Neutral Density Filters to get smooth silky seas

[kipper]

Was out on a photo shoot this morning, I had a +4 ND filter with me and I wanted to take some silky seas but the slowest shutter speed I could get was about 2 seconds. Whats the highest number of stops you can get an ND filter in? I've seen +8, is there more than that?[/b]

[SoCal Steve]

Kipper - I don't know the real answer, but if its full frame I don't see why you couldn't double or triple up on them if they were of good quality. Now I'll sit back and let someone shoot me down. (But that's okay, I'll learn something in the process!).

[redline]

Was out on a photo shoot this morning, I had a +4 ND filter with me and I wanted to take some silky seas but the slowest shutter speed I could get was about 2 seconds. Whats the highest number of stops you can get an ND filter in? I've seen +8, is there more than that?[/b]

i know that you could stack more filters on but i think it going to affect picture quality. maybe wait for a time before just after sunset? or before dawn?

i think an nd8 give 4 stops

[Hlop]

ND8 gives us 3 stops, accordingly to cokin filter system manual.

[Matt. K]

3 stops is correct. No harm if you stack them. Loss of quality is very small.

[kipper]

K, just got to be mindful of vignetting I guess.

[redline]

thanks for clearing that i always remmbered it a half the nd value, oh well

[Onyx]

Yeah, ND stacking works well (just watch out when wide-angling), or there's a ND300 or something for shooting the sun. I bet you could get multiple minute exposures at noon with one of those.

[kipper]

Yeah I think I saw a 9 stop ND filter on adorama. ND-400X must be the one your'e talking about Onyx.

[Killakoala]

I have a special filter for shooting the sun. It's an H-Alpha filter used for astronomy, but works equally well on my 500mm F8 Mirror Reflex lens.

With the stacking of ND filters, if you use the Cokin system you will get away with vignetting at wide angles, but not too wide of course.

[redline]

Hey Killa,
with your 500 mirror, do you use any rear 39 screw-ins?

[dooda]

Why not throw on your polarizer as well, that adds two stops doesn't it?

[kipper]

Dooda, I did!

Had ND+4 + CPL

[owen]

according to the B&W manual at filtershop.com.au you can get +2, +4, +8 and also +1000, +10000, +100000 (Just going from memory) Anyone seen values like that before?