250 watt Xenon projector lamp?

[JIM DUNN]

:roll: There is one theatre and one coffee house here in Austin that frequently screen Super 8 films with projectors that apparently aren't made to project over the distance of an average livingroom, resulting in very dark images on the screens. I know that one of them is an Elmo ST800. I think a couple of Elmo GS1200 models use the Xenon 250 watt lamps, and they are pretty expensive. So, my questions are; 1) Can a Xenon 250 watt lamp be used in any of the Elmo 'ST' model projectors? 2) If so, which ones? 3) If so, what, if any, modifications are necessary to be made to the projectors to be able to use this lamp safely and effectively? 4) If not, which lamp would be the brightest (best) to use in the Elmo 'ST' series projectors if, in fact, a lamp other than the original stock lamp can be substituted? 5) Ok, failing all the above brilliant Wylie E. Coyote ideas, what, if any exists, is an inexpensive solution to this microcinematic dilemma?

[David M. Leugers]

There is a well documented modification to the Elmo series of projectors which I believe can be done to the 800. It converts the bulb to a Marc 300 arc lamp and really throws out the light for big screen projections. The marvelous book Super-8mm in the Video Age shows you how to do this. You'll need to come up with the Marc power supply (tons of them around from 16mm projectors) and other parts. Check it out if you're interested. Another approach is to install a 250 watt EJL lamp in place of the usual lamp. You will need to have a 110AC to 24v transformer to power the lamp. I could do this for you and can quote you a price if you are interested. You can email me at dmleugers@fuse.net. Good luck.

[jessh]

Another approach is to install a 250 watt EJL lamp in place of the usual lamp. You will need to have a 110AC to 24v transformer to power the lamp.

Have you actually done this? The biggest concern of course would be that it would generate too much heat, which of course could damage film, melt the projector housing and even start a fire, all of which would be bad :-) The modification would be relatively simple, I believe they are standard MR-16 (or are they 14?) lamps, so there are lots of choices for lamps, maybe even ones that wouldnt requier a different power source, although the built in one might not be able to handle the added load....

~Jess

[David M. Leugers]

No I have not actually done this particular mod to an Elmo. I do know of a Eumig projector modified so, and it does not burn the film and surrounding plastic. I plan to modify one of my Eumigs with the EJL bulb while adding at least a 2400 foot reel capacity for feature projection. Of course, if I feel it needs extra cooling, that would be no big deal to add a more powerful cooling fan installation. I have modified and repaired many projectors and cameras and other equipment. This mod would be no big deal. I modified my Elmo ST800 with a home made five bladed shutter and other tweaks to do 24fps sound transfers. I think there may be many of you out there who could do this EJL bulb mod successfully if you were careful and planned it properly. A steady hand on irreplaceable parts is also a help.

[jessh]

alright, I agree that it shouldnt be mcuh of a problem to provide extra cooling, and depending on the projector might not need it, that mod would be rather easy (for me atleast :-) I may do something similar on my Elmo ST-1200HD at some point, but its rather new to me, I spent a decent chunk of money on it, and is in perfect shape, so I think I will stay away from opening it up until I have the need :-)

how are you going about adding the 200ft reel capacity?

~Jess

[Pedro]

The Xenon technology is not the latest thing in projection, nor it does provide the best amount of light available compared with all the efforts for the modification.

Nowadays the way to go is definitively HTI lamps ("hi power lamp"). The recently had been newly developed by Osram and there are two types available, especially optimized for S8 projectors (two different back focus distances available). Besides other types for 16 mm projectors.

The S8 types have a power consumption of 250/270 W and the 16 mm types 400 W. The light output is 4 times brighter than halogen and two times brighter than Xenon. They have a mirror reflector that fits into the standard sockets of S8 projectors.
The HTI lamps are INTERCHANGEABLE with halogen standard lamps. THat means, the projector can be used at home or for sound track work with the standard lamp and for bigger screens with the HTI lamp, only by exchanging the lamp. Not possible with Xenon.

The lamps are rather expensive (over EUR 200) but their live expection is about 500 hous, as far as I know. For the electrical connection, a supply module is required, that costs about EUR 450. All items are available f.e. at Wittner Kinotechnik.

The projectors, you can have modifyed to HTI or buy ready for HTI are the Beaulieu 708 (all types) and the Elmo GS1200MO. All projectors need an add. fan for cooling the gate area, running independently from the transport motor. Bavaria Munich is offering a conversion service for these two projectors. Others models they do not convert, as they have to give warranty to the final product.
But I can imagine, that other Elmos of similar construction as the GS1200 can be converted in the same way.
Only plastic made projectors will need an external lamp housing with a mirror system.

With these lamps available, I would not spent any effort in Xenon technology.

Pedro

[David M. Leugers]

Thanks for the info Pedro. Great to learn something new as always. I wonder if the Marc 300 arc lamp power supply would work for the HTI bulbs? (I doubt it, but it would save a lot of money :? ).

Jessh there are several ways to extend the reel size for a projector. I have been favoring building a "multi-use" supply and take-up that could be used with any projector. This would entail using two motors which would directly drive the reel spindle through a continuous-slip clutch that is adjustable to provide the correct torque. You could also use one motor driving the spindles through belt drives. Some people have just extended the reel spindle arms out to allow bigger reels and making longer belts or springs to drive the spindles just like normal. This project is on the back burner right now. I have been amassing the parts to make a 16mm feature projector that would be a permanent installation taking up to 6,000 foot reels using the Marc 300 lamp and tube amps with stereo sound. All based around the incredible B+H JAN projector. My biggest problem is finding the time to do half of my projects.

[JIM DUNN]

Thanks for all the info, guys....Pedro, you're always several steps ahead!...Just shows how I'm crawling out of the Dark Ages. When I was shooting last, Xenon technology was still hot stuff. Any way I look at it, I think the Austin Cinemaker Co-op bunch is gonna have to sponsor a few car washes to pull this one off.....

[S8 Booster]

Pedro, do you have the name/type/model for the S8 equivalent Osram HTI lamps? ( 250/270 W)

Considering rebuilding the local S8 Clubs Elmo GS 1200 projector.

The Osram WEB pages do not work very well with a MAC IE browser ovbiously. SooooooOOOOO SlooooooOOOOW.

Regards

[Pedro]

The two types available are:
HTI 250W/22
HTI 250W/32

for 22 or 32 mm distance between film surface and lamp.

Available at Wittner:
http://www.wittner-kinotechnik.de/katal ... 50_22.html

http://www.wittner-kinotechnik.de/katal ... 50_32.html

Wittner also is offering the feeding module for it.

Consider, that even with the Elmo GS, there is an additional fan required. As I never had seen a proffesional converted Elmo GS, I cannot tell where exactly they mounted that fan. Only into the external door, or integrated into the lamp house?

Pedro

Pedro

[Old8]

:roll: I apologize for my stupid question, but why use a adapted movie projector instead of a video projector? It's not easier to translate it to video? It's not better a good video projection instead of a poor movie projection?

[jessh]

:roll: I apologize for my stupid question, but why use a adapted movie projector instead of a video projector? It's not easier to translate it to video? It's not better a good video projection instead of a poor movie projection?

yes a _good_ video projection may look better than a _poor_ film projection, but thats not a good comparision as this discussion is how to get a _good_ film projection, a good film projection will look much better than a good video projection, but will degrade the film. Many people prefer projecting film, although it does take more work the results can be great. Plus a good video projector still costs a lot more than a good super 8 film projector.

~Jess

[Old8]

But my point is, even if you install a 250-300W lamp would you achieve a better projection then a video projector (a middle range one, for instance)? Do you thing that those projectors (with 250-230W lamps) are good enough for an audience? :roll: I've never saw one but I doubt. I've never seen good S8 projection with screens wider then 6'. All were dark.

[jessh]

But my point is, even if you install a 250-300W lamp would you achieve a better projection then a video projector (a middle range one, for instance)? Do you thing that those projectors (with 250-230W lamps) are good enough for an audience?

Define middle range, I believe that a quality film projector will have better results than a video projector with a comparable Wattage lamp, the main difference is you get the full resolution and exposure latitude of the film while converting it to video and projecting with a video projector will cut both of these down. IMHO A quality film projector with a 250Watt lamp will outperform a video projector that is putting out the same amount of light.

I've never seen good S8 projection with screens wider then 6'. All were dark. :(

Most likely due to the projectors being used not being designed for that big of a screen and having a lamp that just couldn't put out that much light, if you put a more powerful lamp in it then you can fix this problem.

most video projectors I have used dont perform very well on large screens, and the ones that do are _really_ expensive.

~Jess

[Pedro]

I´ve seen film screening with the Beaulieu projector with HTI lamp on a rather big screen (about 3 meters) last year, also in direct comparison with 16 mm screening on the same screen, with a standard 250 W halogen projector. The HTI S8 projection came out significantly brighter!
To compare the brightness, you can assume up to 250 lm for a projector with a 150...200 W halogen reflector bulb and a 1:1...1:1,2 lens. (Elmo GS 1200MO datasheet: 250 lm). A hti lamp with the same wattage is about 4 times brighter, so with a S8 HTI projector you will achieve about 1000 lm or more. With a good screen, you are in the same brightness range as video beamers. Obviously, with video beamers and modern lamp technology, a even brighter result is achievable (frame diameter is bigger), but the overall result sucks in lack of latitude and resolution and richness/reproduction quality of colors.
Most LCD projectors show uneven focus; The conversion of original film to VHS video tape reduces the existing resolution of about 900...1000 lines to about 230 lines (VHS) and the latitude at least to the half of the original. Mostly, even the transfer quality sucks, as it is not always possible to handle the film contrasts in video. Only films, that had been designed to be transfered later on, come out better. But aren´t it the nice contrasts, that make a projection so fascinating?
Pedro