Better to slide one of the large-sized Multigrade filters on top of the condensers (or other handy place, after the heat-filter but before the neg) maybe? The underlens-filter set use a more rigid material and seem to have a less delicate surface than the tray filters.
I'm using the underlens filters even for a diffusion head now, but only with an MF enlarger and a 90mm lens. In the past, with a De Vere 504 I have used the colour filtration in the head to get round the sheet-filter problem.
EDIT: Then I realised that there is probably no separate, easily accessible area under a cold-light head and above the neg-carrier on a D2. Presumably the bulb is one that gives a sufficient spectrum of light for the filters to do their job so it would be handy to have a way to do it without having to lift the head off every time. Could a self-made drawer be added to the tube that would usually have the condensers inside? - And then use the larger size of Multigrade filters, cut to fit.
Whever I do have to use filters under the lens for projection (other than as a contact printing light
source), I only use the best camera-quality glass filters available. But this is fairly simple because I
do split printing with blue and green, and not variable M vs Y - when I do that, I use a colorhead.
Identical results can be achieved either way.
For the Omega users who may also search this thread in the future, here's the official Omega D-series under-the-lens 3½x3½-inch filter holder (#429-027). (At least as long as this B&H link is good...)
Omega Under-the-Lens Filter Holder with Red Safety Filter for D5-XL and D2 Enlargers
I have a nice used one of these I got from KHBPhotografix for a heck of a lot less than the listed price in the above link. I use it in place of my VCL4500 variable-contrast head when I need something brighter and must revert to a single-tube V54 lamp. Works well for my purposes using the standard Ilford under-the-lens kit.
I have a source for a complete working 500H head, I am tempted...
When I print 4x5 on my 45MXT with the Aristo Cold light, the light source has to be nearly touching the glass carrier to get even illumination. So there is not much room in there to engineer a 6" MG filter drawer..in fact there is none as it is recessed. The other big problem with that is that if you split grade like I do, you are pretty much assured to stir up dust that will land on the glass carrier as you go back and forth swapping filters out.
I am pretty sure the 3x3 under lens filters are just as thin as the 3 1/2 x 3 1/2 and Ilford does state on the box that they can be used under the lens. The filters sit perfectly flat in the Cokin holder, FYI. I also did a test awhile back at 11x14 with my regular Rodagon 150 with and without the filter in front, no difference in overall image sharpness..
Maybe when I print 20 x 24 I will test it again with the new filters and see what comes up. While this is a great craft, there is just not a lot out there for pro level printers in terms of cold light splitgrade, kinda stinks....
If anyone has a viable solution for me to print cold light split grade without putting MG filters under the lens, I am all ears...
Ctein in "Post Exposure" has this to say: "According to my tests, this makes no difference. I set up a high resolution test target with my 55mm Computar lens at optimum aperture and examined the projected aeriel image with no filter under the lens, with modern thin filters under the lens and older cast-plastic filters under the lens. In all cases, I could see a clean 320 lp/mm in the center of the field and more than 280 lp/mm at the corners. I could not convince myself that I saw any degradation in image quality with the filters in place, no matter how hard I looked. As long as your VC filters are not scratched enough to create serious flare, I can see no reason for avoiding below-the-lens filters."
Gotta disagree with my friend Ctein there. And I think I have done at least as much testing relative
to this subject as he has. But one does not need a full range of multicontrast filters. All you need is
tricolor blue and green, provided you have a sufficiently strong light source. Otherwise, actual colorheads for popular 4x5 enlargers are selling for peanuts right now, even entire enlargers equipped with them. That's all you need.
I hear ya, I am not exactly a fan of putting plastic in front of a Apo-N I paid $900 for either, but I am also not a fan of tossing a great closed loop system like my StopClock Vario, sensor and V54 head out the window. Like I said, I will do a test, maybe today even. But I am also very interested in this new setup, it could pretty much solve it instead of juggling filters by hand or in a color head.
Originally Posted by DREW WILEY
I know the color head is an option, but there is a reason why many prefer VC heads or just using the MG filters, we are more the artist type than the number cruncher type and prefer to keep it that way...
OK, quick question about my options:
If I opt for a color head, what would be the best one to get for my 45MX for multi-contrast, splitgrade printing, Beseler / Minolta 45A, Beseler Dichro 45 or 45S and what are the differences?
A dichroic head for split contrast printing? You are going to twist those knobs all the way back and forth twice for each exposure? Even on the systems with buttons, the lamp has to be on to make the change in many cases (though you could put the lens cap on). Maybe I missed something, but didn't you just post that you have been using under the lens filters with no problems and devised a holder for the bigger filters?
Originally Posted by PKM-25
I, however, did the same thing. That is, I devised a large Cokin style under-the-lens filter holder to fit my 300mm lens, then gave that up for a dichroic head. However, the reason had nothing to do with the filters. It was that my coldlight head was uneven.
Well, yeah, the 3.5 x 3.5's are working fine and I would just assume not mess with it, but then I catch flak from Drew Wiley and he makes it sound like I am putting hair gel on my Apo Rodagons....effing maddening man.
Originally Posted by ic-racer
It's easy right now, it works, the light is even, closed loop StopClock Vario works great. I just wish we still had Multigrade / VC heads to buy new or there were enough used in good shape to not fret over it. I think at some point, this is going to bite Ilford in the ass in terms of serious printers looking for serious hardware to use with their fine papers...
These guys, Ilford, Beseler, RH Designs, Modern Enlargerlamps, etc....they might want to get on the same page at some point and carry this all forward a bit better than they are...
I just found this thread in which you give insight, maybe I will give this idea storm a break for a bit and just print...
Is it possible to get hold of some Cokin-P sized rigid optical sheets in 'very yellow' (I suppose 200cc?) and 'very magenta', probably from a movie supplies place? Long ago I was a customer of SRB in the UK, but there are certainly more options in the US. There is nothing magic about the manufacturer's filter material after all. These higher quality filters would be flatter, easier to clean, optically much better and be more robust in use than the gel multigrade filters, and should work fine for split-contrast printing. You could even buy a third one which might look like Grade-3, or so, to simplify the 'average' print.