Quote Originally Posted by leeturner
Hi

I've finally got a darkroom up and running for the first time in 5 years. In my previous darkroom I had a simple condensor with under the lens MG filters.
I managed to get hold of a couple of Durst Mod70 enlargers with the colour heads plus and old L1000 that I'm fixing up.

Last night I tried printing for the first time with the Mod70. I was under the impression that MG paper printed at a default grade (is it G2?) with no filters. So I tried a print with the colour box switched out and the exposure times were much faster than what I was used to e.g. 4 seconds for an 8x10 from a 6x6 neg. Much too fast for me. I then tried turning the lamp down but still not much luck. I then switched in the filters and adjusted them for a grade 2 and the times dropped to a manageable 9 to 12 seconds. Again I thought that with direct light MG printed at approximately grade 2 so are the filters (using Y and M) also acting as a type of ND filter? It looks as though it's going to take me a while to calibrate the filters to my purpose. Is is worth setting up the other enlarger with below the lens filters and adjusting the colour filtration to match these results or should I just do what I used to do and go with what looks right?
Hi !
First of all, if your color head does not have a density filter built in, you can reduce the lamp output by switching to a less powerfull bulb. There are 250 w, 100 and 75 w bulbs avail. of the same design. Downrating is safe (the other way is not, as the current is much higher and heat also came into play)
If this proves insuficient, you can insert a piece of white translucent Perspex above or under the light mixing box in order to reduce lamp output. It's cheap, and esay to install and to change. Inspect it often because with heat, this material becomes yellow and will change the filtration unexpectedly.
Next, without filter, you've got a quite grade 2 exposure, but the paper's speed if greater (see Ilford fact sheet for your paper). As a filter is put into the light path, it will absorb power so the light reaching the paper will be weaker, provided the filters are not worn out. (be carefull if you open the head for cleaning not to put things like WD40 on them, it will destroy the fine metallic deposit making them filters... Been there, done that...)
And go to Mr Butzi web site (or others) and calibrate your dichro head to get proper grades with your setup. Print a grade/filters conversion table and you will have a speed matched head perfect for printing. You can calibrate it for every paper you use, different manufacturers have different "grade" meaning...
Last but not least, consider printing with plain under the lens filters. If your enlarger head is not sturdy and stable, moving from one filter setting to another (say for burning in) during a print session will move the head and ruin the current print. It is much easier to change a filter in a filter holder than to ensure your head doesn't move during dial in. If your lens has a front filter thread, you can put a Cokin or Lee filter holder on it and use this as a filter holder for Kodak, Fuji or Ilford filters. Buy the under the lens type or the Agfa ones. They are made to go above or under the lens.