Tips for using your Mor-Slo™ 10-stop solid neutral density filter

In Black & White, Equipment & Technique, ND Filters by Singh-Ray StaffLeave a Comment

Editor’s note: This post is the second in a series on using solid neutral density filters, arguably one of today’s most popular creative tools for photographers. Singh-Ray pioneered the development of these filters and now offers a choice of  5-, 10-, 15- and 20-stop Mor-Slo filters.

We’re often asked, “Which lens filter should I have in my bag?” but that clearly depends on the types of effects/images you are looking for, the time of day and the lighting conditions. You might, for example, initially use no filter prior to sunrise, add a 5-stop as the light brightens a bit, then switch to a 10-stop as the light brightens more. The exposure chart below gives you some guidelines on which filters will achieve your target exposure times.

To help with that decision, over the next few days we’re posting four brief “tip/fact sheets” on using each of our solid neutral density filters. We hope this is helpful – and of course, if you have any questions, please contact me at

The Mor-Slo 10-stop solid neutral density filter

The 10-stop is most commonly used in bright daylight to lengthen exposure time to 1-4 minutes:
– To smooth out streams, rivers and waterfalls
– To dramatically accentuate cloud motion
– To lengthen traffic trails
– To add time to camera movement techniques, such as pans and swipes
– Can be stacked with a variable neutral density filter or another solid ND to increase exposure time.

In bright light, a 1/250 second exposure becomes 4 seconds and 1/60 becomes 15 seconds.

  • In overcast light, a 1/15 second exposure becomes 1 minute and 1/4 second becomes 4 minutes. To dramatically smooth out water and accentuate cloud movement, try exposures in the 1-4 range and select which fits your vision for the scene.
  • Excellent for black & white, too.

Black and White Photo of a Barn and cloudy sky
Shot by Tony Sweet with Singh-Ray 10-stop Mor-Slo filter

Exposure chart

SRF-Exposure chart rev

Fact: If 100% of the light is transmitted with no filter, only .19% of the light is transmitted with the 10-stop Mor-Slo!

Suggestions for using

  1. Use a sturdy tripod and locking cable release
  2. Close your viewfinder shutter.
  3. As a further precaution against light leaks through other parts of your camera and lens on exposures over 20-30 seconds, cover your camera and lens barrel with a towel or other lightproof material, like a hat.
  4. You will NOT be able to compose, auto or manually focus and determine correct exposure with the 10-stop Mor-Slo attached to your lens.
  5. First, determine the correct exposure time without the Mor-Slo filter attached, then use the table above or a smartphone app (such as ND Timer or LongTime) to obtain the correct exposure time with the filter attached.
  6. Attach the filter to the lens and turn off your auto-focus.
  7. After you have made the exposure, check your camera’s histogram to make sure there is no clipping and that your data is relatively closer to the right side of the histogram than the left side. Adjust your exposure accordingly.
  8. Try stacking the 10-stop Mor-Slo with a Singh-Ray LB polarizer to reduce glare and enhance colors. When stacking, at least one of the filters must have a standard ring mount. Mount the polarizer first on your lens and adjust to the polarization you want, determine correct exposure time without the Mor-Slo attached and then exposure time with the table above or app. Then carefully attach the Mor-Slo, so that you do not change the polarizer setting.
  9. Combine with the Singh-Ray Color Intensifier filter to extend the grey scale and produce more dramatic black & white images.
  10. Vignetting may occur when stacking ring filters and/or shooting at very wide angles. Some customers who regularly shoot at very wide angles find it helpful to use a larger filter and a step-up ring.

Shot by Tony Sweet with Singh-Ray 10-stop Mor-Slo filter

Be sure to visit the “tips & techniques” section of our website at for articles by top pros about using the Mor-Slo and all our other filters.

Singh-Ray Mor-Slo solid neutral density filters are the industry standard for creating images with dramatic blurred motion, long-exposure effects or shallow depth of field, even in bright light. With absolutely no cast!

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