what mm size is your variable nd?
 

I'm putting together my FS100 bid quote with the good folks at Abel Cine here in NYC.

I am going to purchase the kits lens which is a 67mm.

I was going to buy the Heliopan Variable ND.

I would like to eventually use vintage Pentax and Nikon mount glass.

But I am not sure what size to purchase for the Heliopan.

67mm is right for the kit lens but might be too small for unknown future lens.

72mm? 77mm?

So I ask, what mm size is your variable nd?

Thanks in advance.

Be well.

Rob
Smalltalk Productions

Re: what mm size is your variable nd?
 

I use a 77mm ND with step down rings - works on all my lenses, including the stock lens.

Re: what mm size is your variable nd?
 

I've got the Lightcraft 77mm. The front thread is 82mm.

Re: what mm size is your variable nd?
 

Buy the largest one you can afford and that will guarantee that it will work with most decent available lenses in the future. Step up rings are cheap.

Re: what mm size is your variable nd?
 

I just bought a 77mm variable ND, and ordered step up rings (3 different sizes), to fit the 4 lens I have. As I add more lens, I'll buy step up rings to correspond with the size of those.

Re: what mm size is your variable nd?
 

I agree with Chuck about size. In my hast to get a variable ND filter for my FS100 I ordered a 67mm from Genus to fit the kit lens. Later, after looking at other lenses, I found out that that was not the smartest decision. Luckily the Genus variable ND filter was only $150 verses $500 for the heliopan. I like the Genus filter so I'll probably just by an 82mm since I already have most of the step up/down rings to make it work on just about any other lens.

If you have a matte box you can make your own variable ND filter by placing a circular polarizer in front of a linear polarrizer. Rotate one of the filters and you have a variable ND filter that fits any lens you put behind your matte box.

Re: what mm size is your variable nd?
 

Genus 77mm Variable ND and a cheap-o 67-77mm step up ring.

Scott

Re: what mm size is your variable nd?
 

Not sure about older Pentax and Nikon lenses but a VARIABLE ND will not work properly on the lens barrel of the Canon FD mount series. As one focuses these FD mount lenses, the front optic and barrel rotates. As I use various cameras and lenses for different clients, locking myself into any size variable ND filter could be problematic for me. I just stick with either round standard ND filtration or use a matte box with 4x4 or 4x5 ND,s.

Re: what mm size is your variable nd?
 

I beg to differ. My heliopan works just fine with all of my canon fd lenses

Re: what mm size is your variable nd?
 

"...but a VARIABLE ND will not work properly on the lens barrel of the Canon FD mount "

Gabe is correct. Even if your lens barrel rotates it will rotate both filters in the variable ND housing together, causing little or no change. If you are using a straight polarizer, you might have an issue, but not here.

Re: what mm size is your variable nd?
 

Gab and Chuck. Thanks for sharing your experiences with variable nd filters. I will look into them a little more in depth today.

Re: what mm size is your variable nd?
 

Dan, that sounds interesting, but if you know of a matte box with filters that can be rotated smoothly without abrupt changes in exposure (like a variable ND) and without noise (like a variable ND), I would like to own one. I realize those qualities are not mandatory to get a good shot, but it can be nice.

Re: what mm size is your variable nd?
 

Galen,

I don't think that matte box exists! Can't think of that as being an issue anyway. I would simply adjust the filters to get me in the ball part and then fine tune the exposure via the iris. A specifically designed fader ND is a much better option, but the matte box thing works too. I just thought I'd throw it out there. That was all I had when I first got my FS100. It worked pretty well while I was waiting for my fader ND to arrived.

Re: what mm size is your variable nd?
 

While I have a Genus Variable ND filter (77mm), I am eventually going to be adding a matte box and a set of 4x4 ND's in different strengths. I love my vari, but I've seen frame grabs that show a dedicate nd filter has a slight edge in picture quality over a variable filter. Please correct me if I am wrong in that regard.

Re: what mm size is your variable nd?
 

Which variable ND you talking about? Some are good, some OK,
some bad, some horrible, and some (Heliopan) are so good,
they are almost as good as a flat ND.