I am looking at some Russian movie cameras which take this type of film. Is this just regular 16mm double perf film which you slit down the middle after processing or is there something special about it (e.g. size, shape, and spacing of the sprocket holes...)?
There are 4 times the amount of holes as normal 16mm 1R and 2 times the amount in 2R (double perf) - there is an extra sprocket in between on each side to achieve the 8mm pull down capability. Normal double perf wont run and will eventually get chewed up by the claw
(and yip, you do slice it down the middle afterwards)
NOTE: he said the film has to be slit or cut in two down the middle after processing.
You turn the film over in the camera after running it down one side, thus 2 x 25' of uniquely perforated 16mm film become Regular 8mm film.
I have a very weird motion picture print of a silent film in my basement that was, for whatever reason, printed on Regular 8mm filmstock and it plays back very happily in a 16mm projector EXCEPT, it is the ONLY 16mm print I have ever seen in my 40+ year of motion picture experience that can be threaded out of frame!
You could do some neat things with double run film if you had the patience ... Like make a film that projected in 16mm (no split) and the four frames interacted - one side would have to be shot in reverse and with the camera upside down for any sense of spatial or temporal normality to remain ... (%50 the time it would be out of sequence in projecting)
We projected some normally produced but unsplit Double Run a little while back in a 16mm projector... weird in that on each side you were presented with pretty much the same film twice, but it each stream was actually made up of sequentially odd and even frames, in effect a totally different movies that still looked comparably the same...
I should also mention Double Super 8 has different sprockets from Double 8 which will run in 16mm projectors, Double Super 8 will only work once split and then its the same as normal Super 8 (as Kino explained) - see the picture on the box linked above, DS8 is the top and D8 is the bottom silhouette ...
Look for a Russian 16 / 8 mm developing tank - It came with a little gadget to split 16mm into 2x8mm after processing.
IIRC it took 100 feet of film and the later models had a clear spiral for reversal exposure.
Look for a Russian 16 / 8 mm developing tank - It came with a little gadget to split 16mm into 2x8mm after processing.
IIRC it took 100 feet of film and the later models had a clear spiral for reversal exposure.
I have all three models of Lomo tank - the 33' (three of them), 2x50' and the biggy 100' tank - none of them came with the splitter and it wasn't mentioned in the instructions, I wish one of them had, I like collecting this stuff...
They all have clear spirals and the 100' model only does 16 and 35mm (perhaps you were thinking of the stacked 2x50' model where unfortunately you have to split the 100' into two 50' loads) - If the spirals weren't clear they still need gaps for the chems to flow through and light would get though these, perhaps only an issue with super16 where the image area is obscured by the slot much more than the rest of frame - that being said the second exposure is not so time dependent in that I've left film out for days and it still came out fine after the second dev, the slotted areas would catch up the rest over that time period ... You could always use a chemical second dev like Sodium Sulfide to get around any uneven 2nd exposure
Back on topic though >> a friend found a splitter in a junk store in Melbourne, they seller didn't know what it was
Way back in the 1960's and early 1970's in the USA there used to be a kinda sub-industry in home movies with several vendors supplying developing tanks, bulk film and slitting supplies. At one time you could get the Morse G-3 type of crank one way, then crank the other way until done (back and forth), the oversize developing reel type (as now available from the Russians), and the drum dip in a trough type with a crank to turn the drum.