I would be grateful for some explanations how to get sound on 16mm film. I know that there is needed crystal sync device connected with Bolex (I have Bolex EL) and suitable DAT recorder. That is easy. But what happens next in postproduction process? How can I put the sound track on film?
"Putting sound on 16mm film" is done in the final lab process known as composite printing.
Throughout the conventional film editing process, picture and sound are seperate; photographed and recorded on seperate pieces of equipment. The film is developed and printed as "work print" and the audio transfered onto mag track (perferated audio media the same size and length as the matching film). Then the two pieces are "synched" up based on common markers (slates) and often edge coded so the two elements can be realigned once the slates are cut out.
During the editing process, additional audio tracks are often added, requiring a mix-down to join all the dialog, music and effects on one piece of mag track. The edited workprint picture is conformed to the origional camera masters by lining up the edge codes common to both in an A & B roll so the slices can be eliminated from the final print.
The lab takes the A&B rolls of camera negative and times the color and exposure in order to prepare for the 1st trail print. The audio can either be combined with the picture by an edge mag track or by creating an optical negative which is printed onto the composite at the same time as the picture.
If many copies will be required, an internegative is often made from the A&B rolls to save the origional from unnecessary wear, and subsequent prints are made this way.
A good lab will assist you with any and all of these processes and often can either direct you to a negative cutter or due the work for you in house. You will find this to be a complex and costly process, which is why High Def production is becoming so popular amoung producers who used to work in 16mm.
I would also add that, kodak once made 16mm film stock for the camera that already had a mag track on it. I think this was a kind of reversal, ENG film stock. Once you go through your editing and sound work, assuming you do it in the traditional double sync way as so well explained by John you can than have the mixed sound track recorded on the camera stock that has the mag stripe.
This is kind of an odd ball way of doing things but if you only want one copy and then transfer to video this method works, I remember doing in the mid 1980's it saved money and I thought it was rather clever.
You're absolutely right; "mag-striped" reversal film was made specically for single system newsfilm shooting on cameras like the Auricon and CP16. The newsfilm was rushed back to the lab at the station where (in smaller markets) the cameraperson would develop his/her own film and then "displace" the sound into dead sync to cut the origional and then "offset" the sound again so that it could be played in sync in a projector.
Such stock was not intended to be dubbed back onto in the end, there were other low contrast print stocks with mag stripe for this purpose. I'd really be suprised if Kodak (or anyone else) still makes such stock, but it sure brings back memories!