Dry Plates at Night?

[Two23]

Now that I seem to be getting consistent results with the dry plates in day time, I'm thinking of trying them at night. Yes, ISO 2 is slow but if I photo things that don't move very fast, such as buildings, I should do OK. After all, my hero Brassai did it all the time. I even have a beautiful c.1932 Voigtlander Bergheil 6.5x9 with 105mm Heliar to use! My only worry is that since plates are UV/blue sensitive, will they work at night? Most of the light will be coming from artificial sources and I'm not sure there's much UV there. I think I'll avoid trying magnesium flash on the downtown sidewalks. Any thoughts? Anyone shoot these at night yet?


Kent in SD

[Pere Casals]

You can make your emulsion be orthochromatic by the simple addition of Erythrosin during addition, see The Light Farm for recommended dose.

When you wash emulsion the sensitization remains.

You may make the Erythrosin sensitization later, but if done during the addition you'll get twice the effect.

At ISO 2 related exposure you may get plenty of LIRF...

If wanting faster plates I'd recommend "PHOTOGRAPHIC EMULSION MAKING, COATING AND TESTING" book, by Ron Mowrey. It explains how to make an ISO 40 emulsion.

[jnantz]

hi kent
think of them like paper negatives but with the emulsion on glass instead of a paper backing.
not sure if you have a gossen luna pro sbc but they are super sensitive to blue light and have
the ability of telling you hours and minutes as exposures as well as short exposures.
i've shot both glass and paper negatives at night and the exposures were long, used a flash too
( regular Xenon ) sometimes and it worked well .. it might be worth exposing a few sheets of paper
first ( as a dry run ) before you use the glass ... seeing the glass is $$ and the paper is ¢¢

sorry for directing you to my website, but this image
http://www.nanianphoto.com/blog/colo...01-172-col-sm/
was taken at dusk ( sun was down it was kind of dark but not pitch black night )
and on a 4x5 glass plate ... i tinted it using PS, it wasn't a color plate or series of RGB pan plates scanned as a trichrome

have fun !
john

ps. while i don't do this, some folks preflash paper to contain the contrast, it might be worth experimenting doing
that with glass if the difference between bright and dark is drastic ...

[Two23]

I'm using the Lane plates, and don't have any experience with paper negs. I've shot LF at night before, of course, but mostly using HP5. I generally use a Minolta IVf meter. Let's say I take a night reading with that, is there a rule of thumb as to how much longer I should expose a plate? It must be possible because I have photo books from the 1920s and 1930s that contain night photos with no flash.


Kent in SD

[jnantz]

I'm using the Lane plates, and don't have any experience with paper negs. I've shot LF at night before, of course, but mostly using HP5. I generally use a Minolta IVf meter. Let's say I take a night reading with that, is there a rule of thumb as to how much longer I should expose a plate? It must be possible because I have photo books from the 1920s and 1930s that contain night photos with no flash.


Kent in SD

hi kent,

im probably not the best person to ask, i kind of wing it
by doing sunny 11 and work backwards from there.

i goooooogled "night exposure calculation paper negative"
and came across this article on flickr
https://www.flickr.com/groups/101104...7629875522452/
it kind of is what i do and explained better than i could explain it ...

maybe jason has some pointers ... ?

have fun !
john

ps i'd definately practice with paper first, paper's cheep...

[Nodda Duma]

No real pointers — I haven’t tried but it would be an interesting exercise — except try doubling your metered exposure time to compensate for reciprocity.