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View Full Version : What is the point of collodion?



Jerevan
12-09-2010, 12:49 PM
I know that this is really out on the fringe of emulsion making, but why does one use collodion for wet plates? What better (or different) properties does it have compared to gelatin or gum arabic?

Barry S
12-09-2010, 01:37 PM
Collodion has some unique properties that make it well suited as a carrier for silver salts. It's soluble in ether and alcohol--two solvents with low boiling points and high vapor pressures. This allows the collodion to set and dry quickly. Once the collodion is set, it forms a stable permeable layer that can be sensitized, exposed, developed, and fixed. When the collodion dries, it forms a very thin, tough layer--impermeable to aqueous solutions. Collodion is also extremely sticky--it will adhere to just about any surface. Gelatin and gum arabic are soluble in aqueous solutions, so a surface coating will dry much more slowly.

Hexavalent
12-09-2010, 01:46 PM
And collodion smells great!

jnanian
12-09-2010, 02:42 PM
And collodion smells great!

dr hunter s. thompson has spoken :)

dwross
12-09-2010, 10:15 PM
I know that this is really out on the fringe of emulsion making, but why does one use collodion for wet plates? What better (or different) properties does it have compared to gelatin or gum arabic?

Great question, Jerevan!

I seem to remember a story that Dr Maddox, who's credited with discovering gelatin as an emulsion base, was motivated by the smell of ether. He hated it! I've heard of worse motivations for discovery:).

Gelatin dry plates were seen as a real breakthrough in photographic technology. Mostly, at first, it was about convenience. You could make the plates ahead of time, take them into the field and bring them back weeks or months later for processing. I can't even imagine how nice it must have seemed not to have to haul your darkroom every place you went. And, even with your darkroom (wagon or tent) at your elbow, in hot, dry conditions it could still be a challenge to get a plate poured and exposed and developed before the collodion dried and became unusable.

After gelatin came along, it was discovered that silver bromide could be used instead of the silver iodide in the collodion process (And my history goes way soft here. Someone who does wet plate could tell more about the details.) Using gelatin let the silver bromide, which is inherently much more sensitive than silver iodide, be 'ripened' at high temperatures for a long enough period of time that it got even more sensitive, i.e. 'faster' speed. Convenience, combined with better speed, pretty much revolutionized photography, almost literally overnight, especially when commercial manufacturing took over and photographers could buy their materials instead of having to make them on the spot. Of course, that exact artisan characteristic is most of the appeal of wet plate collodion today.

Motto: Never second guess the future, at least as far as historians and artists are concerned!

Photo Engineer
12-09-2010, 10:24 PM
Or, wet plate collodion was used because it worked! It was toxic, flammable and fugitive (in terms of activity) and was quickly abandoned by adherents as soon as dry plate came along. It was never made at higher speed, nor was it made ortho or panchromatic and so it died an honorable death only to linger on by adherents who wanted to sniff ether. ;) JK

PE

Jerevan
12-10-2010, 02:51 AM
"toxic, flammable and fugitive" - in the back of my head I knew there was some hitch. :) Thanks for your answers.

AgX
12-10-2010, 05:53 AM
Gelatin, aside of the feature of yielding storable (before and after exposing) has unique features that are important for crystal growth and sensitivity.

jnanian
12-10-2010, 06:50 AM
aside from being able to be viewed as a singular item
( like a tintype/ambrotype/alumintype/keriktype/schwabtype &C)
collodion negatives can be used to reproduce positives ...
it can be and peeled off the glass substrate and is actually a sheet of celluloid film,
before collodion was identified / re-purposed for a photography the only reproducible negatives came
from the talbotype / calotype ... and even after the "wet plate age" collodion was film's first step
into being a mechanically ( or human ) reproduced positive .. non-safety film, xray film, movie film.
it was only after the fire are the cleveland clinic that safety film was invented
http://www3.gendisasters.com/ohio/2728/cleveland,-oh-clinic-explosion-fire,-may-1929

collodion has a lot of other uses too.
it is used in the record industry to make blanks / lacquer plates ( what first pressings are made from );
it is used in the explosives trade to make "stuff" ( made from guncotton );
fingernail polish; and "new skin"
and it still has medical uses ... and is in things like compound w. and new skin (like a clear bandage)

the whole collodion bandage thing has reminded me about people
self combusting " it happens all the time" ... now it all makes perfect sense :confused:

Kirk Keyes
12-11-2010, 11:23 AM
And collodion smells great!

HMMMMmmmmm....

I love the smell of ether in the morning!

wildbillbugman
12-11-2010, 11:34 AM
nor was it made ortho or panchromatic

PE[/QUOTE]

Although there was quite a bit of research done to make a panchro Collodion. Trere are many references to a "near-panchro" collodion.
Bill

Jerevan
12-12-2010, 12:52 PM
I looked around a bit on the 'net and found a dry emulsion collodion recipe which looked interesting at first but then it came around to the usual "dunk it in some ether" in the end anyway. However it was interesting in the sense that it reminded me of an early version of a silver gelatine emulsion. I wasn't aware that the dry version collodion existed.

dwross
12-13-2010, 09:45 AM
I've often wondered why you don't hear more about dry collodion work. There's a bucket of historical info out there. Carey Lea is a good source, available as a google book. starting on p. 261.

http://books.google.com/books?id=RxK0KRnzuwcC&printsec=frontcover&dq=inauthor:M+inauthor:Carey+inauthor:Lea&hl=en&ei=SDgGTaq4C4q6sQPG4LDfDQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCMQ6AEwAA#v=onepage&q&f=false

It looks like there are some options that don't involve ether (Unless I'm missing something. I understand next-to-nothing about collodion). ex. 'The Coffee Dry Process' on p. 276.

Re collodion color: Wall writes up pages of details in his 'History of Three Color Photography', 1925.

An aside: I love the history of my copy. It was a gift in 1950 from Eastman Kodak Company Research Laboratory to Dr. J. Eggert at the Photographisches Institut in Zurich. Dr Eggert pasted the letter from Kodak on the inside front cover. The only part of me that seems to want to move this morning is my fingers, so I'll type in the body of the letter:)

"Dear Dr. Eggert,
It has recently been brought to our attention by Dr. Spencer that you are desirous of obtaining a copy of Wall's "History of Color Photography", but that you have been unable to obtain one on the Continent. I understand from Dr. Spencer that he also has been unable to find a copy of this book in England.

Upon receipt of Dr. Spencer's letter I inquired of the librarian about the possibility of our having an additional copy of Wall's "History of Photography" which we might send to you. I find here is a copy, and I am very happy to be able to present it to you with the compliments of the Kodak Research Laboratory in the hope that you will find it useful in connection with the work at your Institut.

With kindest personal regards,
Yours sincerely,

(indecipherable signature) "

Jerevan
12-13-2010, 10:11 AM
From my late night reading yesterday on the dry collodion, it seems like a case of "too little, too late". It was too slow compared to the wet plates. A few enthusiasts did a lot of experimenting but the professionals never jumped on that train. I saw that Mark Osterman is going to do a workshop on the dry collodion emulsion paper stuff (Aristotype) during next year.

I wonder if the flammable properties of collodion is still there when it is dry? If so, it looks like an interesting combination with paper. :)

By the way, it is always interesting to know the history of things, like your copy of that book. It lends some character to it. Rather formal english, though.

Kirk Keyes
12-13-2010, 09:17 PM
"Dear Dr. Eggert,
It has recently been brought to our attention by Dr. Spencer that you are desirous of obtaining a copy of Wall's "History of Color Photography", but that you have been unable to obtain one on the Continent. I understand from Dr. Spencer that he also has been unable to find a copy of this book in England.

Upon receipt of Dr. Spencer's letter I inquired of the librarian about the possibility of our having an additional copy of Wall's "History of Photography" which we might send to you. I find here is a copy, and I am very happy to be able to present it to you with the compliments of the Kodak Research Laboratory in the hope that you will find it useful in connection with the work at your Institut.

With kindest personal regards,
Yours sincerely,

(indecipherable signature) "

That's pretty cool! I love when I get books like that. So far, my best one on photography is merely stamps from the 3M library...

Photo Engineer
12-13-2010, 10:00 PM
Yeah, I have a few like that too. I never gave it a thought.

I was sitting in Jack Thirtle's office when the new Mees and James came out. His secretary came in to give it to him and he took the old one off the shelf in his book case. Then he turned to me and said something like "Ron, you want this old thing?" and so I have Jack Thirtle's copy with his "autograph" on the inside. I have Haist with a personal autograph "For old times sake, Grant". More like that. Maybe someday, someone will have some of my books. Of course they will be written by someone else except for my own book.

PE

Kirk Keyes
12-14-2010, 11:18 PM
Maybe someday, someone will have some of my books. Of course they will be written by someone else except for my own book.


I certainly want your signature in my copy of your book when comes out. And maybe even an inscription if possible!