It appears some of our repetitive block error symptoms may have been due to reel-arm spindle condition.
After my service to those things seem much improved.
https://www.film-tech.com/vbb/forum/...l-arm-spindles
Our house SRD print that was exhibiting the reptative errors timed with reel rotation now ran flawlessly on one projector. Another reel from that print was almost flawless on the other, but read errors were no longer sync'd to the timing of the upper reel rotations.
We did also take the opportunity to inspect upper reel arm alignments using AFG-1 alignment film. Our Simplex 35/70 arms don't seem to have a happy perfect slot placement for ideal alignment without adding some kind of adapter. Best we can get is either no flange rubbing but reel slightly out of alignment with rollers (putting more tension on operator side of film), or where we were before, with reel in plane but just a hair proud towards the operator (inner flange rub), but better tension alignment. We opted to leave it with the latter for now.
Announcement
Collapse
No announcement yet.
Library of Congress Prints
Collapse
X
-
Originally posted by Brad Miller View PostBut if you run your "house" reel of film, I'll bet you don't see those blips on the waveform, do you? When acetate film shrinks, depending on how it was wound and stored will often cause a tiny, tiny, tiny bit more shrinkage on one side (or point) of the stored reel...which is likely what you are seeing on the scope.
Below are pictures of how I typically setup rollers for the running of loops. If done properly, these rollers can live there permanently like this and not interfere with running of reels. (Ideally I would have used a longer bolt on top of the SRD penthouse, but again since there is effectively zero tension there when running a loop, a short twist like that isn't hurting anything.) The reason for this is you don't want to start scuffing up the SRD track...or in the case of these pictures, you don't want to scratch up your target loop. Plus this design keeps the film from dangling in front of the lens when you are making critical adjustments.
Remember my warning. Most reels from Goldberg, even as recent as 2024 built reels, are NOT in-round. So just because they are new really makes no difference. The question is are the hubs perfectly round, and are they actually perfectly centered?
Picture 1 shows the 35mm path utilizing all digital formats.
Picture 3 shows the feed reel mounted on the back of the console. To swap formats the shafts and rollers just pull out like a Kelmar rewind table for swapping. The recessed rectangle on the back of the lamphouse is where a film cleaner mounts.
What is an AFG-1?
Leave a comment:
-
Originally posted by Ryan Gallagher View Post
I have AFG-1 in route that might prove useful in the alignment space for mounting and dismounting our DTS readers in the future. Ideally I'd love to get our quick release plates back in working order, that or a custom mount for the 70mm DTS in a way that can utilized without making the stack taller.
Pics below are of how I handle the different penthouses.
Picture 1 shows the 35mm path utilizing all digital formats.
Picture 2 (with the lights off) is the 70mm film path which simply follows a diagonal path entering (or bypassing) the DTS70 reader and directly into the mag penthouse.
Picture 3 shows the feed reel mounted on the back of the console. To swap formats the shafts and rollers just pull out like a Kelmar rewind table for swapping. The recessed rectangle on the back of the lamphouse is where a film cleaner mounts.
Leave a comment:
-
Originally posted by Ryan Gallagher View PostHaving said all that, I may personally pick up one FT 35mm reel to use as a baseline to compare how much our house reels are contributing to tracking problems.
That and/or bring in my NIB sheet metal style goldberg reels for comparison.
This link is of is a video showing how those mass-produced 4 inch cores used in clip-together reels aren't even centered. What happens is every single revolution you have looser and then tighter backtension as film is pulling off of it.
www.film-tech.com/ubbpics/off-center-cores.mp4
Leave a comment:
-
But if you run your "house" reel of film, I'll bet you don't see those blips on the waveform, do you? When acetate film shrinks, depending on how it was wound and stored will often cause a tiny, tiny, tiny bit more shrinkage on one side (or point) of the stored reel...which is likely what you are seeing on the scope.
Also is your "house" reel of film you use for testing something that is basically junk, meaning you can cut it up if you need to? If so, cut yourself a healthy size loop (10-12 feet, but not so large that it drags the ground) from the END of that roll and the END of that reel running from a reel vs. that loop (which will have effectively ZERO backtension on it).
Be careful that when running the loop it isn't dragging on anything. Below are pictures of how I typically setup rollers for the running of loops. If done properly, these rollers can live there permanently like this and not interfere with running of reels. (Ideally I would have used a longer bolt on top of the SRD penthouse, but again since there is effectively zero tension there when running a loop, a short twist like that isn't hurting anything.) The reason for this is you don't want to start scuffing up the SRD track...or in the case of these pictures, you don't want to scratch up your target loop. Plus this design keeps the film from dangling in front of the lens when you are making critical adjustments.
- Likes 1
Leave a comment:
-
For reference, here is our scope view and windras symptoms on that print. If you watch the scope closely you can see these "blips" on the right hand of the waveform that were periodic in nature (period associated with reel turning rate).
Scope View
https://drive.google.com/file/d/1TNQ...usp=drive_link
Windras View
https://drive.google.com/file/d/1Voe...usp=drive_link
Leave a comment:
-
Having said all that, I may personally pick up one FT 35mm reel to use as a baseline to compare how much our house reels are contributing to tracking problems.
That and/or bring in my NIB sheet metal style goldberg reels for comparison.
Leave a comment:
-
Originally posted by Brad Miller View PostRyan, your SRD issues has nothing to do with your arm alignment or feed clutch tension setting. Issues like SRD tracking will show up more on smaller hub reels.
......
1. Upper reel arms were removed and re-installed/aligned using the FT reels after removing our 70mm DTS readers before Brutalist.
2. A house print that normally tracks fine, also had some additional similar issues on both machines when under test (using the same set of house reels).
But I believe you that a bulk of this tracking issue can be possibly be ascribed to print condition, original track printing, or reel core size/condition and perhaps something bent or clutch condition/behavior. It just feels like there is something "different" now in tracking behavior linked to the reel rotations that wasn't present last season running 35mm on these same reels, that visually run well except for slight flange rubs in some spots (no pinches). But that something different could easily be a bent shaft like you suggest among the possibilities.
I did not have an ample service window before this one to take apart the clutches and check the felt condition, which I will do. I may pick up a cheap dial indicator to get a final word if and how bent our existing spindles are, visually I had moved the best ones to the feed arms previously. I have AFG-1 in route that might prove useful in the alignment space for mounting and dismounting our DTS readers in the future. Ideally I'd love to get our quick release plates back in working order, that or a custom mount for the 70mm DTS in a way that can utilized without making the stack taller.
If it was only this shrunken print I would not look any further, but our house print doing it too is the fact that indicates something has in fact changed worth looking into. And the only "known" variables changed since last season were the clutch tension retune, and the fact the upper arm comes off and on unfortunately in our 70/35 changeover procedure (at this time).Last edited by Ryan Gallagher; 02-22-2025, 10:32 AM.
Leave a comment:
-
Ryan, your SRD issues has nothing to do with your arm alignment or feed clutch tension setting. Issues like SRD tracking will show up more on smaller hub reels. The Film-Tech reels are simply more gentle on film than other reels. They are lightweight, have 8 inch hubs and the hub will spin perfectly true whereas many Goldberg and other types of metal reels don't even have a truly round hub or one that is properly centered. Those issues create the bouncing on every revolution that you are seeing.
The other possible culprit is that your feed arm shafts are likely slightly bent or there is a little bit of a "tight spot" at some point in the revolution of the reel. Sometimes putting new felt pads on can fix this, other times it's a slightly bent shaft or worn out plates. In short, you need to look at your feed arms and your feed reels because that's where your issue is.
Also remember that shrunken film generally will not track as well as unshrunken/polyester film on SRD error rates. You are blaming lateral tracking in WinDRAS on the feed arm alignment when in reality the cat702 has rollers to force-align the film laterally as well as the Davis loop itself. This completely throws that theory out the window. Your lateral tracking concerns are due to the print having shrinkage (and also possibly the quality of the printing and any wear in the SRD area). Its as simple as that.
There is nothing to fix.
Don't re-adjust your feed arms. Also don't go tightening up the feed arm clutch or you will just become one of those theaters that cinch scratches the ending of every reel. The feed backtension needs to be as loose as you can get away with using the largest reels. Everything smaller will have more backtension by definition at that setting, so adjusting for the largest reel will work fine all the way down to 2000 foot shipping reels with smaller cores. Instead look into the 2K reels you were using and the clutch for a slight tight-spot in the revolution as I noted above.
Leave a comment:
-
Oh and I meant to share their inspection report we got upon request for anyone curious about NAVCC reporting format:
Attached Files
Leave a comment:
-
Woo, first NAVCC screening was a relative success! Thanks for all the assistance and perspective.
Excellent looking print, though slightly shrunken Acetate (.3%).
Our only gotchya was that our last 35mm running was Brutalist on 24" FT reels with thicker flanges. Our Arms/SRD alignment was tweaked to be quite flawless with those. A slightly shrunken acetate print back on our 6-hole house reels was less than happy in the block error domain (more than usual horizontal alignment variation in WinDRAS). Averaged 5-6 error rate but with lots of individual F/errors. Mostly stayed non-reverted though, only we noticed.
Always something to fix. Arm alignment combined with print and reel condition is my first brush diagnosis, cause there were repetitive aspects to the block errors that seemed to correspond to interaction with reel flanges and print oscillating a bit on the first couple 702 rollers. I include reel condition because we had one reel that performed quite a bit better. These are the same "best we have" reels that haven't caused such issues in the past.
A second guess would maybe be feed tension is on the low side and contributing, it was backed way off to a minimum condition for the 24" reels prior. But I would assume that impacts vertical jitter more than horizontal alignment.
And then obviously, seek better house reels. My personal 7 goldberg cast ones came to the theatre today, but did not deploy them for this screening, gotta at least run a house print off them before I claim them to be better than existing.
PS, please someone demote me from my new "Film God" status. I am not yet worthy. ;-)
Leave a comment:
-
Originally posted by Jesse Crooks View PostPosting from my phone so it was too much of a pain to figure out how to attach the booking doc quoted above. Your programmers should have received it. If you can’t get a copy of it let me know and I can post it here at a later date.
The additional documents they provided me (claiming it is everything) are, I'll share the ones without personal info on them:
- Attachment B Loan Confirmation Sample
- Attachment C LCR 3-242
- Paramount Theatre Loan Agreement
- Paramount Theatre Venue Report
- Our Date Specific Screening Attachment (Loan Confirmation)
- Welcome to the Loan Program DocLast edited by Ryan Gallagher; 02-11-2025, 04:09 PM.
Leave a comment:
-
Originally posted by Frank Cox View PostI'm a bit surprised at the requirement to use tape to hold the ends of the film down on the reels.
I've never seen one of these but I assumed they would use those heavyweight paper reel bands with the red string. I was told masking tape (of any kind) was a bad thing, until the last few years I had film here when the reel bands seemed to disappear.
I think the industry moved away from the bands generally due to not holding the wind as securely in place for shipping? Or just availability of those bands. I've only seen bands on a handful of original vintage release prints so far, but don't have a large sample size.
When I do encounter bands, I still use artist tape under them.
Even the higher quality colored "painters tape" is no good for longer term application... the adhesive still turns to a gooey mess over time.
That said, I don't know what they do at the archives for storage... they may very well remove all tape upon return inspection and store them with an archival band of some kind.Last edited by Ryan Gallagher; 02-11-2025, 03:17 PM.
Leave a comment:
-
I'm a bit surprised at the requirement to use tape to hold the ends of the film down on the reels.
I've never seen one of these but I assumed they would use those heavyweight paper reel bands with the red string. I was told masking tape (of any kind) was a bad thing, until the last few years I had film here when the reel bands seemed to disappear.
- Likes 1
Leave a comment:
-
Originally posted by Jesse Crooks View PostIn the booking guidelines (a separate doc than the ones you’ve provided) they explicitly state:
“At no time may Library prints be viewed on a film viewing machine or projected other than for the specified play date agreed upon in the Loan Confirmation.”
The first time we booked a print from them I emailed Lynanne to ask whether this forbids the screening of test reels, and she confirmed that was the case.
Just run some PA-35. Not as good as running the actual film but good enough that the audience won’t have a clue unless there is some very wonky framing on a matted print, etc. The volume is usually the only thing you actually have to worry about, hence my previous recommendation of having people besides the film projectionist dedicated for that purpose. Any minor discrepancies in focus or framing between the test film and the feature should be minor enough that the typical viewer won’t have a clue. In their estimation, it’s better than doubling the wear on R1 and R2 at every venue (as is the typical practice).
As a side note, knowing that most venues usually test the first two reels I always pick the shortest reel (usually the last) to get the volume on prints we’re allowed to test. Saves time and puts less wear on the reels everyone else is running.
As for the rewind table situation, it blows my mind that the powers that be want to operate a 70mm venue but won’t provide the minimum requirements for safe film handling. They should be ashamed. For the cost of shipping a couple 35mm prints you could probably replace the rewind table and projector clutch parts you need. Unfortunately it’s a common occurrence. The people holding the purse strings don’t understand it, so they don’t want to pay for it. They don’t know that your reputation as an institution is on the line.
As for the resistance on modest items towards improvements, it's not actual resistance. It's more of a human bandwidth and org-chart issue here, those that have purse decision/execution power (or a budget, if such a thing exists), are stretched thin as far as attention and role. It's not so much the dollar value that is the problem, it's the delegation, approval, and acquisition process. I've gotten minor equipment type things on a project by project basis (with more success than many predecessors), but it often takes up to a year or a budget cycle to materialize. I am self-compelled to provide exact links and costs for anything that is not on amazon, or risk tripling acquisition time. If it involves tracking down more rare items or quotes, the attention problem only compounds itself. I can do that leg work too, but not sure it would be appreciated as a time saver, rather than stepping out of an invisible lane. I can go around the busy person (and have), but that is also not appreciated.
I can only speculate as to why it's this way, I'm on the outside looking in, in fact none of production dept. really has even minor purchasing power without running things up the respective flagpoles, and often whole campaigns.
We have time and no money, they have the money and no time. But I digress.
Leave a comment:
Leave a comment: