How to Use Singh-Ray’s Mor-Slo Filters to Create Long Exposures (April Newsletter)

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It must be spring, because I’m thinking of waterfalls photography and how to create that silky, soft look with water. If you’ve been following my photography, you know that many of my photos use that effect to even out the surface of Lake Superior or the ocean to carry the sky’s color throughout the scene. Recently, I upgraded my filter system to Singh-Ray’s Mor-Slo filters and want to write up a primer on how to use Singh-Ray’s Mor-Slo filters to create long exposures — I get asked this during my Lake Superior photography workshops and wanted to write something for folks that can’t make it to my workshops. Last year, I wrote about how to use vari-nd filters for waterfall photography, so this year, I decided to write about how to use solid neutral density filters to do something similar.

Create Long Exposures with Singh-Ray’s Mor-Slo Filters

Singh-Ray’s Mor-Slo filters currently come in three different intensities: 5-stops, 10-stops and 15-stops. The more stops that the filter has, the darker it is, which means that you can create a longer exposure. Each stop that the filter has doubles the length of exposure from the last stop. So, a 5-stop filter would double the exposure five times. I have both the 5-stop and the 10-stop. The longer exposures blur action, so the surface of the big lake or ocean looks like fog (see the header image).

I find that during the sunrise and sunset, because the light conditions change so quickly, the 5-stop seems to work better for me. With a 5-stop, I can keep my exposures around 30 seconds to 1 minute. With a 10-stop at sunrise and sunset, I find that exposures are often as long as 8 minutes. The light changes significantly during that time frame, so I’ve found that you just don’t get the best color during sunrise and sunset with an 8 minute exposure. For something that long, the color needs to stay constant if you want to capture it.

Click the following images to see them larger for examples of a shot with the filter and one without the filter. The shot without it is 1/30 of a second long the shot with the 10-stop Mor-Slo filter is 30 seconds long.

To use Singh-Ray’s Mor-Slo filters to create long exposures just follow these steps (Note: this works with any ND filters):

  1. Put your filter holder on your lens.
  2. Compose and focus.
  3. Turn off your focus system (see How to Use Rear Button Focus for a better autofocus setup on your camera).
  4. Switch to manual mode.
  5. Set your aperture based on the depth-of-field you need. For landscape photography, usually around f/11 to f/16.
  6. Adjust your shutter speed to center the exposure scale.
  7. Shoot a test shot and adjust your exposure as needed.
  8. Insert your Mor-Slo filter or other ND filter into the holder. Make sure that it’s in the closest slot to the lens.
  9. Adjust your shutter speed based on the number of stops. See below for the ways to do this.
  10. Take the picture.

Adjusting the Shutter Speed for ND Filters

You can adjust your shutter speed several ways to account for the density of Mor-Slo filters. The first involves math. You simply double the length of the shutter for each stop. For example, if you’re using a 5-stop Mor-Slo and you start with an exposure of 1 second before you put the filter on, you end with an exposure of 30 seconds.

  • 1st stop: 1 second x2=2 seconds
  • 2nd stop: 2 seconds x2=4 seconds
  • 3rd stop: 4 seconds x2=8 seconds
  • 4th stop: 8 seconds x2=15 seconds (note that in camera stops the next step is 15 and not 16)
  • 5th stop: 15 seconds x2=30 seconds

nd filter calculationsThe second way is you download an app to do the calculations for you. Usually, you have to select your shutter speed without the ND filter and then select the intensity of the filter and it will tell you how long you need to set your exposure.

There’s also this handy chart that I made for you. To use the chart, you find your shutter speed without the filter in the left column and then follow the row to your filter and it will show you the exposure. This way is one of the easiest ways. You can download a pdf of the chart formatted to fit on a 4×6 inch index card.

  • DownloadND Filter Exposure Chart [pdf] — A filter chart that shows the required shutters speeds when you add a 5-stop, 6-stop or 10-stop Mor-Slo filter or the Lee Little or Big Stoppers.

The way that I like to do it is by just counting the number of turns on my shutter speed dial. I have my camera set up to adjust my shutter speed by 1/3rds, so three turns of the dial equals a change of one stop. You can find out how you have your’s set up by checking your menu items or by setting your camera on manual and setting your shutter to 1 second. Turn it to 2 seconds and count the number of clicks it takes to get there. If it’s three, then you have it set up for 1/3rd. If it’s two, then you have it set up for 1/2th. For thirds, multiple 3 by the number of stops to get the number of clicks you need to turn it. For 1/2, multiple 2 by the number of stops to get the number of clicks you need to turn it.

  • 5-stop: 1/3 = 15 clicks; 1/2 = 10 clicks
  • 6-stop: 1/3 = 18 clicks; 1/2 = 12 clicks
  • 10-stop: 1/3 = 30 clicks; 1/2 = 20 clicks

You can also count it off by stops. For example, 1-2-3 turns = 1 stop, 1-2-3 turns = 2 stops, etc…

But if you’re just learning, it’s nice to have a chart to check in the field, because they you can concentrate on the photography and not the math.

Upcoming Photography Workshops

These are the upcoming photography workshops that have space in them.

  • Lake Superior Kayak Photography Workshop: A three-day workshop that mainly takes place on Lake Superior. We’ll use tandem kayaks for stability and visit Tettegouche State Park and Palisade Head, which have the most dramatic landscape on Minnesota’s coast (assuming the weather is good — I switched this to June to take advantage of June’s typical calm waters. It’s one of the calmest months). We’ll paddle through sea caves and under 200 foot tall cliffs while photographing everything. This may be the last year that I offer this workshop.
  • North Shore Fall Photography Workshop  – 5 day: One of the most loved workshops, because when the colors change the hills surrounding Lake Superior change to a fiery red and yellow. Over five days, you’ll photograph the landscape and learn the best techniques for capturing fall color on the north shore as well as learning how to make eye-catching seascapes. This workshop has been a popular one since I started offering it, so get signed up soon.
  • Great Smoky Mountain National Park Fall Photography Workshop: Last year, I ran a trial version of the workshop and it went well. This year, I know the park even better than I did before. This is the plan: we’ll go high on the mountains for sunrise and sunset and then into the valleys and gullies to shoot waterfalls during the day. I could call this workshop the peaks and streams workshop.

Select Images for March – Click to see larger

March felt like a busy month for me with trips to the Badlands and Florida, two workshops and teaching at a seminar. I also took a full week off from photography, which is something that I seldom do, but I needed a mental break from it. Here are a few shots from the month.

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Showing 2 comments
  • Bill Gosma

    Are these Singh-Ray ND filters also capable of blocking IR? I’m wondering how they fair from the standpoint of being a truly ‘neutral’ density effect on the image (i.e. NO red or blue color-cast)

    • Bryan

      You’d have to ask Singh-Ray about whether or not they block IR. The 5-stop Mor-Slo looks close to or neutral to me. The 10-stop Mor-Slo has a cyan cast. It’s significantly less of a cast than what I’ve seen from Lee or Formatt Hitech. If I want to correct the cyan cast, it’s easy to do so when processing the RAW files.

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Standing on fast ice next to Lake Superior. Minnesotastarburst and field of flowers