Mimicking an ambrotype/tintype positive with normal film - ??
What got me thinking about this was a very underexposed negative that I took on Ron Mowrey's AZO emulsion; made at the Rochester workshop and coated on melinex film. Not knowing the speed really, I had to guess, and the result was the thinnest neg you can imagine!
But, it exhibited a positive image against a darkground quite well, exactly like an ambrotype or a tintype; which are effectively just underexposed negatives.
Most people are familiar with the phenomenon, particularly with a film like Delta 3200 or something. But I'm wondering if there's some way to really accentuate the effect with normal medium/slow speed films; TXP320, Delta 100, etc.
Are there some kind of "tricks" you can employ in the developer, or do you have to rely on gross underexposure? That latter's not an ideal solution since it might ruin your tonal scale.
I know that collodion folks often, or at least historically, would have had 2 different developing & exposure schemes. 1 to produce a good negative and the other 2 produce a good positive. I wonder if we can gleem anything by comparing two such recipes...
Now imagine if you could get a good "positive" developer in a monobath. Jeez... you might be able to set up shop on a streetcorner and start producing one off positives for folks!, assuming you also found a nice way to mount the film.
Looking forward to your input!
I'd think it would be hard to accentuate the effect. You need a thin image to make an ambrotype/tintype work. If you experimented with any type of film, you probably could make it work. You might try painting the back of the film base black, too.
if you make a glass plate ( dry plate ) using black glass
and then carefully bleach +weak fix the image you might be able to do this.
What about full exposure, and weak development? IDK... just throwing that out there.
I was thinking that you could mount it with the base facing out for protection, and to see it in proper orientation, and then put something dark behind it. Imagine coating emulsion on obsidian!
john, are you talking about taking a full neg and then reducing it?
I'm hoping someone with some collodion expertise might chime in; I'm really curious about the differences between an otherwise identical collodion emulsion, but the 2 different developing procedures.
Unless you use a film with an extremely clear base, I would think viewing the image through the film base would show more base and fog density than you would like. You have some variables here to experiment with - film (or other substrate), exposure, development, developers, bleaching, final mount. You might experiment with liquid print emulsion on black glass or plastic, if you can find a way to make it stick. Transferring an instant film emulsion to a black backing might work. You're just going to have to roll up your sleeves and try it!
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You're right Pete, you can only do so much in your head; gotta get the hands involved.
However, this isn't something I can afford to investigate at present, unless it just happens by happy accidents. You're probably right that the base won't be that pleasing to view through, though ambrotypes are seen through their base, only it's glass.
Who knows, maybe we'll hit on an idea if we gab enough..
Originally Posted by holmburgers
hey holmburgers -
the way the gelatin tintype plate worked is just like you are talking about
the emulsion was painted on a black surface ( blackened tin, black glass )
made the exposure and then bleached it +fixed it.
rockland colloid's process works the same way ...
the clear bits don't bleach at all ( nothing there, so they show the black behind it ) and
the black bits get lighter/bleached ... the mid tones stay around the same.
i am sure if you put some of your azo emulsion on something black you could probably do the something similar ...
without exposing yourself to cyanide
Read the Essay "Dangers in the Dark" on the late Bill Jay's website. There apparently is no reason to use potassium cyanide to fix wet-plate images. Plain old sodium thiosulfate will work, and was available to photographers in the 19th century. Some "authority" said cyanide was superior and everyone jumped on the bandwagon to the detriment of many. A very interesting read with Jay's sense of humor included.
I will note that I do not play with wet-plate chemicals and processes and see no reason to do so. Experienced users of these processes may tell me I'm full of crap, but that's okay. My kids tell me that all the time.
That's why it would be nice to find a safe & easy way to get a similar look.
Uranium or mercury toning/intensification can produce a nice 'postive' negative. Not exactly off-the-shelf chemistry, nor health-friendy though.