check your manual and see if there is a setting called 'Lo'. Note that ISO 50 is not necessary, ISO 100 will work just fine! What you often find is that cameras have 'native' ISO's and then some extra's. These extras are not real ISO settings, they are ISO's generated in-camera, much like jpg vivid etc. A camera can have say ISO 100-6400, which can be pushed to ISO 50, or ISO 12,800. These often do no have a setting for them like your usual ISO, in that they will often show as Hi 1/2/3 or Hi 0.3 0.6, or Lo .3 or Lo 1, etc.
However you can shoot using and ND400 at ISO 100 and get brilliant results.
"It is one thing to make a picture of what a person looks like, it is another thing to make a portrait of who they are" - Paul Caponigro
Constructive Critique of my photographs is always appreciated
Nikon, etc!
RICK
My Photography
Thanks so much for the info. I looked through the manual again and found a setting called L which is sopposed to be ISO 50. However I will take your advise and stick to 100