Page 3 of 5 FirstFirst 12345 LastLast
Results 21 to 30 of 47

Thread: Actual image sizes - what size images you really get with various sizes of film

  1. #21
    Andy Eads
    Join Date
    Jul 2001
    Location
    Pasco, Washington - the dry side of the state
    Posts
    211

    Re: Actual image sizes - what size images you really get with various sizes of film

    Quote Originally Posted by Jac@stafford.net View Post
    No. I wrote about film holder sizes.

    So tell us how "the fim speed of Tri-X DOUBLED in one day"
    What day?
    My understanding is that the film speed for black and white films was published one full stop slower than the official ANSI standard to accommodate the sloppy shutters in cheaper cameras. B&W film had enough exposure range to handle the frequent over exposure. As shutters became more trustworthy, the industry decided to remove the one stop "safety factor". I did a cursory search but could not find a firm date. I recall it happening in the early 1970's. The manufacturers did not apply the safety factor to color materials because they had no exposure latitude to speak of.

  2. #22

    Join Date
    Feb 2015
    Location
    Sheridan, Colorado
    Posts
    885

    Re: Actual image sizes - what size images you really get with various sizes of film

    Instead of doing some "cursory searching" or "recall", I'd suggest some actual researching, such as reading Richard Henry's 10+ page history of film speed in "Control in Black & White Photography". It has nothing at all to do with "sloppy shutters". From my experience "sloppy shutters" tend to be slower, not faster -- thereby SOLVING the problem you suggest -- not creating it.

    Perhaps ASA or ISO has a definition of "sloppy"?!?!?

  3. #23
    Jac@stafford.net's Avatar
    Join Date
    Dec 2012
    Location
    Winona, Minnesota
    Posts
    4,087

    Re: Actual image sizes - what size images you really get with various sizes of film

    Quote Originally Posted by Andy Eads View Post
    [...] I did a cursory search but could not find a firm date I recall it happening in the early 1970's.
    Look two posts before yours. See quoted part of article.

  4. #24
    Andy Eads
    Join Date
    Jul 2001
    Location
    Pasco, Washington - the dry side of the state
    Posts
    211

    Re: Actual image sizes - what size images you really get with various sizes of film

    Quote Originally Posted by xkaes View Post
    Instead of doing some "cursory searching" or "recall", I'd suggest some actual researching, such as reading Richard Henry's 10+ page history of film speed in "Control in Black & White Photography". It has nothing at all to do with "sloppy shutters". From my experience "sloppy shutters" tend to be slower, not faster -- thereby SOLVING the problem you suggest -- not creating it.

    Perhaps ASA or ISO has a definition of "sloppy"?!?!?
    Thank you for your comment.

  5. #25
    Andy Eads
    Join Date
    Jul 2001
    Location
    Pasco, Washington - the dry side of the state
    Posts
    211

    Re: Actual image sizes - what size images you really get with various sizes of film

    Quote Originally Posted by Jac@stafford.net View Post
    Look two posts before yours. See quoted part of article.
    Thank you for your comment.

  6. #26

    Join Date
    Jul 2016
    Posts
    1,199

    Re: Actual image sizes - what size images you really get with various sizes of film

    Quote Originally Posted by Andy Eads View Post
    My understanding is that the film speed for black and white films was published one full stop slower than the official ANSI standard to accommodate the sloppy shutters in cheaper cameras. B&W film had enough exposure range to handle the frequent over exposure. As shutters became more trustworthy, the industry decided to remove the one stop "safety factor". I did a cursory search but could not find a firm date. I recall it happening in the early 1970's. The manufacturers did not apply the safety factor to color materials because they had no exposure latitude to speak of.
    It happened in 1960, with norm ASA PH2.5-1960

    "The method to determine film speed was refined and previously applied safety factors against under-exposure were abandoned, effectively doubling the nominal speed of many black-and-white negative films." (Film Speed, wikipedia)

    Since 1960 you have some 3.3 stops form spot photometer recommended exposure to the toe, this is areas underexposed by 3.3 stops are recorded in the film toe (as toe position is defined by ISO, and with "normal" development). Before 1960 there were 4.3 stops. For this reason some classic photography books are teaching different recommendations.

    Also it has to be noted that photometers are not very well specified by norms, 1/6 stop difference can be found. Also different photometers may have different spectral sensitivity, so different models may differ depending on subject color. And to add some confusion, this effect also depends on particular film spectral sensitivity and filtering.

  7. #27
    Jac@stafford.net's Avatar
    Join Date
    Dec 2012
    Location
    Winona, Minnesota
    Posts
    4,087

    Re: Actual image sizes - what size images you really get with various sizes of film

    All this accurate information should alert some of diehards using old Weston meters to second-think.
    I have over a dozen. Three are responsive. And wrong!]

  8. #28

    Join Date
    Feb 2015
    Location
    Sheridan, Colorado
    Posts
    885

    Re: Actual image sizes - what size images you really get with various sizes of film

    But many old &/or inaccurate, non-adjustable meters can be used by changing the film speed, and then testing it on a gray card in the sun -- or the coffee cup test -- or the f-16 rule -- or even a northern sunny sky.

    And any meter -- even TTL meters -- should be tested once in a while against one of these, or another meter.
    Last edited by xkaes; 11-Oct-2017 at 05:56.

  9. #29

    Join Date
    Jul 2016
    Posts
    1,199

    Re: Actual image sizes - what size images you really get with various sizes of film

    Quote Originally Posted by Jac@stafford.net View Post
    All this accurate information should alert some of diehards using old Weston meters to second-think.
    I have over a dozen. Three are responsive. And wrong!]
    Well, today it is easy to check a meter... I've a W Euro-Master that is pretty wrong, but a friend has another one that nails the same than a Nikon F5 does.

    Anyway some of those diehards don't event need a photometer AA adjusted his most iconic shot by just smelling the moon !

  10. #30

    Re: Actual image sizes - what size images you really get with various sizes of film

    Quote Originally Posted by Pere Casals View Post
    Well, today it is easy to check a meter... I've a W Euro-Master that is pretty wrong, but a friend has another one that nails the same than a Nikon F5 does.

    Anyway some of those diehards don't event need a photometer AA adjusted his most iconic shot by just smelling the moon !
    Dang, AA musta had a better sniffer than my bloodhounds!

Similar Threads

  1. Question about film sizes
    By patois in forum Darkroom: Film, Processing & Printing
    Replies: 0
    Last Post: 8-Dec-2010, 16:50
  2. Plate sizes to standard sizes
    By Archphoto in forum Cameras & Camera Accessories
    Replies: 7
    Last Post: 23-Apr-2009, 14:06
  3. Actual image size on 7x11, 7x17, and other ULF negatives?
    By Steve Goldstein in forum Darkroom: Film, Processing & Printing
    Replies: 6
    Last Post: 22-Apr-2008, 04:14
  4. Stored Image Sizes
    By eric black in forum Digital Processing
    Replies: 5
    Last Post: 15-Nov-2007, 07:16
  5. Image sizes
    By Ray Dunn in forum Darkroom: Film, Processing & Printing
    Replies: 2
    Last Post: 16-Dec-1999, 18:14

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •