Safelight filters - 0A vs. 0C?

[Scott --]

Hi, all -

I need to cut some paper that recommends using an 0C safelight filter. I have an 0A filter. Any good for this? How do they compare? I'm new to this stuff...

Thanks,
Scott

[rippo]

i have no idea.

however you could skip the filters and safelight and get this instead. it's a red LED light that fits in a standard household light socket.

i bought something similar (which they've discontinued). it's bright, so bright it hurts your eyes to stare at it. but it's such a specific frequency of red, it doesn't fog paper nor ortho film. i've tested it to be sure. the company tells me the link above is for something very similar, but i haven't tested that particular model.

it's priced right too. something to consider.

[davidb]

0C is for multigrade paper

0A is for graded paper and should not be exposed to 0C light.

[Michael Gudzinowicz]

Years ago I ran tests of VC papers with a variety of OC filters and they will fog the papers, though slowly. I covered the OC filters with a sheet of dark red acetate and there was no fogging even when the paper was held against the light for minutes. Instead of a "bright" OC filter, I use several of them covered with acetate. They are also safe for most lith films.

[alec4444]

i have no idea.

however you could skip the filters and safelight and get this instead. it's a red LED light that fits in a standard household light socket.

i bought something similar (which they've discontinued). it's bright, so bright it hurts your eyes to stare at it. but it's such a specific frequency of red, it doesn't fog paper nor ortho film. i've tested it to be sure. the company tells me the link above is for something very similar, but i haven't tested that particular model.

it's priced right too. something to consider.

This is intriguing...can you tell me a bit more about how rigorous of a test you did? Thanks!

--A

[rippo]

i seem to recall getting some tips from apug...it's been awhile, but here's what i think i did.

i took a sheet of 8x10, and mentally divided it into quarters (whew, that was tough!). i covered the lower half, and exposed the upper half to the safe light for six to ten minutes (i don't recall the exact time) on the enlarger's baseboard. but whatever the time was, i had somehow worked out it was more time than the print spent in the wet.

i exposed the left half to a negative i'd already printed with that evening, so i knew the exposure was right. so the left half was getting an image on the upper left (exposed to safelight), and the lower half (unexposed). i developed as normal. i compared the left side to see if the highlights of the image looked any different in the top and bottom sections. and i also checked to see if the blank right side showed any fogging between top and bottom sections.

it checked out fine.

your mileage may vary!

[lenser]

From an on line Kodak Safelight filter publication:

KODAK
Safelight
Filter


Color


Use

OA


Greenish yellow


Black-and-white contact and duplicating materials, projection films

OC


Light amber


Contact and enlarging papers

OO


Light yellow


Flashing halftones made through a KODAK Contact Screen for contrast control

1


Red


Blue-sensitive materials and most phototypesetting materials

1A


Light red


Slow orthochromatic materials

2


Dark red


Fast orthochromatic materials, green-sensitive x-ray films

3


Dark green


Some panchromatic materials

6B


Brown


Blue-sensitive x-ray films

7B


Green


Some panchromatic materials

8


Dark yellow


Color print and color intermediate motion-picture films

10


Dark amber


Color negative papers, materials, panchromatic black-and-white papers

11


Appears opaque,
transmits infrared
radiation


For use with infrared inspection devices

13


Amber


Color negative papers, panchromatic black-and-white papers

GBX-2


Dark red


Most blue-sensitive x-ray films, most green-sensitive medical x-ray films

Hope this helps.

[Glenn Thoreson]

I've always used a red safelite with Ilford and Agfa VC papers with no problems at all.

[Darren Kruger]

I need to cut some paper that recommends using an 0C safelight filter. I have an 0A filter. Any good for this? How do they compare? I'm new to this stuff...

See if you can find a tech document online for your paper and see what it says. I've seen reference to a paper that is safe under OC but not OA (Kodak Kodabrome.)

If you can't find a datasheet, do a safe light test with a sheet of paper and see if it fogs. Kodak has a publication (K-4, How safe is Your Safelight?) which goes into detail on safelights and how to test your safelight.

-Darren