Some SRD titles showing "reverted" (but not all titles?)

[Ryan Gallagher]

Just popping in to update/close this thread.

After landing some uninterrupted maintenance time, both JJs now have our NEW diodes in the 702 modules (prior "working" but aged diodes+modules are now back on the bench as emergency backups).
Redid full calibration with a scope and WinDRAS (an FTDI serial adapter cable was the trick there).

After that fun I redid both our cooling loops too. Booth Progress! Cheers.

[Brad Miller]

Have A24 contact me. We can likely remove that green scratch.

[Ryan Gallagher]

Post screenings update. Thanks for the hive mind assistance.

SRD stayed in the 2-4 range for both prints on both projectors with no dropouts that we saw. These prints were in amazing condition num001 of Pearl and num002 of X
............(except 1 issue).

R4 of Pearl Print num001 has an unfortunately placed vertical emulsion scratch the ENTIRE length of the reel. Noticed in our inspection and could see it by eye and flashlight after the feed reel and before any of our readers. So sad. Just left of center, about the worst place to have one, green unchanging line with a sister dashed line near by. Letting A24 know via our inspection report.

But other than that very successful double feature night themed night. About half sold (1250 seat house). Many in cosplay/costume.

Will intend to redo reader alignment with our NEW diodes very soon, after WinDRAS is working. No 35mm booked for a bit, so maybe I'll get to that next assuming I can snag some maintenance time.

Cheers!

[Marco Giustini]

The top trace represents the red light picked up by the sensor when a sprocket hole passes in front of the sensor. If you manually slowly move the print in front of the reader (Assuming your processor still passes the data) you'll see the top trace and data trace alternating on the scope.

If the top trace is uneven, it means the light is uneven. This could be alignment but also dirt or damage on either the light source or the photocell.

I would flatten it regardless - that said I don't know how you can get that weird curve - it would usually drop on one end, not drop and recover. Give the whole thing a good clean as well!

[Ryan Gallagher]

Marco, I did give a shot at adjusting the module on the "poorer" of the two waveforms initially... I seemed to be able to flatten it but only at a loss of output, and considering I could not adjust that diode any higher and we were reading DD, let it lie at the slightly askew but closer to 4v signal. Is that slanted upper trace indicative of a horizontal alignment issue?

I have a FTDI serial adapter on the way also, at least I know that is a different chipset. I also still have an XP laptop floating around at home in disuse, I might have to marshal it into service.

Yeah we have DCI and dolby techs out at minimum once a year for SXSW or other high profile premieres. But with the minimum we book 35mm, and almost always rolling with blue-ray backups, techs for the older gear have not really been in the cards unless it becomes obvious it's outside our (my) capabilities to address. For digital we have the luxury of usually piggy backing our tech's onto festival/premiere budgets.

Before I began the stewardship of this booth, 35mm was definitely on the chopping block, but after some well received and executed bookings last season it seems we have elected to attempt to keep the capacity, at least for another phase of enjoyment. It's been almost a decade since this house booked 70mm. Among a full retune of 35mm (still some other points to address there), I'm inching my way towards that goal too (see the XD10 update thread). Hard to find time when the house is booked to the gills with live events you have another role on. ;-)

[Marco Giustini]

Ah sorry I missed that the LED was not new. Still, you might be surprised on how much extra light you can get if you play with the adjustment.

In my experience with the 650 serial, if the 650 likes your serial port, it will just work. Really no need to fiddle with the settings (but please give that a go!). It's just that some adaptors don't like the 650 - or viceversa! I've tried the 650 setup software just the other day with a new Windows 11 installation and it worked. This is with the USA-19HS. I do know there are several HW versions though. I remember a colleague had the same exact model but mine would connect to a USL product, his wouldn't, not even on my laptop.

Well done and I hope you can improve even further! It reminds me when my reader started misbehaving but we didn't have the money to call a tech so I borrowed a scope (along with the person who knew how to use it!) and we tried. The improvement was immediate and lasted until the cinema was knocked down so happy days

[Ryan Gallagher]

Thanks all.
As I mentioned these LED modules were working pulls from our older 701s in a pinch. So it doesn't surprise me that one of them is close to end of life (this house used to run a platter and one projector). My intention is after this engagement to swap to the actual NEW diodes that I soldered in but are yet untested, and put these back into emergency status.

I only have two USB-Serial adapters at the moment, but they are both showing up as Prolific drivers. I have a Windows Vista, 10, and 11 to choose from without fighting with virtual machines. Only tried with the Vista so far. Will Give those serial port settings Markus suggested a try next. The Vista machine had 650 setup on it already, so presumably someone had it working in the past.

After the deep read through the manual sections and WinDRAS docs, I am suspecting both readers at minimum need a focus adjustment. Will do all the other things then too once I have WinDRAS working alongside the scope (and proper 2mm pin probes in hand).

We'll roll with the improvements we managed so far for tomorrow, both prints confirm DD now with little evidence of failing over, as well as my personal print that previously wasn't working either. So at least we know our efforts had tangible results in the positive.

In our first effort we were mis-reading the manual thinking the data trace wanted to be at 4v, but we also thought the half divisions were in fact 1v. LOL, Our errors kinda cancelled out. I revisited yesterday and did it proper aiming for 4v on the open sprocket trace.

[Gordon McLeod]

I'm just gonna throw in my 2 cents: I last aligned 2 BACP readers a year ago.

You are not aligning to get the lowest error rate, even new prints can have 3s, 4s 5s and even 6s. You are aligning to get the best chance of reading the Dolby blocks. Each trailer or feature reel is different.

The scope is the best way to get the waveform looking great and getting the DRAS to register. Running both at the same time is best.

Once you have the scope looking good use the DRAS to fine tune.

Jitter, is what I find, causes the highest error rates. Get this as low as you can first. Rollers, back pressure etc.

The focus should be 70+, should be easy to do on most prints.

Azimuth 0 and Lateral position 0.0.

I also found that the voltage should be between 3v and 3.5v for best results overall. As you go over 4v the error rates go down but once you get too bright errors spike and you start getting 7s and Fs.

For led brightness a good place to start is the Histogram, there are 2 lines (white and green). Try to get those close together.


The 650 and the DA20 need 9600 baud 8n1, from what I remember. Try 38400 if that doesn't work.

I had lots of problems with WinDRAS on modern machines (win10) so I have an old XP laptop that runs it great.

Good luck.

I run legacy software in Oracle virtual box

[Markus Lemm]

I'm just gonna throw in my 2 cents: I last aligned 2 BACP readers a year ago.

You are not aligning to get the lowest error rate, even new prints can have 3s, 4s 5s and even 6s. You are aligning to get the best chance of reading the Dolby blocks. Each trailer or feature reel is different.

The scope is the best way to get the waveform looking great and getting the DRAS to register. Running both at the same time is best.

Once you have the scope looking good use the DRAS to fine tune.

Jitter, is what I find, causes the highest error rates. Get this as low as you can first. Rollers, back pressure etc.

The focus should be 70+, should be easy to do on most prints.

Azimuth 0 and Lateral position 0.0.

I also found that the voltage should be between 3v and 3.5v for best results overall. As you go over 4v the error rates go down but once you get too bright errors spike and you start getting 7s and Fs.

For led brightness a good place to start is the Histogram, there are 2 lines (white and green). Try to get those close together.


The 650 and the DA20 need 9600 baud 8n1, from what I remember. Try 38400 if that doesn't work.

I had lots of problems with WinDRAS on modern machines (win10) so I have an old XP laptop that runs it great.

Good luck.

[Marco Giustini]

the 650 can be fussy about the serial port! No, it doesn't have to be in a special mode. If your serial adaptor doesn't work, try another one. The Tripplite USA-19HS used to be one of the few working reliably.

The first picture definitely needs a tweak! The top trace - which you rightly say should be at 4 V - is not flat. That means that one side of the soundtrack is getting more light than the other. You should be able to adjust the LED until the level is maxed AND flat. I never worked on a 702 so I'll let you discover how to adjust the LED by reading the manual from page 6

I'd not expect the LED trimmer to be maxed out with a new LED, particularly with a 702 which is one of the best readers you can get.

While you have a scope, also run WinDRAS and check the FOCUS value there. The scope is handy to set the trace to an acceptable position, then you have to look at DRAS. Same with the lateral position and azimuth. But the main adjustment, the light amplitude and flatness, are very important and must be performed before you do anything else.

Glad you're going somewhere! Keep us posting!

[Ryan Gallagher]

Does the CP650 have to be in "setup" mode for serial communication (WinDRAS) to function? Tried connecting regular using the correct com port and no luck.
Maybe it is a baud rate/parity thing. I didn't see those references in the docs.

Ryan

[Ryan Gallagher]

Thanks mark. I eventually did see that part referenced in the manual. Ahead of ya and already ordered two from Digikey and some 50ohm RG58 extensions to pair with them.

Also in hindsight, I now understand that the top trace in the waveform is the open sprocket light, and THAT is what they want you to tune to 4-4.5v, not the data trace. I think we overshot a bit and is evidenced by at least one projector diode LED sitting on amber with no film present.

These diodes were working pulls off our 701s from the back room. I have to revisit this calibration soon anyway when we decide when to put on the "new" diodes that I soldered into the old modules. Sooner the better I think so these can remain functional spares with a little life left in them for emergencies.

[Mark Gulbrandsen]

I used these. A set lasts for ever. They have gotten pricy, but are worth it.

[Ryan Gallagher]

Note, I did not have ideal probes. Channel 1 Video was McGuivered from some very sharp multi meter probes and a bnc to banana probe. Clamp channel was a 1x proper probe. Not sure I was getting the best image due to this.

Any recommendations for probes or an insert that will hold itself in the tiny probe points on the cp650?

[Ryan Gallagher]

Thanks for the tips all.
We did find time this afternoon while a live show was onstage rehearsing to go through the motions.

With a scope image we were able to get closer to the recommended led output. We started getting non-reverted DD at that stage. We adjusted the modules slightly to try to improve the waveform and reduced errors further.

One module is basically out of trim headroom now but giving us a solid 2 rate on the prints we have handy. The other module has headroom still but we could not get it any better than 6s on these prints.

Perhaps the lens assembly needs a focus adjustment still, but we successfully restored function on the problem prints. (it was always functioning on our trailer reel(s)).

I’m attaching our two scoped images if anyone has any advice for further improvements.

1st is the no headroom 2s unit.
2nd is the headroom 6s unit.