ISO: the biggest change in photography the past 10 years!

February 25, 2012 @ 8:00AM

ISO: the biggest change in photography the past 10 years!

It did so quietly, but photographers are finally waking up to the power of ISO.

By Haje Jan Kamps

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News > Feature Articles

We all know that the triumvirate of exposure are shutter speeds, aperture, and ISO. It's this dastardly trio that operates like security guards to photons, standing there, ear-piece in their ears, saying "Oi, if you're name's not down, you ain't coming in".

The head security guard, Mr Aperture is restricting the flow of how many photons can come in at the same time. Dr Shutter Speed is opening and closing the doors to the club for various amounts of times - if he opens the door for a long time, lots of people get in. If he throws the door open and kicks it shut again, only a few people get in. Professor ISO is the allegory-wrecker who just stands there, scratching his head, wondering how the hell he fits into this whole 'club' scenario.

The ISO game-changer.

The point I was going to make, however, is that something has changed over the past ten years, and ISO has taken over power impressively quickly...

Shutter speed has remained stable; typical shutter speeds on a SLR camera range from 30 seconds to 1/4000^th of a second. That's 17 stops of difference.

Apertures remain unchanged; typical aperture ranges for a standard prime lens go from f/1.8 to around f/19 or thereabouts. That's about 7 stops of difference.

However, the biggest change comes from ISO-land. Only 10 years ago, you'd be nuts to use films slower than 3200 or so (don't get me wrong, I loved my ISO 3200 T-Max... But that bad boy was grainy.). On digital cameras, ISO 1,000 was merely 'manageable' in 2002... That's only ~4.5 stops - a lot less than the range of light adjustments you get out of your ISO settings.

Compare that with the shots that are coming out of the current generation cameras. The Sony NEX-7, for example, was determined to have "quite useable results"at ISO's up to 6400, and the same verdict fell for the Nikon D3 camera:

That, ladies and gentlemen, is huge. It means that whilst the aperture and shutter speed range has essentially stood still for ten years, useful ISO ranges have increased from 1000 to 6400 - or from about 4.5 stops to 7 stops of useable range, which means that ISO now matches your aperture control when it comes to being able to control the brightness of your photos.

It might sound pretty subtle, but if you think about it, it's quite the revolution: It means that ISO, which used to be merely a fine-adjustment tool only 10 years ago, can now be used as a major component in your exposure decisions...

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Comments

Wigwam Jones

2 months ago

I agree, but let us not forget dynamic range; the 'fourth leg' of the aperture/shutter speed/ISO tripod. While related to dynamic range, acceptable high-ISO capability is not exactly the same as acceptable dynamic range. For this, we still have a ways to go with digital. I'm sure we'll get there, though.

Matthew Wagg

2 months ago

I agree with your post ISO has been a huge influence on digital photography. As it is a software algorithm it is not subject to the mechanical constraints of the shutter speed and apeture.

However I do have to point out a couple of flaws in your article.

The part where you're talking about film speeds, ISO3200 is a very fast film. You say you'd be nuts to use a slower speed film? ISO 100 is a slow film. I think what you meant was you'd be nuts to use a faster film.

DC Wells

2 months ago

To continue your nightclub analogy, ISO is the DJ or host who figures out how to make a good party (photo) with the number of patrons (photons) -- whether few or many -- who are allowed into the club.

boydg

2 months ago

I think digital has revolutionized photography through more than ISO, though it was obviously a huge player. With the higher iso's being usable and being able to switch iso's at the touch of a button or even automatically has definitely preserved memories that would have been lost otherwise opportunities. I also might argue that the combination of screen made and erasable memory cards has changed the industry the most. I am completely self taught because I could instantly see what I did wrong and correct myself. I would have never been able to achieve this with film. It has greatly accelerated the learning curve with photography in a way film could never do. Also I believe photoshop has definitely revolutionized the finished images as well and is worth mentioning.