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The difference in enlarging lenses



 
 
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  #1  
Old January 28th 04, 08:49 AM
John
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Default The difference in enlarging lenses

Hello,

I recently purchased a Elwood enlarger with a pair of
Wollensak Graphic Raptar lenses. Specifically the enlarger is a late
model, all cast aluminum 5X7 Elwood. While quite large it is also
quite light and I can easily pick up the entire unit and move it
without any disassembly.

Regarding the lenses, the better of the two Graphic Raptars is
7.5 inch/192mm f/4.5 lens which is in very near mint condition. The
161 mm certainly appears to be in excellent condition as well but
there are a couple of cleaning marks in the coating.

Here's where my quandary starts.

I also purchased a 180/5.6 Componon-S last year. While it was
used, it's in mint condition and was shipped with all the original
documentation and packaging. I've mounted this lens into a Durst lens
cone which was subsequently mounted to the lensboard for the Elwood
using screws at roughly 120 degree spacing.

I selected a portrait of my son that I had shot on my 5X7
Linhoff using Kodak Tri-X which has a fabulous scale and prints
wonderfully on a G2 Galerie. I made prints from this negative using
the unusual 5X7 cast metal carrier of the Elwood complete with both
upper and lower pieces of glass at the same magnification and using
the same f/11 aperture.

What I see in looking at both of these prints side by side and
with a 6X loupe, is only a slight increase in contrast. That's it.
Shouldn't there be other visible differences between what is
acknowledged to be one of the best lenses available today and a lens
that is generally considered to be mediocre and somewhat antiquated
today ?

Regards,

John S. Douglas, Photographer - http://www.darkroompro.com
Please remove the "_" when replying via email
  #2  
Old January 28th 04, 09:06 AM
Martin Jangowski
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Default The difference in enlarging lenses

John wrote:

What I see in looking at both of these prints side by side and
with a 6X loupe, is only a slight increase in contrast. That's it.
Shouldn't there be other visible differences between what is
acknowledged to be one of the best lenses available today and a lens
that is generally considered to be mediocre and somewhat antiquated
today ?


Your findings are identical to my experiences. I compared a new
Schneider Apo-Componon HM 4/150 with a silver Tessar-type Componar
from the 60's, enlarging a extremely sharp 4x5" negative.

When enlarged to 24x30cm (about 2.5x) you could see _no_
difference, even with a strong loupe. At 40x50cm (rougly
4.5x enlargement) the Apo was better at the edges, with a Peak
grain focuser one can see it has a better flatness of field.

Both lenses were used 2 stops down, the Apo at f8 and the
Componar at f11. The Apo had visibily more contrast,
a little more magenta took care of that (I think it is
a difference of about 10-15 ISO-R or 1/2 grade).

I think that even old LF-enlarging lenses are good enough.
The real differences show with smaller formats, but even
then you have to go pretty low to see big differences.
A test with a 2.8/50 Apo-Rodagon, a 2.8/50 Componon-S,
a 4.5/50 Focotar and a 4/60 Rodagon shows that it's only
possible to identify the Focotar because it hat some
curvature of field. (24x36 enlarged 10x to 24x36cm, all lenses
stopped down two stops). It is easily seen with the 10x loupe
of the Peak, but more difficult to identify on paper. The
other three show only infinitesimal differences.

A three lens Trinar was easily identified ;-)

Martin
  #3  
Old January 28th 04, 12:24 PM
Bob Salomon
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Default The difference in enlarging lenses

In article ,
Martin Jangowski wrote:

2.8/50 Apo-Rodagon


Or 50mm 2.8 Apo Rodagon-N?

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  #4  
Old January 28th 04, 02:53 PM
Martin Jangowski
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Default The difference in enlarging lenses

Bob Salomon wrote:
In article ,
Martin Jangowski wrote:


2.8/50 Apo-Rodagon


Or 50mm 2.8 Apo Rodagon-N?


No. It was the "old" Apo-Rodagon without suffix. However,
I had both the latest Apo-Rodagon "N" in 2.8/50 and 4/90 on
loan here and compared them to my "old" Apo-Rodagons with
the same focal length. With a carefully aligned enlarger,
no differences visible, tested at 2x, 6x, 10x and 15x enlargement
(90mm) and 4x, 8x, 12x, 20x (50mm). So I decided to keep my old
glass. All my enlarging lenses are used at two f-stops down from
full open.

Ok, I will do a test with the 4.5/90 Apo-Componon HM, it is said
this is the best enlarging lens in this focal length. We'll see...
In the mean time I think the quality of my enlarging lenses
is no real problem.

Martin
  #5  
Old January 28th 04, 03:52 PM
Bob Salomon
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Default The difference in enlarging lenses

In article ,
Martin Jangowski wrote:

Bob Salomon wrote:
In article ,
Martin Jangowski wrote:


2.8/50 Apo-Rodagon


Or 50mm 2.8 Apo Rodagon-N?


No. It was the "old" Apo-Rodagon without suffix. However,
I had both the latest Apo-Rodagon "N" in 2.8/50 and 4/90 on
loan here and compared them to my "old" Apo-Rodagons with
the same focal length. With a carefully aligned enlarger,
no differences visible, tested at 2x, 6x, 10x and 15x enlargement
(90mm) and 4x, 8x, 12x, 20x (50mm). So I decided to keep my old
glass. All my enlarging lenses are used at two f-stops down from
full open.


In a glass negative carrier as the lenses are designed to be used with?

Ok, I will do a test with the 4.5/90 Apo-Componon HM, it is said
this is the best enlarging lens in this focal length.

Who says? You will find as many, or more, saying the same about the 75,
80, 90 and a05mm Apo Rodagon N.

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  #6  
Old January 28th 04, 04:13 PM
jjs
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Default The difference in enlarging lenses

In article ,
Bob Salomon wrote:

[... ]


In a glass negative carrier as the lenses are designed to be used with?


Bob, are you saying that the glass carrier is part of the optical formula?
Does a glass carrier do more than simply keep the negative flat? Tell me
it does so that I have some rationalization for the dust I put up with.
  #7  
Old January 28th 04, 04:38 PM
Nicholas O. Lindan
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Default The difference in enlarging lenses

"jjs" wrote

Does a glass carrier do more than simply keep the negative flat?


Oh, absolutely:

1) Attracts dust: helps keep the rest of your darkroom dust free

2) Creates Newton's rings: Adds color and pattern to your pictures

3) Decreases contrast: Keeps those pesky highlights under control

4) Alters light path: Helps achieve that sought-after 'soft focus' look

5) Shatters when dropped: Maintains full employment in the glass industry


--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
  #9  
Old January 28th 04, 04:42 PM
Bob Salomon
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Default The difference in enlarging lenses

In article t,
"Nicholas O. Lindan" wrote:

1) Attracts dust: helps keep the rest of your darkroom dust free


Film also attracts the dust in your darkroom.

2) Creates Newton's rings: Adds color and pattern to your pictures


Not when AN glass is used

3) Decreases contrast: Keeps those pesky highlights under control


Says who?

4) Alters light path: Helps achieve that sought-after 'soft focus' look


Nope. It is above the lens not below it

5) Shatters when dropped: Maintains full employment in the glass industry


Butterfingers?

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  #10  
Old January 28th 04, 04:58 PM
jjs
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Default The difference in enlarging lenses

In article ,
Bob Salomon wrote:

The glass carrier does 2 things that are critical for optimal results
when enlarging.
1: It holds the film flat over the entire area of the film that is being
printed.
2: It prevents the film from moving during exposure.


Okay, I knew that. I was wondering if there were some magic I had overlooked.

As to dust I don't find it to be a problem with glass as if there is
dust on the glass there would be dust on the film. And I would prefer to
clean glass rather then film.


My darkroom is pretty much stone-age, almost literally. The house is quite
old for this part of the country (1886); stone basement and the house is
small. Dust is problem. It does not help to have a woodworking shop next
to the darkroom door. I'm really 'into' dust management, but that's an
ariticle in itself.
 




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