Motion picture film

[AgX]

Kino,

Are there really cameras where the sprocket wheel is not used for pulling the film? There is a design where the clutch drive of the sprocket wheel is disengaged when the back is open, so it only seems to be idle in such a case.

 

[Photo Engineer]

The takeup spool provides a measure of positive pull on the film, but as the spool increases in diameter, it would change the distance between frames if only the spool were functional. I'm afraid that AgX is correct, the sprocket wheel is advancing the film by an exactly measured amount in both 35mm still and MP cameras. The difference is the precision with which this is done. Since the film is still in a regular 35mm camera there can be more slop in the sprocket holes to allow for easier threading.

In an MP camera, steadiness and precision are important and high speed is the norm. I have seen high speed cameras running at such high speed, that a 1000 ft roll is used up in an eyeblink. I have seen a jam of estar film in one that ripped the sprockets off the wheel and spread them around the room. The estar would not give enough and sliced the sprocket gears off. This camera, BTW, had a drive with a gear shift to get up to speed.

I used to read "The Journal of High Speed Photography" as it was one of our mainstays at Cape Canaveral, and they discuss the needs of MP for this type of precision. Tight, exact sprocket holes help supply this!

PE

 

[Kino]

Kino,

Are there really cameras where the sprocket wheel is not used for pulling the film? There is a design where the clutch drive of the sprocket wheel is disengaged when the back is open, so it only seems to be idle in such a case.

OK, let me revise that drive part; some 35mm still cameras drive from the takeup spool but measure out the length of the frame via the sprocket wheel, while others drive via the sprocket wheel and measure at the same time.

Either way, I maintain that tooth shape on 35mm still camera transport sprockets is not all that critical if simply used as a single strip image making machine.

As for motion picture work, I think that has been covered sufficiently.

 

[fschifano]

Most of the good stuff has already been covered. From what I've gathered, it's not so good to process ECN-2 films in C-41 chemistry. But the B&W stuff is ok as long as there is no remjet coating on the back. That stuff will surely make a mess, and it's not something that I'd like to deal with.

I have used a fair bit of Eastman 5222, and I like it a lot. There is no remjet, and it performs very well in D-76. There is no issue with the shape of the sproket holes in any of the cameras I've used it in. I run it for 7 minutes in D-76 1+1 at 75F (24C).

 

[Larry Bullis]

Check out that grain--

35mm frame full width
Edwal 12

 

[2F/2F]

IMHO the major thing motion film has to offer we still shooters is a fast tungsten neg. stock, which *is* excellent stuff for low light shooting. I find everything else about it to be quite a hassle. It is cheap, but not all that cheap, it is hard to find processing, processing is expensive, they look at you like you are a space alien when you ask them to push it, and if NOT pushed, it does not print well without scanning and Lightjet. I also hear that it archives very poorly, although I do not know if this is actually true. Doesn't make much sense to me, unless the in-camera film is not that important to archive compared to prints.

Another cool thing about it is that you get a neg strip and a print strip back.

 

[Kino]

It archives no better or worse than regular still film, if you are speaking about dye fading, it all has about the same fugitive qualities in fading, but I agree 100% about the hassle.

That is the reason these labs went out of business; it's too labor intensive for the profit margin and IF you need to push it a stop, well the price goes through the roof.

Modern Motion picture images are intended to be viewed at 24 or 25 frames per second and when you reduce it to 1 per however long you want to stare at it, it looses quite a bit of quality in a relative sort of way...