Film holders with metal slides any better for infrared?greenspun.com : LUSENET : Large format photography : One Thread
Have a chance to pick up a number of older wood film holders in excellent condition. All have metal darkslides. Will the metal slides be any better for infrared film than the plastic ones?
-- Dan Smith (email@example.com), December 27, 2001
Although I have no experience shooting with infrared film, the metal slides might actually be a bad choice. From what I understand of infrared radiation, it is (for all practical terms)the equivalent of heat radiation. Since metal slides have a higher potential capacity to absorb and radiate heat, they are likely to cause fogging.
You might want to test the suitability of holders by using your reflected light meter. Since most light meters are sensitive to infrared radiation, pointing the meter at a metal slide and comparing the reading from that of a non-metal slide may be informative. This suggestion by the way is prompted by a series of old articles in Photo Techniques that dealt with understanding the behavior of light meters, including how meters react to infrared radiation. One of the tests suggested was to meter a glowing hot plate, and various other sundry items that absorb, reflect, or emit infrared radiation. This includes, among others, certain fabrics in socks!
-- Rico Obusan (firstname.lastname@example.org), December 27, 2001.
Dan, I don't have the answer to your question, but before we get too offtrack I wanted to respond to Rico's post. The infrared spectrum is divided into 2 sections, near and far. The far portion measures heat, and is NOT picked up by film. FWIW, the infrared that exposes our film is the portion of infrared near the visible spectrum, called Near Infrared. It is between the visible and far infrared. We cannot see or feel it in any way.
I've never shot infrared sheet film, but from everything I've read (and I just thumbed through my infrared book) it won't make a darn bit of difference.
-- Jennifer Waak (email@example.com), December 27, 2001.
Dan, I've used both types of dark slides and not had any problems. I was careful to keep the holders in an insulated bag and they came out only when the exposure was to be made. Be aware that some older bellows are not IR safe. However, it is a simple matter to test. Good shooting.
-- Andy Eads (firstname.lastname@example.org), December 27, 2001.
I've used plastic ones (Lisco/Regal)with Kodak 4x5 infrared (before it was dropped) without any problems.
-- Brian Ellis (email@example.com), December 28, 2001.
I tested 3 varieties of 4x5 filmholders for leaking IR: fidelity, riteway, & older metal body/metal darkslide Graflex (not Graphmatic) holders.
None leaked any light when exposed from all sides to both sunlight and bare incandescent bulbs.
So... the metal darkslides work fine, but seem to offer no advantage.
-- John O'Connell (firstname.lastname@example.org), December 28, 2001.