Question about neutral density filters, non-grad

[nufenstein]

How much density is enough? Will a standard .9 produce a noticeable drop in shutter speed? Any brands recommended over others? I would be looking to add blur to moving water (waterfall, waves) in partly cloudy conditions and at sunset.

I already have a Cokin 4x6 .9 Soft GND mainly for sunsets (not the best, produces a slightly purple color), but want to shoot at wider apertures and get the benefits of motion blur...

I am leaning towards a b+w 1.6, but wonder if that will be usable during the waning light hours (sunset).

FYI, I plan on possibly stacking my 4x6 and this screw on filter...

Any help would be greatly appreciated.

[NashBoarder]

Interested to see what others say as well. I am looking to get some myself.

Here is what Grizz recs btw

"I use all Singh Ray filters. The starter Grad ND set that I recommend is a 2-stop soft step, 2-stop hard step and 3-stop Reverse ND Grad. All in the 4x6 size. "

[andrewmc]

how do these work, if you have a 77mm diameter lens, do you buy an adapter ring for a cokin filter holder, then the filter holder its self and then the filters?

[nufenstein]

Nash, my question is related to non graduated ND filters...

Andrew, you pretty much have it. You can either buy an adapter and cokin holder to hold the square filters, or just hand hold them. So far I have found that hand holding is a bit of a chore, especially if not setup on a tripod using a remote release...but not impossible. The most difficult part is ensuring that the filter is flush with the lens, without losing your framing....

[Staggerwing]

As you probably understand, each 0.3 in ND corresponds to a 1 stop reduction in light (logarithmic scale). Therefore, a 0.9 ND would be 3 stops, while the 1.6 would be a little over 5 stops.

Only you can decide if that is enough. For the 0.9, if you were shooting say 1/60s @ f/4, then adding the filter would take you to 1/8 @ f/4, and the 1.6 would take you to 1/2s @ f/3.5 (5 stops worth on shutter speed, and an extra 1/3 stop on the lens, to make 1.6).

From a practical standpoint, having these in Cokin P, or other slide-in format, makes sense. Going to be tough focusing with a 1.6 grad in place; and installing a screw-on filter in a tough location is a pain. Stack only if you have too.

[andrewmc]

Thanks for the response. Specifically do I need to buy a "P" series adapter ring, then a "holder" that attaches to this that holds the P series filter?

Sorry for appearing to be an idiot.............

[nufenstein]

Excellent advice stagger. I suppose i should just examine the types of pictures I want to shoot on flickr, note their associated shutter speeds, and make my decisions based on that. Thank you. I imagine that stacked cokin's will produce a strong hue shift. Should've gone Singh...

[Staggerwing]

Yep, that is the way it works. A Cokin "P" series is the cheap, but perfectly serviceable, way out for larger slip-in filters.

If you want to spend the big bucks, you can go 3"x3" filters, and a Lee filter holder.

[Damon]

If you're looking at 4x6, get HiTech. Great quality, great price.

My round filters are all B&W, but the higher end hoya's are good too.

[nufenstein]

anyone heard/use optiflex gelatin filters? specifically the ND ones?

[hitek79]

I have a three and nine stop filter. For really soft water, 5-6 stops is a minimum. I like the 9 but it's too dark sometimes. It's hard to autofocus sometimes.

http://www.tonystreks.com/photos/242261416_z9Erm-XL.jpg

[nufenstein]

That image is lovely. Thank you for the insight. I am trying my luck on a set of .3-.9 gelatin filters. Hoping their thinness allows them to be stacked with minimal color aberration.