Blackmagic Forum

I have always used Individual density ND on my cameras. I have never used a Variable ND for reason most of you know why. However, for once I need to be super efficient and I need to be using circular NDs. So changing NDs will be a bit of a problem. This is where I think a VND will be useful. Since I never bothered with VNDs, I did my research and I want to get your experiences with the best VND for me to acquire. Based on what I research, tested, etc., I found that the only VND I found suitable to work with is the SLR Magic 82mm Self-Locking Variable Neutral Density 0.4 to 1.8 Filter (1.3 to 6 Stops). This seem to have the least artifacts and issues of polarized VNDs. Also, I found it to work well with my current Firecrest IR Cut filter. If you have experience with this, will you recommend it. If not, what circular VND would you recommend and why? Thanks in advance.

Please don’t be offended if I don’t directly respond to the post, unless I have questions or need clarification. Please continue on with the conversation as I attentively will be a fly in the wall learning from your experiences.

I use the SLR Magic Vari-ND 82mm which includes 86mm threads on the front of it. That’s handy to add either an additional Kenko Tokina 86mm IRND for very bright conditions or the SLR Magic 1.33x-65 Anamorphot adapter. As a neutral density filter, it’s not perfect and adds some yellow to the look or may have some slight image degradation, but I’d say it’s very good and hasn’t ruined a shot. Don’t screw anything completely tight though as that can seize up. Its convenience is appreciated when you need to avoid the extra time of swapping NDs in he field.

rick.lang wrote:I use the SLR Magic Vari-ND 82mm which includes 86mm threads on the front of it. That’s handy to add either an additional Kenko Tokina 86mm IRND for very bright conditions or the SLR Magic 1.33x-65 Anamorphot adapter. As a neutral density filter, it’s not perfect and adds some yellow to the look or may have some slight image degradation, but I’d say it’s very good and hasn’t ruined a shot. Don’t screw anything completely tight though as that can seize up. Its convenience is appreciated when you need to avoid the extra time of swapping NDs in he field.

Thanks Rick. I’ve not noticed the yellow when I checked out the SLR magic although I will say that was the slight concern I had when the was checking out the Tiffen variable ND. So if both does have that yellowish tint, then could these two VNDs be comparable and both recommended? Also, why would you put an IRND in front of the VND? Don’t you just need an IR cut since the VND already is? And why in front and not behind the VND?

I've used the SLR Magics for years now in run and gun situations. Just replaced my first sets in fact. Much prefer plain ND's over VND's but the size of the package does not always make that practical. Got to say I do like built-in's a great deal. Know that they're not quite as good but for what I mostly shoot they make me a better shooter.

Ellory Yu wrote:… why would you put an IRND in front of the VND? Don’t you just need an IR cut since the VND already is? And why in front and not behind the VND?

In a very bright day in some settings such as the beach, a desired exposure easily can require at least 8 stops of filtration with your fast aperture. So the Vari-ND May need help. The Vari-ND has a few controls so it’s much thicker than a screw-on filter. If you’re shooting with a wide angle lens, and add the additional 82mm ND filter between the Vari-ND and the taking lens, you might get a vignette. However if you add an additional 86mm filter to the front of the Vari-ND, you’re good to go without vignettes at wide angles.

As mentioned I have 2, 4, 6 stops 86mm filters for the Tokina Cinema ATX 11-20mm zoom that has a 86mm thread and as the Anamorphot 1.33x-65 also attaches to the taking lens via an 86mm thread so I haven’t had any additional expense. So I play it safe and use those filters if needed on the Vari-ND. YMMV.

My screw-on IR Cut is also the Schneider B+W 86mm thread so it almost always goes on in front of the Vari-ND as well. No vignette.

Even the best VND's a compromise in terms of image quality esp if you are shooting people as the unavoidable polarising effect makes skin look terrible. I've never found swapping fixed ND's an issue and there are now even magnetic adapters to make it even easier.

John Griffin wrote:Even the best VND's a compromise in terms of image quality esp if you are shooting people as the unavoidable polarising effect makes skin look terrible. I've never found swapping fixed ND's an issue and there are now even magnetic adapters to make it even easier.

That’s interesting. I’ve never noticed the polarizing effect on skin, though that makes sense. Do you have any examples by chance?

Variable ND's are terrible and I would highly recommend against them unless you have no other option possible.

I've been grading a feature film and half of the outdoor footage has a horrible green tint because they were using cheap VND's with their steady cam rig.

But feel free to use it, until it finally hits you that the price that you're paying in the quality and sharpness of your footage is too high.

Kays Alatrakchi wrote:I've been grading a feature film and half of the outdoor footage has a horrible green tint because they were using cheap VND's with their steady cam rig.

I think we are aware of some green cast on some VNDs. Since you said they were using cheap VND and attributing the green tint to it, are you saying that the expensive brands of VND won’t? If so, which expensive brands / high end VNDs would you say will not have such artifacts?

Kays Alatrakchi wrote:I've been grading a feature film and half of the outdoor footage has a horrible green tint because they were using cheap VND's with their steady cam rig.

I think we are aware of some green cast on some VNDs. Since you said they were using cheap VND and attributing the green tint to it, are you saying that the expensive brands of VND won’t? If so, which expensive brands / high end VNDs would you say will not have such artifacts?

Kays, I’m all in favour of avoiding cheap filters, but I can’t feel confident in condemning all variable NDs. Best to use quality individual IRNDs when you can. If the artifacts include the dreaded X-factor on a sunny day, the SLR Magic Vari-ND II attempts to prevent that my topping out at 6 stops. If the artifacts include an uneven shift in blue for the sky, you can usually mitigate that by rotating one or more controls on the Vari-ND, but it is easy to miss when shooting. There is the issue of colour shift in certain positions, but very few normal IRND products are free of that too as I recall.

That’s been discussed over the years. Lee filters perform well but not perfect. Panavision’s filters top grade. I think John Brawley had both. The Japanese filters are excellent, Mitomo TrueND (which are actually IRND).

I've been using the B+W XS-Pro ND-Vario 1-5 MRC nano filters since two years on my PCC4k when filming outside. They do not interfere with the sharpness in any way and no X artifact. Depending how you screw them on, you might get a slightly different color cast (which is very low anyway).
Also shot many, many interviews with them and I have not seen the so called "terrible skin effect".

I've been using a Revoring VariND for around a year now, and it's been wonderful. It's a very good filter combined with a very clever mounting system that cuts down a lot on how many step up/down rings you'll need.

rick.lang wrote:Kays, I’m all in favour of avoiding cheap filters, but I can’t feel confident in condemning all variable NDs.

I think it's fair to say that most people in the market for VND's are not looking to spend $500+ on a good one. So I just prefer to tell people to avoid using them just to be on the safe side.

In my experience, the convenience simply isn't worth the potential issues -- most of which can be easily missed if the monitoring on set isn't proper.

Unfortunately the person who usually has to suck it up and try to fix it is the colorist, as the DP is rarely blamed for it. Then all of a sudden the client is looking at me and wondering why half of their film looks like crap and it will never be able to be 100% matched to the good stuff.

It makes me angry just thinking about how many projects I have worked on have been ruined by this.

I used the word "cheap VND" but on this particular feature all of the rental gear came from Panavision, so chew on that one for a bit!

Thanks, Kays. Very interesting additional information to digest.