iso question

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broni74

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hi newbie here! this is a daft question i have just bought a bronica etrs and some film 400 speed, as i am used to digital and can set the iso am i right in thinking that the film will have to be shot using more or less light depending on the film speed 400,100,50?

mark
 
Yep,thats why the pro boys who used medium format (before digital) had multiple camera backs to they could change film speed during a shoot,its also why they used polaroid backs so they could nail the exposure before shooting.Ah the benefits of digital!
 
Spot on Mark :)

ISO is actually a hangover from the film days and stands (I think) for International Standards Organisation. They set the benchmark so all the manufacturers produced film with the same exposure characteristics even if the grain and colour rendition was different.

So you got ISO 50, ISO 100 to roughly ISO 1600.

The digital ISO is just replicating the grain (by noise) so they called it ISO so as not to confuse us old farts :) The ISO on digital is actually the sensitivity of the sensor to light which is a bit different.

HTH
 
You can push or pull film by many stops but you can really change ISO mid-roll because you can only process the film as a whole and the timings will be for specific film speeds.

How are you metering - metering prism? Handheld meter? You'll have to input an ISO into the meter so it can aim to give you an exposure.

I used to love pushing B&W film like Fuji Neopan beyond the set ISO by three or four stops to really increase contrast and grain size.
 
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thanks to all for the replys, i dont have a meter so would it be worth buying a metered prism or a sekonic hand held?
 
Yes :) Or if you have a DSLR you could use that to take readings.

A metered prism takes reflected light readings (light coming off your subject), a sekonic will take the reading of the light falling on the subject.

Have a look on the sekonic website for a full explanation. :)
 
The main reason for having multiple backs is because you only get 15 shots to a roll of 120 film on 645 and it takes a while to reload.

One of my fond (?) memories as an assistant was re-loading Hasselblad backs (only 12 shots per roll on 6x6) and it was hard work keeping up :eek:
 
AliB said:
Spot on Mark :)

ISO is actually a hangover from the film days and stands (I think) for International Standards Organisation. They set the benchmark so all the manufacturers produced film with the same exposure characteristics even if the grain and colour rendition was different.

So you got ISO 50, ISO 100 to roughly ISO 1600.

The digital ISO is just replicating the grain (by noise) so they called it ISO so as not to confuse us old farts :) The ISO on digital is actually the sensitivity of the sensor to light which is a bit different.

HTH
Click to expand...

ISO actually stands for International Organization for Standardization but the countries that use it decided on ISO as the standard acronym. So no matter what "International Organization for Standardization" translates into in various countries they still use ISO.

The standard for digital still cameras, which includes ISO speed ratings is ISO 12232:2006
 
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