________________________________
jondotrogersatntlworlddotcom
============================================

You could use the 75mm for both 35mm and 6x6 but the 55mm lens will give
greater magnification with 35mm negatives for any given enlarger height.
Unfortunately the 55mm lens will not "cover" the entire 6x6 image so you
can't use it to make bigger prints from the 6x6.

--
darkroommike
"Gabriel" wrote in message
...

Okay - this might sound like a dumb question - the "new" enlarger I just
picked up (1960s vintage Opemus III) has two lenses, with the numbers
4.5/55
and 4.5/75 on them. 4.5 is the maximum aperture, of course, and I presume
the 55 and 75 refer to focal lengths. Why would I want this choice of
lenses, and under what circumstances might I prefer one over the other?


Thanks,

Gabriel

In article ,
"Mike King" wrote:

You could use the 75mm for both 35mm and 6x6 but the 55mm lens will give
greater magnification with 35mm negatives for any given enlarger height.
Unfortunately the 55mm lens will not "cover" the entire 6x6 image so you
can't use it to make bigger prints from the 6x6.

You would also find it very difficult, if not impossible, to make larger
then an 8x10 and possibly even an 8x10 on the base board with the 75mm
from a 35mm neg.

--
To reply no_ HPMarketing Corp.

ahhhh..... of course. Told you it was a dumb question. :-]

Thanks,


Gabriel

"Bob Salomon" wrote in message
...
In article ,
"Mike King" wrote:

You could use the 75mm for both 35mm and 6x6 but the 55mm lens will give
greater magnification with 35mm negatives for any given enlarger height.
Unfortunately the 55mm lens will not "cover" the entire 6x6 image so you
can't use it to make bigger prints from the 6x6.

You would also find it very difficult, if not impossible, to make larger
then an 8x10 and possibly even an 8x10 on the base board with the 75mm
from a 35mm neg.

--
To reply no_ HPMarketing Corp.

On 19 Mar 2006 in rec.photo.darkroom, Gabriel wrote:

ahhhh..... of course. Told you it was a dumb question. :-]

Rule of thumb is that 'normal' enlarger lens for a given negative size is
roughly the same as 'normal' taking lens, or roughly the diagonal of the
negative.

--
Joe Makowiec
http://makowiec.org/
Email: http://makowiec.org/contact/?Joe

In article ,
David Nebenzahl wrote:

To expand on this just a little, another rule (rule of pinky?) is that
while you shouldn't use a lens with a shorter focal length than what is
"normal" for the format

Unless you are going to use a wide angle enlarging lens to allow you to
make very high quality prints 30% larger then a normal focal length
enlarging lens at the same negative to baseboard distance.

--
To reply no_ HPMarketing Corp.

On Sun, 19 Mar 2006 15:56:05 -0800, David Nebenzahl
wrote:

To expand on this just a little, another rule (rule of pinky?) is that
while you shouldn't use a lens with a shorter focal length than what is
"normal" for the format, you can use a lens that's longer; in fact, some
folks even recommend this, as it eliminates any concerns about lens
coverage of the negative. *However*, if you do, you'll find that this
limits the size of enlargements you can make.

Which I have to wonder as to how valid this is for the current lenses
on the market as I found that putting a 135 El-Nikkor into the Elwood
allowed me to make enrgments that seem identical to those made with
the 180mm Coponon-S. Of course I'm only making 2X enlargements ;)

==
John S. Douglas
Photographer & Webmaster
www.legacy-photo,com
www.xs750.net

On Sun, 19 Mar 2006 19:25:06 -0500, Bob Salomon
wrote:

To expand on this just a little, another rule (rule of pinky?) is that
while you shouldn't use a lens with a shorter focal length than what is
"normal" for the format

Unless you are going to use a wide angle enlarging lens to allow you to
make very high quality prints 30% larger then a normal focal length
enlarging lens at the same negative to baseboard distance.

Bob,

Would you take the time to share with the group the optimizations for
the different focal length lenses ? As I remember from our
conversation a couple of years ago, most enlarging lenses are
optimized for 6~10X.

==
John S. Douglas
Photographer & Webmaster
www.legacy-photo,com
www.xs750.net

This is my guess ... (correct me if I am wrong):

The 75mm has the correct focal length to magnify the 35mm film size to a
usable projector height and the coverage (field of view to cover the size
of the negative).

The 55mm lens has a wider coverage to take into account the larger size of
the negative and also magnify the film to the similar projector heitht of
the enlarger.



Gabriel wrote:


Okay - this might sound like a dumb question - the "new" enlarger I just
picked up (1960s vintage Opemus III) has two lenses, with the numbers
4.5/55 and 4.5/75 on them. 4.5 is the maximum aperture, of course, and I
presume the 55 and 75 refer to focal lengths. Why would I want this choice
of lenses, and under what circumstances might I prefer one over the other?


Thanks,

Gabriel

--

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but it includes an annual free trip around the sun.
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