My Omega Condensers have scratches - any negatives (hah) with using a diffuser?

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Originally Posted by Bob Salomon

Just get a fine line permanent black marker and fill it in. Grinding it out will change the curve.

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There's your answer; Bob beat me to it. It is standard practice with lens defects just to black them out. The same should apply to condenser lenses. However, I could be wrong... you may see the black just as you see the scratch in your prints. It should be easy to try, though. Use paint or something you can remove easily for the test.

Still, finding replacement condensers shouldn't be all that hard either.

And, I'm curious why you (and others) seem to need a red filter to compose. I compose the image on the back of a scrap sheet of paper in the easel using white light. I compose and focus with the lens wide open, then turn off the light, close down and insert a piece of photo paper into the easel and expose. At no time during exposure do I need to use a red filter... Maybe you're doing something more exotic that I do.

If you really do need your red filter, what's to stop you from just making one to fit into the filter holder you are using with your cold-light head? I assume you are filtering somehow and using VC paper. A piece of rubylith or the like cut to the right size would work just fine.

Best,

Doremus

As an update, went ahead and sprung for another condenser set so we'll see how that goes, though I may still try the permanent marker trick (as well as using the diffuser that came with the cold light) just to see what comes of it.

Couple things in regards to LEDs - to each their own, of course! But I want to highlight a few points I do think are worth discussion. I think LEDs can be the final potential solution (though honestly I do like the look I get with condensers). Thing is, I don't want a fixed delay - I want no delay, and likewise I think not having grade 5, even if I don't use it all the time, is a step backwards.

I could probably be ok with a grade 4 but for split-grading having that 5 can come in handy and likewise while getting it right "in camera" is the goal, sometimes stuff happens. I have a few negatives that were fogged due to a light leak in the camera. They scan in well enough to manipulate but in the darkroom having that #5 has really helped. Granted for at least one of them I'll need to make a copy negative still.... I don't think white LEDs quite get you there but blue-violet LEDs may and in that case one would need likely a grid of R,G, and BV LEDs ("RGB" LEDs may not work here either as the blue isn't blue enough - this is based on what I've read from others trying that out so take this with a big of a grain of salt).

In the case of the delay, that's very solveable and almost a hard requirement for me. I already do test strips with the light on the whole time and just turn on the metronome. But being able to have instant-on is a really great feature of LEDs. They can beat out anything else (incandescent and cold lights) so to me that's a HUGE feature. Solving it requires switching the DC side so timers could be modified perhaps (instead of a relay, wiring up a transitor, e.g.). In the case of something like the Maya Darkroom timer coming out, since it's Arduino-based, could mod it pretty easily (I think he might be working on that). Pretty sure the Intrepid Enlarger uses this principle (DC switching).

All told, I thought about making an LED head for the D2. I had planned on using a circular PCB that fits into the condenser cylinder and uses some diffusion panel. the PCB would need an edge spacer so the LEDs don't sit right on the diffusion panel but I think that could work. There's formulas that can be used to know how many to wire in series vs parallel based on the supply voltage so that's easy enough. Laying out the LEDs nicely was the hard part. I need to crunch the numbers on that to optimize spacing between each LED while keeping in mine the cylindrical nature of things.

The other complexity, as noted above, is a switching solution. Either one that can use an AC supply to switch the DC side or having a timer that just switches the DC supply off/on directly (like the Maya or Intrepid noted above). Then just need to figure out how bright I want the thing (if I didn't want to use PWM dimming or something like that - which itself points out how fast LEDs can turn on and off since PWM dimming is just turning the LEDs off and on really fast).

Otherwise, honestly having used the Cold Light, I don't really mind the ancient incandescent setup on my enlarger :) It works, well, minus these scratches, womp.

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Originally Posted by m00dawg

As an update, went ahead and sprung for another condenser set so we'll see how that goes, though I may still try the permanent marker…

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A new condenser set was a wise move.

If you find one of the new condensers also has scratches (alas), put that one in the top position. It will be further away from the negative and less likely to be in focus. And if you discover both condensers, once again, have scratches, put the worse one on top. (Did you try putting the worse condenser of your old pair on top?) Worth some testing before you reach for the black marker.

Here's hoping your new condenser set is perfect. ;^)

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Originally Posted by Doremus Scudder

And, I'm curious why you (and others) seem to need a red filter to compose. I compose the image on the back of a scrap sheet of paper in the easel using white light. I compose and focus with the lens wide open, then turn off the light, close down and insert a piece of photo paper into the easel and expose. At no time during exposure do I need to use a red filter... Maybe you're doing something more exotic that I do.

Best,

Doremus

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I also compose on a white scrap piece of photo paper (at working aperture though), but once I put in my to be exposed photo paper, I recheck through the red filter if I did not move my printing easel (It's sometimes sticking out over the base board) or if I missed taht I composed with teh non -exposed part of the negative). More importantly I flip in and out the red fiter with complicated dodges and burns (so I know roughly were to hold my hands or cards)

Best,

Cor

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Originally Posted by Heroique

A new condenser set was a wise move.

If you find one of the new condensers also has scratches (alas), put that one in the top position. It will be further away from the negative and less likely to be in focus. And if you discover both condensers, once again, have scratches, put the worse one on top. (Did you try putting the worse condenser of your old pair on top?) ...

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I will confirm this -- I had a bank of D5-XLs that I maintained and I had to sometimes move the condensers around to avoid a scratch on the flat surface from being too close to the negative and would start to come into focus with the negative...a black marker would make it even worse.

Occasionally the students would scratch the bottom of the bottom condenser with the negative carrier...too expensive to replace on our budget!

I have a very old Beseler CB7 which came to me with a hard to research AGFA color head on top of double condensers

The head 'lamp' has a square inch 120 VAC white light 'panel' that runs hot and had a failed internal fan for cooling

The 3 color filters moved in and out by levers, I presume they were NOT modern Dichroic filters

I replaced the fan with a pancake computer fan, but then found a newer and far better CB7 with a Dichroic color head and now use that sometimes, but usually a incandescent double condenser head. I don't make darkroom color prints.

As for LED, you seem up to date, a DC relay is easy, you know that

You may want to research what others have already done with LED placement, manufacturer and color temps, some are posted here, but always hard to find anything here. Check YouTube with on YT search as Google seems to ignore YT...

Are you aware of Heiland https://heilandelectronic.de/led_kaltlicht

swap top to bottom condensors n see if that makes any difference?

I guess I stand corrected about using something opaque to black out the scratches. Since the scratch can come into focus, so can the black mark.

Here's hoping your new condenser set does the job. Maybe you can mix-and-match if you have a good one still in your set.

Just ruminating here about LEDs; I don't see why one couldn't mix some blue LEDs in with the mix in order to get a good grade 5. Test against an incandescent source with a #47 blue filter. Heck, all you really need for B&W printing are blue and green LEDs as long as they match the spectral range of the paper and overlap somewhat in spectral output. Then you could put green on one circuit and blue on another and have a continuously variable contrast control. Finding the right LEDs seems the challenge here.

Another thought: will your D2 accept a regular Chromega color head? If so, that's an elegant solution and a nice way to print VC. Finding one used with a working power supply shouldn't be that hard.

Best,

Doremus

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Originally Posted by Doremus Scudder

I guess I stand corrected about using something opaque to black out the scratches. Since the scratch can come into focus, so can the black mark.

Here's hoping your new condenser set does the job. Maybe you can mix-and-match if you have a good one still in your set.

Just ruminating here about LEDs; I don't see why one couldn't mix some blue LEDs in with the mix in order to get a good grade 5. Test against an incandescent source with a #47 blue filter. Heck, all you really need for B&W printing are blue and green LEDs as long as they match the spectral range of the paper and overlap somewhat in spectral output. Then you could put green on one circuit and blue on another and have a continuously variable contrast control. Finding the right LEDs seems the challenge here.

Another thought: will your D2 accept a regular Chromega color head? If so, that's an elegant solution and a nice way to print VC. Finding one used with a working power supply shouldn't be that hard.

Best,

Doremus

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Agreed on the new set! Here's hoping! Thanks for the help everyone!

Forgot to mention why I like a red filter - I don't need it all the time but it's a nice to have and tend to use it if its there. One place I really need it was when I made a darkroom printed photobook. For doing multiple photos per "page" I had to do masking and composing across multiple negatives for the same paper. I dunno how I would have done that without a red filter.

On the LEDs, yeah really good call on blue! It seems like some white LEDs may be getting better than even a few years ago so there's a chance they might work. Adding a few blue LEDs in the light matrix wouldn't be that hard though. If I went with R, G, and B then, with the help of a controller, I could do my own grades without needing filters (I believe the Interpid enlargers also does this).

For the color head, I look around every now and then but the good ones seem to be rather pricey :/ Seems like it's the best non-LED solution though for most purposes. I'm a little worried I won't have enough room in my tiny darkroom for the power supply, but if I find one for a reasonable price I'll likely grab it up. Would be nice to (when I have a larger space) try my hand at color prints!

Filling scratches can work on a lens, but not for light projection optics... They simply hold back the even cone of light that illuminates the material then projected by the lens... (If you put a black spot anywhere in a condenser set with a Sharpie, grease pencil, or even dust or spots, it would be clearly seen, even if was just projecting white light onto a piece of white paper)... It's just how it is, and you can radically change focus while viewing that paper, and blob will change, but not go away... That's why condensers always have to be perfectly clean...

Steve K