Archived posting to the Leica Users Group, 2003/12/07
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Henning, I hadn't thought of that, but it obviously is true -- that the Rollei filter is ground for the 75mm lens (the Bay II filter, that is), and that it wouldn't be accurate on another focal length. Using the Rollei with the Rolleikin in order to use HIE is a pain, but the results can be very gratifying, and it is simple and easy to shoot IR film that way. Too bad Kodak never made HIE in 120. The Konica 120 IR film is a diluted imitation of the real thing. Your experiences with the Panasonic are very interesting. I should try that with my Canon S50 which has a B&W mode: the screen shows a B&W image, the only B&W viewfinder I know of. I'll see what it does with various filters. Can you post any of your IR experiments? Bob > > Leica made IR filters, generally equivalent to Wratten 89B, but with > no optical adjustment such as the one for the Rollei. The latter > works even less well for the Leica than the Rollei. > > A focus adjustment is lens dependent, filter dependent and film > dependent. If the Rollei filter is made for a specific lens, it's > important to find out what film it's made for. Most likely HIE, but > not necessarily. Again, note that this only works for a specific lens > formula. The possible variations is the reason that Leica no longer > puts an IR correction mark on the focussing mount of lenses. You > gotta find it for yourself, for your parameters. > > With Leicas, the fact that the filter could be used on a variety of > different lenses means that no specific optical adjustment should be > made in the filter, but that tests should be made with the specific > lens/film combo for each filter. > > On a related note, last weekend my son and I were playing with his > Panasonic LikaLeica, and discovered that it had significant > sensitivity even with an 87C filter. An 87 seemed the best match for > the camera, or possibly an 88A (which we didn't try). Reasonable > exposure times, and a very clear IR effect. The strange thing was > that if you used an 89B, the picture came out red, but if you used an > 87C, it came out B&W. There must be firmware in there that switches > to B&W past a specific spectral response; it means that the Panasonic > engineers were planning for this camera to be useable in the IR. > > -- > * Henning J. Wulff > /|\ Wulff Photography & Design > /###\ mailto:henningw@archiphoto.com > |[ ]| http://www.archiphoto.com > -- > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html