8mm Forum: Film Projecting

This is topic Film Projecting in forum General Yak at 8mm Forum.

To visit this topic, use this URL:
https://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=8;t=002173

Posted by Graham Ritchie (Member # 559) on May 27, 2012, 06:50 PM:

Its been a lot of fun of late making this 80 year old projector run with Digital sound. Lucky for me I had the chance to get my hands on a lot of bits and bobs, when last year the cinema closed down. The thing that took the most time was cutting up and making fit an old Bauer sound head between the projector and lamp house, just managed it. Lately I got the loan of a Scope film called "The Rocket Post" about a German rocket scientist who goes to West Coast of Scotland in his attempt to send the mail by rocket from an island to the mainland. I ran this 35mm print through the Digital reader fitted just below the front spool box with the sound being fed into a Dolby processor and Ultra Stereo unit, from there into the multi channel input on the Yamaha Amp. The sound quality was amazing. I dont think I have ever heard that good with dvd etc through that amp. Last week it was the turn of "Dances With Wolves" 3 hours of it non stop fed from a platter. This time using the reverse scan IR/LED of the old modified Bauer sound head. Once again I was really surprised how good the sound was eg the sound of crickets out the Left surround, at the same time dogs barking Right surround, plus nicely balanced sound from left and right front with very good and clear centre channel. So thats it folks a projector from the 20s a twenty year old movie...for me thats paradise.

Bauer sound head...soon to get cut/drilled to fit.

It just made it plus a quick black paint job.

The Digital reader just fitted under the front spool box, adjustment for sound/picture sync was done on the processor.

I made this to fit onto the analog reader thats bolted to the modified Bauer sound head. The adjustable drag roller smooths things out, plus getting the bottom loop just right from the intermittent sprocket.

Graham.

Posted by Colin Robert Hunt (Member # 433) on May 28, 2012, 02:39 PM:

That's a fantastic story Graham. Very well done on this old projector and your experteze in restoring this projector to life. You must be very proud of yourself and feeling a scence of acheivment in this project. Just shows that these projectors outlive the digial ones's of today on showmanship. Please post some more pictures of this machine.

Posted by Pasquale DAlessio (Member # 2052) on May 28, 2012, 03:34 PM:

Graham

PLEASE keep those pictures coming. I love reading your posts and looking at the pics. Now...let's get started with the video!

PatD

Posted by Claus Harding (Member # 702) on May 28, 2012, 04:29 PM:

Awesome work!

Posted by Graham Ritchie (Member # 559) on May 28, 2012, 06:12 PM:

Thanks everyone
When I started doing Scope I really wanted to keep the top and bottom masking fixed, so the height would remain the same as a flat print. The side masking moves out which unlike Super8 and dvd I have to lower the top masking to get the ratio right. It took a bit of experimenting and working on the Scope aperture plate to get it as close as I could. I still loose a little bit on the sides but its nice to be able to use the full screen.

Getting my hands on those platters I have two, was a real plus. At the time I had not thought of using them, just 6000ft reels. I think people that I know thought I was nuts. [Roll Eyes]

They did try to sell a lot of this stuff early on but nobody was interested...just as well.

Loading "Dances With Wolves"

Just about finished loading "Dances With Wolves" it would have to be the longest non stop run on the Ernemann. Even though the platter is about 30 feet away it runs great, just like it did every day during those 20 years at the cinema. [Smile]

On the night.
I have a couple more photos I can add later.

Graham.

PS Pat good point on the video. I should do something and put it on you-tube.

Posted by Bill Brandenstein (Member # 892) on May 28, 2012, 07:47 PM:

Never did see "Dances" on the big screen. Too bad it's a little far to pay you a visit!

Remarkable photos and work! Thank you as always for a memorable thread!

Posted by Akshay Nanjangud (Member # 2828) on May 28, 2012, 09:13 PM:

Superb! Have to love Graham.

Posted by Bill Brandenstein (Member # 892) on May 28, 2012, 10:28 PM:

Graham, how can the Dolby reader run AFTER the picture and still be able to be run in sync? I've never heard of that before.

Posted by Graham Ritchie (Member # 559) on May 29, 2012, 12:29 AM:

With analog sound, its recorded 21 framas after the gate so threading the film is important for it to be in sync. In this case it was a matter of making the Bauer soundhead fit, with the hope I was not to far out frame wise. Watching the screen eg when a door shuts, clap hands etc something I can refer to, told me the sync of picture and sound was good... lucky on that one

With the digital reader thats different again, with the digital track its 26 frames before the picture. I was well out with this one, but managed to watch the screen again and adjust the delay on DA20 processor to get it as close as possible, cant fault it now. There are test films for this purpose, but I dont have one.

One of the tests I did when running the digital track, is to place a piece of paper between the lens and lamp on the digital reader. Shutting it down, as the film was running caused the processor to switch straight back to analog, IR/LED, removing the paper it went straight back into digital, so if I have a faulty digital sound track the processor will always switch over and back if the signal returns.

I am certainly not an expert when it comes to sound systems and dont have an oscilloscope but found by pluging in a stereo headset on the main amp with its multi-channel inputs and checking the LED level rise and fall on each channel on the monitor, plus a good test reel of film with a wide range of sounds and adjusting the IR/LED and cell while listing on the headset I think the analog sound pretty close, it sounds good.

More bits from the cinema [Smile]

...I fitted a new potentionmeter for an external remote volume. This is wired up to the back of Ultra Stereo unit and contols both digital and analog sound levels.

during the Dances With Wolves screening I would check the platter in the garage every so often, as usual running great.

Graham. [Smile]

Posted by Jerome Sutter (Member # 2346) on May 29, 2012, 08:39 AM:

Fantastic! Excellent post and pictures. Great Job! [Smile]

Posted by Bill Brandenstein (Member # 892) on May 29, 2012, 01:02 PM:

I second that! So Graham, you answered the technical issue, and that is that the digital sound is even farther ahead of the picture than analog. Because all of the readers I've ever seen are on top, those Dolby units are buffering a lot of data waiting for the picture to catch up! But I'd always figured that with that arrangement, the digital sound was at "0" frames advance so a film repair would always read the sound in sync. See, just goes to show that it's not a good idea to make assumptions!

Posted by Graham Ritchie (Member # 559) on May 29, 2012, 08:52 PM:

Thanks everyone and if anyone on the forum ever comes out this way for a visit, do look us up and I will give you the grand tour.

Regards Graham. [Smile]

UBB.classic^TM 6.3.1.2