Enlarger light source

[BSCG]

I have recently acquired an Durst 670 enlarger (colour head with filters) as i also shoot 6x7. i am having problems with muddy prints, without the ability to dial in any contrast with VC paper :bang:. I have checked all variables except the enlarger light source. What is the correct bulb/light source for this enlarger, could this even be the problem?

Thanks in anticipation.

 

[Chriscrawfordphoto]

Do you mean when you dial in the color correction filters, you still get muddy prints? Are the filters even working? I have never used a durst but on my Beseler colorhead, there is a lever to turn off the filtration so that even with filtration dialed in, you still get plain light. Does yours have something like that? Maybe the filters aren't turned on. Magenta filters will increase contrast, yellow will reduce it on a color enlarger.

 

[BSCG]

Hi, yes there is a switch to engage the filters, however i get muddy prints when the filters are turned on or off, and when i dial in magenta i get the same result. I presume the filters are working because the light source visibly changes colour

Cheers

 

[David William White]

What kind of bulb have you got? Settings can be different for each manufacturer of paper, so best to check before following Ilford settings if you are using Forte paper or something.

I don't know if this helps, but the approx. settings I found for Ilford MGIV on my Saunders/LPL head are:

Grade 1 = 30Y
Grade 2 = 0
Grade 3 = 40M
Grade 4 = 100M

If you have gel sheet filters that you can borrow, it should be easy to match the hue on your head to white light through those sheet filters.

 

[marcr1230]

You might try developing a sheet of paper after leaving it unexposed for a minute ir two on the enlarger base. You might have a light leak or a bad safelight. Lay something on the paper photogram style to detect a problem

 

[BSCG]

I could try Ilford Multigrade filters, instead of the ones fitted.

Cheers

 

[BSCG]

Hmm safe light probs, i will do that thanks.

 

[Al Kaplan]

All the various brands of filters work pretty much the same, all based on the orginal DuPont Varigam paper from the 1950's. Not all brands will give you the exact same contrast but it'll be pretty close. You can freely interchange Kodak, DuPont, Ilford, and the few other brands that appeared over the years.

You either have a light leak or bad safelight fogging your paper or it was stored someplace with too much heat, or (unlikely) a source of radiation.

You should be using a Kodak amber colored OC safelight filter or equivalent. The yellow OA isn't safe with variable contrast papers. Don't even consider using a red one.

 

[Ronald M]

What Al said or you have something wrong in the paper developer.

I assume you mean low contrast and no real black no matter how much exposure you give it. If you can get a pure black no matter what, mix a new batch of paper developer. Fogged paper will make a black given enough exposure, but the whites and perhaps borders will go grey.

 

[Dwig]

What Al said or you have something wrong in the paper developer. ...

Seconded, its most likely the developer or how you are using it. It could also be that you are horribly overexposing the print and yanking it out of the developer early. If you are using a decent negative for your prints, you should get a good print without any filters.

Slide the negative slightly aside and do a test strip from the "clear" film between images. Develop the test strip for 1 1/2 minutes regardless of how light or dark it gets and fix it completely before viewing. Keep repeating the test strips until you find the shortest exposure that gives the maximum black. Now print your test image at that exposure time and develop for the full 1 1/2 minutes. If the print's shadows are significantly too light the negative was overexposed. If shadow detail is lacking its underexposed. If the highlights aren't good then the negative was mis-processed.

BTW, I assume you are actually using a variable contrast paper. The filters don't alter the contrast of all papers, only VC papers (Multigrade, Polycontrast, ...).

 

[BSCG]

Thats right no real black matter.

Thanks Gents for all your comments

 

[Al Kaplan]

Let us know what happens.

 

[BSCG]

Of course I will let you know all ASAP.

Thanks again.

 

[dfoo]

...
You should be using a Kodak amber colored OC safelight filter or equivalent. The yellow OA isn't safe with variable contrast papers. Don't even consider using a red one.

I use a red safe light with Kentmere and Ilford VC papers, and it seems safe to me (I did a safe light test it didn't show any issues).

 

[ddutchison]

In addition to all the good points above...

In addition to all the good points above...

First off, once your eyes have become adapted to the low light levels in the darkroom, you should not use a super bright light to evaluate your fresh prints.

Ideally your prints should be evaluated under close to the same lighting conditions as they will be displayed - once your eyes have re-adapted. Either give your eyes a couple of minutes to get used to the inspection light, or put your inspection light on a dimmer, or both.

Second, "Dry-down". All prints will look brighter and contrastier when wet, and It varies from paper to paper (glossy RC paper is the least effected, matt fiber paper is the most - but all types are effected to some degree). Use a hair-drying gun to dry the surface of your test strips (while your eyes are re-adapting to normal light) before performing any critical evaluation.

 

[sepiareverb]

Leave a sheet of paper with a developing can lid on it out on your easel for ten minutes, leave another in your developing tray for ten minutes before you mix developer with your safelights on.

If you see any trace of the lid on the developed paper you have safelight fog.