Seeking advice about plates.
I recently acquired an Ica Volta 146/1, which came with three plate holders. When I opened the package up for a look, I naturally examined a holder, and pulled out the dark slide. Inside, I found a light coloured thing which, on subsequent examination and removal turned out to be a glass plate. That plate is now hopelessly fogged of course, but the other two holders have not been opened.
I'm trying to work out what to do with the plates inside (there are plates inside - each holder weighs 139g, and the removed plate weighs 33g). The notable difference is that the dark slides on the unopened holders are held in place with tape - the one that I opened had no tape on it.
My options appear to be to assume they have already been exposed and develop them, or assume that they are unused and I thus expose and develop them.
The only clue I have is the existence of the tape holding the dark slides in place. Is it possible that there was some usage convention, where one loads the plates and then tapes the slides in place to indicate that they are unused? Sort of like breaking a seal to use them. Or could it be the converse, where a dark slide is taped once the plate has been exposed, to ensure that the plate isn't exposed twice? The logic works either way, but perhaps there was a convention at some point regarding how this was done. Any clues would be much appreciated.
I'm aware that I could develop one plate and see if there's an image on it - if there is I assume the other plate also has an image, and develop that too. If there isn't, I assume the other plate is also blank and expose it first. Ideally, though, if the tape means the plates are unused, I'd like to have the opportunity to expose both of them.
On the subject of exposing and developing... What sort of emulsion speed should I be using for exposure? And what about developer and developing time? Assuming the plates are ortho, can I develop by inspection with a standard red safelight (albeit kept away as much as possible)? Is a film developer like HC-110 okay?
Yes, HC-110 would be a fine choice. At the age the plates are at, I'd assume an EI of about 10. They might have been as fast as 25 or 50 new, but they aren't now.
If they're sort of a pale sickly green color, they are probably orthochromatic.
The conventions are for dark slides with color coding (white unexposed, black exposed), or with bumps (originally the nail heads for the handle) bumps out for unexposed, bumps in for exposed.
Yes, sickly pale green colour on the plate. Is it not possible to put a plate through a development cycle (under a safelight) and, if it doesn't develop, wash the developer out, dry it off, and make an exposure on it? I don't recall which way round the untaped dark slide was, but I have a feeling it was the same as the other two - I don't remember a feeling of one being different from the others (but I didn't notice that the others were taped, either).
Some photos below of the two taped plate holders. One has been taped up with broad tape, and the other with narrow tape. There is also a remnant of broad tape on the latter, as well as a number, 29, printed (not hand-written) on a small piece of paper stuck under the tape. The camera and 3 holders came in a leather box-type case which is just big enough for these - certainly not big enough to hold 29 or more plates.
The number also repeats, as if it came from a roll of paper with the number on it all the way through. Could this have been applied by whoever supplied the holder loaded with a fresh plate? Would camera owners have bought rolls of paper with printed numbers to do their own indexing of holders? Wouldn't they have just hand-written the number on a label, or painted it on somewhere?
Holder 1, dark slide side.
And the other side.
Holder 2, dark slide side.
And the other side.
Close-up of the number.