ISO

[airgunr]

Basically it's the speed of the film or How much light is needed to expose it properly.

If you have ISO100 film, on a sunny day outside you would set your shutter speed to 125 (closest to 100) and your F/Stop to f/16 for proper exposure.

If you have ISO200 your shutter would be 200 with f/16
ISO400 is a shutter of 400 with f/16
ISO800 is a shutter of 800 with f/16
ETC.

A "Fast" film needs less light or a "Faster" shutter speed for the same exposure.

F/Stop, shutter speed and film speed are all interelated. Get a good book on basic photography and it will all be explained.

 

[arishia]

Ok, thank you. So basically f/16 is the normal or average f/stop? I will try to get a book on basic photography, thank you!

 

[etaf]

theres a number of free online courses - i have listed them here

http://www.dpforums.com/forum/showthread.php?t=2162

you may find them interesting

 

[selmerdave]

Save it, it may not be the greatest 800 film out there but there are plenty of occaisions when an 800 film could come in handy, and grain is not always a bad thing. One case in point is when you need flash power. 800 film gives you the equivalent of almost three times the flash power of 100 film, so your GN 80 flash allows the same shots with 800 film as a GN 225 flash would with 100 film! Also, available light photography at night sometimes lends itself to a grainy look.

Dave

 

[airgunr]

Ok, thank you. So basically f/16 is the normal or average f/stop? I will try to get a book on basic photography, thank you!

Yes and no. I used f/16 because it refers to the "Sunny 16" rule. Basic exposure for a given ISO film is the closest shutter speed to the ISO and f/16. You can modifiy it from there if you have an old manual exposure camera. It came from the days before internal light meters and automated shutter, apature, etc.

I would suggest you pick up a copy of John Hedgecoe's book, "The New Manual of Photography". There are others that are probably just as good but I've read this particular one and it is very good. It explains all those basics of photography in short (2 pages) sections that are very easy to understand as well as giving good examples. In my opinion it is well worth having as a resource in your library.