Hello

I'm considering buying some tungsten lamps, and have some specs from various manufacturers. Most detail the light output as either 'lux' or 'foot candles' at various distances. I'd like to know if there is a formula that would allow me to convert these figures into f-stop/shutter-speed and film-speed combinations so that I can work out which lights will afford me enough depth of field and a fast enough shutter speed for portraiture.

I don't live near any dealers, so am unable to take a meter reading of the different lamps, and most of the lamps are sold through film/video dealers who are not clued-up on stills-photography.

-- David Nash (nashcom@btinternet.com), June 14, 2000

Answers

I have a set of the cheap 3 light Smith-Victors (sold as a kit, about $180 from Adorama and others), which use two 500W and one 250W lamps, and if I recall properly, I was getting about 1/125 at F5.6 or so on VPS (at EI 125). However, after experiencing the heat of tungsten lights, promptly bought some electronic flash units. Subjects also squint under the bright lights, so it was difficult to get decent shots. Tungsten isnt kind to food or living things (but they work fine for still life/product shots, if the objects can stand the heat).

-- Ron Shaw (shaw9@llnl.gov), June 14, 2000.

Hi,

For low budget tungsten light, try Britek (800.925.6258). They have the QW-1000N, 1000 watts, color temp 3200K, fan cooling. Priced about US$100.00. They have a special kit with 3 of those lights, 3 stands with bags, an alum. case, 2 umbrellas, all yours for $382.50.

-- dan nguyen (dan@egmail.com), June 14, 2000.

Your best bet is to go with halogen lights which are a true 3200K as opposed to tungsten lamps. Lowel makes a range of excellent, efficient equipment for a reasonable price that will give you decades of reliable use.

For portraits I too recommend you use electronic flash instead of "hot lights".

-- Ellis Vener (evphoto@insync.net), June 15, 2000.

This is not an answer. In fact I'd like to ask more question on this subject. I am also thinking buying some tungsten lights, in particular lowell tota. But, if I mainly use it for close-up of flowers, will the heat be a problem? I also considered flash. But high power flashes are expensive, can somebody tell me what is least w/s I need for the following situation: 1:1 ,f 22 or 32 on EI 50 or 100 films? Thanks.

-- tao wu (twu@math.nwu.edu), June 15, 2000.

Hot lights will certainly wilt the flowers, unless you back them off quite a bit, which causes a harder light. You also will need heat resistand diffusers. I highly recommend electronic flash and diffusers. If getting F22 at EI 50 is a problem, try multiple bursts. For a bargain in flash units, I highly recommend the Adorama Flashpoints.

-- Ron Shaw (shaw9@llnl.gov), June 16, 2000.