Other: FX6 Variable ND vs. Tiffen .9 ND filter

Doug Jensen

Doug Jensen

Veteran
Recently there was a post on another thread that said Sony's Variable ND Filter technology was flawed and not as good as using a traditional glass ND filter. So I decided to shoot a few test shots with my FX6 to see if that was true or not. In these split-screen tests, the Variable ND Filter (set to 1/8 ND) is on one side of the screen . . . and a very good Tiffen .9 ND filter (3-stops) is on the other. Both were shot with the exact same camera settings (S-LOG3) and only very minor adjustments have been made in Resolve to fine-tune and match the exposures. Having the white card in the shot helped me match exposures and check for white balance variations -- there were none.

Can you tell which is which? Please watch the video and come to your own conclusions. If you want to know which is which, read the description on the YouTube page.

 
Detail looks similar. Both are sharp enough but each a little different. I am going to say ABBB for the Tiffen as there is a slight green cast. Or the opposite (not sure which one is giving the green cast).
 
Would be interesting to see how it compares with footage of reflective surfaces and sky. From my brief digging around the FX6 uses polarization to a certain extend in its ND. At least it seems not to deal well with circular polarizers filters on the lens.
 
Doug, I’m sorry I haven’t looked at the test yet. I’m in the middle of something.

but I wanted to quickly note a couple of things.

Tiffen are poor compared to other brands of ND for purity.

Arri FSND, Lee Cineglass, Mitomo and Nisi are all much better.

You really see the differences at deeper stops too. So like 1.8.

also in my experience with other eNd, the issue is also at deeper stops, wider lenses. Like with a variable pola, because they are basically polarising light, you can get color impurity in the corners especially.
 
At that level (solid glass, non-variable 3-stops), the Tiffen is more than good enough and one would be extremely hard-pressed to see any difference between it and any of the more pricier ones above.

Once you're diving into 5-stops and 8-stops+ to battle IR, especially in a variable ND filter, it becomes a mess quickly with cheaper glass.
 
The time ive struggled with (tiffen) vnd was filming plastic and through windows and plastic car headlights
some odd rainbows appeared.

ive no deep experience with the fx6

i would look for struggles at obtuse angles (wide lenses) deep stop and synthetic materials. (Which may challenge any nd system)
 
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Ha, ha. The comments here illustrate why most people won't waste their time doing tests because matter how you do them, it never satisfies the Monday morning quarterbacks. "You didn't use the right filter." "You didn't use the right f-stop". "The weather was wrong." You used the wrong lens and/or focal length". "You didn't stand on your head and tap your toes." Some people don't have time to watch a 45 second video, but they have time to voice an opinion on why the test is flawed or should have been done differently. Fine, I look forward to seeing someone else's tests that have been done "correctly" and that show variable ND to be flawed in some way. Until that occurs, I contend that there is no meaningful difference between glass filters and variable ND.

Totally predictable. :)
 
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bobtronic said:
From my brief digging around the FX6 uses polarization to a certain extend in its ND. At least it seems not to deal well with circular polarizers filters on the lens.
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I already debunked this myth two years ago. If you've got some video that shows something different, post it.

 
Yep, you can't win on the internet. :( It is great to do public tests though as they really help. I know you will not, but don't get discouraged as we need solid knowledge out there!

I agree, after watching the video that there is no reason to avoid the internal ND. I would not expect Sony to release a product with that large of a shortfall either.
 
As I said I had not watched the tests. I am away from home.

I care a lot about ND filters and that’s why I wanted to comment.

It is easy to Google tests for Tiffen filters and the results are consistent.

Tiffen is not great ever. It is a red flag to me to say filter test and Tiffen as a bench mark.

https://vimeo.com/571068396

in this link you can see even on ND3 they have a different cast.
 
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bobtronic said:
Thanks, wasn't aware of that video. Does the FX6 VND affect reflections on cars and windows such as seen by polarizers?
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Not that I am aware of. I'll admit that I've never specifically looked at that effect, but the VND is not a polarizer so I'd be really surprised if it any kind of a polarizer effect. And I have used a polarizer a number of times with my cameras that have VND and never noticed any problems with color or anything else.
 
Doug Bee said:
As I said I had not watched the tests. I am away from home.

I care a lot about ND filters and thatâÃÂÃÂs why I wanted to comment.

It is easy to Google tests for Tiffen filters and the results are consistent.

Tiffen is not great ever. It is a red flag to me to say filter test and Tiffen as a bench mark.

https://vimeo.com/571068396

in this link you can see even on ND3 they have a different cast.
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The video you linked to uses Tiffen IRND filters. I don't use IR filters and make no claims about them. You may be comparing apples and oranges. If you watch the video I posted there is no green cast like you saw on the other video. Do they even say what camera they used?

Are you suggesting that we extrapolate from this one test that all Tiffen filters are substandard? If so, I don't agree. I've been using all kinds of Tiffen filters for more than 40 years and never noticed any problems with any of them. I also have various ND filters from Hoya and B+W and have not noticed any difference between them and my Tiffens. Is that because, in your opinion, the Hoya and B+W brands also junk?

In all seriousness, send me a 77mm ND filter of your choosing and I will shoot another test. PM me and I will give you my shipping address.
 
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As a general note to this conversation...every camera has a built-in IR filter. The filter passes and blocks wavelengths.

Without one we'd have purple footage from our cameras.

All companies have pretty good ones (they need to), but IMO Blackmagic is definitely at the bottom of the list (I have replaced them myself). JB is using a BM camera in the video above and many DPs (regardless of the camera) look for IRND filters - which sometimes aren't called that but still have IR passing/blocking properties (the literature varies) - because they perform better than regular NDs at higher levels of filtration.

Our cameras need help to control the color shifts at massive amounts of ND, but not at 3-stops.

With that said, I actually have never seen anyone criticize Sony's ND; I think it's pretty phenomenal what they are doing there especially because it's variable.
 
NorBro said:
With that said, I actually have never seen anyone criticize Sony's ND; I think it's pretty phenomenal what they are doing there especially because it's variable.
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I agree sony ND (and IR control) is excellent. BM fall far behind without 30 years in digcam business. Also buying a mirrorless and plonking on some bit of glass from amazon falls way behind too.

Folk suggest that F55 fx6 fs7 are expensive when they cost the same as a mirrorless with some posh ND and an XLR box. Without the wire guts hanging out the side like some impaled robot.

--

On a side note I feel that IR filtrtion is a thin line. Weak IR will lead to purple blacks as per the EX1 but stronger IR may IMO damage skin tone (especially on fat white men) and sony my have overcompensated from the IR of the ex1 and made the 'poor' sony look with too strong an IR cut.
 
Doug Jensen said:
Not that I am aware of. I'll admit that I've never specifically looked at that effect, but the VND is not a polarizer so I'd be really surprised if it any kind of a polarizer effect. And I have used a polarizer a number of times with my cameras that have VND and never noticed any problems with color or anything else.
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Thanks. Most drop-in, clip-on VNDs are polarizers that's why I was curious. I have a Meike drop-in VND and while it's pretty ok it shows polarizing effects in reflections, e.g. the typical remove reflections effect. Not as strong as a typical polarizer though.
 
bobtronic said:
Thanks. Most drop-in, clip-on VNDs are polarizers that's why I was curious.
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Yeah, Sony uses technology that simply makes the ND glass darker or lighter by adjusting the voltage applied to it, kind of like a dimmer on an LED light. Just dial-in exactly what level you want without any chance of detrimental side-effects like those glass VNDs that use opposing polarizers. I have one of those filers and never use it because of the potential side-effects which aren't always immediately visible in the viewfinder during the heat of shooting. On my cameras that do not have built-in ND I prefer to use screw-in .6, .9, and 1.8 ND filters when necessary so I can keep my lens wide open. It's a pain, but worth the trouble.
 
Doug Jensen said:
Yeah, Sony uses technology that simply makes the ND glass darker or lighter by adjusting the voltage applied to it, kind of like a dimmer on an LED light. Just dial-in exactly what level you want without any chance of detrimental side-effects like those glass VNDs that use opposing polarizers. I have one of those filers and never use it because of the potential side-effects which aren't always immediately visible in the viewfinder during the heat of shooting. On my cameras that do not have built-in ND I prefer to use screw-in .6, .9, and 1.8 ND filters when necessary so I can keep my lens wide open. It's a pain, but worth the trouble.
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That's encouraging to hear about the Sony VNDs. I usually opt for external screw-ons like you (a set of Tiffen NDs) but wanted to give the drop-in VND a shot on my A7IV.
 
I'm surprised by the aggression and defensiveness. You have posted a test, and even put in the form of an experiment, postulating a hypothesis that you're testing to answer a question of the internal eND filtration being as good as external filters.

I finally watched it. I suspect you've flipped the A and B a few times as the "green" shot keeps changing. A sf the Tiffen on the first one, then I think it flips and then I think it flips back again. It's hard to tell with this subject matter.

Did you do anything in post to alter the shots? Are they normalised or corrected in any way?

I'm challenging the methodology of the test. I'm not attacking you. I just saw Tiffen as a benchmark as being problematic.

In the circles I work, that is narrative drama, everyone knows Tiffen aren't the best ND filters to use.

I posted a link and I also posted some of the potential times that eND can be troublesome. You just attack the link? It's clear that the cast isn't from IR and is camera irrelevant. It was just the first one I found. Then I am supposed to help you do your experiment properly and send you a filter?

Here's another from another DP on a different camera. You can still see how GREEN they are.
https://www.youtube.com/watch?v=3oefLDnP2mk

Wait you still think Tiffen are OK, it's OK I found another test. Look how GREEN they are on an Alexa with yet another DP.
https://vimeo.com/199711953

Took me about 60 seconds to find these. I'm sure there are others out there. All Tiffen, the IRND, the NATural, the Water White and the regular Tiffen ND...they're all like this.

I also know this because I have been a part of a lot of not-public tests and have seen time and time again that Tiffen are poor performing ND's. If you are using NON IR ND's then they are likely even worse because they are older. Most modern ND's aren 't even IR filtered, they are actually "full spectrum" meaning that they block IR the same as visible light. Arri's FSND stands for FULL SPECTRUM ND.

eND has been a round a while. Panavision actually announced this guy back in 2018.
https://www.panavision.com/camera-an...ail/lcnds-lcnd

I've tested it a few times. And guess what. Color purity is a problem, especially in corners, on wider lenses. Not as bad as variable ND, but similar types of problems.

You're also maybe not so aware, but the last time I checked, eND is done by using what is basically an LCD panel and then using a current to slowly darken the frame. Guess what an LCD panel is doing to the light...it's POLARIZING it.

I have some friends that work for CMotion and they make a device that is basically a high end variable ND. When I spoke to them about eND, they said they had experimented using them but found the color purity problems to be too difficult to overcome. They instead have custom made polarizers and prefer them. They do think the eND will become useable for their customers in the near future, it just wasn't there yet.
https://cinefade.com

I guess my final note would be...why is it that they don't have eND on the higher end Sony cameras? Venice 2 has an 8 position MECHANICAL filter wheel...no eND.

Now, maybe on this camera, Sony have done some great work and there are very few situations where the eND's are a problem and that's worth celebrating. I've never used it, I have no experience with it, only with Venice and F55.

But it's not so awesome that you're attacking me for simply bringing up what I think is a pretty valid point that comes from my own experience. You didn't address the other initial potential issues with eND I brought up either. Testing with a long zoom isn't the way to find the issues. It's on very wide shots that I've seen problems. I hope you test for them. You are the one that put the test out there, you posted it in a forum that invites comment. And yeah, this is the downside of posting a test.
 
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