Xícara de Café Posted March 20, 2020 Share #1 Posted March 20, 2020 (edited) Advertisement (gone after registration) Hello, I'm getting what I assume are newton rings with a Focotar 1c. I've never noticed them before with my prints but i've got them on the last two prints using different negatives. I know the 1c has some sort of attachment to avoid the problem but I don't have one. Is there another solution? I'll paste below a snap of what's happening. Thanks, P.S. I just noticed that the enlarger head was not clamped in to place with the two latches either side. Might that have caused the problem? I guess so, I'll try again..... Edit 2. No it wasn't the problem. But at least I now know what I'm looking for and can see the rings in the projected negative. The negative is a bit curved and the frame is right at the end of the cut. I'll try to massage it back to a straight form.... Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Edited March 20, 2020 by Xícara de Café Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/307646-newton-rings-with-focotar-1c/?do=findComment&comment=3935469'>More sharing options...
Advertisement Posted March 20, 2020 Posted March 20, 2020 Hi Xícara de Café, Take a look here Newton rings with Focotar 1c. I'm sure you'll find what you were looking for!
Xícara de Café Posted March 20, 2020 Author Share #2 Posted March 20, 2020 I can resolve the problem by releasing the clamping mechanism a bit. Is that what one's meant to do with the Focotar when this occurs? Presumably now however the negative won't be as flat as it was when fully clamped down. Link to post Share on other sites More sharing options...
Michiel Fokkema Posted March 20, 2020 Share #3 Posted March 20, 2020 You need the AN glass that fits on the condensor that lies on the negative. Quiet rare though and therefore quiet expensive. Link to post Share on other sites More sharing options...
Xícara de Café Posted March 20, 2020 Author Share #4 Posted March 20, 2020 1 minute ago, Michiel Fokkema said: You need the AN glass that fits on the condensor that lies on the negative. Quiet rare though and therefore quiet expensive. Thanks, but in lieu of the AN glass, is easing the pressure on the clamp the only solution? Link to post Share on other sites More sharing options...
Tmx Posted March 20, 2020 Share #5 Posted March 20, 2020 (edited) If you use glass then anti newton glass is the only solution. At least as far as I know Edited March 20, 2020 by Tmx Link to post Share on other sites More sharing options...
gbealnz Posted March 21, 2020 Share #6 Posted March 21, 2020 They occur at the negative area, and happen when two surfaces are in close contact. An option is to slightly shim one side, so the two areas form a very fine "wedge". NOT a huge amount, so you lose flatness of the neg, but enough to shake the issue. Given you can see them while viewing try a few differing pressures, and "wedges", can't hurt. Gary Link to post Share on other sites More sharing options...
Xícara de Café Posted March 21, 2020 Author Share #7 Posted March 21, 2020 Advertisement (gone after registration) Thanks gbealnz. "shim" = shave away? What exactly? I found another thread on another forum about this and some people suggested making a mask to fit between the neg and the condenser. I've made one from a plastic card which slots over the neg holder, and will try. I'll sand it smooth before then! : Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 1 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/307646-newton-rings-with-focotar-1c/?do=findComment&comment=3935774'>More sharing options...
Xícara de Café Posted March 21, 2020 Author Share #8 Posted March 21, 2020 Yes, the mask seems to be working well Link to post Share on other sites More sharing options...
gbealnz Posted March 21, 2020 Share #9 Posted March 21, 2020 NO, not shave away, that would be too drastic for me, LOL. Add a bit of thickness to one side perhaps. Not where the film can touch it, but off to the sides. From your pics, the film appears to sit within a very slight channel. Maybe try a small square of something like masking tape, the square about the size of your fingernail, so not big. Put one on the right hand side (or left, doesn't matter) next to the locating peg. And another near the shiny metal clip. So one on the top right, one on the bottom right, but nothing in the middle, where the film would be. This hopefully should keep the right hand sides slightly apart, and the left hand sides together (as they are at the moment). Hard to describe, and I might be way off track, but try it. Gary 1 Link to post Share on other sites More sharing options...
M.Hilo Posted March 22, 2020 Share #10 Posted March 22, 2020 What you should prevent is the glossy (upper) side of the negative touching the lower glass of the condenser. I use black pvc sheet and make masks. Works fine. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 1 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/307646-newton-rings-with-focotar-1c/?do=findComment&comment=3936951'>More sharing options...
eilert anders Posted April 30, 2020 Share #11 Posted April 30, 2020 Newton rings are usually concentric to the center of the negative. Your observation that the negative is at the end of the strip is probably the cause of the aberrant rings. I had a problem with Newton rings once, and attributed it to the humid conditions in the darkroom and to residual surfactant on the negative left over from washing the negative in the final step of film development with Photo Flow washing aid. I no longer use a washing aid as the final step in washing the negative before hanging to dry. I now wash the negative with two consecutive baths of distilled water before hanging to dry, and I do not strip the water off with a squeegee or other mechanical device. I just hang it to dry, drops and all. The result is no water marks and no surfacant on the film left over from the wahing aid. Since using this procedure, I no longer have a problem with Newton rings. I also noticed mildew on some of my ancient negatives that I washed with photo flow. Another reason not to use it or similar washing aids. Link to post Share on other sites More sharing options...
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