I want to get my Dad a light box for Christmas, can someone provide recommendations for one. He will use it for both color negative and slide/transparencies. (so I need color corrected which raises another question - does 5000K mean color corrected, B&W only here)
(and yes photography is a family thing - Mom will be getting an attachment for her Daylab and I am expecting some 4x5 equipment)
Just Normlicht is the industry standard, if you want to go top end. Kaiser and Cabin are nice, and there's a decent thin Cabin portable. The little Logan lightpads are cheap and portable, but not as well made or as bright as the others--cheap enough that you could buy one as a display unit, say, if you wanted to give someone an 8x10" transparency.
I can't recommend any that are on the market since I did not like any of the ones I saw in the stores (photographic and arts suppliers) in terms of cost, color accuracy, sturdiness and finish and decided to build one myself.
Its fairly easy to build one. I built mine as a light table with wheels and it is 2 feet wide by 4 feet in length. It uses 2 Phillips 5000K "Natural Color" tubes with a CRI of 92. What really matters is the Color Rendering Index, which is on a scale of 0-100, with 100 being the most accurate, full spectrum light.
The top of the light table has a 1/4 inch milk white acrylic sheet (supplier: wholesale supplier for store front signboard companies) on top of a 1/4 inch glass sheet (supplier: replacement glass shop).
One thing to remember is that the tubes should be around 18 inches (or more) from the glass surface so that the light is evenly diffused. Thats where the 1/4 inch thickness of the acrylic sheet also comes in. If I were to make it scratch resistant, I would sandwich the acrylic between the 1/4 inch glass and another 1/8 inch glass sheet.
The total cost including wood, paint, tubes($6.5x2), glass ($50), acrylic ($26), nails and screws was around $110.
Setting all humility aside ;-), I believe, the results are much superior to what I have seen elsewhere.
One potential issue whether you build it yourself or purchase one is to be careful that your lightbox is not much brighter or dimmer than everyone else's lightbox. I've heard of cases where this could be a problem particularly for people who shoot for magazines and advertising--the transparencies look great on the photographer's light table and the art director says they are underexposed.
I have a Kaiser. Works great. I also have a briefcase model for showing slides to clients at a presentation. (when i did more commercial work). Both work about the same.
Doing limited slide work, I always bracketed and had backup for tables that were different than mine. I almost always liked the ones half a stop to a stop darker than the meter said.