Bryan Petersen talks about the ‘photographic triangle’ of aperture (f-stop), shutter speed and ISO settings as the essential framework for effectively capturing a shot, regardless of whether a speedlight or other tools are used. I tend to shoot in ‘aperture priority’ mode mostly and do not really ever adjust ISO much, usually leaving it on 200 in attempt to have ‘noise’ free pictures.
I have not experimented with ‘flash’ photography, rarely even using the inbuilt one on my Nikon D700. Recently, on several occasions, a decent speedlight would have proven invaluable as I have just used my fastest lens, the AF Nikkor 50mm f1.8 with the shutter wide open and hoped for the best. I have not effectively used the ISO setting (and have left the camera on automatic white balance too) but have been conscious that this was an area of my photography I needed to develop.
NB I do covet the SB-900 i-TTL Speedlight and will hopefully aquire one this christmas, if I’m good, but still, of course, need to master ISO and white balance.
The crypt of a cathedral in Viborg, Denmark proved a great place to practise. The light was streaming through the window and I set my D700 and AF Nikkor 24-70 mm lens to an aperture of f2.8, shutter speed of 1/160 and to ISO 2000. I was happy with the result.
What advice do you have about ISO settings?