|
AJUK
|
|
()
|
|
13/05/2007 12:36
|
|
|
|
|
|
|
Green Colour Safelight
|
|
What possible use is this? No wonder the guy at college had never herd of a colour safe light. I mean either the paper is sensitive to this green colour or it isn't, why does it need to be so dim?
|
|
|
Re: Green Colour Safelight
|
|
Standard colour safelight - generally very dim, but paper isn't fast, and not sensitive to this colour.
|
|
|
|
Re: Green Colour Safelight
|
|
Quote:
What possible use is this? No wonder the guy at college had never herd of a colour safe light. I mean either the paper is sensitive to this green colour or it isn't, why does it need to be so dim?
Years ago they were used with panchromatic films for visual development and had to be very dim. They were almost useless but people persevered, mainly I think, because development by time alone hadn't been universally accepted.
|
|
|
|
Re: Green Colour Safelight
|
|
But are`nt green safelights only to be used for a very short period of time when using colour paper? IIRC
|
|
vicb981
|
|
(journeyman)
|
|
13/05/2007 16:07
|
|
|
|
|
|
|
|
|
Re: Green Colour Safelight
|
|
I gather that the wavelength used in the safelight does not affect the paper. I have an amateur one - and it's useless. Possibly the pro ones are better. I gave up using mine (for the little colour printing that I did) and just fumbled about in total darkness.
|
|
|
|
Re: Green Colour Safelight
|
|
KODAK OA Safelight Filter / Greenish Yellow. For use with bluesensitive films.
KODAK 3 Safelight Filter / Dark Green. For use with panchromatic films.
KODAK 8 Safelight Filter / Dark Yellow. For use with Eastman color print and intermediate films
|
|
|
Re: Green Colour Safelight
|
|
I seem to remember that a very dim green safelight was reccomended for Cibachrome, although I never tried it myself. Thankfully, my darkroom (my parents cloakroom) was small enough that I couldn't get lost in the darkness!
|
|
|
|
Re: Green Colour Safelight
|
|
Very dim green safe-lights are used with the 'develop by inspection' (DBI) method of development, using pyrogallol/pyrocatechin developers, mostly by large format photographers who wish to control development/contrast very finely. These developers substantially de-sensitize the film to green light, and mean that it is possible to inspect the film part way through development under the safelight, in order to judge the remainder of the development time/water baths/etc.
|
|
|
|
Re: Green Colour Safelight
|
|
I have a safelight for reversal or negative colour printing, but it's not green - more a sort of orangey-brown colour. The light is provided by LEDs, and certainly is much dimmer than conventional safelights for B&W work, but just adequate for being able to see the slots in the deep tank, or to work out where the box of paper is - not much more than that.
|
|
John_K
|
|
(addict)
|
|
01/12/2007 16:34
|
|
|
|
|
|
|
|
|
Re: Green Colour Safelight
|
|
I still print colour negative film and use a DUKA colour safelight. for both the RA4 and monochrome. The bulb is a sodium vapour type and starts off very dimly taking up to 10 mins to get to the brightest point. The light levels are quite good with B&W but for the colour you have to dim the light by means of a sliding shutter, but not to the point where it is useless. Used at ful brightness with colour yiou will fog the paper.
From 6 feet I can see what to do clearly and slice up paper with a guillotine quite easily.
Without one I would have to give up. There is no equal.
|
