20W
, what sort of exposure times do you use Paul?
And how do you position the box? Sit it atop the OTA, or on a bench at a distance? I have not ventured into the realm of light boxes, one thing that worries me is introducing an artificial gradient. I think I would be happy with a dim enough light source such that the shutter/blind travel time is an insignificant % of the overall exposure time. The other concern;real or imagined is if the light box diffuser surface is not perpendicular to the optical axis, this could lead to an unwanted gradient. Been thinking of trying it out though because it can be a real pain setting up in daytime. With the flat gathering method I use I've found it best to use a mid day(ish) sky rather that twighlight (contrary to the words of the Gurus) because of the rapid change of light levels around dusk or dawn.
Quote:
Originally Posted by [1ponders]
I've been using standard 20W 12V halogens (couldn't get the ultra whites  ) and the box works a treat. What I did have to do though was hook the bulbs up in parallel (as suggested elsewhere) and install a dimmer switch on the 240V side of the transformer. Does a great job. |