18th November 2004, 11:10 PM
135 was the product code given by Kodak Eastman for the 35mm film.
35mm film has the dimentions of 24mm X 36mm, thats the physical size of the film negative.
Since this is the focal lens corrosponds to the film size. a 50mm lens is only 50mm when in respect to a 35mm film negative. But what happens when u get a smaller film neg like APS or a smaller area like a CCD sensor?
You get a crop. They will specify how much smaller, some are 1.5X smaller some are 1.3X smaller some are 1.6X smaller. that 1.somethingX is the crop factor, the number u shld multiply your lens focal length by to get the "new" focal lenght caused by a smaller than 135/35mm negative/CCD
18th November 2004, 11:19 PM
A P S - C
APS film, the FILM FORMAT that is on it's way to oblivion, we still often hear "APS-C size"
This is because many D-SLRs have an imaging sensor(CCD/CMOS) close to the APS-C size. These sensors are called "APS-C-size sensors" even though most people don't know how big that is.
APS-C is one of the three picture sizes provided by APS film which is smaller than 35mm film. The C (Classic) size measures 16.7 x 25 mm with an aspect ratio of 2:3 similar to 35mm film.
The APS-H size is slightly wider, and the APS-P size is for panoramic photos.
Notice the word FILM FORMAT, it's nothing special, Format just means a convention, something that has been been around and become a standard.
So 120 FORMAT or MEDIUM FORMAT just means that there is a standardized negative out there. 135 FORMAT like 35mm FLIM FORMAT just means its a standardized FORMAT like written letters have a standardized FORMAT, begin with dear sir/mdm and end off with yours, blah blah blah
not to be confused with PRINTING standards, like 4R 5R 6R 8R and S8R and so on..
Last edited by moos blues; 18th November 2004 at 11:23 PM.