Luminous Landscape Forum

Equipment & Techniques => The Wet Darkroom => Topic started by: Czornyj on February 26, 2010, 12:53:25 pm

Title: Problem with Durst AC800 and B&W multigrade papers
Post by: Czornyj on February 26, 2010, 12:53:25 pm

I recently bought Durst AC800 enlarger - it's perfect for color negatives, but when working with B&W it can only be calibrated for medium gradation, and I can't find the way to use color filters while exposureing multigrade papers (in B&W mode only density channel can be corrected). Does anyone know some workaround of that issue?

Title: Problem with Durst AC800 and B&W multigrade papers
Post by: JeanMichel on February 28, 2010, 02:34:35 pm

Hi,

Ideally you would use actual multicontrast filters, but you can use the enlarger's colour filters to control the contrast.
Here is the information that Ilford provided some years ago.
For Durst Colour Heads:

Contrast 0 use 110Y
1/2 use 90Y
1 use 70Y
1 1/2 use 30Y
2 use no filtration
2 1/2 use 30M
3 use 45M
3 1/2 use 55M
4 use 95M
4 1/2 use 130M
5 apparently that contrast is not available using a Durst head; for an Omega head they recommend 150M

I Hope that this helps you.

Jean-Michel

Title: Problem with Durst AC800 and B&W multigrade papers
Post by: Czornyj on March 02, 2010, 06:26:39 pm

Quote from: JeanMichel

Hi,

Ideally you would use actual multicontrast filters, but you can use the enlarger's colour filters to control the contrast.
Here is the information that Ilford provided some years ago.
For Durst Colour Heads:

Contrast 0 use 110Y
1/2 use 90Y
1 use 70Y
1 1/2 use 30Y
2 use no filtration
2 1/2 use 30M
3 use 45M
3 1/2 use 55M
4 use 95M
4 1/2 use 130M
5 apparently that contrast is not available using a Durst head; for an Omega head they recommend 150M

I Hope that this helps you.

Jean-Michel

Thanks!
The problem is more prosaic - the enlarger is so smart and computerised, that I can't figure out how to set color filtration for B&W exposures at all

Title: Problem with Durst AC800 and B&W multigrade papers
Post by: Eric Myrvaagnes on March 03, 2010, 08:18:19 am

Quote from: Czornyj

Thanks!
The problem is more prosaic - the enlarger is so smart and computerised, that I can't figure out how to set color filtration for B&W exposures at all

How do you set it for color printing? Can't you specify Y and M filter values? The enlarger doesn't need to know that you are printing B&W.


I never used a big Durst, so a description of what settings are available might help.

Eric

Title: Problem with Durst AC800 and B&W multigrade papers
Post by: Paul Eby on May 14, 2010, 08:38:18 am

Quote from: Czornyj

I recently bought Durst AC800 enlarger - it's perfect for color negatives, but when working with B&W it can only be calibrated for medium gradation, and I can't find the way to use color filters while exposureing multigrade papers (in B&W mode only density channel can be corrected). Does anyone know some workaround of that issue?

Have you tried sandwiching an unexposed (developed) strip of colour film with the b&w neg then print in colour mode? We used to do this back in the day of film 1hr. print processors.  - Paul