A Common Misconception About ND Filters

ND filters are fantastic pieces of kit for a number of applications, but there is a powerful use for them that sometimes gets overlooked through misconceptions. In this video, see visual examples of exactly what an ND filter can do for you.

When I was first introduced to ND filters, I distinctly remember thinking they were for landscapes, or darker filters like the ND32 were for long exposures. In fact, I bought some for that very purpose, without truly understanding the value they can add elsewhere. 

This changed on a fashion shoot some years back where I had a model in front of the ruins of a castle at golden hour. I liked the scene as a whole, but the sun was at the wrong angle for a shot I had in mind and the castle became a little overwhelming in the final frame. That is, it drew the eye away from my model, which is the last thing I wanted. So, I knew I could lower my aperture — perhaps even wide open — and get the best of both worlds. However, I had to overcome the age-old problem: if I lower my aperture, I will have to use High-Speed Sync (HSS) on my flash, which I didn't have the option of. If I used just the max sync speed, even at ISO 100, the image was blown out. So, I added an ND filter to take a couple of stops of light out of the image.

In this video, see visual examples of exactly that and how ND filters can be useful in your portraiture when you're battling against bright natural light and the balancing of your own equipment.

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Miguel Gonzalez's picture

@Magnusdiv on IG - ND filters are a great way to get the most power out of your Godox ocf. When using hss it lowers the amount of light per stop.So I usually keep a few handy if the sun is blaring. Thanks for the tip.

Jesus Arias's picture

@OrangeFallPictures on IG - For someone who shoots a lot in daylight/golden hour, this information is greatly appreciated. Thank you for posting your behind the scenes, huge fan of your content.

Alfredo Robles's picture

@supr3me_trekkie on IG. I have not bought an external light yet, but i have been following you for a while. Just found your youtube channel 2 weeks ago. All i got to say is your a master in your craft. Thank you for all the info you share to us!

Adam Chandler's picture

Such a great point and, yes, I believe a common misconception. What a simple and brilliant way to effectively increase the power of your strobe while also benefiting from being able to use shallow depth of field and, potentially, faster recycle times. I'd pondered getting a 600 WS strobe to replace my 200 when shooting at the beach and instead ordered a nice 3-stop ND filter for a fraction of the cost of a new strobe. Thanks for shedding light ;) for me on this topic and in such a clear way.

Brian Albers's picture

@whats_with_the_astroturfing_on_this_post? on IG

Sams Legends's picture

@samslegends on IG - i have never thought about the combination of an nd filter and my flash. Makes totally sense. I used them only for filming and long exposures during daytime

J. H.'s picture

This is NOT about using a flash. This is a common method to achieve a shallower depth of field.

It's quite simple and has been thought of for decades: with the aperture you control (mainly) the amount of flash light, with the shutter speed the amount of ambient light (the ratio between the two light sources). This is, of course, a simplification. It has to do with the power of the flash and its distance from the subject.

1. When you can't shorten the shutter speed any more, you use an ND filter or H-Sync (and not HSS).
2. When you want to lighten up your subject, use a flash.
3. You can change the amount of flash light either by changing the power of the flash or by moving it to or from the subject.

Of course you can combine those methods.

BTW: What is this nonsense: "@Some Nick on IG" If you chat on IG, please stay on IG.

Benoit Pigeon's picture

You show strobes and explain well why HSS isn't always the best, but you did not mention two things. I'm sure not all your viewers are on a budget because I see your videos here on Fstoppers, so for them you could mention true, up to full power with Hypersync. You show a strobe and a hot shoe mounted light, but you don't show what a 4 stops (1/16 of the light) filter actually looks like and how dark it is when the face of your model is backlit with a sunset behind. If budget people can't afford a good battery powered strobe, then they can't afford the needed modeling and one that will last long enough. May be a third video?

Vangelis Medina's picture

Ok, you did not understand how to use ND filter with flash.

The model face will be bright as the shot without the need, ND filters do not change the light ratio between ambient and flash.

Simple because the 4 stops ND will dark both the sunset background and the model face by 4 stops.

And the photographer will change the camera aperture from F/8 to F/2, bringing back the same exposure as without the filter.

Benoit Pigeon's picture

You are talking about the technic and resulting effect, I am talking about what the photographers see with a 4 stops darker screen or view finder in a backlit situation.

Benoit Pigeon's picture

Francisco, what did I write that deserves a thumb down?

J. H.'s picture

I think you did not understand what he said. Hint: The dynamic range of the scene is far too wide for the sensor. Even our eyes would not see much of the face with the sun in the background.
That said: FIRST you expose for the ambient light (or the sunset in this case), use a ND filter IF you need an open aperture and cannot choose a faster shutter speed than the flash sync speed. THEN you add the necessary amount of light with a flash tube to expose the object (the face) correctly. OR you do not use a ND-filter but use a H-Sync-cabable high-power flash. In this case I guess 400Ws is plenty enough, 250Ws probably work well.

J. H.'s picture

Hey Francisco, instead of thumbing down, please tell us what you do disagree about. Correct me, i If am wrong. You stepped forward with your video. But honestly, I think you need a lot more experience before talking about such matters. Why do you do such videos? To teach people or to collect followers. Please keep in mind where you are here. This is not your average youtube people.