stupid question, put my mind to bed please

Battou

TPF junkie!
Joined
May 10, 2007
Messages
8,047
Reaction score
66
Location
Slapamonkey, New York
Website
www.photo-lucidity.com
Can others edit my Photos
Photos NOT OK to edit
Film Speed

When I went to school is was ASA, now it's ISO. If I read things correctly ASA - 800 is the exactly same thing as ISO - 800, In other words the film is the same just the letters on the box are diffrent, correct?

or am I wrong?
 
What was the ASA leads the ISO photographic standards group - they are not competing in any way. The ASA standards became the basis of the ISO standards.

ASA (American Standards Organization) became ANSI (American National Standards Institute) who became the lead organization for Technical Committee 42 of the International Standards Organization. TC42 is responsible for photographic standards.

They amalgamated the ASA and German DIN film speed ratings into one document as the ISO speed rating. Originally ISO speeds would be written as 'ISO 100/21' for example, with the 21 being the DIN logarithmic speed. That practice is no longer followed universally, and the DIN rating has been left off the most recent speed standard for digital cameras. Therefore the ASA rating has simply become the ISO rating, as the ASA standard went international. It isn't so much that ISO took over from the ASA, but that the ASA rating system took over the world.

Best,
Helen
PS The Wikipedia article on film speed standards needs a major revision - it is neither accurate nor complete.
 
ASA (American Standards Organization) became ANSI (American National Standards Institute) who became the lead organization for Technical Committee 42 of the International Standards Organization. TC42 is responsible for photographic standards.

They amalgamated the ASA and German DIN film speed ratings into one document as the ISO speed rating. Originally ISO speeds would be written as 'ISO 100/21' for example, with the 21 being the DIN logarithmic speed. That practice is no longer followed universally, and the DIN rating has been left off the most recent speed standard for digital cameras. Therefore the ASA rating has simply become the ISO rating, as the ASA standard went international. It isn't so much that ISO took over from the ASA, but that the ASA rating system took over the world.

Best,
Helen

Yeah I was able to find that information on Wiki, it was the ANSI change discusson that got me lost and started spinning my head. but It makes far better sence now that I take the film it self out of the thought process wile reading.
 
Yeah I was able to find that information on Wiki...

You were? It isn't all in the Wikipedia article. Your comment seems a little dismissive. Should I not have bothered giving a more complete answer? This is a genuine question, not a snide remark. If nobody wants this kind of detail I won't bother.

I was editing my previous post while you wrote that. As I mentioned in the edited part of the post, the Wikipedia article has errors and is incomplete. I wonder if the people who wrote it have actually read the relevant ISOs (see the discussion page).

Best,
Helen
 
You were? It isn't all in the Wikipedia article. Your comment seems a little dismissive. Should I not have bothered giving a more complete answer? This is a genuine question, not a snide remark. If nobody wants this kind of detail I won't bother.

I was editing my previous post while you wrote that. As I mentioned in the edited part of the post, the Wikipedia article has errors and is incomplete. I wonder if the people who wrote it have actually read the relevant ISOs (see the discussion page).

Best,
Helen

No, it's not that you shouldn't have given a more complete answer, In fact it was Wiki's need of revision that caused the confuson in the first place.

I just poorly worded my responce, I have a tendancy to do that from time to time.
 

Most reactions

New Topics

Back
Top