Auto ISO at 800 in bright sunlight?

Discussion in 'Nikon DX DSLR' started by Red1, Jul 16, 2007.

  1. Hi All, I have my D200 set up with the "Nikonians" recommended custom banks. In Bank "D" the "Action" settings recommend auto ISO. Today I was shooting motorcycles in bright Southern California sunshine. I was in Manual mode at 1/500 SS and f11. The ISO was set to auto. Now I'm looking at my shots in Lightroom and I see that the auto chose 800 ISO and the pics are very grainy. Does anyone have any idea why auto would select 800 in bright sunlight? I metered off the sky and the cmaera showed 1/500 at f11 as a correct exposure...
    Any thoughts would be apreciated.
  2. F11 at 1/500 is a very small amount of light entering the camera (even in broad daylight). The ISO bumped to compensate. If you want to avoid this open up the f stop considerably. I don't know what lens you were using but try something around 5.6 or faster.

    "metered off the sky and the camera showed 1/500 at f11 as a correct....."

    Yes it was the correct exposure for ISO 800. Had you been at 100 ISO the exposure would have been 3 stops different. Something like 1/500 at f 3.5

    Exposure is a combination of 3 elements. (shutter, app, ISO)

    Hope that helps some.
  3. the 'auto' part of 'auto ISO' means the camera will adjust the ISO for you and you get to choose the fstop and shutter speeds,. you choose f11 and 1/500 and the camera decided iso 800 would give you the right exposure,.

    if you had choosen f8 and 1/500 the camera would have picked iso 400 etc

  4. Thank you for the great explanation!
  5. In a situation like that I prefer to use shutter priority mode, set the shutter speed I need to catch the action, and let the camera choose the aperture and iso.
  6. Little Cub

    Little Cub

    Feb 13, 2007
    Vegas, baby!
    Hi Guys!

    Could you explain what you mean by metering off the sky for your shots? Does this mean setting your aperture to what you would like and finding out what the shutter speed will be? Sorry if this is a really dumb question! lol

    Little Cub