Anyone has experience with variable neutral density filters?

I wonder whether anyone can recommend the variable neutral density filters sold by Singh-Ray. Thanks.

You are asking about their 2-10x screw-in 77 mm ND, not their rectangular graduated ND filters, correct?

This is what I am asking about : http://www.singh-ray.com/varind.html

Highly recommended. I recently bought the Vari-N-Duo for a shoot in the southwest. I opted for the standard version versus the slim version. This filter is rather thick (not quite an inch) due to the integral warming CPL...as such, on my 5D2, it will vignette up to about 33mm focal length (I think the slim version vignettes up to 28mm). It seems expensive up front, but when you factor in the cost of individual ND filters, as well as the cost of a quality polarizer, my feeling is that its a wash. Plus, you basically need to carry along only a single filter.

Very easy to use...once my aperture has been determined, I simply adjust the polarizer and dial in how much ND I want. Then its just a matter of adjusting my shutter speed dial until I zero out the exposure. Pretty simple, and extremely convenient.

I couldn't tell you how thick the Vari-ND is, but the basic operation would be the same as I described above.

Argyle, do you have any samples with the Vari-N-Duo at 24mm on FF? Would like to see how much vignetting there is.

argyle wrote in post #8412460
Highly recommended.

Thanks for this Argyle. I am now debating between the Vari-ND and the Vari-N-Duo. I already have a CPL from B+W. What do you think?

I have Vari-ND, i don't use it due to vignetting, i don't plan to buy Vari-N-Duo for same problem, so i just go with normal slim ND or 4x4 to avoid vignetting, and i can use another filters with it.

Tareq wrote in post #8415834
I have Vari-ND, i don't use it due to vignetting, i don't plan to buy Vari-N-Duo for same problem, so i just go with normal slim ND or 4x4 to avoid vignetting, and i can use another filters with it.

Thanks Tareq. At which focal length does it start vignetting?

cfibanez wrote in post #8415884
Thanks Tareq. At which focal length does it start vignetting?

Maybe Below 28mm or 30mm, i can't remember but i will check that later.

Tareq wrote in post #8416154
Maybe Below 28mm or 30mm, i can't remember but i will check that later.

Good, thanks. Was that on FF or crop?

cfibanez wrote in post #8416215
Good, thanks. Was that on FF or crop?

It was on FF

Tareq wrote in post #8416451
It was on FF

OK, that's about 18mm on a crop body.

They also sell a thin version with lower vignetting. I guess it was the normal ring version the one you tested, or?

cfibanez wrote in post #8416511
OK, that's about 18mm on a crop body.

They also sell a thin version with lower vignetting. I guess it was the normal ring version the one you tested, or?

Thin? I think they never have thin at all because i ordered the thin one for wide angle and it is never thin, even my Cokin old CPL which is maybe 8mm or 10mm is thinner than it.

I just placed the Vari-ND on my 24-70, i can see vignetting at 24mm and when zoomed up to about 28-30mm the vignetting reduced, i was shooting with CF cards on my camera, just watching the LCD and the viewfinder even one time only.

I can't post any sample at all because my MBP is not working, so i hope others will post samples for you.