I thought I would start by explaining (in a nutshell), what an ND filter actually is, and then go from there.
ND stands for Neutral Density. This reduces the intensity of a light-wave across the entire surface, while not altering the color values within the image.
An ND filter blocks light from entering through the lens to affect exposure time - this could be shots taken outside on a sunny day or inside with studio lights.
Think of ND filters as Sunglasses. It's literally a sunglass for your lens.
You might have seen these filters before, as they are usually circular screw-in-type attachments that attach right onto your camera's lens. They commonly come in various densities like 0.03 (~ND0), 0.06~ND64+, etc., depending on how dark you want them to get based on what environment you're shooting in.
These are the numbers we were referring to in the last section.
The number before 'mm' is the size (or diameter) of the filter/lens you're putting it on.
An ND filters number (ND2, ND4, ND64, etc.) - actually referred to the denominator (bottom) of a fraction. It's super easy to understand and grasp, so bear with me here.
The fraction represents how much light passes through the lens.
Example: if you have an ND2 - in fraction form that would be 1/2 (because 2 is on the bottom, on is always one top) - this would mean that an ND2 filter would only allow in 1/2 (half) the amount of light than without it.
Another example: ND64 - 1/64 or 1/64ths of the normal amount of light. ND1000 - 1/1000ths of the light (or 10 stops).
I'll leave a chart below so you can save it. It shows the numbers that their corresponding light stop reduction.
Now that we know what an ND filter is let's discuss a variable version of one.
Variable ND filters are a step up from normal ND filters as they allow you to change the level of darkness, depending on what environment you're shooting in.
A typical variable ND filter is a circular filter attachment that screws onto your lens and has an outer ring with marks at different intervals (such as ND 64+) where each one corresponds with a given setting. Each marking usually represents a stop of light.
We will discuss the pros and cons of a variable ND filter, the pros and cons of a standard ND, and how they compare to each other. This will either solidify that you need a variable nd filter, or you may find you can use a standard nd and be just fine.
Stick around for more juicy bits.
There's a need for a variable neutral density filter (VND) in both photography and videography.
That's right. Photographers and videographers can benefit from using one (we will go into the pros and cons for each here in a bit).
Videographers use them to create a smooth video when filming with shutter speeds too fast for the camera to compensate.
Photographers use them to get evenly exposed shots in bright and low light conditions -- or any situation where you need it darker than what you can achieve in the camera.
Let's talk about photographers and videographers for a little bit.
Photographers would need a variable nd filter for two reasons:
Motion blur is the most common use of nd filters for photographers. To achieve this you need slow shutter speeds. The slower the shutter speed, the more blur you'll have in your image. But we know that the slower your shutter speed, the brighter your image will become (your sensor is exposed to light longer, making your image brighter).
To negate all of that extra light, that's where neutral density filters come into play.
Take landscapes, for example - anytime you see a waterfall or the ocean, and the water is super milky and smooth, they used low shutter speeds and/or a neutral density filter.
The same goes for a cityscape where the people and cars are just a blur, but the buildings are crystal clear.
Now - a variable ND filter makes this even easier by having the power to adjust exposure by spinning the outer ring instead of switching out filters.
You can check out my article on the best shutter speeds for video - it goes way more in-depth behind the 'science' of shutter speed for video...
But, 'cinematic' video depends heavily on shutter speed. Therefore, your shutter speed settings should be double that of your frame rate.
The 'cinematic' frame rate is 24. So you would want 24 fps all the time (or edited down to it if you're going for slow motion).
Your shutter speed would have to be 48 (or more commonly, 50).
In most cases, a shutter speed of 1/50 would cause most scenes and environments to be blown out. This is when you would need a variable ND filter.
The fact that it's variable allows you to adjust your exposure without switching filters (like you normally would if you were using standard, single stop, and filters).
Pros for using a VND as a photographer include:
Cons for using a VND as a photographer include:
There are many pros to using a variable neutral density filter as a videographer. Those include:
Cons for using a VND as a videographer include:
In recent years, companies such as Polarpro and Hoya have created hard-stopping VND's. This is essential to avoid the dreaded black X. This happens when the filter goes past the maximum or minimum points of effectiveness. Hard-stopping filters eliminate that.
They've also created 'click' positions based on f stops. This means that the filter will click into place for every stop in the filter's range. This eliminates questioning if you're on a certain stop, makes for being very consistent across multiple lenses/scenes, and most importantly - stops the filter from turning by accident.
This was the main reason why I stopped using VNDs for photography. I would constantly bump the filter when putting my lens down at my waist - I have since used them now that there's a reliable 'click' system (Polarpro).
It's simple, really. Craftsmanship.
With a $200+ filter, you'll get glass optics (versus resin/plastic on cheap models), thicker/more effective coatings, and a better image overall.
Chromatic Aberration is a major concern with cheaper lenses. You'll notice it from time to time in really bright environments... it'll paint the edges of your subject - and before long, you'll be looking for a better filter.
Generally speaking, we don't recommend anything below $70 - for this very reason. But, you'll notice (just like we have over the years) - sometimes it passed to pay a little more.
Choosing an nd filter that works for what you need isn't very difficult. You only need to make a 'decision' on one thing - what do I shoot the most?
Here are a few tips we'll give you when choosing the right ND filter for yourself.
If you're a photographer and shoot a lot of long exposure pictures... Get an ND filter that hits 10 stops (ND1000). You may never need it (typically under 10) - but you never know, it'll always be there if you need it.
If you're a photographer shooting with off-camera flash - you'll most likely never have to go above 5 stops (ND 32), your camera can stop down the rest if need be (with shutter speed/below 100 on ISO/shoot in HSS if you need to).
If you're a videographer shooting at 24 fps, you'll, again, probably never got above ND32 or ND64 - or 5 and 6 stops, respectively.
While we will give our 'best' recommendation, I thought it would help you by including different price tiers. Price, generally, is related to quality and reliability (and also warranty), so this is how it's going to go.
We will structure it into three different tiers. These will be:
Each will have 3-5 filters that we recommend for each - along with their pros and cons. Most of the links below will be for 67mm filters. Check your lens to see what filter size it takes.
Let's start diving in!
K&F concepts have been around and built a name for themselves over the last few years.
They're known for well-rounded, affordable filters. From clear filters to Ifra-Red - they offer it all for the most part.
This lens, in particular, is very inexpensive and produces 8 2/3 stops of adjustment in a single filter. All of that for >$40. Let's take a look at some of the specs...
Nearly 9 stops of light reduction - with 9 'points' of adjustment marks on the outer ring.
This is a great filter for someone just getting started and wants to try one out without breaking the bank. However, be aware of the cons/issues that come with buying one.
Gobe has recently changed its name to Urth. Supposedly it better represents what they're trying to protect and want to support.
I am not recommending Urth because the same ND filter under their new name is $15 more.
If you're on the fence about an ND and are in the entry-level phase of your journey - you need to pick one up while supplies last.
Don't wait too long and end up spending $60 on the same lens (instead of $45).
If you find the link has expired and I haven't fixed it yet, here is the link to the Urth version.
As far as the filter goes, here are the specs:
As you can tell, a few things are very similar to this compared to the K&F version.
Again, pick this up if you're on the fence. I'm sure it won't be long before this thing is completely sold out, and you'll have to purchase it at a much higher price (only because of a name change)
Don't let the name fool you; this isn't Tide detergent - and won't make your camera smell as such... lol.
Seriously though, Tide optics hit the market in August of last year. They've received relatively great reviews in the last year.
Their name is the companies passion for the Ocean and making it a clear, more inhabitable place for all ocean life.
The 67mm is priced right under $40 - with more or less depending on the size.
A Tiffen variable ND filter is regarded as one of the market's best entry-to-intermediate type nd filters. I'm sure at some point you have heard about them or researched them on your own.
This was the exact ND filter I had before taking a break from them and coming back with a pro version. I'll say, while I was using it, I had zero issues with it.
The 67mm version comes close to our entry-level price limit of $100 (Priced currently around $85).
Freewell has a damn good reputation. They hit the market in late 2019 - and have accumulated raving reviews on both Amazon and B&H. It says a lot about their product.
Where do we start... well,
There's only one:
This is a fantastic company/brand and product overall. However, you get all of this for slightly more than a Tiffen standard - so is it a better buy than a Tiffen variable nd filter? Honestly, it probably is.
You can't go wrong - and there's even a 2 filter bundle. It's the 2-5 stop and 6-9 stop filter combo. Of course, you won't save any money by purchasing it, but at least the option is there as a convenience.
The moment has been around for a little while. You may have heard about them in the past when they partnered up with any and every camera-related youtube channel to showcase their smartphone lenses.
Well, they have branched out and have started to sell variable ND filters (and other filters) - to those who're in need!
Regardless of the one single con... this is a great addition (or first time) variable ND filter that'll last you many, many years. Moment variable ND filters are here to stay!
Nisi has a good reputation in the filter department. Their filters are as advertised and fall pretty much dead center in the mid-tier price range (about $140 each).
As you'll see from the specs (and much like Hoya) - you get what you see. There aren't any extra bells and whistles (like a travel bag, etc.). But what you do get works.
If you can look past a couple of negatives, this is an excellent, reliable option.
**This is the 77mm version -the 67mm version is back-ordered at this time. It should be back up soon!**
I have used Hoya many times in the years I have been a photographer. They're an excellent company with top-notch products.
No- you won't get all the little bells and whistles you would get out of other lens companies... But what you will get is a piece of mind in knowing that what you're purchasing and bringing with you to sessions will work correctly.
Many photographers, from beginner to pro, speak of and rep Hoya filters daily. They have had a following for years - and it's clear why. They care deeply about quality and attention to detail. We, as consumers, benefit greatly from that.
PolarPro is one of the most trusted brands in the world of camera filters. They make not only circular nd filters, but they also make filters for drones, GoPros... basically anything with a lens.
As you can imagine, with a reputation as such - quality would match. Well, that's correct too. As would the price you can imagine for that.
Yes, PolarPro is expensive, but trust me, they're more than worth the money if you take care of them.
When narrowing down the best variable nd filters, a polarpro variable nd filter doesn't disappoint. However, we have another version that might be better for your needs - so stick around for that here shortly.
This VND is nearly identical to the one above - only one difference - it's the mist version.
This filter will give your images a 'mist' effect - almost a glow. Think ethereal.
As you can see, you're getting all of the perks of the regular version - plus mist. However, one thing that's not really mentioned - 'click' locking stops.
That's right; this is the only filter on this list with everything that would make a filter great—hard stopping ring, forward and backward. 'Click' activated stops, so you know when you're perfectly dialed in - and premium materials and glass.
The con(s) are pretty much the same...
This is one of the best variable nd filters with mist on the market. Don't hesitate if this is something you're on the fence about but can afford.
More so, get them while you can. They're constantly sold out. At the time of writing this article, they're currently out of stock. Bookmark this page to check to see if it's in stock (the links here are active and pull data in real-time, everyone you look at the page).
There are a few mistakes that people make when choosing/purchasing a variable nd filter. Let's go over them now, so you don't fall victim to these mistakes (like I did over the years).
This is quite common, believe it or not.
You'll want to check the thread size of your lens to get the correct thread size. Check this article to learn how to check your thread size if you don't know how to already.
Keep reading to learn how ordering the wrong size can be a good thing and save you money in the long run (even though I wouldn't recommend choosing the wrong size on purpose).
Remember, the number after ND indicates the strength of the tint.
Generally speaking, a good place to start (if you aren't sure) would be 1-5 stops.
This would be ND2-32. You could go for ND2-4 to ND64 if that's the only option you have. 5-6 stops of light reduction is plenty for everyday average use (for both photography and videography).
You'll find that you will only need a 6-10 stop ND filter is for long exposure photography. You'll be hard-pressed to find a situation where you'd ever need that strong of an nd filter in videography.
Stick with 1-5 stops to start if you aren't too sure.
I know that everyone has a budget. Unfortunately, not everyone can afford top-of-the-line equipment. Hell, some can't justify purchasing a lens for more than $300, let alone a filter.
Believe me; I get it.
But, refrain from expecting the best from inexpensive equipment.
If you're experimenting and starting out using filters, purchase an inexpensive K&F Concepts filter and experiment and learn from it. If you want better results, upgrade to something of higher quality.
Because when it comes to filters, lenses, teleconverters.. etc. (basically anything with glass) - the quality of glass and parts is everything. Everything from the coatings to the glass quality all affects the way light is manipulated when passing through.
Keep this in mind when making your purchase. First, purchase the best you can afford. If you can't afford it now but need something better... save up for it instead of settling for something of sub-par quality.
Now for a couple of mistakes when using the nd filter. These are common for the idea that you're in the middle of a session. Your mind is running... thinking of so many things at once... these things can be overlooked - and once noticed, maybe too late to fix.
Like mentioned earlier in the article, this is something that I would constantly do which ultimately made me move to a fixed nd filter instead of a variable. I later purchased a PolarPro variable ND filter because I love variable nd filters so much.
Be aware of how you're moving your camera. For example, if you have a filter with a smooth turning ring/adjustment (with little resistance), it will not take much for the filter to move and change, thus adjusting your exposure.
In the middle of a shoot, this change could be minor and not really noticeable. However, you will notice it when you offload the footage and realize you were over or underexposed and can't save it. Not saying you can't save anything... but this has happened to me, and I don't wish it on anyone.
The same goes for putting your camera down on its side (with the end of the lens touching a surface. The same thing can happen when you pick up the camera.
Just be aware and keep it in mind.
**Image above: I barely got away with the highlights in the background. Even though I was using a VND, it helped but almost destroyed the photo (other photos in the series were completely blown out)
This is common among beginners.
But keep your exposure meter in mind when adjusting the filter. Your exposure should touch 0 or neutral. A slight under or overexposure won't hurt much but don't go extreme with it.
There are limits to what you're able to recover from both shadows and highlights - don't push it too much.
If you find yourself with a variable nd filter that's too large for a lens you have - don't worry - step-up rings can help you with this.
Step-up rings are rings that thread into themselves. For instance, if you have a 67mm lens but a 77mm filter... you would thread a 67mm step-up ring onto your lens, then a 72mm ring into that, then the 77mm ring into that. You'd then be able to thread the 77mm filter into the 77mm filter ring. Simple, right?
This can save you heaps of money. In addition, these allow you to thread filters onto a lens that you'd normally have to purchase an entire separate filter for.
The only problem with step-up rings is the inability to use traditional lens hoods while using them. Keep this in mind when using step-up rings—a small price to pay to save potentially hundreds of dollars.
Whew! That was a long article. If you made it this far and read everything, I applaud you. It's a lot of information to take in, and I hope you took notes of anything that didn't make sense to you.
At this point, you should know what an ND filter is, what makes it a variable ND filter, the pros and cons of each, and the best variable ND filter based on price/budget. Lastly, what you should keep in mind when purchasing and or using one, you're all set!
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Until next time, keep creating!!!