Anyone ever reversal process Rockland emulsion?

[Paul Verizzo]

I have a friend who is a jaw droppingly accomplished photographer. The first time I went to her house, I was swept by a positive glass plate she has hanging on an indirect sunlit window. The subject matter is a woman dressed in 1950's Dior style, shot on a white seamless paper, she just floats in air. My friend stumbled across this and bought it on the cheap, as I recall. It has just enough "distress" to lend a sense of time and authenticity.

I actually think about it from time to time and have pondered about replicating the idea for both artistic and perhaps commercial reasons.

Since a very large format camera is out of the question for many reasons, my thinking is along the lines of enlarging a 35mm or 120 negative onto Rockland emulsion that, in turn, is on acrylic or glass. Then, of course, reversal processed.

Anyone have any experience on this? I'll try to ask them, but I figger I'll go to those who know!

 

[himself]

I've done similar, but I don't think you need to use a reversal process...

If you just coat glass/acrylic with liquid emulsion (I use rollei black magic) and then enlarge a negative on to it with your normal process (as if it was a paper print) - a normal process will give you a positive image anyway.

You'll probably have to consider coating the glass with gelatine or a clear polyurethane varnish, so that your emulsion sticks better.

 

[Paul Verizzo]

Well, gobsmack me feeble brain. I guess I was stuck in a cross breed thinking of large format and enlarging.

Thanks for making me out to be an idiot, ha ha!

 

[removed account4]

the problems i had with varnish / urethane on glass as a sub layer is that it yellows with age
if you can find the bible "silver gelatin" by martin reed &al. it is worth every penny you pay for it.
i got my copy 15 years after i started doing it, and if i had it in the beginning, it would have made things
much easier

good luck !
john

 

[himself]

Well, gobsmack me feeble brain. I guess I was stuck in a cross breed thinking of large format and enlarging.

Thanks for making me out to be an idiot, ha ha!

well, you're completely welcome.

One thing I've also noticed (and this is from contact printing rather than enlarging), is that the emulsion seems to need less exposure than paper would - I have no reason why this might be, but all I can say is that from my experience an 8 second exposure on paper is about 5/6 on emulsion+glass.

 

[himself]

the problems i had with varnish / urethane on glass as a sub layer is that it yellows with age
[...]

John,

I've heard that from a couple of people and it's one of the reasons I switched to gelatine...
too be honest - none of my prints are old enough to have browned yet, so I'm happy to take your word as writ on that

Have you got any old prints with gelatine and how are they holding up if you do?

 

[removed account4]

hi himself

i have some gelatin coated things from the mid 1980s, look as clear and beautiful as
the day they were printed. i also have things that urethane was one of the componants
( when i was doing materials testing i tested everything i could find, and different combinations of everything
from salt to albumen to collodion to rubber cement to glues to urethanes &c and i still have shards of glass
that had urethane on them ) and they have an amber-golden hue to them

i know of a guy here in town who used to paint canvas with urethane and print on them, his clients LOVED the yellowy hue, but its not for me

.. beleive it or not i gave up on a sub layer altogether !

unless the emulsion ( i use old rockland, old meaning 10-15 years expired so the gelatin is sometimes broken down ) i just coat on
the glass, and put it on a cold stone, cold metal / something very cold to chill fast the emulsoin and it sticks to the glass just as well,
if not better than when i used to sub layer it. i didn't believe it when i first read it could be done - i was skeptical because i had done similar, but without the cold
and it developed on the plate absolutely beautifully, but as soon as it went into the fix, the emulsion lifted floated around, broke in to a zillion pieces or went down the drain.
but that is what i do now and it works great with cold... i've coated as big as 8x10 in the last year, no problems with lift or frilling to speak of ...
and i hope to coat bigger pieces to print /expose onto in the months to come ..

its great to read of others who enjoy doing this sort of stuff !
http://thelightfarm.com has a TON of information for people coating "stuff"
with emulsion, whether it is stuff you make yourself ( instructions + recipes for that there too )
or you use pre-made ... its worth the trip

have fun!
john

 

[dwross]

...
One thing I've also noticed (and this is from contact printing rather than enlarging), is that the emulsion seems to need less exposure than paper would - I have no reason why this might be, but all I can say is that from my experience an 8 second exposure on paper is about 5/6 on emulsion+glass.

Some of the light passes through the glass plate and then bounces back and exposes the emulsion again (although essentially instantaneous with the "first" exposure.)

 

[Paul Verizzo]

Some of the light passes through the glass plate and then bounces back and exposes the emulsion again (although essentially instantaneous with the "first" exposure.)

Interesting. Of course, you could lay it on a black surface. OTOH, it is what it is, and comparing it to paper doesn't matter.

 

[removed account4]

hi paul verizzo

himself was refering the the speed increase on glass plates ( without an AH layer )
it had nothing to do with paper, but glass which is what YOU were talking about

 

[himself]

Some of the light passes through the glass plate and then bounces back and exposes the emulsion again (although essentially instantaneous with the "first" exposure.)

that sure would explain it...
but then I've also noticed the same increase in sensitivity when printing on ceramic tiles - do you think this could be the same thing, but rather than because of it being transparent, is because of the high gloss of the tile?

John,

thelightfarm is great, I've spent loads of time reading through it and then through it again!

I'm not so sure about coating just the glass tho', I've never had any luck with it and wasted quite a bit of emulsion - but cold really works?
that's interesting, maybe I should try again.

Interesting. Of course, you could lay it on a black surface. OTOH, it is what it is, and comparing it to paper doesn't matter.

this is true, but it's just something I noticed, and something to take in to account if you plan on doing test prints on paper first, or using exposure times you already have for prints you've made in the past.

 

[dwross]

I've never coated on ceramic tiles. Very interesting about the speed increase there. I could be convinced that gloss plays a role. It doesn't take much light bounce to cause halation on film without anti-halation backing.

Another thought (and strictly a speculation off the top of my head) is that a paper print has less perceived dynamic range so you have to expose it more in order to achieve the density required for deeper blacks (??)

 

[himself]

I've never coated on ceramic tiles. Very interesting about the speed increase there. I could be convinced that gloss plays a role. It doesn't take much light bounce to cause halation on film without anti-halation backing.

Another thought (and strictly a speculation off the top of my head) is that a paper print has less perceived dynamic range so you have to expose it more in order to achieve the density required for deeper blacks (??)

hmm maybe, so then would that mean if coated on paper it would be slower(?)
I have coated it on matt masonry paint and although I was printing different negatives, the exposure times were similar to the tiles (and glass).
so it would seem that halation maybe only part of the reason...

could the thickness of the emulsion have anything to do with it?

 

[dwross]

All things being equal (primarily the light source and the developer) the speed of an emulsion is its speed, regardless what it's coated on. That's set in the making. There could be a perception that it is slower if it doesn't look dense enough. The thickness of the emulsion could definitely come into play, especially if the paper it's coated on is rough. The emulsion on the hills of the texture could be almost non-existent, depending on the coating technique.

Also, mat masonry paint wouldn't necessarily eliminate expose-augmenting light bounce if the paint is light-colored. Extra light needn't cause visible halation to affect the exposure.
Different negatives make it hard to judge exposure times. Negatives can look almost identical, but still require different exposures. That's one of the reasons exposure discussions on forums can go 'round and around. People end up trying to describe different parts of the elephant, and not even know it.

 

[himself]

All things being equal (primarily the light source and the developer) the speed of an emulsion is its speed, regardless what it's coated on. That's set in the making. There could be a perception that it is slower if it doesn't look dense enough. The thickness of the emulsion could definitely come into play, especially if the paper it's coated on is rough. The emulsion on the hills of the texture could be almost non-existent, depending on the coating technique.

Also, mat masonry paint wouldn't necessarily eliminate expose-augmenting light bounce if the paint is light-colored. Extra light needn't cause visible halation to affect the exposure.
Different negatives make it hard to judge exposure times. Negatives can look almost identical, but still require different exposures. That's one of the reasons exposure discussions on forums can go 'round and around. People end up trying to describe different parts of the elephant, and not even know it.

sure its speed is its speed, but I might not have made myself clear by using the term "speed". What I meant was its "perceived" speed (as you say with regards to density) - as in, if it appears to be less sensitive, then it could be said to be less sensitive; in the sense that switching between the two mediums and working with the same negative you would have to take into account this "perceived" difference in sensitivity (its sensitivity being defined by its speed after all) and adjust your exposure accordingly...

so not a different speed, but rather a different speed (speed being shorthand for what I just said).
does that make sense? I'm not sure it does

anyway,

with regards to light-coloured paint, wouldn't light-coloured paper also cause the same problem if that were the case?
but I think you're right about the smoothness of the coating making a difference. Coated perfectly evenly on a smooth surface will definitely make an image look "darker".

oh and by the way, and to bring the thread back to its original question/wider theme...

have you ever tried reversing a glass negative?
I've wanted to try it, but from what I've read, most seem to think that the emulsion when coated on glass is too delicate to survive the process.

 

[dwross]

Yes, you make sense. It comes down to how precise you want to be with vocabulary. We all carry with us a personal vocabulary – the way we think about things. It’s how creative people operate. It prevents being locked into a pre-existing linear paradigm that doesn’t allow new thoughts or invention. Now, does that make sense?

On a forum like APUG, though, it is probably best that we at least share our understanding of a concept – precisely as you did so well with “speed.”

Apologies. Not sure what you mean in reference to the OP. I took it to ask about reversal processing. You answered that one. Are you referring to physically reversing the emulsion? That can be done. Not hard. It’s an "emulsion lift (or transfer)" and the sheet of emulsion can be transferred to any surface. I don’t know if this helps, but it’s what I can offer. http://thelightfarm.com/cgi-bin/htmlsectiongen.py?chapter=DryPlatePhotography2

 

[himself]

Yes, you make sense. It comes down to how precise you want to be with vocabulary. We all carry with us a personal vocabulary – the way we think about things. It’s how creative people operate. It prevents being locked into a pre-existing linear paradigm that doesn’t allow new thoughts or invention. Now, does that make sense?

On a forum like APUG, though, it is probably best that we at least share our understanding of a concept – precisely as you did so well with “speed.”

Apologies. Not sure what you mean in reference to the OP. I took it to ask about reversal processing. You answered that one. Are you referring to physically reversing the emulsion? That can be done. Not hard. It’s an "emulsion lift (or transfer)" and the sheet of emulsion can be transferred to any surface. I don’t know if this helps, but it’s what I can offer. http://thelightfarm.com/cgi-bin/htmlsectiongen.py?chapter=DryPlatePhotography2

yeah, that makes sense, I think... or at least what I understood of it

true, true.

and so within this new spirit of being more clear - I'll try to make myself more understood again
the OP originally asked about using a reversal process on a glass negative, so while he didn't need to do that for what he wants to do,
I'm now wondering if it's possible to do it for what I want to do.

which is - if I were to make a dry plate negative using normal emulsion, would it then be possible to develop this as a positive rather than a negative, like you can with film, or at least most film?

you know; develop, bleach, re-expose, develop, fix.

or, as I have read, would the emulsion be too delicate for such brutal treatment?

 

[urnem57]

What developers does Rollei Black Magic work well with? The data sheet suggests Rollei RPN Developer, but that stuff is difficult/impossible to find in The US. Thanks!

 

[fiddle]

 

[urnem57]

That applies to Foma Emulsion. At least that’s what he used in the video. Do all of these emulsions react the same way? I’m looking for answers from those who have used Rollei Variable Contrast Black Magic. And any info on the uses of Rockland’s 3 part Tintype developer. Will that work with these emulsions on surfaces other than black metal?