--- astrodeb@charter.net wrote:
I used google.com and found the light box Russel Croman uses. I may make mine according to his design. http://www.rc-astro.com/equipment/light_box/ Debbie
P.S. - Another thing to watch for is putting too much light out the diffuser panel. With respect to my design, I did an very rough measurement of its luminance using any old analogue light meter for photography (Capital CDS light meter). The Capital meter is intended to read reflected light down to about 2 or 3 EV. I do not own a digital light meter. When using this meter during twilight, I can reliably read down to EV1-EV2, usually about 5-10 minutes before nautical twlight. At or just after nautical twlight, the Capital CDS meter can be pegged by putting my finger over the sensor. The meter just raises off the peg during nautical twlight. The light meter has a very similar response when held 6 inches above the outer diffuse panel of my design. So, I would put the luminance of my unit between EV0 and EV1, which per tables by Ken Rockwell and others, puts the brightness of my design somewhere between: EV Lux Footcandles 0 0.23 2.5 1 0.46 5 Basically, you want to aim for a light that is EV2 or lower and definitely not EV4,5,6. - Canopus56 (Kurt) References to EV-lux-lighting tables http://www.fredparker.com/ultexp1.htm#evfclux (by Fred Parker) http://www.kenrockwell.com/tech/ev.htm (by Ken Rockwell) http://home.pcisys.net/~rlsnpjs/minolta/ev%20lv%20asa.html (by Dick Sullivan) __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com