today I'm going to talk about ISO
after making a few videos on ISO a few of you commented pointing out my
mistakes I did get a bit of misinformation on ISO so this video is
going to correct those mistakes there is quite a lot of misinformation about ISO
from its origins to how it works in my ISO invariance video I got caught out by
this misinformation now this will teach me not to scrimp when it comes to doing
research on a certain subject now I've been a photographer since the mid 90s
but I didn't really worry too much about the terms and terminology of photography
so in making these videos I'm learning a lot about photography and I hope you are
too by incorrectly said that it was the
international standards organization it's actually the International
Organization for Standardization it is an independent non-governmental
organization the members of which are the standards organizations of the 164
member countries it is the world's largest developer of voluntary
international standards and facilitates world trade by providing common
standards between nations when they first set up the organization if they'd
have used the acronym iOS then in different languages in different
countries it would have a different acronym so they settled on ISO this is
short for ISOs which is equal or the same as in Greek this is quite clever
because they're all about standardization they actually
standardized their name and branding with photography the International
Organization for Standardization came up with a standard for emulsion based film
in the late 70s you wouldn't want to get a film from a different country or a
different brand that had completely different levels so if companies used
this standard you'd know that ISO 100 from one brand would be the same
worldwide and would also be the same as ISO 100 from other brands when it came
to exposure values in the United States of America film used to have an AAS a
number on it this stood for the American standards Association in the early 1940s
the ASAE set a standard for film speed for negative
can white film originally a si values were referred to as American standard
speed numbers or a si exposure index numbers in Europe in the mid-to-late
1930s they had the din system this once again was all about film speed and how
they could standardize it since 1974 the a si and di n film speed standards have
been combined the arithmetic is a scale corresponds to the a si arithmetic
system therefore if the ISO number doubles this refers to the doubling of
the sensitivity of the film used to see a film with ISO 200 / 24 or you might
have seen ISO 100 / 21 for a long time now film and digital cameras follow just
with the arithmetic numerical system the correct way to pronounce it is I so I
thought it was ISO as in an acronym but I got this Rob I'll probably keep
pronouncing it like this because I've pronounced it as an acronym for so long
but I'm gonna try and correct myself and pronounce it I so nowadays the term I
say has become synonymous with digital photography if you want to increase your
exposure you can raise your ISO if you want to decrease your exposure you can
lower ISO when you raise your ISO you're increasing the voltage that runs across
the sensor this amplifies the signal as you amplify the signal you'll brighten
up your image but if you push ISO too far you'll introduce digital noise as
not all cameras are equal you'll have a signal to noise ratio some cameras have
better signal-to-noise ratios others have worse also some cameras have ISO
invariant sensors if you're not sure about ISO invariants click on the I in
the corner this will take you to another of my videos each camera has a base ISO
and this is the best eye so that you can take photographs or film at most but not
all cameras have this base ISO set at 100 so if you keep your ISO at 100
you'll get a really good quality image as long as you expose it properly with
the other two principle settings another way that ISO changes
your photograph here's when you increase your ISO your image will become less
saturated this is because as the light drops increasing the ISO will amplify
the signal from the sensor the amount of light is still dropping
but the ISO is keeping the settings the same by this amplification method one
more thing with I save Toni Northrup made a video recently showing how ISO
100 differed from brand to brand and also within brands on different cameras
this is quite interesting and it's worth a watch so click on the eye in the
corner or the link in the description to his video however for most of us this
won't matter too much if you shoot with one camera you know what ISO 100 is and
you know what ISO 1600 is you'll get used to the ISO levels in that camera
you might find that when you switch to another brand or another camera or a
more modern camera you may notice the difference but I never have but he does
have a point that it should be standardized across
the cameras when actually isn't I tried the test and this is what I found
I have the gh4 the RX 10 the rx100 the a7 r2 and the a7 3
hopefully that's cleared up I say in making these videos every now and then I
will make small mistakes and if you spot any of them please do comment below I'm
learning so much from making these videos and it's great to hear that you
guys are learning from them as well and that's about it so I say who comes from
the Greek term I sauce which means equal or the same as when you increase your
iPhone you increase the voltage that runs across the front of your sensor and
this amplifies the signal that comes from your sensor and lastly it's
pronounced ISO are not is PO as always if you like what you see give me a
thumbs up if you didn't give me a thumbs down and for weekly tutorials hints and
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see you in the next one