How To Ensure Flatness of Negative in Carrier
Is there a recomended way to ensure flatness of a negative in the carrier? I focus according to the grain focuser - then I move it over abit and the image becomes blury/a tad out-of-focus. I use a top and bottom plate, not glass. What about tape? What kind?
I am into bondage...masking tape is fine. So is electrical tape, transparent tape, blue-masking tape, gaffer's tape, etc. I apply tension in both directions...negs from 35mm to 4x5. Usually tape down one side and then attach the tape to the other side of the neg and pull the neg tight...then do the same with the long ends of the film.
At least with LF landscape, a bad day of photography can still be a good day of exercise.
What enlarger, what kind of head (condenser, color, variable contrast), do you have a glass negative carrier?
And what size film?
If you use tape, make sure you clean off ALL the adhesive. Any left behind if in the wrong place could get onto a negative.
I use goo-gone to remove tape adhesive. But you then have to wash the goo-gone off, so I follow up with 99% rubbing alcohol, then soap and water.
Also if tape is left for too long, it could become heck to remove. I just spent about an hour scraping and cleaning off old masking and gaffer tape from a carrier that I bought on eBay. The carrier is good, the tape I do NOT want.
Glass is the traditional way to ensure a FLAT negative. But then you have 4 additional surfaces to clean and keep free of dust.
Another oldtimer's trick is to pre-warm the negative by turning the enlarger on and allowing the negative to pop. Then you focus and expose.
A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.
~Antoine de Saint-Exupery
Everybody works differently, but I use a double-glass negative carrier with an anti-newton top glass for every enlargement, regardless of negative format. This insures absolutely flat projections. Flat enough that they can be used in a pinch for rough enlarger alignment.
The extra dust-collecting surfaces have never been a problem for me. I store the carriers in ziploc bags until needed, and return them promptly. A simple quick spritz of canned air removes any settled dust particles immediately before insertion into the enlarger. And once inserted, the glass surfaces are totally covered and protected from further dust.
The reward for this small amout of extra effort is corner-to-corner perfectly sharp grain in all enlargements that show grain. And I can't remember the last time I had to spot out a white dust shadow from a print.
[Edit: But before worrying about carriers with tape or glass, you must make certain that your enlarger's negative stage is not out of alignment. If the stage is not perfectly parallel with the surface of your easel, and both of those are not parallel with your enlarging lens stage, you will never be corner-to-corner sharp.]
Last edited by Ken Nadvornick; 03-18-2013 at 09:14 PM. Click to view previous post history.
Reason: Added [Edit]...
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—'blanksy', December 13, 2013
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Keeping the negative flat
I use a LPL 6700 colour enlarger and this had serious problems with the negative 'popping' when it got warm - usually after careful focussing. I took a leaf out of Leitz's book which they used on their V35 enlarger and that was to place a glass on the top half of the 35mm negative carrier so that it came into contact with the negative and kept it flat.
The glass is from a 35mm slide mount, using anti-newton ring glass and is only .8mm thick. It is held in place with a strip of double sided adhesive tape on one side only. There is not a lot of extra glass around the edges of the negative carrier to spare (Approx 1 mm) so the glass has to be positioned quite accurately. I can now focus the negative, make the print, remove the negative and replace it with another and be sure the focus will remain the same.
Oddly though, when using 6x6 and 645 negatives in the other carrier, the 'popping' problem doesn't seem to exist!
Assuming alignment is perfect, the answer is glass.
I'll check for alignment. Now about the glass. Doesn't it degrade the image? Or is it a benefits outweigh risks?
IF the glass is CLEAN and scratch-free, your images will be just fine.
Yes it is another 4 surfaces to clean and keep clean, but the payoff is a FLAT negative, and one less variable to deal with when printing the "perfect" print.
The tradeoff for glassless is, 4 less surfaces to clean, but the negative can bow or pop.
Either choice has trade-offs and is a compromise in something.
For me, my plan is use glassless as normal practice, but to have a glass carrier to use if and when I want/need to. This lets me use whichever negative carrier that I want/need to, rather than be stuck with one type of negative carrier. Example if I have a particularly troublesome bowed/curved negative, I would just swap from glassless to glass, problem solved. Or if I decide later to just go with glass, I already have it.
BTW glass has another benefit...$ You don't need a lot of different negative carriers for the various size films, you only need the one glass carrier.
DF, if you are worried about glass quality, dust etc, and you are using small format negatives, you can first try using glass only above the negative. This helps a lot vs no glass. The reason is that deformation of the film from heat buildup tends to be in the upward direction, so having glass on top of the negative can help the popping issue a lot.
Originally Posted by DF