Hi Guys - I am intending to buy either the ND400 or ND500 filter. When I search in ebay, there are quite a number of ND400 including Hoya; however for ND500 (which apparently is a real 9 stop) only a company called Light craft workshop sells it.

Also there is the 'Fader' kind that you can rotate to get between a 2 stop and 9 stop in the same filter (although reviews say that this is more for video photography but can be used for normal photography as well).

Any idea which is the way to go?

Thanks a lot - DJ