non-contact platinum print?

[bob_bobene]

I hope this question makes sense - are there any ways of printing platinum/palladium via normal enlargement from

a "small" negative? I.e. synthesizing the emulsion for visible light, or something...

 

Thanks

b

[leicaglow]

Yes. It is because the process is not a "chemical" one, but rather a "mechanical" one. Snoop around a great site on processes at alternativephotography.com.

[leicaglow]

One thing that I might have mentioned: if the issue for you is that you don't have a large format camera, there are processes from both analog and digital images that can create a negative for you of any size you need.

[richard_ilomaki7]

The easiest "Normal" way, and I assume you mean wet chemistry, is to make an enlarged film positive onto the film size you want your

finished print to be, then contact print that positive onto the same size film again, then make a platinum contact print. There is no way to

make a platinum print directly from any enlarging process, at least that anyone has tried and found practical. The iron salt -ferrous

oxalate- that is the actual light sensitive chemical requires much much more exposure than silver does, and UV to boot!.

 

I did the interpositive with one print and it took me 2 full evenings and about $20 worth of 8x10 film in exposure and development trials.

The finished print is beautiful and the effort was justified, as it is my favourite image of my younger daughter when she was 13.

 

I also scanned a 35 mm negative into Photoshop, then had a service bureau make a neg, then contact printed it onto Pt/Pd coated

paper. A third way is to get a 35 mm or MF colour slide, then enlarge it onto B&W large format film and then make another contact print.

 

These days the easiest way is via scanning a neg, or an original digital image, then making a negative on a good inkjet printer, as

described by Dan Burkholder in his books.

 

It is still a lot of work, unless of course you go large format- usually 5x7 or larger. I have also made a few miniature contact prints from

MF negs. That btw, was why I entered the whole LF field.

 

Cheers

[jack_welsh]

Bob, the most important point is that the processes such as Platinum must be contact printed. I did an Argryotype

on a rainy day and I had to expose the neg for 30 minutes. to an hour. My James Reilly book said that in the old

days to expose an Albumen or salted paper. It was not unheard of to take several days on occasion and that's with

silver. When I did the carbon, salted paper, 30 years ago. I could take Kodak duplicating film. From a MF neg

enlarge it, and go straight to an 8x10 neg. My 4x5 isn't bad, But, I do want a 5x7!

[frank_menesdorfer]

No, the exposure time would be tooooooo long. The old processes require contact printing metods. You must find

your way as others stated here above to a duplicate, either mechanical "analogue" or digital. Just imagine what it

could take if you print with Gum? If it's possible, I have never even thought of try it. :-) The process require

overprinting at least four times to get something out of it.

God luck to you!

[frank_menesdorfer]

The other problem is which I forgot about is the old processes need a lots of ultra violett lighting which is not coming from out your enlarger that much also even with contact is good to have a special glass over the neg which is not blocking much of that UV light

[bob_bobene]

Thanks to all for your responses. The question was rather ill-posed but I think I've got the answers. The situation is - I want to make a Pt print from a 35mm negative, but I do not have a UV booth, can't do it on the sun, and the print should be larger then would be practical to do by contact - even if I produce one digitally... So I thought maybe there's a way to modify the chemistry so as to make the process sensitive to non-UV light and expose the thing ion the enlarger, but perhaps I want too much:)

 

thanks to all

[frank_menesdorfer]

Bob, UV it's not a problem, here in Sweden you see those sun bulbs in every corner in those junk shops practicaly

cost nothing. I think they called sylvania and are over 200 Watts, that would be good to print with as it's a copy of

the sun :-) You need about 20 minutes to expose maybe shorter it deepens how far you have the lamp from your set

up. You just need to wait a couple of minutes before you print so it's get a full effect. Better light faster printing like if

you get a carbon light than you down half of that time. Yes you can print under the sun too, carry out your set up in

a black plastic bag.

 

About the chemistry. If it were possible it had been done for a long time ago.

[frank_menesdorfer]

Hey, now you can all shut me with the gun as I've got the worlds craziest idea here. What if somebody modify an enlarger put in a carbon arc light and make the head ventilated with the fan? The condensor lenses and the lens will block some UV light thats for sure but?????? Now I sense all the guns pointed at me :-)

Does anyone did try this before? I think this is more like a question to Michael.

[richard_ilomaki7]

Frank

 

Not only does the glass block a lot of UV but ordinary film does as well. I tried making the same print using film and Mylar, both same size contacts. The film took 4.5 minutes exposure 2 inches under my custom built UV source, where the Mylar took 35 seconds exposure. Extend that time difference to the distance for a 10x or more enlargement and you see how long it would be.

 

If you constructed an arc souce with fan, using non-UV-opaque glass for the lens and stabilized it for vibration and heat effects on the neg, it would cost you about $thousands and thousands and thousands.

 

The answer is still "no".

[frank_menesdorfer]

Yeah, I think that I can imagine that one complete gum would take me a 400 years to comlete. :-)

So how many black tubes you got under that custom built box?

[richard_ilomaki7]

Frank

 

I have 6, 18 inch tubes, with 1 inch between each.

[jack_welsh]

Bob, you don't have to expose in the sun. It can be done in the shade, etc.

[frank_menesdorfer]

Richard

 

The block of UV by the film is new for me never heard it of before. Does the base fog cause the problem or the the base or both of tham? Probobly both.