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Author Topic: Elmo's Poor Design
Paul Adsett
Film God

Posts: 5003
From: USA
Registered: Jun 2003

- posted September 18, 2008 09:27 AM      Profile for Paul Adsett     Send New Private Message       Edit/Delete Post 
Do you find that you are constantly fiddling with the focus when running films on your GS1200, especially when using an f1.0 lens?
I find this to be the case on both my GS's and have concluded that it has nothing to do with the film or the lens itself. The problem lies in Elmo's poor design of the lens holder, which permits small misalignments of the lens to occur even after you have initially focused the picture. Bear in mind with a fast f1.1 or f1.2 lens the positional accuracy of the lens probably has to be within .001 or .002 ins to get really sharp focus. As I see it, the GS lens holder design is a failure on that criteria because:

1. The length of the cyclindrical lens holder is much to short in relation to the lens itself. Basically you have a long heavy glass lens cantilevered out from a short lens snout.

2. The lens does not ride on a precise location. Yes, there are 3 flat areas on the inside of the snout, but I would not call these precision. They are rough and have sharp edges.

3. The little spring loaded ball is insufficient force to remove all the 'slop' from the lens holder.

4. The two oversize holes on the lens holder and the little adjusting screw on the side provide capability for vertical and horizontal plane alignment of the lens, but make it virtually impossible to do so accurately, because you are constantly juggling the "cross talk' between these two adjustments.

So overall, I give Elmo a poor grade for this very crucial part of the GS design.

In contrast, I find that I never have to adjust the focus on my Eumig 938 when fitted with the f1.0 Kodak Ektar lens. Adjust it once, and it stays dead nuts through the whole reel. Set it and forget it. And the reason is obvious. Unlike the Elmo, the Eumig lens is heavily spring loaded into a massive V-GROOVE precision machined directly into the chassis. This groove engages most of the length of the lens, and the lens 'overhang' is nowhere near that of the Elmo. So the lens stays put, and 10 out of 10 for the Eumig designers in this critical area.
Bottom line is, film projection on the 938 is a very relaxing experience whereas the GS projection needs constant monitoring for focus and is therefore less enjoyable.

--------------------
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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David Pannell
Phenomenal Film Handler

Posts: 1072
From: Horsham, West Sussex, UK
Registered: Nov 2004

- posted September 18, 2008 09:48 AM      Profile for David Pannell   Author's Homepage     Send New Private Message       Edit/Delete Post 
Paul,

I have the same experience with my ST 1200 HD and the 1.1 lens.

Do I feel a project coming on???

Are you going to tackle this one, or shall I have a go at it?

The only thing is, is that I won't be able to get down to it for some time.........maybe you would like to start it off.

Cheers,

--------------------
Dave.

Valves and celluloid - a great combination!
Early technology rules OK!

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Claus Harding
Phenomenal Film Handler

Posts: 1149
From: Washington DC
Registered: Oct 2006

- posted September 18, 2008 10:15 AM      Profile for Claus Harding   Email Claus Harding   Send New Private Message       Edit/Delete Post 
David,

I was about to post the exact same thing (ST1200HD/1.1 lens), but I didn't know if the lens mount was the same as on the GS.
Well, count me in among the ones who feel that particular design could have been better.
(I still wouldn't trade the ST for anything but a GS, a Fumeo or a Beaulieu, but this focus issue is a valid point.)

Claus.

--------------------
"Why are there shots of deserts in a scene that's supposed to take place in Belgium during the winter?" (Review of 'Battle of the Bulge'.)

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Osi Osgood
Film God

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

- posted September 18, 2008 10:23 AM      Profile for Osi Osgood   Author's Homepage     Send New Private Message       Edit/Delete Post 
Hoo Hoo!

What is this I hear? Problems with the almighty ELMO?

"snicker snicker", goes the proud owner of the EUMIGS!!

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

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Gary Crawford
Jedi Master Film Handler

Posts: 979
From: Manassas, VA. USA
Registered: Jun 2003

- posted September 18, 2008 01:34 PM      Profile for Gary Crawford     Send New Private Message       Edit/Delete Post 
The problem on the Elmo's seems to be inconsistent from machine to machine. I have a half dozen st1200Hd's...two 800's and a 180....I don't have a 1.0 lens, but I do have two 1.1's and I have focus stablility issues with only two of the 1200's....in both the lens sits in there fairly loosely. The others are very very good on maintaining focus. When I have had to use the other two machines....I've either used the 1.3 lens that came with it ....or taken a small piece of duct tape and taped the lens down carefully after focusing. Seemed to work ok.

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Joerg Niggemann
Expert Film Handler

Posts: 127
From: Germany
Registered: May 2006

- posted September 18, 2008 02:01 PM      Profile for Joerg Niggemann   Email Joerg Niggemann   Send New Private Message       Edit/Delete Post 
This thread takes us back to Paul's beloved masterpiece "Elmig GS 938" once again [Smile]

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Alan Rik
Film God

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

- posted September 18, 2008 02:09 PM      Profile for Alan Rik   Email Alan Rik   Send New Private Message       Edit/Delete Post 
I use to have the problem with the GS and the 1.0 lens. But when I switched it out for the Schneider 1.1 all is perfect.
The lens holder assembly on the Beaulieu is MUCH better as well. The lens gets locked onto a holder and then the holder goes forward or back depending using a very fine adjustment. Its very precise and stays put!
With the Eumigs the manner in which you are supposed to focus the lens is not very precise. You turn this knob but it seems to have a little play. You never feel its truly dialed in like with the Beaulieu.

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

- posted September 18, 2008 03:17 PM      Profile for Kevin Faulkner         Edit/Delete Post 
Yes I have to agree with all that has been said. Focus or should I say maintaining focus cane be a real chore sometimes.

Now I have suggestion for you all with focus problems. Check to see if it always goes out in the same direction. Do you always have to move the lens back again towards the gate to get it in focus?

I conducted some tests a few years a go and I found I got much better stability by removing the spring strip from the lens holder which pushes against the back of the lens.

My theory is that with the spring pushing on the rear of the lens and the natural vibration from the machine that the lens moves forward on its own.
I ran a machine without the spring which I think is there to keep the lens focusing pin forward in the focus worm. Without the spring the lens is slightly more floppy when adjusting the foduc. I didn't go much further than this with my tests but I'm sure this is what is happening and I'm sure the focus held better.

Anyone fancy following this theory up....DAVID?

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Patrick Walsh
Jedi Master Film Handler

Posts: 723
From: Christchurch, New Zealand
Registered: Jul 2006

- posted September 18, 2008 08:53 PM      Profile for Patrick Walsh   Email Patrick Walsh   Send New Private Message       Edit/Delete Post 
MY GS HAS FOCUS PROBLEMS AS WELL, ALSO MINE HAS THE TENDENCY TO BE OUT OF FOCUS ON ONE SIDE OF THE SCREEN FROM TOP TO BOTTOM..... ANY IDEAS WHAT THAT IS?????? [Confused]
PAT

--------------------
"Raise The Titanic!", It would of been cheaper to lower the Atlantic!

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David Kilderry
Jedi Master Film Handler

Posts: 963
From: Melbourne, Victoria, Australia
Registered: Feb 2006

- posted September 18, 2008 09:51 PM      Profile for David Kilderry   Author's Homepage     Send New Private Message       Edit/Delete Post 
Yep, spot on Paul. My two ST 1200 projectors have always suffered from the focus problem.

I can tell you it is even more of a pain when your projectors are in a separate projection room!

David

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John W. Black
Jedi Master Film Handler

Posts: 536
From: Deptford,N.J.
Registered: Mar 2008

- posted September 18, 2008 09:56 PM      Profile for John W. Black   Author's Homepage     Send New Private Message       Edit/Delete Post 
I finally get to rant an opinion I've had for years.Elmo is the most overrated projector out there.I've had a gs-1200,which was a fussy diva of a machine for the money.The person who got me stared in film collecting when I was a child was a projector repairman.He purchased one and hated it.The framer is always a pain,film jumps if everything isn't perfect.He did like the GS800.I also had a couple ST1200s M/O.Same jumping problems and truth be told,The Chinon 9500 reproduced optical tracks much better.
I'm glad to see others don't worship at the alter of Elmo,I never understood it and never will.

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Beat em or burn em,they go up pretty quick

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Alan Rik
Film God

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From: New York City, NY, USA
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- posted September 18, 2008 10:33 PM      Profile for Alan Rik   Email Alan Rik   Send New Private Message       Edit/Delete Post 
It could be that you got a "bad" Elmo GS1200! I know that there are a lot of them around. With all the electronics that you have in there...if the previous owner didn't take care of it you can bet somewhere down the line you will have problems. It isn't perfect but I have to say I have owned many hi end Super 8 Projectors. After trying them all I have come full circle and realized for me...the GS1200 is the best one. It may not have the sharpest focus all the time like the Beaulieu, or the huge reel capacity of the Fumeos, or the cool mixing console of the Eumigs...but it seems to be the best of all the projectors around. Great bright picture, very good sound, Pulse sync, 1200ft reels, optical reproduction...just a great machine. And now I'm looking to get another Xenon machine. I had a total of 3 in the past and I let them all go. What was I thinking? [Smile]

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Graham Ritchie
Film God

Posts: 4001
From: New Zealand
Registered: Feb 2006

- posted September 19, 2008 12:10 AM      Profile for Graham Ritchie   Email Graham Ritchie   Send New Private Message       Edit/Delete Post 
Hi Pat
In this picture there is a small adjusting screw on the bottom of the lens barrel you can just see this and is for adjusting the focus, even it up "left or right" , not for top or bottom.
-
Excuse the reflection in this photo this is due to my "ultra clean gate" [Smile] kidding aside...once the lens holder is aligned top/bottom, left/right the projector should run fine. I have my GS1200 adjusted for the least film resistance through the gate and it runs really smooth. The Elmo design might not be the best but I would not to change it for any other make of projector, one must also remember that films do shrink and dry out over time so focus problems can occur and its not always the projectors fault. I do have films that need constant watching when running, in saying that I also have films I can leave alone and the focus stays fine throughout, Super8 film is more critical focus wise than 16mm simply due to its small frame size, well thats my tuppence worth [Wink]

Graham. [Smile]

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Paul Adsett
Film God

Posts: 5003
From: USA
Registered: Jun 2003

- posted September 19, 2008 09:41 AM      Profile for Paul Adsett     Send New Private Message       Edit/Delete Post 
I tried something last night which seemed to help quite a bit with the focus retention issue, at least on my particular projector. I removed the flat spring which is on top of the lens barrel (the one which pushes down on the ball) and bent it into a downward curve by about 30 degrees. Then I reinstalled it over the ball. When you do this the spring force on the ball is increased significantly and it seems to hold the lens in place much better, with a lot less wobble. After doing this I ran a whole reel of one of my sharpest prints and the projector stayed in focus all the way. Something you might want to try, and it is only a 5 minute job.

--------------------
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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Maurice Leakey
Film God

Posts: 5895
From: Bristol. United Kingdom
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- posted September 19, 2008 09:48 AM      Profile for Maurice Leakey   Email Maurice Leakey   Send New Private Message       Edit/Delete Post 
With my luck the spring would break.

--------------------
Maurice

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Osi Osgood
Film God

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From: Mountian Home, ID.
Registered: Jul 2005

- posted September 19, 2008 09:49 AM      Profile for Osi Osgood   Author's Homepage     Send New Private Message       Edit/Delete Post 
Trying to be a help for once (at least with the GS 1200), could it vary with the film? If the film is aged and perhaps even warped, it may slide through the film gate with more difficulty, therefore causing a slight vibration, causing the focus to go a-wry?

Is it on all films going through your GS1200 Paul?

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

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Gary Crawford
Jedi Master Film Handler

Posts: 979
From: Manassas, VA. USA
Registered: Jun 2003

- posted September 19, 2008 11:59 AM      Profile for Gary Crawford     Send New Private Message       Edit/Delete Post 
I don't own a GS1200 ...yet...but I do have half a dozen st1200hd's and a D model and an older plain green 1200 as well...and two 800's and one 180...and I can say for sure, I have never had a problem wit film jumping or losing loops with any of them. I do have one I've had since it was new back in 75 or 76...and it's beginning to get a little unsteadiness to it, but that's it. All my 1200's take splices like they aren't there. I run film that goes from brand new today to films I bought in the early 70's...and still no real problems. I have had sometimes some clatter or jitter with a few films...and a little film cleaner /lubricant took care of it. I am not mechanically endowed, so the most I've ever done to these machines is change belts, clean heads and paths...and clean and regrease gears. I do know people with GS1200's that have the machines spend more time on the bench being worked on than on the projector stand showing movies. I have heard , even from the earliest days of the GS that it was a little more finicky with film....not as forgiving of any little defect or flaw with the film. Not so with any of the ST1200's I have.

And, as I said earlier in the thread, only two of them seem to have problems holding focus.

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Bill Brandenstein
Phenomenal Film Handler

Posts: 1632
From: California
Registered: Aug 2007

- posted September 19, 2008 03:34 PM      Profile for Bill Brandenstein   Email Bill Brandenstein   Send New Private Message       Edit/Delete Post 
Lest you choose to worship at the Eumig shrine too quickly, let me add that the 938 might be a crackerjack machine, but that the 800 series units must certainly be sloppy in focus by comparison. At least that's been my experience.

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

- posted September 19, 2008 04:45 PM      Profile for Kevin Faulkner         Edit/Delete Post 
Paul, Your suggestion with the top spring on the ball bearing may also be a counter measure to what I was saying in my earlier thread.

As for the Elmo's being finicky with film problems etc that has not been something I have encountered either unless the machines have been badly maintained or fiddled with.
What I will say is that green film and old film runs better if lubricated other than that they are as reliable transporting film as any other projector.

Top to bottom focus is achieved by slackening the two screws which hold the lens holder to the machine and then moving the whole assembly forward or back to achieve optimum focus in that plane. Do not move the lens assembly up or down as this will move the pressure plate position with regards to the gate.

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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John Clancy
Phenomenal Film Handler

Posts: 1954
From: Cornwall
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- posted September 20, 2008 03:39 AM      Profile for John Clancy   Author's Homepage     Send New Private Message       Edit/Delete Post 
I have three GS1200's and don't have this problem on any of them. And that's with the F1.0 lens installed in each of them.

--------------------
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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Adrian Winchester
Film God

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From: Croydon, London, UK
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- posted September 20, 2008 09:02 AM      Profile for Adrian Winchester     Send New Private Message       Edit/Delete Post 
I've never had the pleasure of using a Eumig 938, or any Eumig beyond the 826, but I must say that the focussing knob/mechanism on all of the 800 series projectors I've owned has been so poor that Eumig should certainly have learned how NOT to keep a film in focus by the 900 series!

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Adrian Winchester

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Maurice Leakey
Film God

Posts: 5895
From: Bristol. United Kingdom
Registered: Oct 2007

- posted September 20, 2008 12:18 PM      Profile for Maurice Leakey   Email Maurice Leakey   Send New Private Message       Edit/Delete Post 
A problem with the later Eumigs is the small plastic pin on the lens which mates with the focus knob. This pin wears down with use and then becomes "sloppy" in the helical groove.

--------------------
Maurice

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David Pannell
Phenomenal Film Handler

Posts: 1072
From: Horsham, West Sussex, UK
Registered: Nov 2004

- posted September 20, 2008 01:20 PM      Profile for David Pannell   Author's Homepage     Send New Private Message       Edit/Delete Post 
Kevin, Paul et al,

Maybe I'm getting a bit too technical here, particularly in view of the 2 simple remedies already described, but I'm thinking in terms of a locking thumb screw arrangement with a tapped hole somewhere on the lens holder, so that the threaded portion of the thumb screw just bears onto the lens barrel when screwed in 'finger tight'.

I don't know how feasible this would be, as I'm just thinking aloud at the moment, so to speak. I'll have to investigate further.

Any thoughts?

--------------------
Dave.

Valves and celluloid - a great combination!
Early technology rules OK!

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Martin Jones
Phenomenal Film Handler

Posts: 1269
From: Thetford , Norfolk,England
Registered: May 2008

- posted September 20, 2008 02:12 PM      Profile for Martin Jones     Send New Private Message       Edit/Delete Post 
Maurice,
I succesfully repaired a broken off focus pin on my Eumig 926 by filing it flush to the lens barrel, carefully drilling a 3mm (?) hole just through the barrel, tapping with a steel screw bolt and then fitting a nylon screw. Finished off by cutting the head off the screw. Snug fit in the snail cam and rock steady focussing.

Martin

--------------------
Retired TV Service Engineer
Ongoing interest in Telecine....

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Maurice Leakey
Film God

Posts: 5895
From: Bristol. United Kingdom
Registered: Oct 2007

- posted September 20, 2008 03:01 PM      Profile for Maurice Leakey   Email Maurice Leakey   Send New Private Message       Edit/Delete Post 
David

My early Bell & Howells in both 16mm and Standard 8 have the feature you describe.

Loosen the thumb screw, rotate lens for focus, tighten thumb screw.

Martin

Sounds wonderful, although the tapped hole is no doubt quite short so as not to contact the inside zooming part of the lens.

--------------------
Maurice

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