Re: "blacklight" tubes and light sources in general

Iain,

The difference between normal output 20w and 40w tubes is length,
i.e. the 24" tubes put out 20 watts, the 48" tubes, which are twice
as long, put out twice as much. But there is no advantage to the
longer tube except that you can expose a larger print with them.

There are of course such things as high output (40 watt 24" tubes)
and very high output (75 watt 24" tubes) but they require special
ballast and the gain in printing time is not worth the extra expense
(which is considerable), IMO.

Sandy

>Thanks to all for your various responses. In my haste I did forget
>to mention which processes I am interested in. To begin with I am
>doing cyantotypes as I feel this has fewer variables than some other
>processes. Once I feel I have this under some sort of control I
>expect to also start gum soon after.
>
>I think I will pursue the fluorescent tube approach, in part because
>I think it will prove more convenient to have my source enclosed in
>a smallish box. That said I have another question:
>
>Is more UV generally better? I have found a source for 40w tubes of
>the same size as the 20w I have been considering. Apart from more
>heat is there any reason not to prefer these?
>
>Thanks again
>
>Iain
Received on Mon Feb 14 12:35:42 2005