Lightbox/exposure design and tube spacing

[washy21]

Hi All

I have commited myself to building a lightbox and will be using a really solid office desk as the base. I intend to document the process to pass on anything I gain. But I was wondering about the spacing of the UV tubes in relation to the size of desk I have bought, and of course more importantly the relationship to the screen and effective stencil area.

Andymac has (by numerous PMs - so thanks Andy) suggested that 6" is the optimum spacing. but in relation to my screen size I was wondering if anyone could look at the image and pass comment on the placement of tubes: do I really need more tubes and less spacing or less tubes? The image is to scale so it is an accurate view from above.

Best Wishes

All sizes | Lightbox Design 01 | Flickr - Photo Sharing!

[B-DROID]

I think if you were to space them any closer you would end up getting hot spots on your screens. The 6" spacing looks pretty ideal, that and Andy knows his stuff.

[Andymac]

Why not at 5? The outer bulbs in the 6 spacing are useless.

I think I said this before and maybe it didn't come across. We don't give out the exact height or the spacing on our Eagle Flourescent tube units. You would have to talk to a customer (Delicious Design, Black Swan, Caughtin Customs, Broken Bones Press, John Brown University,) as the height and spacing has a lot to do with the type of bulb, and it was arrived at by a lot of experimenting at our factory. We also have a reflector behind our bulb array.

If you can, arrange them how you think but maybe make it so you can move them if you have to. You will know quickly if you are getting banding on your exposure.

[washy21]

Why not at 5? The outer bulbs in the 6 spacing are useless.

I think I said this before and maybe it didn't come across. We don't give out the exact height or the spacing on our Eagle Flourescent tube units. You would have to talk to a customer (Delicious Design, Black Swan, Caughtin Customs, Broken Bones Press, John Brown University,) as the height and spacing has a lot to do with the type of bulb, and it was arrived at by a lot of experimenting at our factory. We also have a reflector behind our bulb array.

If you can, arrange them how you think but maybe make it so you can move them if you have to. You will know quickly if you are getting banding on your exposure.

Thanks Andy. I'll take this advice and just experiment. I'll report back for the community when it's done. Sorry for the numerous posts on this issue - I'll refrain from that