Jitter in camera, then projector

[Mitch Perkins]

I've been using the whack 'n wind method when faced with jammed carts. This results in short lengths of clear film when projected [cart removed from chamber and hand-advanced in sunlight].

I can report that my projector lost the loop just at the point some of these clear sections entered the gate. This happened three times. Other clear sections ran through the projector without incident.

A reasonable conclusion is that jitter is caused by improperly spaced/sized perfs, but only *sometimes*!

OTOH, given that projector PDCs are more point-like than camera PDCs, and therefore tolerances are greater in the projector, it could be that jitter is always caused by inconsistent perforation of the raw stock.

Mitch

[S8 Booster]

just a curiositö of matter but:

allthough long time since last checked: from memory the Bauer projectors has a "second claw" to advance the film in case of a primary claw failure alt perf problem.

how is your projector designed and if it has a "second claw" how does it turn out when the bad areas are passed..
does it "self repair" / recover??

shoot......

[aj]

I've been using the whack 'n wind method when faced with jammed carts. This results in short lengths of clear film when projected [cart removed from chamber and hand-advanced in sunlight].

I can report that my projector lost the loop just at the point some of these clear sections entered the gate. This happened three times. Other clear sections ran through the projector without incident.

A reasonable conclusion is that jitter is caused by improperly spaced/sized perfs, but only *sometimes*!

That would be something. Doesn't this show when you put two long stripes of film on top of each other? Then the perfs should align perfectly in places and somewhat less in other places. Since there was some play designed into the standard the deviation should be noticeble, I think.

[David M. Leugers]

Mitch if this turns out to be the case, wow this is bad news. I have experienced this with Fomapan R-8mm and DS-8mm rolls, but if Kodak is having problems with accurate perfs....

I don't know about the Bauer S-8mm projectors (I always wanted some of their top models), but double claw projectors usually will not help the situation if the perfs are not spaced properly. Double and triple claws (like in B+H 16mm) help when one or two perfs are damaged the film will be advanced properly because one of the claws will use a good perf to advance the film. This is why B+H 16mm sound projectors will run film other projectors won't. 8)


David M. Leugers

[Mitch Perkins]

Doesn't this show when you put two long stripes of film on top of each other? Then the perfs should align perfectly in places and somewhat less in other places. Since there was some play designed into the standard the deviation should be noticeble, I think.

Yes, I haven't done that yet. I'll try to do it before I turn the film in...

Mitch if this turns out to be the case, wow this is bad news. I have experienced this with Fomapan R-8mm and DS-8mm rolls, but if Kodak is having problems with accurate perfs....

Maybe they'll fix it...meanwhile there is also the wobbling, prone-to-jamming take-up core issue. I wonder if the perfs could be responsible for "setting up" the wobble?

I don't know about the Bauer S-8mm projectors (I always wanted some of their top models), but double claw projectors usually will not help the situation if the perfs are not spaced properly. Double and triple claws (like in B+H 16mm) help when one or two perfs are damaged the film will be advanced properly because one of the claws will use a good perf to advance the film. This is why B+H 16mm sound projectors will run film other projectors won't.

Yes, I believe they would run rope, if needed...~:?)

GS1200 has dual claw PDC, but it didn't help in these cases.

Mitch

[pbrstreetgang]

Mitch wrote:

A reasonable conclusion is that jitter is caused by improperly spaced/sized perfs

very reasonable Mitch.

Sometime ago I laid a long section of jittery 64t film across a hell bright light box and used an eyeglass to inspect the perfs. conclusion:


THE TRAILING EDGES of the perfs are crooked, really crooked... slanting downwards from the outside in, and not at all symetrically aligned as they must be to ensure solid rego. the naked eye simply can't see it.

could... might be the jitter/jam problem so many shooters are experiencing right now.

Is Kodak (or whoever) using perf machine[s] that are worn beyond acceptable working tolerances... Mmmmm?

I somewhere have macro digital pictures on my pc of what I found. When I find them I will post. and, even more annoying, is my last 64t cart stopped at 40ft!! and that's not the first time. It's all the time to varying degrees. Plus it was the worst jittering cart I've had to date. Pro8 100D is no better either.

Thought maybe all this was just teething problems but now I'm pretty certain it's something more sinister.

I'm in the process of contacting Kodak to discuss the issue. If nothing is resolved I'm never buying 64t again as it's a vote of no confidence on my part. It's simply not good enough when you're shooting someone's wedding, or a short film, and your cart jams, jitters and stops short. and maybe I don't wanna use neg stocks?

It's a real shame because I love shooting super8mm and have the utmost respect for those who have kept the format alive.

a...

[Mitch Perkins]

THE TRAILING EDGES of the perfs are crooked, really crooked... slanting downwards from the outside in,

It's not impossible that that's on purpose; the tips of the passive action PDCs seem to be "double-angled", slanted vertical relative to film plane and buffed on one edge - this in conjunction with an angled trailing edge might have been found to produce the most stable images.

Maybe not. Interesting...

Can you compare the trailing edges of the perfs of the jittery stuff to some old Kchrome?

Mitch

[vidwerk]

Similar problem happened with me. But it my case, the jitter in projector was caused buy torn perfs when the camera jammed.

vidwerk.

[pbrstreetgang]

Mitch wrote:

It's not impossible that that's on purpose

honestly Mitch, I don't think it's possible that it's on purpose. I stand by my findings that jitter (vertical up and down movement) is an asymetrical perf problem. I do accept that I'm analyzing the film through a macro lens and so any slight imperfection is like WOW! man that's huge.

I just had a look at the perfs on my latest cart and they are all over the show. Some perfs aren't even cut out properly while others cut into the actual frame area where some don't. There is an inconsistency here. Though some are better than others, perfect in fact and not slanted. But maybe I'm just being picky? It's got to be perf imperfection though. And it's such an annoying thing, this jitter. It's driving me up the wall! Does anyone have this problem with 100d? I must check that.

Cart jitter befuddles me. Correct me if I'm wrong but when each frame is exposed to light for that very instant, it's not moving. So how does cart jitter affect registration? If it was you'd have blurring of the image[s] and I've seen that with some transfers I've done in the past. Can someone please enlighten me.

I'm still waiting for Kodak to contact me regards this matter.

If you want to see the results of my last jittery cart go to http://www.relicfilms.blogspot.com and check out the first clip the one with the cactus at the beginning and you'll see the problem I'm experiencing (and surely others too).

regards,

andy... :? :?

[Mitch Perkins]

[...] I stand by my findings that jitter (vertical up and down movement) is an asymetrical perf problem...

I just had a look at the perfs on my latest cart and they are all over the show. Some perfs aren't even cut out properly while others cut into the actual frame area where some don't.

In that case, I stand by your findings too. ~:?)

Correct me if I'm wrong but when each frame is exposed to light for that very instant, it's not moving. So how does cart jitter affect registration?

One possibility is that the pull down claw, especially if it retracts passively, catches on the trailing edge of the perf, bumping it upwards while the shutter is still open. In this case there would be slight blurring in the image on certain frames.

Similar problem happened with me. But it my case, the jitter in projector was caused buy torn perfs when the camera jammed.

Excellent point! I've only had cart jam tears that affect the leading edge of one of two consecutive perfs "involved", (one tear between two perfs). GS1200 has dual-claw PDC, so theoretically you only need one good leading edge for any two perfs, but it's no guarantee...

Mitch