Re: Wet / dry plate photography
Quote:
Originally Posted by
Tin Can
a negative is made by coating glass or clear film with emulsion
you MAY use the same chemistry to now print the negative onto paper or whatever, making a positive
most do use different chemistry for each part of the process
but not necessarily necessary
a dime contact imaged onto a negative will be a clear hole
when the negative is contact printed onto paper it is a black hole
enlargers just make things bigger
Thanks, I got that part. But I am asking about the emulsions and the developers. I am quite familiar with what an enlarger does. Here’s my question - if I put Foma Emulsion (for example) on a glass plate and develop in in HC 110, I will get a negative. Got it. But if I put that same emulsion on a different glass plate, expose it to a negative from an enlarger and develop it in Dektol (for example) will I get a positive print? These are 2 different applications of the same Foma Emulsion. Follow what I’m getting at here? Is it possible for the same Foma emulsion to be used to produce positive & negative images? The part that seems strange to me is that photo paper has an emulsion and film has an emulsion, yet they aren’t the same emulsion, are they? Hopefully that explains my question better, thanks.
Re: Wet / dry plate photography
They can be the same emulsion
I suggest you try it
Re: Wet / dry plate photography
Quote:
Originally Posted by
Tin Can
They can be the same emulsion
I suggest you try it
I am going to. Thanks. It just struck me as odd that the same emulsion can do both. I guess the halides don’t care where the photons are coming from.
Re: Wet / dry plate photography
Never say or write their names!
They hide in Darkness
Just do it, we learn fastest....with less words
Quote:
Originally Posted by
urnem57
I am going to. Thanks. It just struck me as odd that the same emulsion can do both. I guess the halides don’t care where the photons are coming from.
Re: Wet / dry plate photography
Quote:
Originally Posted by
urnem57
This may be a dumb question, but here goes. I am completely new to dry plate/glass plate/tintype/prints made on glass plates photography and don’t completely understand emulsions & developers. Liquid emulsions (Foma, Rollei Black Magic, Liquid Light) can be used to produce both a negative image (exposed with a camera) and/or a positive image (exposed with an enlarger)? Do I understand this correctly with the only difference being the type of developer used (film/paper)? When I buy paper & film, they are not the same emulsions on both surfaces, are they? If it is the case that the same liquid emulsions can produce negative and positive images, how is this possible? I need to understand which emulsion(s?) I need for the following: 1. producing negatives on glass plates exposed with a camera. 2. producing positive prints with an enlarger on glass plates. 3. for tintype images, will any of these emulsions work provided they are put on a black plate and developed with Rockland’s tintype developer?
Thank you and I am looking forward to the education & better understanding before I jump in.
As they say: There are no dumb questions. This one comes up often. Here's the simplest answer I know. With the exception of specialized formulations, all emulsions are "negative" emulsions. The emulsion on a dry plate, or a sheet of film, or a sheet of paper are all negative emulsions. That's why you can make a paper negative from a sheet of enlarging paper. When you expose a piece of paper through a negative (either as a contact print or an enlargement) you get a "positive" because more light gets through the thin areas of the negative (the shadows) than through the thick/dark areas of the negative (the highlights). You've essentially reversed the density values. If you used a positive emulsion (used to called Direct Duplicating Film), you'd just get another negative, rather than a print.
Re: Wet / dry plate photography
Thank you. This explanation allowed me to “get it” Off to Freestyle....
Re: Wet / dry plate photography
There are some very kind people on here. Ask away. That’s one way we learn.