using a colour head with black and white

[Victor Samou Wong]

Just wondering if there's a difference between using an chromega D set on 'white' and a dedicated b+W enlarger. Trying to solve a dull contrast problem with AGFA fiber paper.

Cheers

[Juergen Sattler]

Vic, I don;t know anything about the Chromega D, but on my color enlarger I have to dial in filters to get the desired contrast in B&W - I am pretty sure you have to do the same. Check on paper manufacturer's website - they typically give you a starting filtration for the film/paper combo you are using.

[Jeff Graves]

Vic, When you switch the lever to "white" the filter stage is shifted away from the light source effectivly turning it into a dedicated b & w head.

[Wayne]

The color temperaure may still be slightly different between the 2, and this may (I'm guessing) give you slightly different contrast on VC papers with no filtration. The Chromega bulb's color temp is 3400° Kelvin and many dedicated B&W bulbs are in the 3000-3200 K range.

[Colin Robertson]

The issue here may be your light source. In many dedicated black and white enlargers the light passes through a set of condensors before reaching the neg. This tends to produce crisp, contrasty illumination. The ChromegaD will be a diffuser set up. That is, even when set to "white" it provides softer light. I recently started shooting 5x4, and was initialy disappointed at how flat my first prints looked. You'll either need harder paper, or you may want to reassess your development times to produce negs which suit the Chromega/Agfa combinaion.

[ronald moravec]

My Chromega D prints black and white softer than other diffusion machines I own. It is a about 1 1/2 grade softer than a D2 condenser. Other diffusions are 1/2 to 1.

I increase the magenta on VC to compensate. I do not use fixed grade papers so I can`t tell what happens.

Develope the negs 10% longer to make a match for the paper. Add 10% more if that does not work.