Lesson Learned: ISO vs Shutter Speed

by Liz July. 09, 2008 4792 views

I'm taking an online photo course (in my free time - yeah, more accurately when I should be sleeping!), and one of the first assignments was to shoot three photos, one at ISO 100 with no flash, one at ISO 1600 with no flash, and one at ISO 100 with flash for comparison. Easy enough, but what really surprised me was the very minimal difference between ISO 100 with a longer shutter speed, and ISO 1600 with a shorter shutter speed. Sure, if I enlarge the two I can see more grain in the ISO 1600 shot, but the practical difference is minimal, and would be unnoticeable in a standard sized print. The flash photo is clearly better than either (aided by the fact that I always use a speedlight with diffuser, not the on-camera flash), but still, the high ISO version would certainly be a good alternative. Am I the only bonehead who didn't realize that???? ;)

ISO 100, f/4, 2.5 second; no flash

ISO 1600, f/4, 1/6 second, no flash

ISO 100, f/4, 1/60 second, with flash

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There are 7 comments , add yours!
Tomie Poodle 11 years, 6 months ago

very interesting experiment!

11 years, 6 months ago Edited
Janet Lippincott 11 years, 6 months ago

An online photo course sounds like fun. Must mean you are up as I type this. Another bonehead here; I thought you'd use a faster ISO if there was motion and the photo would have been blurry with the amount of light present. Maybe that's why there's no noticeable difference in a stilllife??

11 years, 6 months ago Edited
Jacki 11 years, 6 months ago

I've gone brain dead on this stuff in the past few years of digital photos... generally speaking, they're "good enough for me"! :-)

I prefer the first two shots (I don't see any difference between them either), especially with the white foreground flower having some shading going on.

So where does one look to find an online photo course??

11 years, 6 months ago Edited
Miclaud 11 years, 6 months ago


11 years, 6 months ago Edited
Gillian 11 years, 6 months ago

I think I agree with LastFrontier; the lighting with the flash seems a little harsh.

11 years, 6 months ago Edited
Vterezia 11 years, 6 months ago

beautiful set:)

11 years, 6 months ago Edited
Deepu S 11 years, 6 months ago

gr8 work...
btw, me too another bonehead :)))

11 years, 6 months ago Edited
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