Film ISO V Digital ISO

Ady N

Ady N

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Would you say 1000 ISO film was the same as shooting 1000 ISO digital speed wise? With digital we think nothing of pushing the ISO into the thousands whereas when I did use film 1000 ISO was fast and seemed fast enough hence my question.............
 
The ISO is what it says, an international standard*.

1000 ISO film was uncommon, and grainy as hell. Most people bottled out at 800.

Digital changed all of that, and continues to do so, not because we've changed the way it's measured, but because digital is so much better in low light. We can shoot things now which we're impossible with film.

*there have always been slight variations in metering from different cameras! and film speed ratings.
 
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Film can be ok in low light just not as much use in action shots ie its not so much that its bad at low light it's that high speed film does not tend to be very wonderful more a matter of what you might chose to shoot in low light with film.
 
Are there specific situations you're thinking of here? I shoot both film and digital but for different things, I still don't think digital can match film for black and white for example (or perhaps I should say I prefer how film looks for black and white).

For me it's about using the strengths of each one rather than one being outright 'better' than the other, right tool for the job and all that. :)
 
PMN said:
...I still don't think digital can match film for black and white for example (or perhaps I should say I prefer how film looks for black and white).
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+1

PMN said:
For me it's about using the strengths of each one rather than one being outright 'better' than the other, right tool for the job and all that. :)
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absolutely... (I'm going to use my favourite "word of the month"... it's getting a lot of hammer recently!) Use the Appropriate one...
 
PMN said:
Are there specific situations you're thinking of here?
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Not really. As Phil has stated, it is an international standard so should be directly comparable. It must be the quality of the sensors now that make old ISO 1000 film look so grainy, was just wondering if the ISO standard was still like for like but it seems so............
 
Back in the day, I often used to push ISO 400 to 1200 and 1600 ISO and print on grade 3 paper I liked the grain and contrast. It's easy to replicate this now in Photoshop but it's not as near as much fun.
 
PMN said:
Are there specific situations you're thinking of here? I shoot both film and digital but for different things, I still don't think digital can match film for black and white for example (or perhaps I should say I prefer how film looks for black and white).

For me it's about using the strengths of each one rather than one being outright 'better' than the other, right tool for the job and all that. :)
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But that's all about subjective issues, the simple question about ISO is objective.

And whether film or digital looks 'better' is subjective.
 
I used to push film to 3200,the best film i found for really pushing hard was Exchrome Tungsten 160 asa :)
 
Phil V said:
But that's all about subjective issues, the simple question about ISO is objective.

And whether film or digital looks 'better' is subjective.
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As you've said, ISO is called ISO for a reason. Surely the sensible way to proceed from that point is to explain how film and digital naturally respond differently and explain why they can't directly be compared?

Even different film formats respond differently, trying to view this from the point of view of ISO being absolute across formats makes absolutely no sense. It's an attempt to standardise things but it doesn't mean a given set of values on every format will give identical results. Various audio recording formats are theoretically or technically capable of achieving the same dynamic range or frequency response (both measurable things), it doesn't mean they sound the same.
 
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It's a tricky one

Despite film ASA being a 'standard' - I found it it inherently variable.

ISO these days is a minefield if you ask me.

What they go up to and what they actually do............;)

 
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Film ISO/ASA was determined by measuring how sensitive the film was to light using a sensitometer and comparing it between a known set of exposure values. In digital cameras the sensor data value is more complex to define due to processor speeds and varies from manufacturer to manufacture. The Marshall Amp analogy is quite a good example of that !
 
Digital ISO is much more consistent and linear than film. It's easy to check as well - just take a shot and wind up the ISO at the same time as raising the shutter speed - mid-tone density will stay the same - in the middle of the histogram. If you did the same with film (heck of a lot of hassle!) you'd often find that fast emulsions failed to hit their marked speed, and might also vary batch to batch.

Having said that, I do a lot of testing of different cameras for my work that involves shooting identical scenes at same exposure values. When they're then imported to Lightroom at default settings, some slight variables are common. But it's not massive, maybe half a stop or so.

Edit: there's another problem with film too - long exposure reciprocity failure. Everything's okay down to about 1sec exposure, but then a theoretical 4secs exposure might actually need 6secs, and a 10secs exposure might need 20secs, then things get rapidly worse so that really long exposures become impractical. There's more - with colour film, the different colour layers have different reciprocity failure characteristics, meaning that a colour cast soon develops and then turns to what's known as 'crossed curves', meaning that it's impossible to correct for accurate colour. That rules out long exposure landscapes using a ten stops ND filter with colour film, and things like star trails are almost impossible. Digital has really revolutionised astro photography.
 
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Ady N said:
Not really. As Phil has stated, it is an international standard so should be directly comparable. It must be the quality of the sensors now that make old ISO 1000 film look so grainy, was just wondering if the ISO standard was still like for like but it seems so............
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1000ISO colour film was grainy as anything. I'd use it in medium format, but never felt happy above 400 in 35mm. B&W was a different matter, of course.
 
HoppyUK said:
Digital ISO is much more consistent and linear than film. It's easy to check as well - just take a shot and wind up the ISO at the same time as raising the shutter speed - mid-tone density will stay the same - in the middle of the histogram. If you did the same with film (heck of a lot of hassle!) you'd often find that fast emulsions failed to hit their marked speed, and might also vary batch to batch.

Having said that, I do a lot of testing of different cameras for my work that involves shooting identical scenes at same exposure values. When they're then imported to Lightroom at default settings, some slight variables are common. But it's not massive, maybe half a stop or so.

Edit: there's another problem with film too - long exposure reciprocity failure. Everything's okay down to about 1sec exposure, but then a theoretical 4secs exposure might actually need 6secs, and a 10secs exposure might need 20secs, then things get rapidly worse so that really long exposures become impractical. There's more - with colour film, the different colour layers have different reciprocity failure characteristics, meaning that a colour cast soon develops and then turns to what's known as 'crossed curves', meaning that it's impossible to correct for accurate colour. That rules out long exposure landscapes using a ten stops ND filter with colour film, and things like star trails are almost impossible. Digital has really revolutionised astro photography.
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That's basically what I was trying to say, you just said it 1000 times better! :)
 
PMN said:
That's basically what I was trying to say, you just said it 1000 times better! :)
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And it's precisely why I never answered the point.
Some people are better at this than others.
 
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