Omega D2 filtration question

newcan1 · Mar 14, 2013

I am restoring an Omega D2, having recently acquired the parts to fix it. It has the original condenser head and I also have an Aristo cold light source for it.

I was wondering how useful it would be for printing with variable contrast black and white papers, or even RA4 color papers. The big issue is how to handle filtration. Would using gel filters under the lens significantly impair image quality? I can't think of another way of putting the enlarger to such use, absent finding a mega-jumbo set of the appropriate filters to go above the condenser.

tkamiya · Mar 14, 2013

It has been discussed/argued to death in the past. Consensus and testing by some (but not by me) shows it makes NO difference. I use under-the-filter kit from Ilford with my D2. It's kind of necessity because otherwise, burning with different grade becomes a risky proposition.

I actually bought a large filter kit for above the condenser use but never bothered to use it in the last two years. I keep mine reasonably clean but it's far from spotless. Yet, my 16x20 print comes out pretty good. Obviously, this is not a scientific statement....

One of these days, I'll experiment by scratching the heck out of mine and do a comparison.

newcan1 · Mar 14, 2013

I wonder if color would be a bit of a stretch though, as it may involve using multiple filters at once.

tkamiya · Mar 14, 2013

Dunno that one.... Isn't color filter always placed above the condenser? I mean, I've never seen one placed below the lens.

jbrubaker · Mar 14, 2013

I printed with D2 enlargers for years in a commercial lab. We always used the large (6" x 6" ?) CP filters inside the door above the condenser. Above the condenser there is little concern about scuffing and dust, and the filters do not have to be gelatin, just the cheaper CP filters. If you're going to be doing color at all, invest in the Omega color head, oor in the Minolta additive electronic head. The Besseler color heads are not as good. ---john.

newcan1 · Mar 15, 2013

jbrubaker said:
I If you're going to be doing color at all, invest in the Omega color head, oor in the Minolta additive electronic head. The Besseler color heads are not as good. ---john.

I guess I'm not familiar with what color heads would fit, and how. There is one called an Omega Chromega D -- would that fit? Or does it only fit later models such as the D5?

jbrubaker · Mar 15, 2013

newcan1 said:
I guess I'm not familiar with what color heads would fit, and how. There is one called an Omega Chromega D -- would that fit? Or does it only fit later models such as the D5?

Yes, the Chromega D head will mount on any Omega D chassis. Here's a quick snap of mine on a D2 XL:

http://truepicture.com/d2.jpg

waynecrider · Mar 15, 2013

On one of my D2's I cut out a filter holder by tracing the negative holder on black mat board, taped two sides together and inserted the filter on top the negative holder. Just make sure there's no light leaks. If there is you can wrap the bottom of the condenser against the filter holder with black cloth or a bandana.

newcan1 · Mar 16, 2013

Well I just purchased a Chromega head (used, cheap, allegedly good condition) and hope it arrives soon. But it doesn't have the extender mounting kit. I'm hoping I can "McGyver" something with the existing brackets and longer tubing, otherwise mounting it is going to get expensive.

It seems to me that the filter size for the condenser head is 4-1/2 inches diameter (but probably a 6in square mount). I have an extensive set of color printing filters that are mounted in 4 inch mounts but the filters themselves are only 3-1/2 inches or so. I wonder what would happen if in mounted them to larger mounts. There may be less light at the edges, but the enlarger bulb is itself rather a point source (it's not 4-1/2 in wide itself) and it might not matter, at least for 35mm and MF (6x6 and 6x9, I don't have a 4x5 camera yet). I may give it a try, it would be interesting to see how a color print would look printed with a condenser light source.

Bill Burk · Mar 16, 2013

Sounds like you've solved your filter problem. I didn't get a chance to tell you that you only "need" three filters for color printing. Red Green and Blue separation filters and expose at different times through each one at a time. But there's not a lot of people who practice that technique.

Hopefully you can find the mounting kit or hack one together.

I use an Aristo grid but graded paper, I find the greenish light kind of wacky for Multigrade.

newcan1 · Mar 16, 2013

Yes Bill - I used to have a Unicolor filter wheel with the red, blue and green filters for additive printing, but the filters decayed long ago. I suppose it might be worth replacing them. But I find it easier to make adjustments with subtractive filters.

I'm still intrigued to find out what happens if I mount say a 3-1/2in filter on a 6in card and use the filter drawer. I'm willing to bet it will be just fine at least for 35mm and maybe medium format.

Bill Burk · Mar 16, 2013

Count yourself lucky - I don't have a filter drawer, so have to use under-the-lens filter. But I have no qualms using under-the-lens filters because of what I've heard through the various experts here.

RalphLambrecht · Mar 17, 2013

under-the-lens-filters can be used without hesitation.

newcan1 · Mar 18, 2013

But what if I were to need say three filters simultaneously? What if I were printing color and needed say 40Y+55M and I needed a 40Y and a 50M and a 5M filter? If they were all slightly scratched, would they still not impair image quality if used under the lens?

ac12 · Mar 18, 2013

One filter is OK, but I would say with 3 scratched filters, you are going to get image degradation.
If you use under the lens filters, part of the routine is to take care of the filters, so it does NOT get scratched.

If your enlarger is assembled, you can test it.
Get 3 pieces of filter material and scratch them up. Then print with and without the filters and see what the difference is.

newcan1 · Mar 18, 2013

Good idea; as a practical matter, the filters I have are in good condition and I'd be unlikely ever to need more than two, because in addition to CMY I also have a set of red (Y+M). I was really just trying to find the edges of the issue.

Hopefully my Chromega head will arrive as advertised and the issue will be moot.

Omega D2 filtration question

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