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View Full Version : help needed: Glass negatives...



gandolfi
08-28-2011, 09:21 AM
I just found in my house some packs of old glass negatives - unopened...

(Don't remember where I got them from...)

I'd like to try them, but I have no idea what iso to try - and what development to use...

Any help from you experts?

First is called "Eisenberger"

Second is Ilford "Auto filter plates"..

Third has only danish text:

"Extra rapide "Ideal"" ---

size is 18x24cm for all....

Could be so much fun to try them out...

werra
08-28-2011, 10:00 AM
Well, Eisenberger and Ilford seem to be ortho, so you can develop them in red light. As for EI.. something around 3-6? Probably even less.

t-royce
08-28-2011, 12:14 PM
Well the Ilford Plates list an original speed of 400 H&D, and a 23 on the Ilford Speed Group. That would be an ASA of 16 DIN of 13 from the chart located here:
http://www.photomemorabilia.co.uk/Johnsons_of_Hendon/JoH_Exposure_Calculators.html#anchorspeed.
As to what the current speed is, that's a whole other question, slower for sure.

Bill Burk
08-28-2011, 01:36 PM
gandolfi,

I have no idea, of course you should probably underrate it due to age/fog.

But I am certainly looking forward to what these plates do in your hands!

dwross
08-29-2011, 10:36 AM
gandolfi,

At the risk of being a wet blanket, I have to say I think the plates have more value unopened than any artistic value you might get from them, even with your prodigious skills. They are likely seriously fogged from age.

That said, you won't need a yellow filter with the Ilford plates. 'Auto filter' means a yellow dye was incorporated in the emulsion.

Since you have limited materials to experiment with, it would be handy to get as much information from as few as possible initial tests. I have an old 4"x5" exposure test film, meant to go over a 4"x5" negative in an enlarger. It has an exposed circle with pie slices of different densities and corresponding suggestions about exposure subtraction. If you load a plate with something like that on top of it, you can give the plate what you are certain is over-exposure and then back off the exposure on the next plate to try to match what you learned from the test exposure. Something to keep in mind about many of the old recipes is that they will actually lose density if they are seriously overexposed -- until they 'flip' into reversal mode (solarization.) Remembering that will make it less confusing to interpret your exposure tests.

d

vpwphoto
08-29-2011, 11:04 AM
I agree.... leave the boxes alone, and if you really want to use them do some research... my best guess they have been exposed to high humidity and excessive heat too many time to be of much use.

Neat find thought.

gandolfi
08-29-2011, 02:03 PM
I understand you both - the plates are proberly gone bad... Bu as it happens, there are 5 boxes in all (50plates).. So I might open one of them gently, without destroying the box and make a test..

I know our museum of photography here in DK would be interested in getting the emty boxes after use.. and my thought was also this: if they are gone bad - then I could fix them out - let them dry and then apply my own emulsion on them.... (pre-made plates)...

I am not sure anyone would actually pay for this stuff.... (would be rather expensive to ship..)

dwross
08-29-2011, 02:29 PM
Understood :) Playing with the old stuff really is irresistible. Make sure you 'show and tell'!

John Shriver
01-30-2012, 08:15 PM
Here's my experience with a box of Kodak Wratten Pan plates. The packaging isn't air-tight like a modern film. So most of the plate was oxidized, and thus not sensitive to light. Only an area about 2x3 inches in the middle of the 4x5 plate was still sensitive. That's because the plates are packed in pairs facing each other, so oxygen didn't get to the middle.

So compose assuming that only the middle is alive.