Hoya HMC NDX400 v Hoya HMC ND400

Hi, Hoya HMC HDX400 v Hoya HMC ND400.... Can someone please tell me what the X is for are they different filters?
Thanks.

Links would help. Off the top of my head, I'd guess that the first might have Hoya's HD multicoating, not merely their lesser grade HMC. But that's just guessing from the product names you've given. Most of the (few) Google hits I got on HDX400 were for a Panasonic camcorder.

Jon wrote in post #10106350
Links would help. Off the top of my head, I'd guess that the first might have Hoya's HD multicoating, not merely their lesser grade HMC. But that's just guessing from the product names you've given. Most of the (few) Google hits I got on HDX400 were for a Panasonic camcorder.

Hi, sorry I do appologise I made typo error I put HDX400 instead of NDX400 in the discription & title of thread.
this is I hope what I was looking at to compare.
http://www.hoya-online.co.uk …9stop-neutral-density.htm
Thanks Again

I'd guess that two different vendors are calling it slightly different things then. Googling ND400 turns up an ND400-X 9 stop ND from Hoya.

Pretty sure that was a typo. The Hoya is labeled as ND400x. 400x is the amount of light it blocks off. The higher end Hoya models are SHMC not XHMC