VC Safelight

[Anscojohn]

Hello All,
Back in the Pleistocene Era I worked as a printer in a BW lab, using Dupont Varilour paper. Our safelights were the Dupont kind of off brown and were really great because it made it very easy to judge a print under safelight. I know red safelights are safe for VC but I find it much harder to judge a print under red light. I have two unused safelights with 5x7 OA filters. Any suggestions about making a cheapo conversion? TIA

John, Mount Vernon, Virginia USA

[Erik L]

Hi John, you can buy 5x7 filters from bh photo for around 10 bucks I think
regards
Erik

[Anscojohn]

Hi John, you can buy 5x7 filters from bh photo for around 10 bucks I think
regards
Erik

Thanks, Erik,
I'll check them out.

John

[dancqu]

I have two unused safelights with 5x7 OA filters.
Any suggestions about making a cheapo conversion?
TIA John, Mount Vernon, Virginia USA

OA. Is that not a yellow-ish green? How about
an orange or red 15 watt? Dan

[ath]

There are some VC papers today which will have issues with other than red safelight.

[Ian Grant]

There are some VC papers today which will have issues with other than red safelight.

Use the closest you can to the manufacturers recommended safelight filter. That may not be a Red filter. There can be a problem with red safelights with VC papers which causes a reduction in the achievable contrast range, it's similar to using pre or post flashing to reduce contrast.

This was the reason some manufacturers like Paterson began making special VC safelights/filters.

Ian

[ath]

There can be a problem with red safelights with VC papers which causes a reduction in the achievable contrast range, it's similar to using pre or post flashing to reduce contrast.

This was the reason some manufacturers like Paterson began making special VC safelights/filters.

Ian

Never heard this before. I'd like to hear the reasoning behind this.
It's clear that even red light is not entirely safe, but (provided same intensity) it cannot be more harmful than light with shorter wave length.

[Ian Grant]

Andreas, go and look at some of the Agfa data sheets for their multi-contrast papers, they have a long section on safelight fogging.

This was from an Agfa datasheet, but it also applies to the problems found with some red safelights and VC papers. There have been a number of magazine articles written about the issue but most pre-date the internet.

Ian

[ath]

Thanks, Ian.
In your cited post you are talking / citing Agfa regarding the fact, that EVERY safelight will eventually fog paper if it is exposed long enough. This is perfectly clear.
However, I'm talking about the fact, that RED safelight is safer than orange, green, brown, yellow, PROVIDED the fact, that they have the same intensity.

A look at the spectral sensitivities makes this perfectly clear.

These magazine articles you cite, were these scientific articles or "popular photography" type articles?
In principle, one could design a vc paper with red sensitivity and a sensitivity gap at, let's say, yellow. Thats how colour paper works. But I'm not aware of a current paper like this.

[Anscojohn]

Man, this is getting complicated.

John, Mount Vernon, Virginia USA