PDA

View Full Version : enlarging negatives to 8x10 and larger for contact printing



ryanmills
28-Apr-2014, 11:49
Are there still any negatives that can be use to enlarge 4x5 negatives to 8x10 or larger for contact printing? I have not done it before and I cant seem to find much on google about how but im also not sure exactly what im looking for. I'm starting to debate if trying inkjet printed negs that I have scanned would be easier.

Randy Moe
28-Apr-2014, 12:00
I will be very interested in this thread.

I have already given up on dig negs as simply too finicky and very expensive.

I have a hard time keeping any inkjet printer working. My volume is too low.

ymmv

Erik Larsen
28-Apr-2014, 12:13
You have a couple options available to you depending how involved you want to get. The simplest way is to use a direct duplicating film like http://www.ultrafineonline.com/ulcotodufi.html It is very simple to use but the contrast controls are not great, basically you will get the same contrast that your original has.

If you need to change the contrast, you can reversal process using a lith film like Arista lith film. The reversal process can lower or raise the contrast of the negative depending on your needs. It is a bit more involved and has more testing to arrive at the end result but allows far more control of the final density of the negative. Here's a tutorial
http://unblinkingeye.com/Articles/NbyR/nbyr.html

Both ways work fine IMO and are relatively cheap to experiment with. Give it a try and report back...

BarryS
28-Apr-2014, 12:20
I've been using x-ray duplicating film to make large negs for alt process. It's a reversal film that processes in paper chems--how easy is that? The film I'm using is Fuji MI-DUP, but I think all x-ray duplicating films work the same way. It's exposed like paper, but is less sensitive--so exposures take longer. The variables you control are length of exposure and length of development. It's best to make multiple test strips at different exposures and develop for different times to dial in the process. You only have limited ability to adjust contrast, so if you need a certain DR for an alt process--make sure you have it in the original neg. You can burn and dodge easily during the long exposure--remember that burning makes areas lighter and dodging, darker. It's very reasonably priced, too.

adelorenzo
28-Apr-2014, 12:35
I've been enlarging 645 negatives onto 8x10 Arista Ortho Litho film that I process in HC-110. Then I contact print back onto FP4 to get a copy negative. A bit cumbersome but the results are good.

I really want to try the Fuji duplicating film but getting it in Canada seems nigh impossible.

BarryS
28-Apr-2014, 12:40
I've been enlarging 645 negatives onto 8x10 Arista Ortho Litho film that I process in HC-110. Then I contact print back onto FP4 to get a copy negative. A bit cumbersome but the results are good.

I really want to try the Fuji duplicating film but getting it in Canada seems nigh impossible.

There must be some x-ray supply dealers in Canada, no? I think they all carry duplicating film.

ryanmills
28-Apr-2014, 14:21
You have a couple options available to you depending how involved you want to get. The simplest way is to use a direct duplicating film like http://www.ultrafineonline.com/ulcotodufi.html It is very simple to use but the contrast controls are not great, basically you will get the same contrast that your original has.

If you need to change the contrast, you can reversal process using a lith film like Arista lith film. The reversal process can lower or raise the contrast of the negative depending on your needs. It is a bit more involved and has more testing to arrive at the end result but allows far more control of the final density of the negative. Here's a tutorial
http://unblinkingeye.com/Articles/NbyR/nbyr.html

Both ways work fine IMO and are relatively cheap to experiment with. Give it a try and report back...

Thanks Erik, I had looked at the ultrafine before but forgot about it. So would you just use an enlarger to make the positive then use that positive right back onto another sheet to get the enlarged negative?

Erik Larsen
28-Apr-2014, 14:30
Thanks Erik, I had looked at the ultrafine before but forgot about it. So would you just use an enlarger to make the positive then use that positive right back onto another sheet to get the enlarged negative?

It's a positive process, so just stick your original negative in your enlarger and enlarge it to whatever size you want onto the duplicating film and it will duplicate your negative - you end up with a duplicate of the original in one step.

ryanmills
28-Apr-2014, 14:35
It's a positive process, so just stick your original negative in your enlarger and enlarge it to whatever size you want onto the duplicating film and it will duplicate your negative - you end up with a duplicate of the original in one step.

Oh perfect, will have to give it a try. I have a color head enlarger but its a bit yellowed. Does not effect anything for b/w since I always have to add a little contrast. Do you know if that would give me an issues with dup film though?

Erik Larsen
28-Apr-2014, 14:44
Oh perfect, will have to give it a try. I have a color head enlarger but its a bit yellowed. Does not effect anything for b/w since I always have to add a little contrast. Do you know if that would give me an issues with dup film though?

No problem I can see unless it's in the red color range as the film isn't sensitize to to red light. You need to give it a long exposure-I think my exposures are around 10 minutes and I'm using a 1000 watt enlarger, it is sloooowww film.

Randy Moe
28-Apr-2014, 14:49
I just looked at some X-Ray dup film and ZZ Medical warns Kodak is UV sensitive only, but Fuji does not specify.

Drew Wiley
28-Apr-2014, 15:11
I prefer the double-negative technique with ordinary FP4. You make a slightly soft full-scale interpositive first, preferably enlarged, then contact print the new neg
to working contrast.

BetterSense
28-Apr-2014, 18:55
I prefer the double-negative technique with ordinary FP4. You make a slightly soft full-scale interpositive first, preferably enlarged, then contact print the new neg
to working contrast.

Why slightly soft? How do you achieve the softness, focus?

bob carnie
29-Apr-2014, 05:24
I think Drew means low contrast, so that when you go to the enlarged neg one does not lose too much at both ends.



Why slightly soft? How do you achieve the softness, focus?

bob carnie
29-Apr-2014, 05:26
When I was making negs traditionally I would make a contact or enlargement on scala and process it at Toronto Image works using their Scala Process.
this cancelled a step and with some trial and error worked flawlessly.

andreios
29-Apr-2014, 05:34
Wolfgang Moersch has a nice description of the process using Wephota FO5 film: http://www.moersch-photochemie.de/files/articles/FO5%20Reversal%20development.pdf