135 mm or 150 mm Schneider enlarging lens 4 x5 ?

To All:

Have seen varying degrees of opinion first, if millimeter size of lens between
135 mm or 150 mm enlarging lens have any distinct advantage/disadvantage over
one another for printing 20 x 24 in B & W printing?

Second, any distinct advantage/disadvantage to go 135 mm or 150 mm in choice of
Schneider Componon-S or Schneider APO-Componon-HM in B & W 20 x 24 printing?

Thanks ahead to all

Jack Eyler

Depends on *what* you are printing ... or are we just to

a
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that you are talking about enlarging 4" x 5" sheet film?





"EXPRODUCER" wrote in message
...
To All:

Have seen varying degrees of opinion first, if millimeter size of lens between
135 mm or 150 mm enlarging lens have any distinct advantage/disadvantage over
one another for printing 20 x 24 in B & W printing?

Second, any distinct advantage/disadvantage to go 135 mm or 150 mm in choice of
Schneider Componon-S or Schneider APO-Componon-HM in B & W 20 x 24 printing?

Thanks ahead to all

Jack Eyler

Have seen varying degrees of opinion first, if millimeter size of lens
between
135 mm or 150 mm enlarging lens have any distinct advantage/disadvantage over
one another for printing 20 x 24 in B & W printing?

Second, any distinct advantage/disadvantage to go 135 mm or 150 mm in choice
of
Schneider Componon-S or Schneider APO-Componon-HM in B & W 20 x 24 printing?




For big enlargements, the longer the lens the better. You'll get better
definition in the corners. So go with the 150mm.

I don't see what an APO lens will do for you if you're enlarging B & W. The
virtue of Apochromatic lenses, as far as I know, is that they bring light from
different colors to a common focus.

So, unles you have evidence that an Apo-Componon has better resolution than a
plain Componon, I wouldn't spend the extra money on one.

Bob G

"Bob G" posted:
"...
I don't see what an APO lens will do for you if you're enlarging B & W. The
virtue of Apochromatic lenses, as far as I know, is that they bring light from
different colors to a common focus.

So, unless you have evidence that an Apo-Componon has better resolution than a
plain Componon, I wouldn't spend the extra money on one.
...."

Does the enlarger use *white* light? You are correct when you posted "The
virtue of Apochromatic lenses, as far as I know, is that they bring light from
different colors to a common focus" ... but NOT correct when you assumed that B&W
negatives would not benefit from the use of an apochromaticaly corrected lens.

UNLESS the enlarger is fitted with some kind of monochromatic filter to allow only a
single color of light to be projected ... an Apo lens **will** be superior.

RSD99 wrote:
"Bob G" posted:
"...
I don't see what an APO lens will do for you if you're enlarging B & W. The
virtue of Apochromatic lenses, as far as I know, is that they bring light from
different colors to a common focus.

So, unless you have evidence that an Apo-Componon has better resolution than a
plain Componon, I wouldn't spend the extra money on one.
..."

Does the enlarger use *white* light? You are correct when you posted "The
virtue of Apochromatic lenses, as far as I know, is that they bring light from
different colors to a common focus" ... but NOT correct when you assumed that B&W
negatives would not benefit from the use of an apochromaticaly corrected lens.

UNLESS the enlarger is fitted with some kind of monochromatic filter to allow only a
single color of light to be projected ... an Apo lens **will** be superior.



Normal black and white paper is fitted with a filter that emphasizes blue
light to the exclusion (partial, I admit) to other colors. In fact, my
focusing gizmo even comes with a deep blue filter (47B or something like
that) so what I see and what the paper sees is pretty much the same. It is
too deep to focus by, so I do not use it.

--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 241939.
/( )\ Shrewsbury, New Jersey http://counter.li.org
^^-^^ 17:30:00 up 14 days, 18:13, 4 users, load average: 4.13, 4.10, 4.06

4 x 5 sheet

EXPRODUCER wrote:
To All:

Have seen varying degrees of opinion first, if millimeter size of lens between
135 mm or 150 mm enlarging lens have any distinct advantage/disadvantage over
one another for printing 20 x 24 in B & W printing?

Second, any distinct advantage/disadvantage to go 135 mm or 150 mm in choice of
Schneider Componon-S or Schneider APO-Componon-HM in B & W 20 x 24 printing?

Thanks ahead to all

Jack Eyler



A shorter focal length lens will allow you to make bigger prints at the
maximum height of the enlarger lens. A longer focal lens will tend to
have more uniform illumination. Also, it is probably harder to maintain
high quality over the field with a shorter focal lens.

(EXPRODUCER) wrote in message ...
To All:

Have seen varying degrees of opinion first, if millimeter size of lens between
135 mm or 150 mm enlarging lens have any distinct advantage/disadvantage over
one another for printing 20 x 24 in B & W printing?

Second, any distinct advantage/disadvantage to go 135 mm or 150 mm in choice of
Schneider Componon-S or Schneider APO-Componon-HM in B & W 20 x 24 printing?

Thanks ahead to all

Jack Eyler

150mm is the "normal" focal length for 4x5. The "normal" FL for a
format is ususlly the diagonal. A 135mm lens is a "wide angle" lens
for enlarging, allowing larger baseboard images for the same enlarger
height, it is mainly advantageous where the column height is limited.
The greatest difference between the two is fall off of
illumination. The narrower the required coverage the less the fall off
will be. If you can make your large prints with the longer lens do so.
In fact, if I had the capability of having a long enough throw I would
use about an 210mm lens for 4x5 because of the improved illumination.
The 135mm will do but you will probably find you mist burn in the
corners. I use a 135mm lens and do this routinely except where I've
had to crop a lot.
For very large prints, and I think 20x24 is getting there, you
might also check the optimum magnification of the lens. Most modern
top of the line enlarging lenses specify the magnification range they
are optimised for. The difference in image quality is not large but a
lens which is optimised at the magnification you will be using will be
able to use larger stops for the same quality. This may be significant
where large prints are made since light at the easel may be marginal.
AFAIK, none of the current crop of "apo" enlarging lenses is a true
apochromat. They are acromats (corrected for two colors) of a very
high degree of correction. Despite the fact that B&W papers are either
blue sensitive (fixed grade) or orthochromatic (variable contrast) the
correction of apo lenses still tends to be better than cheaper lenses.
There is also the issue of visual vs: photographic focus. This is
likely to be closer as the chromatic correction of the lens is
improved.

Richard Knoppow
Los Angeles, CA, USA