making BW neg from color tran with type55?

[vicgin]

Has anyone tried to make a BW neg from a color tranny with their enlarger?
Have a great Velvia 4x5 which would make a wonderful hand tinted print. Want to try exposing a Polaroid type55 negative under an enlarger.
Anyone done it or tried it?
Regards, Herbert

[Glenn Thoreson]

I've never used Polaroid film, but it works very well with others. You may need a lens in a shutter to do this, or a neutral density filter, to get the time slow enough. Just take a meter reading off a neutral gray area of the projected photo, and use that for you starting exposure time. It's not really any harder than taking any other photo. Good luck.

[Mark Sampson]

I think you'll find that the Type 55 will be too contrasty. In the late '70s the lab I worked at used Super-XX to make b/w internegatives from transparencies. Two reasons; it had matched color-response curves, and a very long exposure straight line, which allowed for an increased exposure/lessened development method that captured all the tones from the contrasty transparencies. Of course S-XX is long gone; If I was to try this today I'd probably start with TMX-100.

[Mark Sampson]

Another tip from those days; the green layer of tranny film holds the resolution, so try using a deep green filter, say a Wratten 58 or 98(?) when you make your interneg.

[Gene McCluney]

I think the best way to make a b/w negative from a 4x5 or larger transparency is to do it by contact. Put the original transparency and the b/w film emulsion-to-emulsion sides facing in a contact printing frame and expose to the light of your enlarger, then underprocess by 30% to 50% in your usual b/w film developer.

[Filmnut]

I definitely agree that contact is the best way to go, but there are a few issues.
A print from a well done contact interneg will look much like it could of been done from a camera neg, the projected neg will be softer, and lacks the crispness of a nice LF neg, but also it will depend on what size of print you plan to make as to whether or not you feel that the a contact neg is an advantage or not.
A used to do this a lot commercially before d*****l overwhelmed everything. The problem with a contact, is that it is VERY unforgiving of ANY marks or fine scratches (not to mention dust), even if you cannot see them through the tranny in normal viewing, which then prints black on the final print.
This is a simple technique that I used, in the last few years of my interneg making, and it worked very well.
As mentioned, keep the original and the B&W film in emulsion to emulsion contact with each other, then suspend a diffusion sheet one to two inches above the frame that is holding the film together, which really diffuses out the light, so that any minor imperfections will not show so much. Everything does have to be spotless clean, though it won't hide any dirt that slips in. Some may argue that this can reduce sharpness, which is true, but any reduction in sharpness with this method is only a fraction of the sharpness lost through even the best optical systems.
This technique was the better than any other that I used when doing internegs.
If you have reasonable darkroom skills, you should be able to make a good interneg, although you may have to go through several sheets of film till you get the exposure and processing the way you want it.
Good Luck!
Keith