Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,972   Posts: 1,558,673   Online: 984
      
Page 5 of 6 FirstFirst 123456 LastLast
Results 41 to 50 of 52
  1. #41
    cmacd123's Avatar
    Join Date
    May 2007
    Location
    Stittsville, Ontario
    Shooter
    35mm
    Posts
    1,085
    .... and speaking as a hobby Moviemaker, polyester needs a tape or Ultrasonic $plicer, while acetate can be spliced with good old Film cement. The Poly movie print stock often has an almost iridescent look on the roll due to the antistatic coating on the back.

    A film jam on Poly is also likly to damage the equipment as Poly will not tear easily.

    I have heard that some folks find that slides on Poly stock will not work in some mounting machines as the film needs a very sharp blade to cut cleanly.
    Charles MacDonald
    aa508@ncf.ca
    I still live just beyond the fringe in Stittsville

  2. #42
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,227
    Images
    65
    I have seen MP film on Estar destroy a camera during a run at high speed. This was 35mm in a 1000 ft roll running at such a high speed that the entire roll was used in less than 1 minute. During the jam it tore the teeth off the sprocket wheels and bent the drive shaft rather than break.

    Can you imagine what a jam would do to a coating machine at 1000 ft / min? It can bend the entire machine out of alignment.

    PE

  3. #43
    Europan's Avatar
    Join Date
    May 2009
    Location
    Basel, Switzerland
    Shooter
    Multi Format
    Posts
    68
    A Photosonics at over 300 frames per second? Only a razor blade close to the main sprocket would have been necessary to prevent damage.

  4. #44
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,227
    Images
    65
    At that speed? The test lab was filled with parts and torn film before anyone could react. During actual use, you cannot get to the main sprocket AFAIK. This may have been reported in "The Journal of High Speed Photography", but IDK the camera model at this time.

    PE

  5. #45
    Prest_400's Avatar
    Join Date
    Jan 2009
    Location
    Spain
    Shooter
    Med. Format RF
    Posts
    544
    Polyester seems to have some interesting advantages, and it's drawbacks don't seem that important on still cameras. I'm curious on how it doesn't seem to have replaced Tri-Acetate on the still film market; obviating maybe 135 with motor winder use.
    What would happen if the same thickness and material between the three kinds of finish (135, 120 and sheet) were used? I guess it would be an issue for roll film cameras when it comes down to winding tolerances. But it would maybe make lower scale manufacturing easier (one master roll for everything).

  6. #46
    cmacd123's Avatar
    Join Date
    May 2007
    Location
    Stittsville, Ontario
    Shooter
    35mm
    Posts
    1,085
    Quote Originally Posted by Prest_400 View Post
    Polyester seems to have some interesting advantages, and it's drawbacks don't seem that important on still cameras. I'm curious on how it doesn't seem to have replaced Tri-Acetate on the still film market; obviating maybe 135 with motor winder use.

    The last couple of years worth of EFKE production were on Polyester, as are all the Maco films derived from industrial film made by Agfa Belgium. The main problem is light piping. Motion picture Print stock has been on Poly for years, the esta strenth is needed for the Plater drive systems where an entire feature 12,000 ft is stored on one roll

    Quote Originally Posted by Prest_400 View Post
    What would happen if the same thickness and material between the three kinds of finish (135, 120 and sheet) were used? I guess it would be an issue for roll film cameras when it comes down to winding tolerances. But it would maybe make lower scale manufacturing easier (one master roll for everything).
    The movie print stock was made thinner than the acetate to give it about the same stiffness so that the film would run comfortably on existing projectors. in this application the thickness of the film does not matter to foucs as the emulsion is generally facing the machined fixed part of the gate on the lamp-house side. Sheetfilm is made these days in thick poly as it is stiffer than acetate and stiff is needed to hold Flat. Sheet film thickness would be too hard for roll film cameras to deal with. even film as think as the Poly Movie print might be a bit stiff.
    Charles MacDonald
    aa508@ncf.ca
    I still live just beyond the fringe in Stittsville

  7. #47
    Europan's Avatar
    Join Date
    May 2009
    Location
    Basel, Switzerland
    Shooter
    Multi Format
    Posts
    68
    Quote Originally Posted by Photo Engineer View Post
    During actual use, you cannot get to the main sprocket AFAIK.
    Oh, no, I meant to say a blade installed already so that the misaligning film would cut itself off.

    I know that it is fast.

  8. #48
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,227
    Images
    65
    Quote Originally Posted by Europan View Post
    Oh, no, I meant to say a blade installed already so that the misaligning film would cut itself off.

    I know that it is fast.
    I suspect that the blade would break before it cuts off. And it could scratch well behaved film.

    PE

  9. #49
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    23,227
    Images
    65
    Quote Originally Posted by Prest_400 View Post
    Polyester seems to have some interesting advantages, and it's drawbacks don't seem that important on still cameras. I'm curious on how it doesn't seem to have replaced Tri-Acetate on the still film market; obviating maybe 135 with motor winder use.
    What would happen if the same thickness and material between the three kinds of finish (135, 120 and sheet) were used? I guess it would be an issue for roll film cameras when it comes down to winding tolerances. But it would maybe make lower scale manufacturing easier (one master roll for everything).
    If you used one support for all films, for starters, if you used thicker support for 120 and 35mm, you would get fewer exposures per roll. If you used thinner film for sheet film, it would sag and buckle.

    But, there is more to this than thickness, there is also size changes (Estar has virtually none, but acetate has quite a bit). and then there is the need for a lot of antistatic materials on motion picture films to prevent marks on the film due to high speed travel through the cameras. For that you need rem-jet. The list of "crossover problems" is quite long and involved.

    PE

  10. #50
    Europan's Avatar
    Join Date
    May 2009
    Location
    Basel, Switzerland
    Shooter
    Multi Format
    Posts
    68
    Quote Originally Posted by Photo Engineer View Post
    I suspect that the blade would break before it cuts off. And it could scratch well behaved film.
    Only fears. Would you have suspected the camera failing transport film at 320 fps?

Page 5 of 6 FirstFirst 123456 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin