When you mention the words “neutral density filters” most photographers instantly think you are talking about landscape photography, landscape photography equipment and how to improve your landscape photographs. Okay, neutral density filters are important in the landscape photographer’s kit bag, however they are just as important in a portrait photography kit bag.
Well, I guess this isn’t strictly true because if you shoot portraits in the studio environment you won’t need nd filters as they will be of little use.
If, however, you shoot portraits outside you will find neutral density filters come in very useful and may just save the day in enabling you to capture portrait photos that would not have been possible if you had not had a neutral density filter in your photography bag.
When taking portrait shots you want to make sure the subject is the focal point, and the best way to do this is to make sure the background isn’t distracting. Achieving a non-distracting background is simple in the studio, however when not in the studio ensuring a non-distracting background may be a little more tricky. The easiest way to get a non-distracting background and ensure the subject is the focal point of the photograph is to make the subject tack sharp and intentionally blur out the background, which obviously requires a wide aperture (i.e. low f-stop).
The more distracting the background the wider the aperture you need to throw the background out of focus, and this could lead to exposure problems. If the ambient light is good it may not be possible to open your lens right up and achieve correct exposure. Sure, you can set the camera to the lowest ISO however the light may still be “too good” to use the lens wide open and achieve the effect you want. This situation typically occurs outdoors in sunny conditions.
When taking outdoor portraits in sunny conditions the only way to slow down the exposure enough to use the lens wide open is to shoot through a neutral density filter. You can use screw in neutral density filters or square nd filter systems, the choice is entirely up to you. Personally, I prefer to use screw in neutral density filters because of the way I shoot portraits. When I shoot portraits I move around the subject, exploring different positions and different angles and with the neutral density filter screwed in to the end of my lens I have the freedom to mover around as much as I want. Using a square nd filter system in this situation would slow me down, hence I don’t use one.
I always carry three neutral density filters, being a 1 stop, 2 stop and 3 stop. In my experience I use 2 stop neutral density filters the most, however there are times when the 1 stop and 3 stop are needed, so I make sure I always carry these too.
It is possible to buy a variable nd filter, which is a neutral density filter of different strengths. I like the idea of carrying a single nd filter so I bought a variable nd filter and tried it out. The variable nd filter I bought (made by Hama) was utter rubbish and I would never recommend it. Using the variable nd filter resulted in a significant reduction in image quality, which was so extreme the photo was un-usable. I also found that a “dark cross” appeared in the photo, and after a bit of research this seems to be a common problem with all variable neutral density filters.
Since my wasted photography session with a variable nd filter I have not used one since, I will never use one again and I will simply carry a selection of neutral density filters to cover the situations I need.
Even though neutral density filters are meant to be totally neutral, i.e. and not affect the colour in any way, this is not the case. Regardless of how much you spend on nd filters or how good the manufacturer’s claim their nd filters are all of them will give a colour cast, and the extent to which will vary from manufacturer to manufacturer.
Colour casts are easily corrected with photo editing software, so make sure you always shoot in RAW format when using neutral density filters. If you have to shoot in jpeg for whatever reason you need to use a custom white balance when using neutral density filters to make sure there are no colour casts in your portrait photos. When setting the custom white balance make sure you set it with the appropriate neutral density filter attached to the lens.
BUYING NEUTRAL DENSITY FILTERS
Whilst you are wise to spend a little money on neutral density filters there is no need to spend a fortune on one. Cheap and nasty nd filters degrade the quality of portrait photos so much they aren’t worth buying and using, whereas very expensive neutral density filters will only work as good as slightly cheaper nd filters. The key is to be buy nd filters that are priced between the super cheap and super expensive neutral density filters.
The neutral density filters I use are made by Hoya and I have to say that I am more than happy with them. These neutral density filters are well made, i.e. well machined and easily screws in to (and more importantly, out of) my lens filter threads, tough and durable and have a minimal colour cast. Whilst colour casts are easily corrected I prefer to use nd filters with the weakest colour cast, which is understandable.
Neutral density filters are too expensive and I make sure I always have a spare of each type. I learned to have a spare the hard way, when during one of my early paid portrait shoots I dropped the neutral density filter breaking it in the process and neither of my other filters nailed the exposure as I wanted it. Needless to say the final photos weren’t much cop, the client wasn’t too impressed with the photos and not having a spare neutral density filter in the correct strength made me look like a right amateur. Please learn from my mistake and experience and make sure you always have spare nd filters on your portrait shoots.
Keen photographer addicted to cameras, lenses and everything photography related. Feel free to follow me in my photography ramblings, and if you have any thoughts, comments, queries or anything else to add I would love to hear from you.