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View Full Version : Ready-Made emulsion speeds?



DannL.
10-16-2013, 11:34 AM
I am curious as to what speeds are available in ready-made emulsions such as Liquid Light, etc? Primarily I would be interested in faster speed emulsions. I'm currently using Liquid Light at ISO 1 with good results.

I understand that by adding developer to an emulsion a speed increase may be realized. Does anybody know what ratios of what developers = what speeds?

jnanian
10-16-2013, 12:42 PM
hi dannL

you might call rockland colloid and ask them.
they might have data on that subject .. but from what i remember ...
they stopped making that recommendation because it degraded the emulsion ( afterwards ) ...
one way i have increased the speed of my emulsion is by letting it age a little bit.
i have noticed it gets a bit more contrasty and speedy if it is older ...
are you using it in the darkroom or as a negative-material ?
depending on the outside light the speed changes .. more blue light the faster the emulsion is ...
i did my best to try to figure out what time of year the most blue light is .. ( new england )
and mid day ( 11-1pm ) without a cloud in the sky ... usually in the summertime
BUT ...
and you are making photographs in the snow/winter, you get reflected blue light as well as atmospheric ..

hopefully i haven't disinformed you too much !

good luck !
john

DannL.
10-16-2013, 01:27 PM
Thank's John. I'm coating glass plates for use in my cameras. The 5x7 camera is designed to be hand-held easily and I would like to "up the speed" of the plates so that I can use a faster shutter speed and smaller iris sizes.

If I could achieve ISO 100, that would be lovely. But, ISO 99 would be fine also . . . ;-)

jnanian
10-16-2013, 05:04 PM
hi again dannL

have you considered doing this:

http://www.apug.org/forums/forum37/11732-latensification.html
http://www.apug.org/forums/forum37/115740-hydrogen-peroxide-steaming-gain-addl-speed.html

i've often considered hypering stuff, but haven't ...
it seems like you can do it before or after :)

i guess you have to do it a few times to figure out exactly what the insanely fast speed would be! :)

i hope if you consider doing this you post your results !!

john