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Platinum Photography

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Re: Platinum Photography

#11

Post by masfuerte »

dietrichepp wrote: post #9
balou23 wrote: post #7

Earlier quoted context omitted.

I did not really understand this point. >The first reason is linked to one of the drawbacks of platinum photography. Although the resulting images are far superior, platinum does not react as quickly to light as silver. This means that you can only make an image using the contact printing technique Wouldn't that just mean you have to wait longer?

> Wouldn't that just mean you have to wait longer? In theory, yes. The actual values may help. I’ve heard exposure times cited around eight minutes. That’s for contact printing using the sun as a source. I don’t know off-hand how much light an enlarger will deposit on paper, but it is a few orders of magnitude less than the sun. For the sake of estimating, let’s say 3 orders of magnitude. This gives an exposure time…

You can buy 50,000 lumen lightbulbs nowadays which, from 1 metre away, are in the same ballpark as the sun.

Re: Platinum Photography

#12

Post by balou23 »

dietrichepp wrote: post #9
balou23 wrote: post #7

Earlier quoted context omitted.

I did not really understand this point. >The first reason is linked to one of the drawbacks of platinum photography. Although the resulting images are far superior, platinum does not react as quickly to light as silver. This means that you can only make an image using the contact printing technique Wouldn't that just mean you have to wait longer?

> Wouldn't that just mean you have to wait longer? In theory, yes. The actual values may help. I’ve heard exposure times cited around eight minutes. That’s for contact printing using the sun as a source. I don’t know off-hand how much light an enlarger will deposit on paper, but it is a few orders of magnitude less than the sun. For the sake of estimating, let’s say 3 orders of magnitude. This gives an exposure time…

Thanks, that explains it.

I guess good thing you can "cheat" nowadays with digital enlarging (in the case where you "just" want to have a long lasting picture. I have pictures of my great great grandparents, I don't trust that any of my digital pictures will last 4 generations)

Re: Platinum Photography

#13

Post by jmwilson »

There are metal replacement toners that replace the silver in a print with either gold or platinum. This way the print can be made normally with an enlarger and silver chemistry to overcome the contact printing limitation. Toning improves the longevity of the print and provides many of the same tonal effects, depending on how long the print sits in the bath. Unfortunately, the chemicals involved are quite toxic. I remember one of the instructors at the Rayko darkroom in San Francisco running a "toning day" and it was very busy with a number of people coming in to tone their work and share the considerable material and hazmat fees for the chemicals.

"unlike silver gelatin prints that hold the chemicals in a layer on top of the paper, platinum photography uses chemicals that are soaked into the paper, so the image lies embedded in its fibers."

Fiber paper for silver prints is also a thing, and easily available from commercial sources. It requires more extensive washing compared to RC (resin coated) paper, and it tends to curl and warp after wetting. To get prints flat after drying, you need a big heated press that looks like a giant panini maker.

Re: Platinum Photography

#14

Post by tambourine_man »

vGPU wrote: post #4

>You can’t take a small negative and project it onto the paper, as you do with an enlarger for silver gelatin prints. Pretty much sums up the point. Using 8x10 or whatever size negatives when film rolls were coming about is a non-starter for the general public. The cost seems very high as the other commenter has mentioned also. From a quick search purchasing a kit will give you a printing cost of ~$15/photo. This imm…

It's possible to print large negatives from digital files. The results are stunning if you manage to get the curve right.

I've done a few times, lots of trial and error and I never could get a curve that worked perfectly on multiple setups or even on multiple shots with the same setup. A bit of tweaking is required for every shot, in my experience.

It's just that the whole thing is slow, expensive and error prone in every step of the way. It's a labor of love and it shows.

Re: Platinum Photography

#15

Post by dietrichepp »

masfuerte wrote: post #11
dietrichepp wrote: post #9

Earlier quoted context omitted.

> Wouldn't that just mean you have to wait longer? In theory, yes. The actual values may help. I’ve heard exposure times cited around eight minutes. That’s for contact printing using the sun as a source. I don’t know off-hand how much light an enlarger will deposit on paper, but it is a few orders of magnitude less than the sun. For the sake of estimating, let’s say 3 orders of magnitude. This gives an exposure time…

You can buy 50,000 lumen lightbulbs nowadays which, from 1 metre away, are in the same ballpark as the sun.

Do they produce enough UV to expose platinotype? Most of the modern lights you see are LEDs that produce mostly visible light.

You can get UV bulbs, but at this point in our scenario we’re modifying enlargers, and the enlarging lens may focus differently in the UV region from the visible region (something you’d have to check and compensate for). Normally you’d focus an enlarger visually, perhaps with a grain focuser—maybe at this point you’d be focusing manually with the grain focuser in the visible region and then making some calculated adjustment for UV. Or you’d be hunting down a lens which was designed to have the same focal length into the relevant part of the UV spectrum.

Re: Platinum Photography

#16

Post by nyrikki »

balou23 wrote: post #7
vGPU wrote: post #4

>You can’t take a small negative and project it onto the paper, as you do with an enlarger for silver gelatin prints. Pretty much sums up the point. Using 8x10 or whatever size negatives when film rolls were coming about is a non-starter for the general public. The cost seems very high as the other commenter has mentioned also. From a quick search purchasing a kit will give you a printing cost of ~$15/photo. This imm…

I did not really understand this point. >The first reason is linked to one of the drawbacks of platinum photography. Although the resulting images are far superior, platinum does not react as quickly to light as silver. This means that you can only make an image using the contact printing technique Wouldn't that just mean you have to wait longer?

Negatives are smaller than you typically want the final images to be, with contact printing you positive images would be the same size as the negative.

Printing for end user consumption almost always involved enlargement.

The cost, inconvenience, and increased light of large format cameras with silver based films made them unpopular too despite the reduction in quality.

Similar to the quality vs convenience tradeoff that results in people using cell phones as cameras.

Re: Platinum Photography

#17

Post by MobiusHorizons »

masfuerte wrote: post #11
dietrichepp wrote: post #9

Earlier quoted context omitted.

> Wouldn't that just mean you have to wait longer? In theory, yes. The actual values may help. I’ve heard exposure times cited around eight minutes. That’s for contact printing using the sun as a source. I don’t know off-hand how much light an enlarger will deposit on paper, but it is a few orders of magnitude less than the sun. For the sake of estimating, let’s say 3 orders of magnitude. This gives an exposure time…

You can buy 50,000 lumen lightbulbs nowadays which, from 1 metre away, are in the same ballpark as the sun.

How hot are they? You don’t want to scorch anything.

Re: Platinum Photography

#18

Post by davidjade »

dietrichepp wrote: post #15
masfuerte wrote: post #11

Earlier quoted context omitted.

You can buy 50,000 lumen lightbulbs nowadays which, from 1 metre away, are in the same ballpark as the sun.

Do they produce enough UV to expose platinotype? Most of the modern lights you see are LEDs that produce mostly visible light. You can get UV bulbs, but at this point in our scenario we’re modifying enlargers, and the enlarging lens may focus differently in the UV region from the visible region (something you’d have to check and compensate for). Normally you’d focus an enlarger visually, perhaps with a grain focuser—…

This is exactly it. Platinum printing requires UV. All of the platinum printing darkroom setups I have seen all had large and powerful UV sources for contact printing.

Re: Platinum Photography

#19

Post by iNerdier »

jmwilson wrote: post #13

There are metal replacement toners that replace the silver in a print with either gold or platinum. This way the print can be made normally with an enlarger and silver chemistry to overcome the contact printing limitation. Toning improves the longevity of the print and provides many of the same tonal effects, depending on how long the print sits in the bath. Unfortunately, the chemicals involved are quite toxic. I re…

Fibre prints are however still a layer on the surface, usually over the top of a baryta (barium sulphite) layer that acts as a white base. Platinum-Palladium prints really are soaked into the fibre of your paper.

Re: Platinum Photography

#20

Post by iNerdier »

balou23 wrote: post #7
vGPU wrote: post #4

>You can’t take a small negative and project it onto the paper, as you do with an enlarger for silver gelatin prints. Pretty much sums up the point. Using 8x10 or whatever size negatives when film rolls were coming about is a non-starter for the general public. The cost seems very high as the other commenter has mentioned also. From a quick search purchasing a kit will give you a printing cost of ~$15/photo. This imm…

I did not really understand this point. >The first reason is linked to one of the drawbacks of platinum photography. Although the resulting images are far superior, platinum does not react as quickly to light as silver. This means that you can only make an image using the contact printing technique Wouldn't that just mean you have to wait longer?

It depends what you mean by longer. One thing not mentioned is that platinum prints expose under ultra violet light, light which doesn’t transmit as well through glass to begin with, coupled with several orders of magnitude less sensitivity than silver emulsions.

Rather than a few seconds you’d be waiting several days for a comparable exposure.

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