Singh-Ray Vari-ND filter

Willow Dance: 1/15 sec @ f/5.6 ISO 100

As I’ve mentioned, I don’t ‘do’ filters much; however, there have been those times in the mountains and along the Blue Ridge Parkway when I chided myself, on occasion, because I didn’t have a set of neutral density filters.

Sure, sometimes you can accomplish the same effect by stopping down to your smallest aperture and using your lowest ISO. In my case, since I prefer to use my 18-70mm lens, this would be ISO 100 @ f/22. The problem with this is that although you may get the shutter speed that you desire, stopping down increases your depth of field beyond what you may want and it also reduces image quality because of light diffraction while passing through the small opening between the aperture blades. Knowing this, and having done some experiments, I prefer not to go below f/11 on any of my lenses. Around f/8 is where I get the most bang for my buck.

Here is where a neutral density (ND) filter, or set of filters, is really useful. The ND filter, of course, reduces the amount of light going into the lens by a number of f/stops. It’s like putting sunglasses on your lens, except there is no image degradation, nor color shift. Usually, it’s good to have about 3 ND filters, each blocking a different amount of light, for example 1 stop, 2 stops, 3 stops. You could combine all 3 to black a total of 6 stops of light. The disadvantages here are that you have to carry 3 filters, and each time you add a filter, you loose a little bit of sharpness due to refraction between the filters. Also, if you are using wide angle lenses, I’ve seen problems with vignetting.

There is a solution: The Singh-Ray, Vari-ND filter. Wow! What an impressive filter this is. It only comes in 77mm and 82mm thread sizes; however, you can buy step-up rings (lens to filter) to accommodate any lens that you have. I bought the filter and two step up rings, each about $10, a 55mm-77mm and 67mm-77mm and now I can use this filter with any of my lenses. It would certainly behoove you to do this as each of these filters costs nearly $400. I had to sell some more of my stuff that I had sitting around just to buy this! There is one small drawback about using these rings on wide angle lenses. I get a bit of vignetting on my 18-70 at the 18mm range, but it’s no big deal. It’s easily fixed in Photoshop.

ISO 100 1 s @ f/5.6

About the filter:
The filter has a turning front ring with Min and Max markings on it. Min is about 2 stops of light reduction, max yields about 8 stops! Yes 8 stops, 2 to the 8th power, or about 256 levels of light less! You’ve got to see it to believe it.

In using this filter, here is where it comes in handy to understand manual exposure and how to read a histogram. Because this filter reduces the light levels so much, it makes it nearly impossible for the lens to auto focus. Most auto focus cameras need a lens opening of f/5.6 or better to perform auto focus. Well, putting this filter on my 18-70mm f/3.5-5.6 makes it an 18-70mm f/8-11 approximately! Auto focus doesn’t work well here! Turning to maximum density ensures that my AF doesn’t work, so I just focus manually, then move the filter to ‘max’.

Regarding exposure, I find that a maximum density, which is cuts the light by 8 stops, my camera’s meter is generally off about 1 – 1.5 stops in the direction of underexposure; however, it depends on how your subject is lit, so experimentation is the key.

In the field:
When I first got the filter, I wanted to rush of to the nearest stream or moving body of water, such as a fountain or some such; however, I tempered my desire for a few days and came up with a solution that I liked. I love trees, plain and simple. So, I knew that my first tests had to have something to do with trees.

There’s a place near my home called University Boardwalk; I’ve mentioned it before. All along the walking path, there are these beautiful Willow trees dangling over the side and into the water. I love to watch their reflection in the pond. I thought that it would be an ideal subject.

Windy Day! ISO 100, 4 s @ f/8

I’m pretty much a WYSIWYG (What you see is what you get) shooter and will rarely stop more than one f/stop below the widest opening that I have. I’ve always been that way. Please don’t ask me to change now! I have a depth of field preview button, but rarely use it. So, this filter is great for me. I can even shoot with my f/2.8 lens all through the day and shoot wide open!

I can see all types of use for this, especially panning, water movement, portraits (to get nice blurred backgrounds by shooting wide open), capturing cloud movement, etc. As I get more suitable images, I’ll post them and keep you up to date about my use of this filter; however, even after using it briefly, I have to say, I’m glad that I bought it!

Lastly, to our film users (Micki!), this can be used with your film cameras too!

Related posts:

1. Filters
2. Filter fun
3. Photoshop vs. Split ND filters