Anyone aware of a make / model that used mercury or other discharge lamp light source for conventional ie 35mm photographic format slides, not scpecialised large format systems
- posted
13 years ago
Anyone aware of a make / model that used mercury or other discharge lamp light source for conventional ie 35mm photographic format slides, not scpecialised large format systems
I'm a bit lost, here.
Discharge lamps are not continuous-spectrum sources, and would probably not work very well when projecting color images. And with mercury, you'd have to filter out the UV, not to mention the ozone generated by the UV.
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So am I, video projectors and back projected TVs seem to manage fine.
They don't melt or burn like film does.
-- You can't fix stupid. You can't even put a Band-Aid? on it, because it's Teflon coated.
ve
Well, at the very least the 'image' can be electronically colour corrected to compensate for the uneven spectrum of the source. On the other hand, one probably only needs to to provide illumination in the
3 [or 4??] colour layers that slides use. I have not noticed any 'ozone' smell around mid-sized video projectors, so what's with that?Neil S.
Do you need one or are you just thinking out loud? Are 35mm slides still popular? If you're not seeing them maybe the technology isn't calling for discharge illumination.
-- Live Fast, Die Young and Leave a Pretty Corpse
Just curious. Just repaired a Kodak carousel projector with 300W bulb and wondered what the power requirement for a lumen for lumen equivalent discharge lamp would be , or is it just smps gives the edge. But then is there a problem with smps supplying a filament lamp, in the way of thermal runaway
I think the technology is stagnant. Same goes for home movies on film.
There isn't sufficient need to improve the design.
-- Live Fast, Die Young and Leave a Pretty Corpse
Agreed. Slide projectors never got past tungsten-halogen lighting.
Discharge lamps would no doubt be more efficient. But... not only would you have to correct for color balance, but the bulb would have to be "mated" to the projector's optical system.
Large theater projectors are still an arc light ? There must be some sort of white/color balancing scheme for them. Same could be used on other forms of HID illumination.
-- Live Fast, Die Young and Leave a Pretty Corpse
I'm not sure. I seem to recall that some use some form of tungsten lighting. Don't hold me to it.
The "scheme" is simply to have a standardized color temperature. The prints can then be balanced accordingly.
They're used for lighting on film and TV so can be pretty good. As well as for DLP etc projectors.
-- *A 'jiffy' is an actual unit of time for 1/100th of a second. Dave Plowman dave@davenoise.co.uk London SW
On 3/1/2011 9:25 AM William Sommerwerck spake thus:
Nope; xenon arc. Like this:
-- The phrase "jump the shark" itself jumped the shark about a decade ago. - Usenet
I seem to recall that modern cinema projector lamp houses make use of short-arc xenon discharge lamps, but as you said, don't hold me to it ...
Arfa
Speaking of HID lights, does anyone know where I can get a schematic for a Philips EUC 120 C/00 Lampdriver?
Thanks, tm
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