This is topic 250Watt HTI GS1200 Lamp Conversion in forum 8mm Forum at 8mm Forum.


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Posted by Desmond Godwin (Member # 2530) on May 08, 2011, 05:18 PM:
 
Looking thru some of the German Elmo links (and im not advertising anything here,or intend too) I noticed a HTI lamp conversion for the GS1200. I have seen a GS1200 with this lamp conversion.The machine had its standard 3 Blade shutter and i was impressed with the light output.At switch-on the HTI discharge lamp needed a couple of minutes to come up to full
working brighness. It appeared to me that during the span of the 20 min film run that there was some colour temperature change, most noticable on the whiter area's of the film content. The conversion was done with no heat filter in place and a certain amount of extra hum on the audio was present - i suppose due to the 'square wave current' feeding the lamp and producing harmonics that find their way into the sound head's... I think the standard GS1200 with The Xenon lamp is the better option...




 

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Posted by John Clancy (Member # 49) on May 09, 2011, 03:50 AM:
 
Nope, for projection the HTI is far superior as we have proved over the years at the BFCC's. Whether or not near 35mm brightness is a requirement in the home is another matter but there is no way I could go back to a standard xenon after the light output of the HTI.
 

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Posted by Paul Adsett (Member # 25) on May 09, 2011, 07:45 AM:
 
What does HTI stand for?
 

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Posted by Osi Osgood (Member # 424) on May 09, 2011, 10:30 AM:
 
How long do these 250 watt bulbs last in your projectors?
 

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Posted by Jean-Marc Toussaint (Member # 270) on May 09, 2011, 10:45 AM:
 
I must say that John's converted GS is pretty spectacular. I was attending the inaugural screening at the BFCC (a scope reel from El Cid, if I remember correctly) and I almost reached for my shades.
I have a perfectly tuned xenon projector but I see this conversion as an interesting alternative if you can't get your paws on an original machine.
 

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Posted by John Clancy (Member # 49) on May 10, 2011, 02:20 AM:
 
The lamps are supposedly good for 250 hours Osi. But in reality the light output starts falling off noticeably after about 150 hours. Given that I'm now self-employed I've had to reserve the HTI (High Tension Intensity, I believe) just for the conventions as the exchange rate against the [doomed!!!] Euro has rocketed the price of the lamps from around £125 to £200.
 

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Posted by Desmond Godwin (Member # 2530) on May 10, 2011, 08:41 AM:
 
So a standard GS1200 'Xenon' and a 'HTI' converted, stand side by side after 150 Hrs & project the same size picture,which one is going to be the brighter? & due to the cost's of the lamp you
might want to stick it out for maybe another 100 hrs on the HTI -by which time it will have lost nearly all its initial luminosity..Yes there will be wear on the Xenon lamp but it will pass-out the HTI and burn-on bright for another 500 + hrs. I have a EiKi 4000p projector and ite 550 watt Xenon lamp is still going strong after 860 hrs. Let's say 1K hrs for the Xenon (pushing it.) by that time you would have had to replace the HTI 4 Times at a cost (per yorself @ £200 a piece) Where as the 250W Xenon lamp for the GS1200 is weighing in at £270. I disagree with you that the 'HTI' lamp (forget about its initial brightness) is 'far superior' than a Xenon.
 

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Posted by Adrian Winchester (Member # 248) on May 10, 2011, 10:30 AM:
 
Desmond - your analysis concludes that the Xenon is more economic, but I'm sure that John is taking into account the factor of showmanship when it comes to the enormous BFCC screen. When I see the astonishingly bright image at BFCCs, I'm certainly grateful that John has been willing to go to the expense needed to make the presentation so impressive.
 

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Posted by Michael O'Regan (Member # 938) on May 10, 2011, 11:03 AM:
 

quote:

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When I see the astonishingly bright image at BFCCs, I'm certainly grateful that John has been willing to go to the expense needed to make the presentation so impressive.

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I wholeheartedly agree.


BTW, what is the throw distance in the Ealing Hall?
 

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Posted by Colin Robert Hunt (Member # 433) on May 10, 2011, 11:19 AM:
 
Thanks John for bringing the projector to the BFCC shows. A outstanding light output and needed for that 24ft screen. Look forward to meeting it again this week.
 

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Posted by Desmond Godwin (Member # 2530) on May 10, 2011, 02:34 PM:
 
-well at least there will be 'outstanding light output' to fill a 24ft screen left in the Xenon powered projector,long after its HTI equivalent has 'popped its clogs'
 

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Posted by John Clancy (Member # 49) on May 10, 2011, 03:08 PM:
 
Sorry Desmond, the xenon just ain't bright enough. Once you've seen HTI on a screen of this size a standard xenon doesn't come close. I have the HTI with me right now as we're on the road filming - I checked it before we left on a small screen in daylight and it was still bloody bright.

No comparison. It's more expensive but for the purpose I need an HTI for - to showcase Super 8 to the world - it's the best solution on the market.
 

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Posted by Desmond Godwin (Member # 2530) on May 10, 2011, 03:37 PM:
 
Has it been possible for you to measure the centre screen
light flux between the two lamp's (say on your 24ft screen)
I would like to know what reading(s) you obtained..
 

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Posted by John Clancy (Member # 49) on May 11, 2011, 03:30 AM:
 
We did this on my 10ft screen when Bill Parsons first carried out the conversion. I can't recall the exact readings but the light output is something between double to three times a standard xenon.

Of course, Bill Parsons is the master so it's possible his work is the best and brightest of any HTI conversion. At the 50th BFCC when we unveiled the HTI we had the standard xenon running first just so everyone could see how superior HTI lighting is - it made the point and as a result there has never been any discussion on this issue, until now.

One other thing to note is the xenon we use has a two-bladed shutter but this isn't really practical with the HTI as it is so bright, therefore the three-bladed shutter has been retained. I think the film would melt as it went through the gate if we opted for a two-blade!!!
 

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Posted by Ugo Grassi (Member # 139) on May 11, 2011, 08:28 AM:
 
I have both the machines and I run many tests.
The result is that is possible to achieve 1000 lux on one metre screen by both the projectors.
Anyway while with the HTI a three blades shutter is enough (with a"young" lamp) to obtain this value, the"genuine" xenon needs a two blades shutter.
Over 1000 lux is impossible to go. Or with the xenon or with the HTI if the lux on the screen is higher, the film is damaged by the overheat on the frame.
To get a brighter screen a water cooling is necessary.

[ May 13, 2011, 12:52 AM: Message edited by: Ugo Grassi ]
 

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Posted by Winbert Hutahaean (Member # 58) on May 11, 2011, 09:06 AM:
 
I'am really curios to see how 8mm is projected in that really big screen like that?

How the resolution is seen, knowing originally is 8mm width.
 

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Posted by Osi Osgood (Member # 424) on May 11, 2011, 10:25 AM:
 
Let me understand clearly ...

Are these lamps usually used in digital projection TV's? I remember a series of posts on that very subject quite a long while back.

Sheesh! What an enormous cost for one bloody lamp!
 

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Posted by John Clancy (Member # 49) on May 11, 2011, 02:18 PM:
 
Most common use is endoscopy Osi.

Ugo that would explain why my HTI can melt a frame out if it stops in the gate for a fraction of a second - it appear mine is brighter than any other machine. I'm not surprised as it is so visibly superior to the xenon.
 

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Posted by Desmond Godwin (Member # 2530) on May 11, 2011, 02:34 PM:
 
Tkns Ugo for you info on the lumen measurement comparing both the 250W Xenon lamp and the Osram 250W 'HTI' - so you clearly are saying that both lamps are producing 1000 LUX with just a change of shutter on the Xenon Projector (a relatvely easy task)
and then both projectors produce the same light output, except
that the so called 'superior' HTI lamp is starting to 'fall off'
in lumen output from its very first fire-up...
 

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Posted by Ugo Grassi (Member # 139) on May 11, 2011, 04:43 PM:
 
Yes Desmond, right. The HTI lamp inside my converted GS1200 worked for about 120 h. and the light output is lower then the first switches on (30-40% less). Anyway I have to say I stressed the lamp with many strikes, every one for short projections. Probably with a bit of care more the downturn would have been less (20-30%).
John, about the damage to the film over a 1000 lux output, the damage was not a frame melt, but a deformation of the frame. This was on my SMPTE test film on triacetate. Probably a mylar film is stronger.
 

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Posted by John Clancy (Member # 49) on May 12, 2011, 03:21 AM:
 
I'm very wary of putting any Kodachrome through the HTI when the lamp is new Ugo. It does appear from what you've said that mine produces far more light than other HTI conversions - the difference is significant and cannot be compared to the xenon. After about 150 hours the light starts coming down to xenon levels which is okay at home but not for the big screen.

Desmond, I think you'll find a standard GS1200 with a 200 watt genuine ESC lamp puts out more than enough light for your requirements. Installing a two-bladed shutter will increase the light still further and for the average home screen this is more than adequate. HTI is a bit over the top for anything less than 10ft wide whereas xenon is impressive and ESC is more than acceptable. A standard machine should also be cheaper to purchase whereas a xenon carries a premium price and you're probably looking at at least double that for an HTI.
 

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Posted by Desmond Godwin (Member # 2530) on May 12, 2011, 02:45 PM:
 
I don't see in Ugo's post's where he is saying that John's
HTI converted projector is producing 'far more light than other
HTI conversion(s).. What i do see is that Ugo is saying that a
xenon (with 2 blade shutter) and HTI with 3 blade shutter are both producing 1K lux of light (young HTI bulb in circuit) on a
1 metre screen. Ugo has done many test's on these machines and his articles appear in Film magazine's. He also confirm's back to me that this is correct. I find it hard to believe that John
is saying after 150hrs (on the HTI) that its down to the light
output of a Xenon! To prove this i attatch graph's from Osram's
HTI data booklet, I place a line at the 150 hrs. The 2nd graph is to show colour shift's against time..






 

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Posted by John Clancy (Member # 49) on May 12, 2011, 03:58 PM:
 
You've convinced yourself Desmond so I won't bother trying to tell you how bright my HTI is any longer. Fortunately hundreds of people have seen it demonstrated so they know I'm right. But like I keep saying HTI or even xenon is not really required for most home screens. Only film convention organizers who are enthusiasts are likely to ever invest in HTI projection and unless you are as obsessive as I can be I don't think HTI is a consideration.
 

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Posted by Desmond Godwin (Member # 2530) on May 12, 2011, 04:30 PM:
 
I don't need to convince myself John that the 'Xenon' lamp is the better option, I already know it. The fact's speak for themselve's
 

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Posted by Alan Rik (Member # 73) on May 12, 2011, 06:00 PM:
 
For really large projections the HTI is better. Its just a lot more brighter.
I rented out my GS Xenon for a Super 8 Independent Film Festival at the Walter Reade Theatre in NYC to fill up a 25 foot screen. It was ok.. but it just wasn't bright enough. I have seen the HTI lamp on a Beaulieu 708 and it was stunningly bright. It definitely may not be as economical or as compact stylistically as the GS Xenon but if you need really bright images HTI is the way to go in my opinion. Plus you can keep the 3 bladed shutter which is what all the Super 8 films they showed at the festival were shot at.
 

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Posted by Desmond Godwin (Member # 2530) on May 12, 2011, 06:34 PM:
 
You may have missed the top posting's but its already been
verified by Ugo (after a lot of testing) that there is the same light lux from both the Xenon (2 blade shutter) and the HTI 3 blade machine.. Anything more than 1K lux and the film
will suffer... The HTI lamp\lumen life is short so I will just repeat that the fact's speak for themselve's.. The Xenon lamp is the better & more economical option -(if You are bringing
economy into it.)
 

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Posted by Adrian Winchester (Member # 248) on May 12, 2011, 08:32 PM:
 
Whatever grounds you have for saying the Xenon lamp is as bright (and you are clearly driven to making the point as emphatically as possible), you cannot alter the evidence in favour of John's HTI that us BFCC regulars have seen with our own eyes. Year after year, I would see the Xenon image on that enormous screen and although impressive, I'd have to concede that it was a bit dim. Then, with the HTI, it suddenly wasn't dim - it was the sort of brightness you would want when projecting on your home screen. You may feel that this was some sort of mass delusion, but if it was, I'm grateful that it has continued to happen at every BFCC since!

[ May 13, 2011, 04:06 AM: Message edited by: Adrian Winchester ]
 

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Posted by Desmond Godwin (Member # 2530) on May 13, 2011, 10:45 AM:
 
I have no intention to alter any 'evidence' Thank god its something i have never had to do in my lifetime..
My point is that as far as im concerned,and im happy that i have clearly got this point across to you, that the 250W Xenon lamp on the GS 1200 is the better option. I wonder is there any
forum members that would have had their Xenon machine converted
over to a HTI? I will leave this post open for an answer.....
 

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Posted by Douglas Meltzer (Member # 28) on May 13, 2011, 11:01 AM:
 
Perhaps I should add HTI Conversions to the no discussion of politics or religion rule!

Doug
 

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Posted by Claus Harding (Member # 702) on May 13, 2011, 01:32 PM:
 
All of this comes down to the same old question: what are your requirements vs. how much do you want to pay for it?

If you want/need the absolute brightest Super-8 image, then it's HTI, regardless of the cost of the bulb or length of life of same. Footcandles are footcandles. The life of the bulb is a separate isssue.

If you want a very bright Super-8 image (up to a certain screen size) then the Xenon option is both bright and with a better "dollar versus hours" ratio. You get more "life" for your money, at the cost of lower lumens.

I have the standard GS-1200 on my 9-foot screen; it looks decent and the bulbs are about $35 for a 50-some hr lifespan. Compared to a Xenon, this is not 'economical' nor is it enormously bright.

The cost of the 350W Xenon bulb for my 16mm Eiki is about $350 all told, but then again, it is rated at around 1500 hours, so cost-effective, as long as you don't abuse it with hot strikes and such.

An HTI would be screaming at my throw of 22 feet, and would be massive overkill. It could be fun, but not at the cost involved.

Physics don't lie. And you get what you pay for

Claus.
 

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Posted by John Clancy (Member # 49) on May 15, 2011, 12:33 AM:
 
No one is likely to convert a xenon machine to HTI. The conversion is done to a standard machine.

Claus has summed it all up perfectly. I wanted the best possibly Super 8 quality and so I went with HTI. Glad I did and worth every penny. I would not have been satisfied with a half-way house standard xenon. Having said that some xenons are better than others and the same is true of HTI but HTI is so much brighter it's not such an issue.

That's the end of it for me and I won't contribute to this thread again.
 

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Posted by Desmond Godwin (Member # 2530) on May 16, 2011, 02:26 PM:
 
Nope,as i said in my introduction thread the Xenon Lamp is the
better option and i am staying with that.Its really backed-up
by the 1000's of Elmo GS 1200 user's out there that have the
Xenon model..The Xenon machine is mechanically the same as
John's 'standard' version and it could easily be converted to HTI. I just left the thread open it see if anyone has done that
on the assumption that the HTI is so superior.

 

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Posted by Adrian Winchester (Member # 248) on May 16, 2011, 07:40 PM:
 
With respect, that's crazy! A Xenon GS obviously has much higher light output than a standard GS and is generally much more expensive to buy. The idea of converting one to a HTI would be therefore be absurd and I'd imagine there might also be complications in terms of the electronic circuitry.

A Xenon owner has no need of a boost to the light output. Even if one found they needed to regularly project onto a massive BFCC-style screen, it would make far more sense to buy a standard GS for conversion, selling the Xenon for a higher price if necessary, than it would to convert a Xenon.

As for your point that you think the Xenon's superiority is: "backed-up by the 1000's of Elmo GS 1200 user's out there that have the Xenon model", I can't believe you're being serious!

[ May 16, 2011, 10:12 PM: Message edited by: Adrian Winchester ]
 

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Posted by Lee Mannering (Member # 728) on January 09, 2013, 08:20 AM:
 
A couple of years on now since this post started, but seeing as I’ve been busy checking over my Xenon GS I just wondered how people who are using HTI converted machines are fairing? For a good number of years I used to project at a film festival using the Xenon on a whopper screen showing films made at 18 and 24fps so no chance of using a two blade shutter, but the image quality was excellent and is from the Xenon.

HTI feedback anyone?
 

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Posted by Alan Rik (Member # 73) on January 09, 2013, 09:12 AM:
 
Pick me pick me!
I am running a Beaulieu 708 HTI and the picture is brilliant!
The cool white HTI light is very, very bright. I use to own the GS1200 Xenon (2 of them) and while the whiteness of the lamp was great I always felt it just wasn't quite bright enough. I never did have the 2 bladed conversion though. I need the 18fps option as well.
But the HTI which has the 3 bladed shutter is just awesome. The picture has such sizzle and when I use it for scope films..it doesn't lose much light. Just a fabulous machine and the only one I use for Magnetic films.


 

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Posted by Gary Crawford (Member # 67) on January 09, 2013, 11:11 AM:
 
Sorry to extend this thread even more, but at the beginning of the thread years ago....it was mentioned that the HTI conversion resulted in extra hum in the sound circuits. Then that subject was dropped from the conversation. I'm still wondering about that aspect. Also wondering if Leon Norris here in the states has thought about doing these conversions.
 

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Posted by Lee Mannering (Member # 728) on January 10, 2013, 06:25 AM:
 
It would be interesting Gary to see how people who have HTI converted machines are fairing but at present apart from yourself no one seems to be actively using them on here other than once a year at Ealing. I find it a little difficult having been used to the Xenon GS for so many years used at bigger screenings entertaining the notion of HTI although it may well be better today. I’m a bit of a stickler for avoiding extreme modification of machines that were not designed for more recent technology, but that’s just me.
 

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Posted by Dino Everette (Member # 1378) on January 10, 2013, 11:23 PM:
 
The thing that got me about this thread was the bickering, it wS LIKE A "mY DAD CAN KICK YOUR DAD'S BUTT!" and the fact that all of the "evidence" from Ugo about the HTI was not taken from John's machine so it really means nothing, and the only person who mentioned the audio hum was Desmond who clearly was not a fan of the HTI..I am guessing that if there was a noticeable audio hum, all of those people who see John's machine in action at the BFCC each year would have been commenting on it...As a newcomer to the GS I think the lamp output is perfectly fine for home projection, so that is all I need.
 

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Posted by Alan Rik (Member # 73) on January 11, 2013, 02:16 AM:
 
The thing with the HTI machine is that when Beaulieu decided to make a high power light for their 708 they could have gone with the Xenon but they chose the HTI as a modern light source that they felt was a better option.
Yes there are pro's and cons with the HTI like the Xenon as has been discussed here.
I think the reason why the Elmo HTI mods got such a bad rap is that the few of them that are out there have been hack jobs. I am sure that the Parsons/Clancy HTI is a CORRECTLY done mod. Meaning no hum, great light output, etc.
A few years ago I remember hearing that in order to fit the correct lamphouse and other things needed to fit the HTI in the GS1200 you had to remove one of the speakers! So in essence you had a one speaker GS! And you had hum from the Square Wave caused by the HTI lamp!
Many moons ago I was told by Bavaria Film that they were not doing the Elmo HTI conversion any longer but were still doing the Beaulieu. They said it was due to the lack of parts from Elmo and the difficulty level.
My Beaulieu HTI has no hum, is really bright, has both speakers sounding very good, and looks wonderful.
Us discussing the merits of the good and the bad are heated at times but in the end the most important thing is the film we are watching. "The Rose" digest ....even with the HTI....still puts me to sleep!
But I remember watching "Enter the Dragon" digest on my crappy Chinon 4100 and I wore the print out. Friends came over to watch the film over and over. It would jam..break..I would splice...the show would continue.
Such great memories with the 50 watt, film eating Chinon!
 

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Posted by Lee Mannering (Member # 728) on January 11, 2013, 04:44 AM:
 
Interesting reading you guys.
Know very little about these HTI mods hence the interest in how people are going on with modified machines. Looking at the pictures and only guessing that you can use a standard GS1200 as well as a Xenon, or have I got that wrong? I also wonder what sort of expense would be incurred to modify a GS as I sometimes use my Xenon in a cinema type situation and large audiences so if the HTI is a improvement it might be handy to have a lesser GS upgraded.
 

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Posted by Jean-Louis Seguin (Member # 2200) on January 11, 2013, 12:30 PM:
 
I am curious as to whether this HTI mod is available as DIY kit or if the projector has to be sent for modification. Who does these mods? Thanks.

Jean-Louis
 

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Posted by Flavio Stabile (Member # 357) on January 11, 2013, 02:00 PM:
 
Hi Alan, your HTI Beaulieu looks like very nice!

Honestly I would prefer the HTI to the Xenon lamp for the ease of its replacement, when needed.

F.
 

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Posted by Lee Mannering (Member # 728) on January 12, 2013, 05:05 AM:
 
That could be a very good point Flavio.
 

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Posted by Adrian Winchester (Member # 248) on January 12, 2013, 11:59 AM:
 

quote:

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The thing with the HTI machine is that when Beaulieu decided to make a high power light for their 708 they could have gone with the Xenon but they chose the HTI as a modern light source that they felt was a better option.

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