Can you add density to a negative by....

[reggie]

This is a question that only a person with a little imagination and absolutely no knowledge of chemistry can ask. I also watch the SciFi channel. So don't laugh too hard......

Is there a way to add density to a developed and fixed negative using some kind of electro plating. Can you use a small voltage and get some metal (like selenium) to plate proportionally onto the silver in the negative?

Is this essentialy what intensification thru chemical means does?

-R

 

[Dan Henderson]

you can intensify negatives by selenium toning. It works the same way as toning a print adds density, and best of all, is a proportional intensifier, adding more density to the already-darkest areas of the negative, thereby increasing contrast.

 

[GeorgesGiralt]

Reggie,
I once had success doing the following :
Take the not so dense negative, wash it and bleach it using the bleach in a two bath sepia toner.
Re-develop it using PMK at standard PMK regimen. This adds to the silver a nice color. This stain is proportional to the silver which gets developped. So it effectivelly adds to the density of the image.
I've done this process twice to get a maximal stain.
The negs go from barelly printable before the treatment to difficult to print after.
I promised myself to double check time/temperature and film in the spool before proceeding.
Oh, BTW, to plate you must have an electrode. A metal to plate on it. I do not think the plastic film and it's gelatin coating can do the trick.

 

[gainer]

There is, however, a silver intensifier that chemically adds silver to the silver image.
With the bleach-redevelop method you can use any of several redevelopers. The most likely to be on hand is hydroquinone. Its color is not preferred by those who use the dye image for other purposes, being more reddish brown than desired, but it is easy to try. The redeveloper need not be as complicated as the original. The grain size of the silver image will be returned pretty much to the original, so sulfite is not a great requirement, and in fact will reduce the dye density. An alkaline solution of hydroquinone ought to produce results, but you may need a touch of metol and a tiny bit of sodium sulfite. You will have to decide if the results are the ones you want. You will have to use the solution quickly and not expect to keep the used solution for further use.

Give me a while and I will try to be more specific. I need to return to my hideout.

 

[gainer]

The bleach can be a teaspoonful of potassium ferricyanide and a teaspoon of potassium bromide in 500 ml water. You can make it stronger if you are impatient. Bleaching continues to completion at which the film will look much like unexposed film. Redevelopment will also go to completion. You cannot over bleach or overdevelop. Rinse thoroughly between bleach and redevelopment and wash after development. I mean the film, of course. The whole process is done under room light. The bleached film must be exposed anyway, but you can take care of that by developing in room light.

 

[fparnold]

What about just sepia toning? Just curious, but you have to be careful to not overdarken prints when doing it. Would help the archival properties as well.

 

[gainer]

We forgot to mention chromium intensifier. It is a bleach-redevelop process where the bleach is a chromium compound and the developer is any low-sulfite one. There is also a mercury intensifier. Both are hazardous. I doubt you can buy the chrome kit any longer.

 

[Photo Engineer]

OTOH, repeated passes through a Star Gate might work. If it worked, then you might pursuade them from this being their last 10 episodes.

Sorry, I couldn't resist.

PE

 

[Dan Henderson]

you know, of all of the people here, PE would be the one from whom I would expect a scholarly, scientific reply, and the last to post a smart-assed one. Just goes to show you can't judge people by their titles!

Good one, PE.

 

[gainer]

Sometimes we get away from the scholarly scientific community so we can enjoy a little humor once in a while. For 30 years I had to use the third person in technical writing, like: "It was decided that 2.035 grams of anhydrous sodium carbonate should be added to the solution". Now I can say "I decided to throw a little more carbonate in the solution." And most of you know right away that 2.035 grams is just about the weight of a generous pinch. Before, I would have weighed the pinch before I used it.

 

[Photo Engineer]

Patrick;

At my age, I enjoyed watching "Dead Like Me" on SciFi. It was a fun spoof. It is good to say something outrageous or watch something outrageous from time to time. Just for fun.

PE

 

[bdial]

OTOH, repeated passes through a Star Gate might work.

So that would let you go back in time and increase the original exposure?
Sounds very cool.

sorry...

 

[gainer]

Patrick;

At my age, I enjoyed watching "Dead Like Me" on SciFi. It was a fun spoof. It is good to say something outrageous or watch something outrageous from time to time. Just for fun.

PE

When you get to the age I have endured to now you can have even more mental fun but a lot less physical fun. Arthur and his dad blamed itis as they say in these parts has got my joints.

 

[GeorgesGiralt]

"What about just sepia toning? Just curious"
Well, I do not think this will do the trick :
Sepia produce just a different silver product than plain B&W developer. It won't IMHO produce more density than previously available. Bear in mind that on this film, there is only little silver available because the film had been processed and fixed.
PMK like developers will help because during development of the silver salts it ADDS a stain and this stain produce optical densities. So you'll have the previous silver density plus the stain density.
You can let the film sit in the PMK for quite a long time because, as the film had been fixed, you won't be able to over develop. (bear in mind that if you let the PMK stand for too long, oxidation may put undesirable by-products on the film)
Last but not least, you may be able to do a chromium intensifier on the re-treated film to add more density.
Just my 2¢ ;-)

 

[AgX]

electroplating a negative...

Is there a way to add density to a developed and fixed negative using some kind of electro plating. Can you use a small voltage and get some metal (like selenium) to plate proportionally onto the silver in the negative?

That’s an interesting idea. Never thought about it actually.

As you might know in electroplating non-metallic/non-conductive surfaces one technique is to coat an electroconductive lacquer (typically containing graphite) on them. Then this coating is wired as being the cathode (-) in a rather standard galvanic bath.

The suspension of metallic silver in the gelatine of the processed film in a way resembles such a lacquer. IF the conductivity of the processed film would be high enough this could work. It would even have a disproportional effect on the high densities (lights in the negative).
However, what if some conductive islands are situated within a sea of less- or even non-conductive areas?? Even if it would work in principle, it would thus be impractical.

 

[reggie]

Thanks for addressing the topic. I already know about chemical intensification, I was curious about plating metal onto the silver. What I was thinking of wasn't really intensification to change the density range of a negative, but rather taking a piece of processed sheet film and electro-plating one or more metals onto the silver and having the film base pluse the plated metals be the final product, viewable by being lit in various ways.

I was just wondering if was possible to do this plating. If it was, then could different metals be used to layer the platings? Could these metals be of different colors? What would the controlable variables be, etc.

I recall a photographer back in the 80's who exhibited and sold negatives placed inside plexiglass boxes. He placed multiple negatiges inside the box.

I was just thinking of extending that by adding different metals for one-of-a-kind works.

-R

 

[AgX]

Of course, plating differently colored metal layers is no problem in general. In your case one could play with front- and backlighting.
Though, as I put above, electroplating seems impractible. (I am open to learn the contrary. Have you tried it meanwhile?)
Another approach could be to reduce metallic salts without the galvanic process employing the silvergrains as nuclei for such a process thus repruducing the image. (Think of that silver coating one could get inside flasks of used fixer, or the silvering of bulbs.)