Yet another one on contact printing.greenspun.com : LUSENET : Large format photography : One Thread
OK, so I've read everything in these archives about contact printing. With the amount of humidity our air here contains, nothing has worked in my battle against rings. The rings in question form between paper and 8x10 negative when sandwiched in a Great Basin wood, split-backed frame. I like the enlarging papers I'm now using and don't want to print on Azo. Switched from TMY to HP-5 Plus for the Ilford film's less-smooth emulsion. That helped, but was fully successful only on the dryest of our days. My next step will be to replace the old, deteriorated foam on my Patterson Proof Printer with a new sheet purchased from Saunders' parts department. If that results in sufficient and even enough pressure, maybe the problem will go away, but I'm not counting on it.
Some in the past have suggested sponge rubber pads to insure even pressure. Can anyone identify a specific type and source? Also, mention has been made of vacuum frames as the ultimate solution. Condit is often cited as a manufacturer of those. A Web search turns up no Condit presence; the only frames offered by others are huge and hugely expensive. Can anyone provide a URL/address/phone number for Condit, or a lead to any vacuum frame manufacturer that builds an effective product sized (i.e. around 11x14) and priced for the application we're all interested in?
Thanks in advance for your help.
-- Sal Santamaura (email@example.com), June 13, 2000
From the sounds of it you might benefit from using anti newton ring glass in the contact printer.
-- Dan Smith (firstname.lastname@example.org), June 13, 2000.
Yes, you can find it at www.stephenshuart.com.
-- David Goldfarb (email@example.com), June 13, 2000.
Thanks, guys, but I'm trying to cure rings generated between the paper and film emulsions, not between the polyester negative base and the glass.
-- Sal Santamaura (firstname.lastname@example.org), June 13, 2000.
Sal: Go by your local office supply store and get a rubber pad that is made for typewriters to sit on. They are about the thickness of a mouse pad on your computer, only larger. I use one for contacts by sandwiching the neg and paper between the pad and a sheet of 1/4 in. glass. I have never had a problem with rings with either TRI-X or HP- 5 Plus. If memory serves me correctly, the rings form due to a minute seperation between the neg and glass. It could be that your frame is holding the neg sandwich too tight and causing warpage, or it may be too loose. Hope this helps.
-- Doug Paramore (email@example.com), June 13, 2000.
You might check some offset printers and screen printers in your area. Sometimes these shops have an old vacuum frame they don't use anymore since computers have made a lot of darkrooms obsolete.
-- Don Sparks (Harleyman7@aol.com), June 13, 2000.
I replaced the foam rubber on my Patterson with a piece cut from a soft cast for someone's right thigh. I got it from a yardsale. Have you tried different paper surfaces/finishes? In other words, I'd imagine glossy is more prone to Newton's rings than Pearl which may be more prone than matte.
Azo glossy is, well, considerably less glossy than any glossy R.C. The only time I got Newton's was with Ilford glossy R.C. NOT with their Pearl finish when I had to make 75+ prints of a group photograph.
I would imagine some of the more industrious forum denizens have made their own vacuum frames. Maybe you could try the same? I know I have seen articles about them in the past in older amatuer photo mags. I may have a clippin in my files? Interested?
-- Sean yates (firstname.lastname@example.org), June 13, 2000.
Not to be a smart aleck but have you tried a de-humidifier?
-- David N. VanMeter (email@example.com), June 14, 2000.
This doesn't solve the problem Sal has, but is otherwise related to this thread. You can't use an anti newton glass for contact printing, the pattern of the glass will be printed too. It may not be visible with all paper surfaces, but invalidates contact printed films. I haven't found any solution for avoiding newton rings when making contact dupes with larger (4x5 and more) films.
-- Jan Eerala (firstname.lastname@example.org), June 14, 2000.
Doug: There was an earlier thread in which someone, probably you, suggested a typewriter pad. I admit not having gone to an office supply store to check, thinking that typwriters are extinct now and such pads would no longer be available. To assume is foolish; I'll visit Staples, Office Depot, etc. By the way, these rings are definitely between the negative and paper emulsions, not negative base support and the glass. When those latter rings occur, they are almost invisible in the print, having been diffused by 7 mils of polyester.
Don: Thanks for that idea. Would frames from offset and screen printers typically be small enough to fit in my (temporarily) converted bathroom darkroom?
Sean: I've been using only fiber-based glossy papers, including Seagull G, Brilliant Bromide II, Polymax Fine Art and, as a most recent attempt, since its surface seemed not quite as glossy as the others, Ilford MG IV FB. Never any RC. I don't like matte surfaces on aesthetic grounds. Thanks, I would be interested in anything in your clipping file about making vacuum frames.
David: Not a smart aleck question at all. Good point. If these other approaches don't succeed I will investigate smaller dehumidifiers.
-- Sal Santamaura (email@example.com), June 14, 2000.
A typewriter pad update. They no longer exist. Neither the office supply chains nor a local store have any in stock, and the small shop said "they've been out of the catalogs for a number of years." Mouse pads may be a usable substitute, but so far all seem to be 8" x 9 1/2". The search goes on.
-- Sal Santamaura (firstname.lastname@example.org), June 14, 2000.
I just use a piece of double weight glass, the neg, and a piece of paper. I don't use any type of pad at all. And I don't think that I've ever gotten Newton's rings with this type of setup.
-- David Grandy (email@example.com), June 14, 2000.
Sal, I use a 20"x24" vacuum frame in my own screen printing business for contacting ortho positives. I'm sure there are a lot of printers that have these laying around collecting dust. I'm not sure if you can find one smaller than 20x24.
-- Don Sparks (Harleyman7@aol.com), June 14, 2000.
I'm not sure that Condit is still in business but their telephone number is/was (203) 426-4119 and their e mail address is/was ELCondit@Juno.com. I have several of their products, including a pin registration contact printing frame that has never produced Newton rings. Their stuff is expensive but beautifully made and a pleasure to use. If you can reach them, ask to speak with Ray.
-- Brian Ellis (firstname.lastname@example.org), June 15, 2000.
Here's an update. First, Tiffen/Saunders generously sent replacement foam for the Patterson proofer at no charge. Unfortunately, it failed to result in a system that avoided rings. Then, I ordered a frame and glass from Condit. If anyone needs spare parts for Condit equipment, act now: they're going out of business at the end of August. In my case, the Condit frame also couldn't eliminate rings. I next planned to try thick glass on a slab of foam, holding off the dehumidifier option until last. While picking up something in the local Calumet store, I found a Bogen/Technal Proof Printer on their clearance table. It is apparently a discontinued item. Since the 7/32" glass is only loosely hinged on one end and not clamped under any pressure beyond the force exerted by gravity, it is essentially a nicely finished version of the simple glass-foam idea. Success! This week, during some of our highest humidity of the year, ring-free prints were made. TMY could even be printed on Polymax Fine Art, although light rings did result when attemting those negatives on Seagull's glossier surface. With HP-5+ negatives, both papers worked. Thanks to all for your help and suggstions. If anyone has a similar problem and is not lucky enough to find the discontinued Bogen, I suggest heavy glass and a slab of foam. Doug wins the prize on this one.
-- Sal Santamaura (email@example.com), July 22, 2000.