Durst L184 - Making a Grey Print

[Kimberly Anderson]

I'm preparing to make some 12x20 contact prints using the Durst L184 as my light source. I've got the Lacon 380 condensers in the correct orientation and using a 300mm lens. I've gotten the light bulb (500w) as centered as I can get it and it is in the location that gives it the softest focus (i.e. most diffusion).

When I raise the head and lower the baseboard down to where I want to make my contact print, I am seeing a light difference of nearly 1EV from the center of the light patch to the corners. It is quite uniform in all corners. I am measuring with a Sekonic incident meter at the baseboard. The center measures 3.1 and the corners measure 2.3.

Any thoughts? Suggestions? I can do a burn easy enough, but of course I want a completely perfectly absolutely uniformly wonderfuly heavenly lightsource.

[bob carnie]

Hi Kimberly

If you are doing contacts You could put diffusion material in the negative carrier , basically contour mapping to balance out the light source.... This is exactly how large contact printing houses for head shots did it.

I would put mylar top and bottom and once you find the levels match make sure the tissue stays in place ... I could suggest some clear double sided tape.

You have to make sure your neg stage is out of focus and make sure you record your enlarger positions... height bellow draws ext... Using a stopped down lens is not a great Idea if your power is too much ,, try either raising the head
or using ND filters if this happens..

Have fun
contour mapping is spelled out in The Darkroom by lustrumpress.- this is a very old technique that will work well for you.


Others will tell you to make inkjet masks which will work just as well... the tissue is much more cheaper and less trial and error to do.

Bob

[Kimberly Anderson]

Hi Bob,

Thanks for the suggestion. The enlarger *did* come with a 12x12 (actually 11 3/4 x 11 3/4) piece of sandblasted glass that looks much like a view camera ground-glass, but quite a bit rougher. I am *assuming* that it's to be placed in the Filca to give a more diffused light source. I haven't measured light-loss when it's inserted, but from my impression the loss is significant.

Printing times are going to be quite short, so perhaps I ought to insert the diffusion sheet and just see what happens. Oh yes, I did see that you can easily focus on the grain pattern of the diffusion sheet very easily, so that's something to not do I think. ;)

[bob carnie]

Kimberly

Keep out of focus
If this sheet works then bonus.. With the contact process for pt pd we are always use to long exposure.. silver prints should be very fast

If you get very good density across the paper plane then you will be in good shape.

Bob

Hi Bob,

Thanks for the suggestion. The enlarger *did* come with a 12x12 (actually 11 3/4 x 11 3/4) piece of sandblasted glass that looks much like a view camera ground-glass, but quite a bit rougher. I am *assuming* that it's to be placed in the Filca to give a more diffused light source. I haven't measured light-loss when it's inserted, but from my impression the loss is significant.

Printing times are going to be quite short, so perhaps I ought to insert the diffusion sheet and just see what happens. Oh yes, I did see that you can easily focus on the grain pattern of the diffusion sheet very easily, so that's something to not do I think. ;)

[Kimberly Anderson]

Bob,

The prints look great. Thanks for your advice.