100 ISO or 200 ISO - Macro

[ladyLouise]

Hi All, as I am enjoying learning about Macro techniques, I have been looking at others who have taken similar photos that I would like to be able to take in the future!
Question, all the books etc that I have read all state tripod, mirror lock, cable release, self timers etc to ensure good sharpness etc, and say use 100 ISO where possible,

but I have noticed that many of the photos that I have seen, are using 200 iso, can anybody please tell me why perhaps?

I have tried taking some photos and used both ISA's to see if I can tell any difference, sadly I cannot.

Any thoughts please on using 200 instead of 100iso

Thanks as always

Louise

[chris-p]

Hi Louise

There are 2 answers to this. The main one is probably that the photographs were taken with whatever was the native sensitivity of the camera. If you use Nikon, the lowest standard sensitivity is ISO 200, while on Canon (and others) it's ISO 100.
If they're using tripods and cable releases and all that other gubbins, that's probably the answer.

The alternative answer is that they're setting the ISO specifcally to that value for a reason, rather than just the native sensitivity but I doubt it.

[chris-p]

Perhaps I ought to add - using the lowest native ISO is best for image quality, which is why the books say to use ISO 100, as it's often the lowest available.

[ladyLouise]

Thank you