Variable ND Filter

[rexboggs5]

I am thinking about purchasing a variable ND filter.

Any recommendations? (Assume that cost is not a factor :-)

Thanks

Rex

[Hawthy]

People will suggest Cokin or Lee. I bought some cheap GNDs but find that it is easier to bracket three exposures and then blend them in post processing.

[michael_sa]

Hi Rex,
I don't have a variable, but own the Hoya ND4, ND8 and ND400. (2 stops, 3 stops & 9 stops)
Previously had the Cokin system, but got rid of it due to light leakage, weird colour hues and basically I could achieve in post what it was doing anyway.
I rarely use my ND4 and 8, but the ND400 gets a real work out with the type of photography that I like.
I did a quick google and I see that Hoya do a 1.5 to 9 stop variable - which is about 50 dollars dearer than the NDx400 (in 77mm). For me, it would be 50 dollars extra very well spent, as I've lost count of the number of times I have had to remove my ND400 to check focus or composition and it's often at the waters edge or on a pier/jetty or some location where dropping the filter on rocks or through the jetty and into the drink is a very real possibility, so for that aspect alone it would be worth it.
I didn't see any spec on it's width, Vari ND's used to be thicker than standard filters, I'm not sure if they still are, so just be aware if you're shooting ultra wide that it may vignette depending on your equipment. If you think this may be an issue, stack two filters on your WA lens and see if it's visible in the corners.
Hope that helps.
Regards,
Michael

[Hawthy]

Sorry. I thought that you were talking about Graduated ND filters. I never even knew that a Variable ND filter existed. Learn something new every day.

[rexboggs5]

I did a google search, and there seems to be some issues with variable ND filters. They are effectively 2 polarising filters, which it seems can have some issues with image quality that normal ND filters don't have. So for now I think I will stick with my current ND filters - a 10 stop filter and two 4 stop filters. FYI - these days there are some 18 stop filters available, and apparently even a 24 stop ND filter.

Thanks for the replies.

[michael_sa]

Hi Rex, I just read some stuff similar. A pity.
I'd be interested still if any members here have one and what their real world experiences have been.

[rexboggs5]

An article i just read states "If you go beyond the minimum and maximum settings, however, the filters can start to interfere with each other. This creates an exposure variation pattern similar to a cross or X. This X will occur on any type of variable ND filter, no matter what the brand or its price tag."

According to the article the maximum setting seems to be 8 stops of light, so it seems if you keep it restrict its use to that amount, it may be acceptable.

Another article states "The disadvantage [of a variable ND filter] is sharpness and color shifting. Most Variable ND filters are not quite as sharp as a single strength Neutral density filter and all Variable ND filters have color shifts that change depending on the density used. This color shift can be difficult to correct later. Also, it is impossible to accurately tell if the filter is set exactly to a particular density."

So I think I'll stick with the inconvenience of having multiple normal ND filters.

[michael_sa]

An article i just read states
...
So I think I'll stick with the inconvenience of having multiple normal ND filters.

Yes I read all of that (watched some YouTube vids showing the X effect) and also an article that showed lots of artefacts in the highlights - mind you they were extreme pixel peeping in that review, but it's all very disappointing.
So like you, I reckon I'll cross (X pun intended) it off my 2019 wish list:confused013

Regards,
Michael

[MadMax1412]

Hi Guys

My current camera setup has a 62mm and 52mm lens.

I was thinking of getting an ND filter with some step down and step up rings. The step up kit does 37-49, 49-52, 52-55, 55-58, 58-62, 62-67,67-72, 72-77, 77-82mm, and the step down kit does 49-37, 52-49, 58-55, 55-52, 62-58, 67-62,72-67, 77-72, 82-77mm (the product comes with both up and down kits, not sold separately).

Should I buy the 62mm ND filter or would I be better off buying the 82mm (or 77mm) one to future proof myself in case I buy a 82mm lens in the future. I gather it's better to have a bigger ND filter and step down to the lens size then to have a smaller ND filter and step up to your lens size.

Thanks in advance.

[ameerat42]

For me, present convenience would be the go. "What suits me most now?"
It sounds like the biggest would be somewhat unwieldy on your present lenses.
You may: 1) not get such a lens; 2) still not "future-proof" yourself if it breaks
or becomes unusable in the meantime.

- But that's just me. ("Him over there" to someone else :p)

[rexboggs5]

I had a similar dilemma some years ago when I was deciding what size polarising filter I should buy. The fellow in the shop suggested the 82 mm filter even though I didn't have a lens at that time which needed it. I did that, and I am happy with my decision. I now have a Canon 16-35 mm lens and a 24-70 mm lens, both of which need the 82 mm.
Cheers, Rex

[Boo53]

I bought a Hoya variable ND a few years ago and used it a couple of times but the artefacts at each end of the spectrum make it only really useable in the fairly narrow middle range.

It's in a cupboard somewhere now, bought a 6 stop initially that did just as good a job and now have changed to a nisi system

[Demixl]

Oh,guys,thanks for sharring:nod:

[William W]

Hi Guys

My current camera setup has a 62mm and 52mm lens.

I was thinking of getting an ND filter with some step down and step up rings. The step up kit does 37-49, 49-52, 52-55, 55-58, 58-62, 62-67,67-72, 72-77, 77-82mm, and the step down kit does 49-37, 52-49, 58-55, 55-52, 62-58, 67-62,72-67, 77-72, 82-77mm (the product comes with both up and down kits, not sold separately).

Should I buy the 62mm ND filter or would I be better off buying the 82mm (or 77mm) one to future proof myself in case I buy a 82mm lens in the future. I gather it's better to have a bigger ND filter and step down to the lens size then to have a smaller ND filter and step up to your lens size.

Thanks in advance.

1. Step Down Rings are rarely useful tools for Screw-in Filters being attached to the Subject end of any Lens.

2. A 'set of' Step Up Rings may be useful, usually to a Photographer who has a lot of lenses of various Filter Diameters. But buying a "kit of Rings" may be buying a lot of gear that you will never use and gear that might NOT be the most suitable tools for the lenses that you have and often the kit is generally poor quality gear, sold for what seems to be a "good deal".

*

Note that Rings are termed Step UP when they allow a larger filter so be placed on a lens with a smaller filter thread diameter.

It is important to order a Ring using the correct terminology and you have the terms the wrong way around when you write:
"I gather it's better to have a bigger ND filter and step down to the lens size then(sic) to have a smaller ND filter and step up to your lens size."

*

If you did buy an 82mm ND Filter and you wanted to place that Filter on your lens existing 62mm filter thread lens, you will need a Step UP Ring, sized 62 to 82.

Using the kit of Step UP rings you mention, you would need to use FOUR Step Up Rings: 62-67; 67-72; 72-77 and 77-82. This may seem an elegant solution, but it could be a big problem, especially if the lens is a Wide Angle Lens. Similarly (and potentially more problematic) to use the 82mm Filter on your lens with a 52mm Filter Thread, you would need to use SEVEN Step Up Rings: 52-55; 55-58; 58-62; 62-67; 67-72; 72-77 and 77-82.

*

All Rings have a thickness and thus place the Filter a distance away from the end of the lens, therefore two main issues to consider are:

1. will sticking a filter at that extra distance create an OPTICAL VIGNETTE? This means will there be dark areas at the edges of the image because the filter or the rings block some light coming into the lens - this is more probable if the lens is a WA lens. Obviously Step DOWN Rings are more likely to create an Optical Vignette no matter what Focal Length Lens is used and that is why

2. will the added diameter of the filter rings DISALLOW the use of a Lens Hood? (which may mean added Flare or other artifacts in the image).

*

My advice is consider WHY and HOW (e.g. on what lens/lenses) you will be using an ND Filter. And then consider if you have a reasonable expectation (and money) to buy another lens.

If you conclude that you'll use an ND Filter on your TWO existing lenses, then consider buying a 62mm ND Filter and also buy a 52-62 Step Up Ring. (i.e buy only ONE Step Up Ring, not the set.)

If you really expect to buy another lens AND you really expect that you will use the ND Filter on that lens, too, then consider buying the ND Filter to suit you Largest Lens's Filter size and use the FEWEST number of Step Up Rings to accommodate any situation, ideally using only ONE Step Up ring for any situation.

WW

[William W]

Hello, addressing your OP -


I am thinking about purchasing a variable ND filter. Any recommendations? (Assume that cost is not a factor :-)
. . .

I did a google search, and there seems to be some issues with variable ND filters. They are effectively 2 polarising filters, which it seems can have some issues with image quality that normal ND filters don't have. So for now I think I will stick with my current ND filters - a 10 stop filter and two 4 stop filters.

Singh-Ray.

I have used this brand of Var ND. It is exceptional.

I don’t own one: I haven’t the use for spending that much money on a Var.ND.

I have a few of sets of (i.e. sets of same filter size) quality ND Filters. Typically a 3 Stop and 5 Stop. Also I have a couple of 82mm ND’s (8⅔Stop and 5 Stop) and I have various Step Up Rings.

I was introduced to Singh-Ray Var ND Filters by a colleague Colin Southern, Landscape Photographer: you can research more here {LINK} (https://singh-ray.com/equipment-technique/colin-southern-keeps-coming-back-to-his-vari-nd-when-he-wants-to-try-doing-something-different/).
My personal view is a Var ND is a really specialized bit of kit. For example, I don’t do (Landscape) work like Colin does, he has requirement for an high quality Var ND and will use it, often for a number of purposes.

One unique use of a VarND is to be able to bracket exposures, whilst keeping the Tv, Av and ISO constant.

WW