Variable ND filter question

I've been looking at getting a variable ND filter but.....I have 3 lenses with 3 different thread sizes and cant really afford 3 filters

My question is.. Can I just buy a 77mm filter, then use adapter/reducing rings for the other two lenses (67mm and 62mm) or will that not work?

Lenses in question are....(all Sigma)
70-200 f2.8 (77mm)
17-70 f2.8-4 (67mm)
30mm f1.4 (62mm)

I won't use the filter on the 70-200 very often but don't want to rule that out by getting a smaller filter (67mm)

Cheers in advance.

Andy

You can certainly do that. Where you run into problems are with hoods and ultra wide lenses. If you use an oversized filter and then a step ring you likely wont be able to mount your hood over it. Depending on your proposed use this may be no problem or something to consider. With an ultra wide lens, which you didnt mention, you might get vignetting from the lens being pushed farther into the image circle but shouldnt be a problem at 17 on a crop. Have you researched the variable ND's? Some have real issues with patterns on wide shots.

I have an 82mm ND and CPL that I sometimes use on my 70-200 with a step down ring. Works perfect except that I cant use the hood....

gonzogolf wrote in post #15794419
You can certainly do that. Where you run into problems are with hoods and ultra wide lenses. If you use an oversized filter and then a step ring you likely wont be able to mount your hood over it. Depending on your proposed use this may be no problem or something to consider. With an ultra wide lens, which you didnt mention, you might get vignetting from the lens being pushed farther into the image circle but shouldnt be a problem at 17 on a crop. Have you researched the variable ND's? Some have real issues with patterns on wide shots.

Thanks for the quick reply. Lens hood use (or the lack of) won't be an issue and I cant see me using it on really wide shots either. Mostly I'll use it to get longer exposure times for street shots in and around London with the two shorter lenses and the 17-70 will get used in the mid portion of its zoom range anyway.

Eventually, the aim is to get a proper square filter system and this is just a short term fix idea until the funds (and the skills) are in place.

Are you looking at a Variable ND or just a ND filter? Variable ND's transition from say 3 stops to 0 stops in the filter, in which case a square filter is almost a must. For just a standard ND filter, round is fine, buy big and a few step down rings, then you always know it will work no matter the lens you have.

Littlejon Dsgn wrote in post #15794713
Are you looking at a Variable ND or just a ND filter? Variable ND's transition from say 3 stops to 0 stops in the filter, in which case a square filter is almost a must. For just a standard ND filter, round is fine, buy big and a few step down rings, then you always know it will work no matter the lens you have.

You're talking about a graduated ND filter.
Variable ND filters you turn and they become more or less opaque.

Honestly, I'd get one of the cheaper, rectangular filters (Cokin Z, and a 3 stop and 8 or 10 stop filter to go in it. The variables definitely trade off convenience for image quality, in that anywhere under 35mm you can get the strange, cross patterns at higher densities; in which case you've "lost" those higher stops anyway. This combo will easily cost as much or less than one of the good VNDs.

Or, get a 3 and 8 or 10 stop, screw-in plus step rings.

Simpleboy wrote in post #15794763
You're talking about a graduated ND filter.
Variable ND filters you turn and they become more or less opaque.

Yup my bad ... I am still learning all the names for this stuff too lol.

Snydremark wrote in post #15794862
Honestly, I'd get one of the cheaper, rectangular filters (Cokin Z, and a 3 stop and 8 or 10 stop filter to go in it. The variables definitely trade off convenience for image quality, in that anywhere under 35mm you can get the strange, cross patterns at higher densities; in which case you've "lost" those higher stops anyway. This combo will easily cost as much or less than one of the good VNDs.

Or, get a 3 and 8 or 10 stop, screw-in plus step rings.

Check amazon I picked up a cheap filter set with square holder last week. I am using it with some welding glass, but I do plan to give the filters a shot too.

To give a little bit of background, the first ND filter I bought was one of the Singh Ray Vari-ND and used it with moderate success for a year or so. Then I started dabbling with more than the very occasional usage of the filter and ran headlong into the problems these have at wider focal lengths (35mm and wider on my 7D). From there, I went straight to the Lee filters after some research and that's been a much more satisfactory solution. Lee's, of course, are both expensive and difficult to get; so, if you're just getting your toes wet, that's why I'd recommend the Cokins or just a couple of screw-ins.