8mm Forum: Elmo 16-CL Screen Flicker?

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Posted by John Barbour (Member # 3777) on June 24, 2014, 09:52 PM:

Hi all,

Wondering where to start troubleshooting this issue...

I recently replaced the shutter and shutter drive belt in my Elmo 16-CL. Because I want to use the projector for basic recording of film to digital, I replaced the original shutter with a 5-blade (figured might as well since I had to get in there and replace the busted belt).

The operation appeared to go OK. However, now when projecting film onto the screen, there's a noticeable flicker, a shakiness in the image that appears more evident at the bottom (although this location could be my imagination). The film looks OK, and the footage runs fine on another projector.

I should also clarify that I'm NOT talking about a flicker when attempting to record the film through a digital camera. This flicker exists when using the projector as intended, projecting onto a screen.

Any ideas on what to check first?

Thanks!

-John

Posted by John Hermes (Member # 1367) on June 25, 2014, 01:23 AM:

Did you carefully time the shutter to the film pulldown? The claw pulldown needs to occur completely behind one of the shutter blades, while the blade is in front of the picture aperture. A five-blade shutter has pretty narrow blades so it is extra critical. Are you getting travel ghost(a preceding or trailing double image)? That's a sure sign of a shutter out of adjustment.

Posted by Andrew Woodcock (Member # 3260) on June 25, 2014, 06:34 AM:

I am certainly no expert on 16mm projectors but if what was happening to yours was happening to any of my 8mm machines I would also suspect that in replacing the shutter, as well as perhaps not aligning the shutter correct on the shaft in terms of its angular position, it sounds to me as though claw penetration has been disturbed now also. This is typically observed by a shaky image as you describe and on all of my Super 8mm machines can be adjusted once the shutter shaft has been refitted. Do the claws appear to be protruding sufficiently at the point when the film is being drawn to the next frame and at this point in time is the shutter blade covering the aperture?

Posted by John Barbour (Member # 3777) on June 25, 2014, 11:18 AM:

Did I carefully time the shutter and claw? Of course not.

That's definitely the issue. I'll spend some time with it tonight and report back.

Thanks!

Posted by John Barbour (Member # 3777) on June 28, 2014, 10:07 PM:

Well that was a pain in the butt.

I finally got it lined up correctly, but it took lots of loosening, twisting, tightening, turning on, turning off, repeat.

That's not counting the times I forgot to tighten and turned on the projector, or the times I thought I could make it juussst a little bit better and ended up making it worse.

Anyway, it's fixed now, so thanks for your help! I'm still learning about these things.

I've also discovered that, at least in my case, the 5-blade shutter doesn't solve the rolling shutter sync issue completely when recording. I suspect it's because of the inconsistent speed of the projector in general. I'm going to pick up a Kodak Analyst tomorrow (projector # too many) so I'll fool around with that next. I'm hoping the speed adjustment will make it more useful for basic transferring.

Thanks again!

Posted by Kenneth Horan (Member # 3) on June 28, 2014, 10:43 PM:

Hi John, A telecine projector must have a 5 blade shutter as well as be driven by a synchronous motor to insure an exact 24 fps speed. The standard induction motor in the 16CL does not run at exact speed. Even the Kodak Analyst projector with a variable speed control will have to be continuously adjusted and readjusted on the fly and you may still see "shutter bar".

Posted by John Barbour (Member # 3777) on June 28, 2014, 11:23 PM:

Ken,

Yes, I noticed that the projector seemed to do better when it "warmed up," but even that wasn't consistent.

I've got a Keystone k-109 that I've had some success with transferring 8mm, although I've put in an order for a moviestuff Retro-8. I've got far more 8mm than 16mm, and I definitely can't afford two moviestuff units.

I'm thinking I can use the Analyst like the Keystone: recording while keeping a finger on the speed knob to adjust on the fly.

Posted by John Hermes (Member # 1367) on June 29, 2014, 12:29 PM:

Yes, John, adjusting the shutter position in quite a pain. SMPTE used to make travel ghost film which made it a little easier. If the ghost trailed the image, you move the shutter one way if it preceded it, the other way. However, it is easiest to do the adjustment if you have the head out of the projector so you can see the pull down. I'm sorry you did all the work and still have the sync problem. The real telecine machines have the previously mentioned AC sync motor and timing belts and pulleys. I have an Elmo CL-16 M/O TC unit with all this stuff and it works flawlessly. If you find one of these, grab it.

Another way to sync things is with a video camera with variable scan. I have used a regular Elmo 16-CL (three blade shutter) and adjusted the variable scan to eliminate flicker. My projector ran true enough to where there was not enough speed flucuation to cause a problem. This will vary from machine to machine.

Posted by Janice Glesser (Member # 2758) on June 29, 2014, 03:42 PM:

John and John [Smile]

I recently did some test transfers using my Elmo 16CL (3-Blade Shutter) and a Keystone K-160. The 24fps speed of the Elmo 16CL was much more stable than the variable speed Keystone. The results for the Elmo using a 24fps setting on my camera was flicker free. The flicker using the Keystone would come and go. This is probably because the Keystone motor is very old and just can't maintain a contant speed.

Here are two videos of my 16mm telecine setups:

Elmo 16CL
http://youtu.be/qJreKUYjsuk

Keystone K-160
http://www.youtube.com/watch?v=emm1B96pSfw&feature=share&list=UUzhVuBJou11ziWdERi0ZGuQ

Posted by John Barbour (Member # 3777) on June 29, 2014, 05:33 PM:

Thanks Janice!

I'm thinking that I might just re-install the 3-blade shutter on my Elmo 16-CL. I've got a Canon t3i that will do 24fps, so odds are it'll do just as good as it's doing now with the 5-blade and 30fps. I have another 16-CL that I'm currently using for showing films, so this is mainly a backup to fool around with.

I'm also going to look into variable scan cameras, although I have a feeling they will be expensive. Maybe I can find a board component camera that I can just connect to my computer. I dunno; it's fun to fiddle around with this stuff.

Speaking of...met the craigslist guy today with the Kodak Analyst. Was going to pay $30 for one. Of course, he brought two Analysts (one with remote control!) so I paid $40 and now have two more projectors than I really need.

Posted by Janice Glesser (Member # 2758) on June 30, 2014, 12:26 AM:

You never know when you might need one of those extra projectors. I learn something new from each one I get...I have about 25 more than I really need [Smile]

But you said it...it's fun.

Posted by Randy Wheeler (Member # 2141) on July 23, 2015, 04:57 PM:

After several years, I just started having that flicker on my Elmo 16CL or to me it's more of a faint horizontal bar going from top to bottom or vice versa. If I hold onto the take-up reel it will speed up the movement of that bar. Can this be caused by a worn out motor belt? How hard is it to change the motor belt?

I have several variable scan (0.1 shutter speed increments) cameras and none of them could get rid of the rolling horizontal bar though at 1/60 it was the faintest and the higher the shutter speed above 1/60 the horizontal bar got darker and more defined.

When looking at a video waveform monitor the brightness goes up and down as the horizontal bar goes by about 1 time per second.

[ July 23, 2015, 08:11 PM: Message edited by: Randy Wheeler ]

Posted by Janice Glesser (Member # 2758) on July 24, 2015, 11:17 AM:

I also just noticed this rolling banding effect after running a B&W feature I just bought. It's very slight...but I never noticed it before. The film came on 2300ft reels, which the added weight may put more strain on the motor. I have a second 16CL that I'm going to try and see if the banding shows on that projector.

Posted by Randy Wheeler (Member # 2141) on July 24, 2015, 11:32 AM:

One thing I noticed, when doing a film transfer, is that it is more noticeable using a camera with a CMOS sensor than one with CCD chips. Same goes with ghosting on the lower part of the image. My CMOS cameras show it but the CCD camera doesn't.

Posted by John Hermes (Member # 1367) on July 25, 2015, 12:45 AM:

As stated before, these speed issues are because regular projectors do not normally have AC synchronous motors. In addition to a five-blade shuuter you need a sync motor (locked to the AC power line Hz) and timing belts (which do not slip at all). I have Elmo TC (telecine) projectors for both 15 fps silent and 24 fps sound and there is never shutter bars or flicker. When a regular projector is close to speed you may not see any speed issues, but reel load, belts, and other factors may change this.

Posted by Randy Wheeler (Member # 2141) on December 04, 2015, 10:09 AM:

I have an Elmo 16-CL MO and an Elmo 16-CL O and the MO projector has a horizontal bar that cycles from top to bottom about once per second. The 16-CL O doesn't have this problem and here is a video showing the film transfer from both projectors to show the problem. What adjustment is needed to get rid of the horizontal bar from the 16-CL MO?

Elmo 16-CL MO vs 16-CL O

Posted by Janice Glesser (Member # 2758) on December 04, 2015, 10:31 AM:

Randy...to my eye it appears that the 16CL O exposure on the right is slightly darker than the MO. Darker exposures can make the banding more prominent. Perhaps the projector lamp isn't as bright or the lens isn't allow the same amount of light into the camera. I would try adjusting the camera exposure to see if that helps. It could just also be a speed issue with that projector.

Posted by Randy Wheeler (Member # 2141) on December 04, 2015, 10:38 AM:

Not worried about the exposure on the 16-CL 0, it is working fine. You don't notice the horizontal bar going from bottom to top on the left-side video of the 16-CL MO? That's what I'm trying to fix. Variable scan adjustment on my camera won't fix it so that's not an option at this point.

Posted by Janice Glesser (Member # 2758) on December 04, 2015, 10:56 AM:

Sorry Randy...but I don't see the banding. However, that's not uncommon for some people to be more sensitive to flicker. It's just the way our individual brains work. If you are seeing the banding then there could be a timing issue with the shutter on that projector or perhaps try changing the lamp.

Posted by Randy Wheeler (Member # 2141) on December 04, 2015, 11:23 AM:

I'm not talking about a defined bar but you should be able to see a slightly darker band going from bottom to top that cycles about 1 time per second. Other people I've shown this video can see it.

Both projectors are setup with LED lamps and are dedicated film transfer projectors.

Posted by Janice Glesser (Member # 2758) on December 04, 2015, 12:12 PM:

I know what you are talking about. I just can't see it...but that doesn't mean it doesn't exist. Just through the process of elimination...if the lighting is identical then the problem in my opinion mostly likely is in the shutter timing.

Posted by Barry Fritz (Member # 1865) on December 04, 2015, 01:57 PM:

I can see it. Rather than moving from bottom to top, it looks more like the entire picture darkens slightly for an instant.

Posted by Randy Wheeler (Member # 2141) on December 04, 2015, 02:10 PM:

It's definitely moving from bottom to top because when I change the shutter speed on the camera it makes the bar stand out more. A lower shutter speed will slow it down and a faster shutter speed with speed it up but at no time will it stop moving from bottom to top.

I just did an RPM check on both projector shutters and here are the results.

Elmo 16-CL Optical

1442 RPM no film
1435 RPM with film

Elmo 16-CL Magnetic Optical

1438 RPM no film
1433 RPM with film

From this test, with film, both projectors are running at almost identical speeds so the motor speed can be concluded that it is not an issue.

So I can assume an incorrect shutter timing is what causes this problem and nothing can get rid of it except to correctly adjust the shutter timing?

[ December 04, 2015, 04:02 PM: Message edited by: Randy Wheeler ]

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