ISO Question.

photog4life · Jul 11, 2014

Are ISO's universal across cameras? Obviously some cameras will have more noise but as for how much light it actually lets in is it universal across cameras?

The reason why I ask is because when I got my slr I feel like I am shooting at higher ISO's to get the same exposure then I did with my old camera(sony DSC H5 BRIDGE)... but I also didnt shoot with it very much unless I was in bright sunlight because the noise levels were unreal. So i dont know. It was just something that popped into my head.

Thanks for any help to understand and hopefully the question makes sense.

Ysarex · Jul 11, 2014

In theory yes, but camera manufacturers have been known to leave a thumb hanging on the scale at times if it makes the camera stats look better.

Joe

photog4life · Jul 11, 2014

And what does that mean though? I mean they would be pretty close to the same thing then right? Your not gonna lose a full stop? Like on one camera an ISO of 800 shoots more like an ISO of 400?

Ysarex · Jul 11, 2014

photog4life said:
And what does that mean though? I mean they would be pretty close to the same thing then right? Your not gonna lose a full stop? Like on one camera an ISO of 800 shoots more like an ISO of 400?

A full stop is pretty extreme, but I have read camera reviews where the manufacturers have been criticized for stretching the truth nearly that much.

Joe

photog4life · Jul 11, 2014

ok second question.... What does Tv and Av actually stand for? Tv is shutter and Av is aperature but what do the letters actually stand for lol.

JustJazzie · Jul 11, 2014

photog4life said:
ok second question.... What does Tv and Av actually stand for? Tv is shutter and Av is aperature but what do the letters actually stand for lol.

Aperture value and time value I believe.

Braineack · Jul 11, 2014

there's supposed to be an actual SNR measurement standard, yes.

KmH · Jul 11, 2014

ISO stands for the International Organization for Standardization.

Back in the day before the adoption of an international standard film speed (ASA) was tested by the American Standards Association.

Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system. A closely related ISO system is used to measure the sensitivity of digital imaging systems.

photog4life · Jul 11, 2014

Ok. Thanks guys! Stupid questions are done for the day. lol

dennybeall · Jul 11, 2014

The ISO rating is a rating for the sensor that's mounted in the camera but between the sensor and the subject is a lens and it's components as well as whatever is in the camera system for the viewfinder.