Enlarger does 6x9, but condenser unit only 6x6! Advice needed

Emil · Dec 7, 2009

Hello. I have just bought an enlarger for the specific purpose of printing 6x9 negatives. Unfortunately, the condenser lens unit in the enlarger is for 6x6 only. With this unit, the sides of the image fade off rather drastically.

I guess I could look for the correct condenser (The enlarger is an IFF Duogon /S, which I have been able to find nothing about online, so spare parts are hard to come by I think)

But I am more interested to hear if there is a way around this. Could I just remove the condenser lens, or will the image quality suffer terribly? Could I put it on some spacers to bring it closer to the lightbulb, and thereby create a larger column of light?

I will appreciate any help I can get, this project is very dear to me. I have bought this enlarger and set up a darkroom, only for the sake of 24 negatives. These negatives were taken by my father 50 years ago this winter, and the prints I make will be his gift for christmas this year.

Thank you,

Emil

DWThomas · Dec 7, 2009

You might try putting some sort of opal glass in place of the condensers and use it in diffusion mode. (I say this of course, without any idea how this enlarger is set up and constructed.)

ic-racer · Dec 7, 2009

First, make sure you have a 105 lens.

Emil · Dec 7, 2009

Okay, when I remove the condenser lenses, I get the entire image projected onto the baseboard. This is with an 80mm lens. Do I still need a 105 then? DWThomas, I could actually get a piece of glass cut to size, but I'm not sure what you mean by opal. Like the white glass in an opal light bulb? I have no idea where to source that, but maybe white acrylic could work?

Rick A · Dec 7, 2009

Yes, you need a 105mm lens. Your 80mm does not have the coverage for the 6x9cm neg. Whatever lens gives a "normal" view for the format you are using should also be the size lens used for enlarging. examples are: 50mm for 35mm format, 75mm for 6x4.5cm, 80mm for 6x6cm, 90mm for 6x7cm, 105 for 6x9cm, and 135 for 4x5 inch format.

Rick

Andrew Moxom · Dec 7, 2009

Emil, try a 105 mm lens as the 80mm does not have enough coverage for 6x9. The 105mm will allow the lens to be further away from the negative stage where it can provide coverage of the 6x9 neg.

Emil · Dec 7, 2009

I'm pretty sure the 80mm lens i have covers 6x9, i know it shouldn't, but it does. I do not know yet if it is completely sharp in the corners, but it definately covers it. The problem is in the enlarger. It has interchangeable condenser units for 35mm, 6x6 and 6x9, and I only have the one for 6x6. Magnification is not a problem either, since i am printing on 18x24cm paper, and the enlarger goes circa 150cm above the baseboard

Mike1234 · Dec 7, 2009

IIRC, some condenser enlargers have a way to move the condenser up or down to concentrate the light onto smaller or larger areas. This allows shorter exposure times for smaller formats but vignettes on larger ones. Is yours adjustable? It's probably a knob that turns a shaft to raise/lower it. Otherwise, as others stated, try a longer lens.

Rick A · Dec 7, 2009

Is your machine designed to accomodate 6x9cm format? It may only handle 6x6 or 6x7cm formats. If that is the case, then you will need a different machine that will accept the larger negative. Mike1234 is correct in stating the condensers need to be adjusted apart to refocus the light. Your alternative is to remove the condensers and use a piece of opal glass for diffusion. You might like the look of diffusion , as it is slightly softer, and hides dust somewhat.

DWThomas · Dec 7, 2009

Emil said:
... DWThomas, I could actually get a piece of glass cut to size, but I'm not sure what you mean by opal. Like the white glass in an opal light bulb? I have no idea where to source that, but maybe white acrylic could work?

Yes, the diffuse white translucent type. A white acrylic will work as a diffuser, but if there is much heat build-up, it will not be happy for very long.

Even glass with a finely ground surface might work if it is far enough above the negative to avoid the textured surface falling within the depth of field of the enlarger lens focus range.

I'm not sure where one might find opal glass -- perhaps a place that supplies material for stained glass crafts might have something. I'm thinking that years back I've seen that sort of glass occasionally used in lighting fixtures, such as flush ceiling fixtures.

darkosaric · Dec 7, 2009

Just an idea - search for magnifax 3, they can go up to 6x9 and they are very very cheap. I got mine for 20 euros with 105 mm lens.

Emil · Dec 7, 2009

The enlarger is definately made for 6x9, it says so on the front plate. I just checked to see if i could raise the condenser, but there is no clearance because of a huge mirror box just above it. I think my best chance is to find some opal glass and have it cut to size, but i have no idea where to find it. Does anyone have an idea where to look?

MattKing · Dec 7, 2009

Maybe this photonet member could help you:

http://photo.net/photodb/user?user_id=732467

Matt

Mike1234 · Dec 7, 2009

Are you sure the condenser shouldn't be LOWERED?

glbeas · Dec 7, 2009

Emil said:
I'm pretty sure the 80mm lens i have covers 6x9, i know it shouldn't, but it does. I do not know yet if it is completely sharp in the corners, but it definately covers it. The problem is in the enlarger. It has interchangeable condenser units for 35mm, 6x6 and 6x9, and I only have the one for 6x6. Magnification is not a problem either, since i am printing on 18x24cm paper, and the enlarger goes circa 150cm above the baseboard

The coverage in question has to do with the illumination, too short a focal length lens will cause the corners to darken as it is seeing around the edge of the condensor in the way a wide angle lens sees more area in front of you. The 105 hopefully will correct the geometry without changing the condensor.

Maris · Dec 7, 2009

An approach I have used in the past is to make condenser lenses.

Big glass condensers are way too difficult but any lens that converges light should do, even a Fresnel lens. The "whole page magnifiers" I find at my local bargain store for $2 can be cut with scissors to fit an enlarger head. My last lamp-house conversion needed a stack of three Fresnels. The optical quality is terrible but, hey, these are condensers and a sheet of frosted glass smooths out all optical sins before the light gets to the negative. So far, so good. Nothing has melted or caught fire.

Enlarger does 6x9, but condenser unit only 6x6! Advice needed

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