Slide projector - discharge lamp light source?

N_Cook

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Mar 1, 2011, 5:56:02 AM3/1/11

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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

William Sommerwerck

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Mar 1, 2011, 9:09:05 AM3/1/11

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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.

N_Cook

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Mar 1, 2011, 10:01:11 AM3/1/11

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William Sommerwerck <grizzle...@comcast.net> wrote in message
news:ikiune$ahq$1...@news.eternal-september.org...

So am I, video projectors and back projected TVs seem to manage fine.

Michael A. Terrell

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Mar 1, 2011, 10:33:51 AM3/1/11

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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.

nesesu

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Mar 1, 2011, 10:40:26 AM3/1/11

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On Mar 1, 7:01 am, "N_Cook" <dive...@tcp.co.uk> wrote:
> William Sommerwerck <grizzledgee...@comcast.net> wrote in message

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.

Meat Plow

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Mar 1, 2011, 10:47:52 AM3/1/11

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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

N_Cook

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Mar 1, 2011, 10:59:23 AM3/1/11

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Meat Plow <mhy...@yahoo.com> wrote in message
news:pan.2011.03...@lmao.lol.lol...

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

Meat Plow

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Mar 1, 2011, 11:56:27 AM3/1/11

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I think the technology is stagnant. Same goes for home movies on film.

There isn't sufficient need to improve the design.

William Sommerwerck

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Mar 1, 2011, 12:04:28 PM3/1/11

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>> Just curious. Just repaired a Kodak carousel projector with

>> a 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.

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.

Meat Plow

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Mar 1, 2011, 12:16:42 PM3/1/11

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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.

William Sommerwerck

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Mar 1, 2011, 12:25:25 PM3/1/11

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>> 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?

I'm not sure. I seem to recall that some use some form of tungsten lighting.
Don't hold me to it.

> There must be some sort of white/color balancing scheme for
> them. Same could be used on other forms of HID illumination.

The "scheme" is simply to have a standardized color temperature. The prints
can then be balanced accordingly.

Dave Plowman (News)

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Mar 1, 2011, 6:10:13 PM3/1/11

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In article <ikiune$ahq$1...@news.eternal-september.org>,

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 da...@davenoise.co.uk London SW
To e-mail, change noise into sound.

David Nebenzahl

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Mar 1, 2011, 9:20:31 PM3/1/11

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On 3/1/2011 9:25 AM William Sommerwerck spake thus:

>>> 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?
>
> I'm not sure. I seem to recall that some use some form of tungsten lighting.
> Don't hold me to it.

Nope; xenon arc. Like this:
http://www.alibaba.com/product-free/110488871/XENON_ARC_HOUSE_XENON_SHORT_ARC.html

--
The phrase "jump the shark" itself jumped the shark about a decade ago.

- Usenet

Arfa Daily

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Mar 1, 2011, 9:33:57 PM3/1/11

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"William Sommerwerck" <grizzle...@comcast.net> wrote in message

news:ikja7h$qc5$1...@news.eternal-september.org...

>>> 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?
>
> I'm not sure. I seem to recall that some use some form of tungsten
> lighting.
> Don't hold me to it.

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

tm

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Mar 1, 2011, 9:49:26 PM3/1/11

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"Arfa Daily" <arfa....@ntlworld.com> wrote in message
news:r0ibp.62105$VI6....@newsfe29.ams2...

Speaking of HID lights, does anyone know where I can get a schematic for a
Philips EUC 120 C/00 Lampdriver?

Thanks,
tm