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Author Topic: 250Watt HTI GS1200 Lamp Conversion
Desmond Godwin
Film Handler

Posts: 75
From: Ireland
Registered: Apr 2011

- posted May 08, 2011 05:18 PM      Profile for Desmond Godwin   Author's Homepage   Email Desmond Godwin   Send New Private Message       Edit/Delete Post 
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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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

- posted May 09, 2011 03:50 AM      Profile for John Clancy   Author's Homepage     Send New Private Message       Edit/Delete Post 
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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British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Paul Adsett
Film God

Posts: 5003
From: USA
Registered: Jun 2003

- posted May 09, 2011 07:45 AM      Profile for Paul Adsett     Send New Private Message       Edit/Delete Post 
What does HTI stand for?

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The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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Osi Osgood
Film God

Posts: 10204
From: Mountian Home, ID.
Registered: Jul 2005

- posted May 09, 2011 10:30 AM      Profile for Osi Osgood   Author's Homepage     Send New Private Message       Edit/Delete Post 
How long do these 250 watt bulbs last in your projectors?

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"All these moments will be lost in time, just like ... tears, in the rain. "

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Jean-Marc Toussaint
Film God

Posts: 2392
From: France
Registered: Oct 2004

- posted May 09, 2011 10:45 AM      Profile for Jean-Marc Toussaint   Author's Homepage   Email Jean-Marc Toussaint   Send New Private Message       Edit/Delete Post 
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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The Grindcave Cinema Website

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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

- posted May 10, 2011 02:20 AM      Profile for John Clancy   Author's Homepage     Send New Private Message       Edit/Delete Post 
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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British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Desmond Godwin
Film Handler

Posts: 75
From: Ireland
Registered: Apr 2011

- posted May 10, 2011 08:41 AM      Profile for Desmond Godwin   Author's Homepage   Email Desmond Godwin   Send New Private Message       Edit/Delete Post 
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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Adrian Winchester
Film God

Posts: 2941
From: Croydon, London, UK
Registered: Aug 2004

- posted May 10, 2011 10:30 AM      Profile for Adrian Winchester     Send New Private Message       Edit/Delete Post 
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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Adrian Winchester

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Michael O'Regan
Film God

Posts: 3085
From: Essex, UK
Registered: Oct 2007

- posted May 10, 2011 11:03 AM      Profile for Michael O'Regan   Email Michael O'Regan   Send New Private Message       Edit/Delete Post 
quote:
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.
I wholeheartedly agree.
[Smile]

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

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Colin Robert Hunt
Expert Film Handler

Posts: 226
From: Milton Keynes Buckinghamshire
Registered: Aug 2005

- posted May 10, 2011 11:19 AM      Profile for Colin Robert Hunt   Author's Homepage   Email Colin Robert Hunt   Send New Private Message       Edit/Delete Post 
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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Desmond Godwin
Film Handler

Posts: 75
From: Ireland
Registered: Apr 2011

- posted May 10, 2011 02:34 PM      Profile for Desmond Godwin   Author's Homepage   Email Desmond Godwin   Send New Private Message       Edit/Delete Post 
-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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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

- posted May 10, 2011 03:08 PM      Profile for John Clancy   Author's Homepage     Send New Private Message       Edit/Delete Post 
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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British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Desmond Godwin
Film Handler

Posts: 75
From: Ireland
Registered: Apr 2011

- posted May 10, 2011 03:37 PM      Profile for Desmond Godwin   Author's Homepage   Email Desmond Godwin   Send New Private Message       Edit/Delete Post 
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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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

- posted May 11, 2011 03:30 AM      Profile for John Clancy   Author's Homepage     Send New Private Message       Edit/Delete Post 
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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British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003

- posted May 11, 2011 08:28 AM      Profile for Ugo Grassi     Send New Private Message       Edit/Delete Post 
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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Bye
Ugo

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Winbert Hutahaean
Film God

Posts: 5468
From: Nouméa, New Caledonia
Registered: Jun 2003

- posted May 11, 2011 09:06 AM      Profile for Winbert Hutahaean     Send New Private Message       Edit/Delete Post 
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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Winbert

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Osi Osgood
Film God

Posts: 10204
From: Mountian Home, ID.
Registered: Jul 2005

- posted May 11, 2011 10:25 AM      Profile for Osi Osgood   Author's Homepage     Send New Private Message       Edit/Delete Post 
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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"All these moments will be lost in time, just like ... tears, in the rain. "

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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

- posted May 11, 2011 02:18 PM      Profile for John Clancy   Author's Homepage     Send New Private Message       Edit/Delete Post 
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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British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Desmond Godwin
Film Handler

Posts: 75
From: Ireland
Registered: Apr 2011

- posted May 11, 2011 02:34 PM      Profile for Desmond Godwin   Author's Homepage   Email Desmond Godwin   Send New Private Message       Edit/Delete Post 
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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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003

- posted May 11, 2011 04:43 PM      Profile for Ugo Grassi     Send New Private Message       Edit/Delete Post 
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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Bye
Ugo

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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

- posted May 12, 2011 03:21 AM      Profile for John Clancy   Author's Homepage     Send New Private Message       Edit/Delete Post 
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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British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Desmond Godwin
Film Handler

Posts: 75
From: Ireland
Registered: Apr 2011

- posted May 12, 2011 02:45 PM      Profile for Desmond Godwin   Author's Homepage   Email Desmond Godwin   Send New Private Message       Edit/Delete Post 
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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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
Registered: Jun 2003

- posted May 12, 2011 03:58 PM      Profile for John Clancy   Author's Homepage     Send New Private Message       Edit/Delete Post 
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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British Film Collectors Convention home page www.bfcc.biz. The site is for the whole of the film collecting hobby and not just the BFCC.

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Desmond Godwin
Film Handler

Posts: 75
From: Ireland
Registered: Apr 2011

- posted May 12, 2011 04:30 PM      Profile for Desmond Godwin   Author's Homepage   Email Desmond Godwin   Send New Private Message       Edit/Delete Post 
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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Alan Rik
Film God

Posts: 2211
From: New York City, NY, USA
Registered: Jun 2003

- posted May 12, 2011 06:00 PM      Profile for Alan Rik   Email Alan Rik   Send New Private Message       Edit/Delete Post 
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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