I have been using halogen lights for black and white photography. They are relatively inexpensive, and work well. Now I need to do a bit of studio work and I am wondering...

Will halogen lights work well with the Kodak Portra films? Will I need corrective filters?

Thanks for the great forum, and all who submit so much valuable information... -Dave

-- Dave Richhart (pritprat@erinet.com), October 21, 2000

Answers

The source of light isn't that important, it is the quality, i.e. the eveness and so on, that counts. Halogen lights are used quite a lot by professional still-life people and there are no real problems other than heat. On transparency film you would need to use tungsten film or a filter, because halogen lights burn at about 3400 degrees K, not 5000, and in theory you should also filter if you are using negative film, but this degree of filtration is easily compensated when printing. Hope this helps.

-- Garry Edwards (creativephoto60@hotmail.com), October 22, 2000.

i disagree about the source being unimportant - it is just as important as the quality of light (if they can be compared like that). filtration on color neg films can be necessary depending on what you are doing. if color accuracy is important it is advantageous to match or at least approximate the light ct with the film used. while neg allows for a great deal of color correction in printing, cross curves cannot be corrected (color casts in highlights and/or shadows). the newer neg films are better than their predecessors in handling a variety of uncorrected light situations - especially nps/npl with mixed fluorescent/tungsten/daylight - but if poss. i still try to filter when i can. also tungsten lights frequently mean long exposure times which daylight balanced neg films do not handle as well. reciprocity failure and color shifts can and do occur. kodak publishes info on their films. figure out what your shooting situations will be and check their recommendations for the film used.

-- adam friedberg (asfberg@hotmail.com), October 22, 2000.

"Will halogen lights work well with the Kodak Portra films? Will I need corrective filters?"

You will if you don't use a film balanced for 3200K light (and according to my results and to a Minolta Color Meter III, every halogen light I've ever used in a photo is 3200K not 3400K). The filter is an 80A. You can avoid needing a filter (and the resulting 2 stop filter factor) if you use Portra 100T which is balanced for 3200K.

-- Ellis Vener (evphoto@heartstone.com), October 22, 2000.

i prefer to correct on the lights with ctb/cto. it is cheaper and usually more accurate as bulb condition, reflector condition, power line voltage, etc. affect color temperature. with multiple lights each can be properly adjusted. the fewer the filters on the lens the better. then again, it is best to use tungten film with tungsten lights and minimize/eliminate the filtration altogether. generally speaking tungsten lights are 3200K, photofloods 3400K.

-- adam friedberg (asfberg@hotmail.com), October 22, 2000.

re: "also tungsten lights frequently mean long exposure times which daylight balanced neg films do not handle as well. reciprocity failure and color shifts can and do occur."

The newest generation of daylight transparency films are pretty good with regard to long exposures. Fuji RDPIII is void of reciprocity out to about 2 minutes, and has been characterized by Fuji out to 4 minutes. This is actually better than their RTPII tungsten film. Of course, if your shooting with hot lights, your still probably better off shooting tungsten film.

-- Larry Huppert (Larry.Huppert@mail.com), October 23, 2000.