Double condenser modification for Focomat V35
I've been printing with the Focomat V35 the past couple of years and it's great for that classic "lot's of smooth middle tones"-look, ease of use and even illumination. However, I recently began experimenting with a "harder", more grain look and printing that on 12x16 paper. I've been using an old 1c to that end and I really like the quality of light it produces and the shorter times I get compared to the V35. However, it is a bit awkward to print with it because the light falls off about 1 stop towards the edges (I've posted about this but the post has not been approved by the mods yet.)
Anyways, I've learned that the Kienzle offers a double-condenser modification for the V35. The matte diffusor lens on the bottom of the mixing box is replaced with a double condenser system. Has anybody tried this mod? If so, how is the evenness of illumination and how do you like the quality of light it produces?
Your "old 1C", is it the round-without-filterdrawer lamphead version, or the more eg-shaped lamphead?
They take different bulbs.
Do you have a 150 watt bulb, or 75 watt, in your 1C ?
To me you are better off getting the 1C's uneven lighting solved. It is a fantastic enlarger
Around 1987 or so, Leica replaced its diffuser box with a double-condenser version. Enlargers made after this period have the newer box with two condenser/diffusors. I have recently contacted Leica about getting just a diffusor box and it can be had for about $300.
Originally Posted by ~andi
Hilo, I have the grey egg-shaped version of the 1c, no filter drawer, with the long column and the 150W bulb type Philips PF 605. I tried the 75W version Philips PF 603 as well. The 75W version is smaller and has a short neck. It makes little difference in the unevenness (for the overall brightness i prefer the 150W). I tried with and without anti-newton filter and at different magnification factors.
Yes, agree i'd rather have the uneven lighting solved. I wiggled the bloody lamp in virtually all positions and the best i can get is about 1 stop fall-off towards the left/right edges. Top and bottom is little less. Focotar-1, large front element lens. With an El Nikkor 50 it's slightly better from 5.6 up, but not nearly good enough.
How much light fall-off is to be expected with the 1c? Maybe it's just within the norm. I measure about 0.28logD towards the left and right edges, 0.07 towards top and bottom. In the corners I get about 0.31 compared to the center. That's the best I seem able to get.
@Pstake: Thanks for the info. I checked and I already have the new version of the light mixing box. As I understood the Kienzle modification replaces the opal glass condensor with clear ones, thereby converting the V35 in a condenser style enlarger. But I might have misread the description in the catalog.
My V35 (new "Leica" type, not old "Leitz" type) delivers high contrast and even light with sharper grain than most condenser enlargers I've used. Perhaps you simply need to adjust your film exposure/development routine to get the look you want.
As to the Focomat 1C, I have no expertise with them, but I would say that roughly 2/3 of a stop of fall off is to be expected with any condenser system. Both my Beseler 45, and Omega DII, before I put a chromega head on, had falloff of about that degree. Solution: every print on those machines gets a slight vignette burn (almost all of my prints get this anyway, occasionally with an additional edge burn) that becomes an afterthought after a day or two doing it.
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Thanks, I did not realize I have to expect that much fall-off from a condenser system. That scrubs my idea using the Kienzle mod to have both in one machine by a simply switching the mixing chamber.
Doesn't the focal length of the lens have a bigger effect than the fact that it's condenser type?
Originally Posted by Chris Lange
I mean, a longer lens will give more even illumination regardless of whether or not it's condenser, cold head, diffused, etc.
That's a good point...using a longer lens may alleviate a good deal of your problems, provided you're not making large prints. I frequently use an 80mm for 35mm enlargements because I hate banging my head my beseler while focusing a 5x7" print.
Andi, you have the right bulb (the 150 W). I use more than one Focomat 1C and indeed it can be difficult to get it even. If someone knows the procedure, I would also love to know. What I do, is turn off the darkroom lights, bring the enlarger up to about 16X20, close the lens and re-position the bulb by bringing it up or down. I generally get it better, but have to admit I don't really know what I am doing. I have a friend who repaired & serviced these enlargers and I will ask him, but it will take a while before I see him.
Originally Posted by ~andi
When I have a negative that really suffers, I switch to the 2C. That one does a total even illumination of the 135 negs . . .
Which reminds me, have you checked that you condensor is placed correctly, and held tight by the black bajonet ring?
Leica still sell the 'updated' mixing box for the V35 as a spare part, I bought one through the Australian distributor only last year:
Leitz V35 Light Mixing Box
Part # 042-823.260-000
This has two condenser lenses giving much better light coverage. The older mixing box had one lens & obvious light fall-off. Only later models of the V35 had this newer box... obviously the problem was recognised at some point. Many older V35's will still have the older mixing box. Although it looks exactly the same as the old mixing box, the new version has a small plastic 'pimple' near the outer lens that is hard to see but can be felt by finger. I see the difference in prints.
Of course, even with the new mixing box, you still have to use the proper Philips 13139 12v 75w bulb.... which are not cheap & becoming harder to find, but I still get surprised at where I manage to find them.
That all said, I have recently decided to go with the new Heiland Splitgrade LED Cold Light System for the V35.... won't have to bother with bulbs or changing (and probably fading) filters anymore
Last edited by gamincurieux; 09-22-2013 at 09:59 AM. Click to view previous post history.