[photo-3d] Halogen vs Florescence

["Joseph Valvo" <jvalvo@xxxxxxxxxxxxxxxx>]

Reference question regards exact  spectrum of Halogen bulbs, I frankly do not know since only on occasion do I use them, and then only for B&W film (but mostly photofloods) and no need to find out. I do however suspect that the color temperature of halogen is somewhat above 3400K.

Regards determining  which film, keep it simple and use sound reasoning (Get that?). For the audiophiles I say ( as will most others that print and those on this net) proceed as follows:

1. Outdoors and flash use daylight film.
2. If no sun or flash and using daylight film indoors put on a 80A blue filter. Recognize that you will lose about four stops doing this.
3. Alternately for indoors and bulbs use a tungsten film and no filter . Thus no loss of stops.
4. When using tungsten film outdoors, or with flash use an 85B filter and, again, suffer loss of stops.

If you wish Kodak will help you on this and you can get their 800 number from information 1-800-555-2121 (or 1212, I forget).

Frankly I hesitate putting any kind of glass filter in front of my lens. Except for rare exceptions filters are poor quality glass that only tend to degrade performance of a good quality lens. Brent, being a sound system engineer, would you put a 8 ohm resistor in series with a quality 8 ohm speaker in order to make it a 16 ohm speaker?

Back to 5000K florescent---I understand that market savvy super markets use 5000K tubes in their produce department to enhance the color of their product. The product now takes on color similar to that seen in soft outdoor light. Some car dealerships use a mix of 5000 and 7000k bulbs in show rooms to achieve truer color display. Can you image a guy buying a car in an incandescent lit show room. He thought he was buying an orange car but while he was driving it home it turned yellow!

Suggest you keep it simple. Buy a flash and daylight film. Otherwise confusion arises as to---- Which film is in the camera? Which filter is required? Which bulb do I use? etc., etc. Why get tangled up in all that spaghetti? That is, unless you need to for professional reasons.

Joseph F. Valvo
  





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