Whats the difference between!?

dazftw

ISO on rolls of film & ISO setting on the camera?

I just got a bronica sq-a and am curious..

quilmore

if they aren't linked we've been cheated!

DaireQuinlan

dazftw wrote: »

ISO on rolls of film & ISO setting on the camera?

I just got a bronica sq-a and am curious..

how do you mean whats the difference ? They both represent the same thing if thats what you mean. If you're talking about setting the ISO on the film back for your SQA then it makes no difference what you set it to except as a reminder unless you have a metered prism, which should pick up the iso set on the back.

dazftw

DaireQuinlan wrote: »

how do you mean whats the difference ? They both represent the same thing if thats what you mean. If you're talking about setting the ISO on the film back for your SQA then it makes no difference what you set it to except as a reminder unless you have a metered prism, which should pick up the iso set on the back.

Yeah, so the iso setting on the camera has no effect on the pictures at all? Only the iso on the film does?

punchdrunk

surely the ISO on the camera is there to affect the accuracy on the metering?

Burnt

The ISO number indicates it's sensitivity to light; the ISO setting on the camera
tells the light meter what speed of film your using to calculate the exposure. To
achieve the "correct" exposure the ISO setting on the camera should match the ISO number of the film.

unreggd

There is no difference


You set the camera to the same ISO speed as the film

E.g, if you're using a film thats ISO 400, move the camera's dial to 400

They need to be the same for correct light meter measurement


The only time they should be different is if you're pushing, but thats a different thing altogether

dazftw

ah so that's what pushing is.. Ive been reading around and have seen pushing a few times! it makes alot more sense now!

Thanks for that guys!!

CabanSail

The ISO stands for "International Organization for Standardization" (not sure why it isn't IOS though) It used to be known as ASA in the old days. The Film/Sensor ISO is a standard to determine sensitivity to light. It is a linear scale, so ISO 200 is twice as sensitive as ISO 100 ie One F Stop difference. There was also the DIN system which was a logarithmic scale (ASA 100 was the same as DIN 21 & ASA 64 was DIN19 if I remember correctly)

So that a light meter can give the correct readings it has to know the sensitivity. If you are using Film then the Meter has to know how fast the film is, so you need to enter the ISO number. In later model 35mm Cameras the can was DX coded so that the camera would automatically know the film speed.

If shooting Manual & using a Lightmeter you still have to set the meter to the ISO you have set on the sensor.

Alun

CabanSail wrote: »

The ISO stands for "International Organization for Standardization" (not sure why it isn't IOS though)

From their website ...

Because "International Organization for Standardization" would have different acronyms in different languages ("IOS" in English, "OIN" in French for Organisation internationale de normalisation), its founders decided to give it also a short, all-purpose name. They chose "ISO", derived from the Greek isos, meaning "equal". Whatever the country, whatever the language, the short form of the organization's name is always ISO.

DotOrg

asa = american standards association

Anouilh

This thread describes why digital photography has made my life so much easier, given the wild light changes in Ireland.

In the past, I spent a lot of time pushing film or making exposure tweaks in my film camera.

Here are two helpful links:
http://www.p45rant.net/boards/showthread.php?t=77609&page=4

http://photo.net/photography-lighting-equipment-techniques-forum/00MoWM

I never got to the stage where I could ask the people processing my film to change the processing to accord with the pushed film. In fact, I'm only now beginning to make sense of all the details.

Very helpful thread.

DaireQuinlan

dazftw wrote: »

Yeah, so the iso setting on the camera has no effect on the pictures at all? Only the iso on the film does?

If you have a metering prism then the iso you set on the back will be the iso that the prism uses to calculate exposure. If you're just shooting using the WLF then it doesn't make any difference what you set on the back, you'll be using sunny 16 or an external meter anyway.

dazftw

That sunny 16 rule actually works? I will have to give that a go tomorrow! I was using my 5D to meter everything..