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Thread: Why 160?

  1. #31

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    Box speeds are based on log density vs exposure etc. , but they are still basically ballpark figures and the shooting speed depends on the look you want and the way you meter the scene. With colour neg film it's best to lean towards overexposure rather than under exposure. Combine that with most in camera meters being optimized for slide shooting, and 160 allows you to to comfortably rate the film at 100 -125 and have a good margin for exposure error and reasonable sharpness when hand holding. Whereas at 100, you might want to rate your film at 64 which is getting a little slow for taking pictures of people which is what the 160 speed portrait films are primarily intended for.

  2. #32

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    you wouldn't believe me but here is my explaination. The make only 1 film, the true speed is about 160 so they put it 160 for the pro version. For the amateur version they put it in both 100 and 200 speed. One is slightly underated and other is slightly over rated but really is the same film.

  3. #33
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    Quote Originally Posted by Chan Tran View Post
    you wouldn't believe me but here is my explaination. The make only 1 film, the true speed is about 160 so they put it 160 for the pro version. For the amateur version they put it in both 100 and 200 speed. One is slightly underated and other is slightly over rated but really is the same film.
    It's a conspiracy!
    www.EASmithV.com

    "The camera is an instrument that teaches people how to see without a camera."— Dorothea Lange
    http://www.flickr.com/easmithv/
    RIP Kodachrome

  4. #34

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    Quote Originally Posted by Chan Tran View Post
    you wouldn't believe me but here is my explaination. The make only 1 film, the true speed is about 160 so they put it 160 for the pro version. For the amateur version they put it in both 100 and 200 speed. One is slightly underated and other is slightly over rated but really is the same film.
    The general statement is easy to disprove for any given brand of consumer film -- buy a roll of each, expose and process them identically, and then measure the density of the resulting negative. In fact, that's how ISO is determined under the 1987 standard.

    But once you start comparing films across target markets or across time, things begin to fall apart. If you compare the characteristic curve of Kodak 400NC to that for Kodak Vision2 250D, you'll see that they are very similar or identical. While one rating is for still use and one for movie use, one uses the same light meter either way. Plus-X was introduced as an ASA 80 film, was briefly marketed as an ASA 160 film, and finally settled down at ASA 125. (For movie use, it's still rated at ISO 80, but that's due to differences in recommended developers).

    Is there enough slop in the ISO standard for color print film to allow what you suspect? Ask a test engineer, but given the differences I've seen while doing my own EI rating I suspect there is, especially between 160 and 200.

  5. #35
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    Quote Originally Posted by Curt View Post
    Why are the labels on Cranberries upside down according to how the can is opened? I have asked many people that and no grocer knows the answer.

    Maybe it goes with ASA 64. I use ASA because that film is long gone. What's the most unusual film speed listed by a manufacturer?

    I love those King Oscar ones. http://www.kingoscar.com/company

    My step grandfather was Norwegian, we fished and hunted and ate King Oscar Sardines, but I've told that story before...

    BTW: where is Ole these days?
    Now I'm confused, King Oscar was a swedish king? But the sardines are Norwegian?

  6. #36

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    to protect working pro's from people who go into a camera shop? They will look at 160 and shrug...get some consumer 100 or 200 film?

  7. #37
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    Quote Originally Posted by olleorama View Post
    Now I'm confused, King Oscar was a swedish king? But the sardines are Norwegian?
    Thinking about it, it is surprising that the company kept that trademark even after Norway seceded from Sweden. The dissolution of the Swedish-Norwegian union in 1905 was confirmed in Norway by a referendum in which 99.95% voted for independence. And still that stubborn company kept selling sardines named after the Swedish king!

    The probably reason for the dissolution was the extremely ugly union flag, which by the way was nick-named the "herring-salad".


  8. #38
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    Film speeds

    Quote Originally Posted by John Shriver View Post
    The Kodak portrait color negative films have slowly gained speed through the years. Ektacolor Professional S (C-22) and Vericolor S (C-41) were ASA 100. Vericolor II Professional S was ASA 125. Vericolor III was 160, as is Portra 160NC (of course). So it gained speed a third-stop at a time over the last 35 years.

    Of course, with Portra, they also added 400 speed films, and later an 800 speed.
    No photographers that I ever met actually used the box speeds for Vericolor II and Vericolor III films, though. They would typically give 1/3 to 2/3 stops more exposure.

    One lab I worked in some years ago processed aerial film, as well as all of the usual pro formats. I was assigned the task of calculating the actual speed of the aerial film, and comparing it to other films which we processed. Using an EG&G sensitometer, I compared the aerial film to Ektar 25 and Vericolor III, and much to my surprise, all of the films were spot-on for film speed.

  9. #39

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    I begin to suspect that noone ever uses negative film at the box speed (i don't).
    Maybe time for a poll.

  10. #40
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    Quote Originally Posted by Terrence Brennan View Post
    No photographers that I ever met actually used the box speeds for Vericolor II and Vericolor III films, though. They would typically give 1/3 to 2/3 stops more exposure.

    One lab I worked in some years ago processed aerial film, as well as all of the usual pro formats. I was assigned the task of calculating the actual speed of the aerial film, and comparing it to other films which we processed. Using an EG&G sensitometer, I compared the aerial film to Ektar 25 and Vericolor III, and much to my surprise, all of the films were spot-on for film speed.
    It's almost like they employs swarms of people to do tests just like that!

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