Help wanted re ISO setting

[Adrenalin Junkie]

I have tried photography using a Hoya ND400 filter without success. In various forums members using a Canon 5D Mk II and the same filter refer to an ISO setting of 50. I have the same gear but can only get as low as 100. What am I doing wrong?

[ricktas]

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.

[Adrenalin Junkie]

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