As home movie film collectors were we short changed ?

[Paul Adsett]

Hi Adrian. What you describe would have been fantastic - DTS sound on super 8 film prints! I see no reason at all that the time code could not have been printed along the edge of the film (in place of the mag stripe). All you would need then would be a simple DTS code reader attached to the projector ahead of the gate. Sounds like a great test project for somebody!

[Steve Lee]

My thoughts for putting digital sound onto Super 8 go back many years ever since I was demonstrated the system about a year before it was finally released to the industry. The whole thing could have been quite simple to do, or more so possible to do in the future with the technology advances now. Before I try to explain this we need to go back to the 80s and the advances that happened within the industry.

The film industry in the late 80s need to find a way of replacing the black silver optical soundtrack with an environmentally friendly substitute, as the silver was needed to be removed from the theatrical prints before they were incinerated ( it makes you want to cry ). So some bright spark came up with the idea of printing the soundtrack cyan blue for it to be read by a red laser diode, polarizing the blue soundtrack to black, in the same way as 3d works. Just by changing the exciter lamp over to a laser diode made some significant improvement to the optical sound as it increases the frequency response, this was also backwards compatible.

In 1993 DTS was released as sound on disc system, that used a row of dots printed down the inside of the optical soundtrack next to the picture, and produced a timecode to sync the highly compressed Cds with the film. This was by no means perfect as any damage to the disc such as a finger print could result in reproducing scenes from Singin' in the Rain !
In the same year Dolby introduction Dolby digital that used a QR code printed between the sprocket holes, and uses a CCD scanner to read the information.
Both Dolby and DTS had thought this one out from day one, as any projector that ran at 24fps could easily be converted over to digital simply by bolting a reader box onto the projector. Because we are now dealing with digital that uses a buffering system it meant that the reader could be placed anywhere in the film path, and using a digital delay, synchronize the sound to the picture.

This is now where my thoughts come into play. The first would to be to produce a laser diode unit to simply replace the exciter lamp in a super 8 machine, whilst using the same base cap and power supply. As this would greatly improve the optical sound.
The second is to produce a scaled down version for super 8 of a Dolby CAT702 reader to be able to screw down onto a super 8 machine, before the film enters the threading mech. It must be possible to do as we now have better ccd's in our phones than anything that was used by Dolby. The output from this unit could be done via optical cable or hdmi even bluetooth, to connect to a AV amp receiver to decode the 5:1 soundtrack.

Now for the prints. Over the past 20 years there have been so many advancements in film recorder technology, the unit takes a digital source and using raster software converts the image into a composite image, that is then burnt back onto the film using a three pass laser system, I now believe they can produce up to 8k resolution on to film.
It would be to use one of these units that was designed for super 8 film to produce a master negative, including a Dolby digital, DTS and stereo/mono optical all on the one print. For the film source to use a blu ray or 4k disc as the resolution on 8mm is never going to be greater than full HD, this would also allow for the finest restored copy of a particular film for use as a master. After this all of the prints can be run off on a contact printer.

It's just a shame there's no colour print stock available at a sensible price to make this reality.

[Brian Fretwell]

Also don't forget CDS (Cinema Digital Sound) that was used on a very few 70mm films such as The Doors. I believe that was the first one to be used. Also SDDS (Sony Dynamic Digital Sound)

The Dolby Digital system showed their double D logo in every one of those code boxes between the perforations. After a talk where the Dolby rep said that other rivals were using matrix systems compatible with Dolby Stereo and that they were not pleased I asked if that was to disable the decoder if it was absent, (any rival could be prosecuted for using Dolby's trademark I thought) - he said " No the system didn't need all the space". It was also revealed that the digital track was in advance of the picture so that if it failed the system could switch back to the analogue track without a break.

[Maurice Leakey]

Going from left to right on the 35mm strip:-

SDDS (Sony Dynamic Digital Sound)
Dolby Digital
Analogue Optical
DTS Time Code (Digital Theatre Sound)

35mm film audio macro - DTS (sound system) - Wikipedia

[Graham Ritchie]

Brian

You are right about the position of the Digital reader. The delay adjustment is done on the DA20 Digital Film Sound Processor, by counting if I remember right the of frames from the Digital reader to the analog IR sound head, as the Digital data between the perforations will be side by side to the analog track, adjusting the time delay the DA20 accordingly can be up to 135 frames. To double check that you have got it right, watch the screen for something like a clap, an instant sound that matches exactly what you see on the screen, bit like using a clapper board.

Both at the cinema and at home the sound system is set up, so that if you lose Dolby Digital, the Ultra Stereo Unit will switch over, in my case to IR reverse scanning Kelmar Dolby Analog. If the Digital sound comes back, then it switches straight back. A good way to test your system, is to simply place a piece of paper in the Digital reader to cut the light off, and the sound system should switch straight over, testing it this way say a couple of times while a film is running is a good way to see how good things are operating.

However in saying all that I am not in any way a expert in sound systems. I leave that to the folk that know a lot more on the subject

I will say this that I don't see any reason why DTS could not have been used in Super 8. Its a brilliant system if looked after. I was thinking of adding it to the Ernemann 2 but I don't have the room, so Dolby Digital will have to do




However if I was to find the feature to go with this, then I might just find a way to include DTS