The “Five-Stop Effect”

By Tom Bol

Townsend, TN. Great Smoky Mountain National Park.

Townsend, TN. Great Smoky Mountain National Park.


If you have thumbed through the pages of a photo magazine recently, chances are good you have seen the stunning effects created by ND filters. My palms start sweating when I see puffy clouds streaking across the sky. I know these clouds will look magical when I shoot at slow shutter speeds from 1-4 minutes using my 10- and 15-stop Singh-Ray Mor-Slo ND filters. Honestly, I look at clouds differently now knowing what transformative effects I can create using these filters.

Scotland

Scotland

But as much as I use my 10-stop Mor-Slo filter, I have a new favorite Singh-Ray filter; the 5-stop Mor-Slo ND filter. Why would I want a less dark filter? After all, isn’t the idea that the slower the shutter speed, the more dramatic the cloud streaks and silky water will look? This may be true for cloud motion, but I’ve changed my approach to moving water. Here are two reasons I love using the 5-stop Mor-Slo filter, and one reason might surprise you.

 

The silky water effect. As a landscape photographer, I was originally attracted to the ND filters for the ability to blur moving water and surf. I used to follow one rule; slow the water down as much as possible for the best results. Some of these silky water images, especially crashing surf, looked great at 30 second exposures. But as I photographed streams, I began to realize this approach wasn’t always the best. Instead, I liked water that had texture and contrast. Large waterfalls and rivers looked great this way; the texture added tension and drama to the image. And I discovered using a 5 stop Mor-Slo ND filter was just right for achieving the slow shutter speed I needed, generally around ½ -4 seconds. Since most of my lenses have a 77mm filter size, I just attach the Mor-Slo filter to my lens to slow my shutter speed down.

 

Using the 5 stop Mor-Slo has some advantages too. First, I can see my composition. Five stops is dark, but not dark enough that I can’t compose my shot. Second, I am using the thin version, so I don’t have to worry about vignetting that occurs using wide-angle lenses and thick filters. And one other nice convenience of using the 5 stop Mor-Slo ND filter; my camera can autofocus with the filter attached.

 

When I see moving water in my image, I ask myself what am I trying to convey in the image. Am I trying to capture the tranquility and peaceful nature of the scene? Or am I trying to capture a dynamic scene with tension. If I want tranquility, then most likely I will use a long shutter speed for silky water. If I want some tension, then I will choose my 5 stop ND and shoot around 1-4 seconds depending on how fast the water is moving.

Croatia

Croatia

The bokeh advantage. My photography career is diverse. One day I might be photographing landscapes for a magazine, the next day shooting portraits for an advertising shoot. I’m rarely in a studio, but more often in remote outdoor locations. Another aspect of my work is using flash for many of my commercial jobs, especially portraits. I get just as excited photographing an interesting person on location as I do photographing the clouds racing across the Patagonian landscape.

 

Evocative portraits are created using a combination of good rapport, relevant location, effective use of light and solid camera craft. I love to shoot prime lenses, including the 35mm and 85mm f1.4, for my portraits. Being able to shoot at a shallow depth of field like f1.4 blurs the background creating beautiful bokeh and nice separation. Using available light, all I have to do is set my aperture to f1.4 and shoot away.

 

But a problem arises using flash. On a bright sunny day shooting at f 1.4 and ISO 100, my shutter speed might be 1/4000. Since most cameras have a flash sync speed of approximately 1/250, shooting at 1/4000 would result in banding (dark areas in the frame where the shutter curtain blocks flash from reaching the sensor) in the final shot. But if I add my 5 stop Mor-Slo filter, my shutter speed goes from 1/4000 to 1/125, and my flash will work just fine with my camera.

 

Recent developments in high speed sync and hi-sync flash technology have reduced or even eliminated the problems associated with using flash and fast shutter speeds. But depending on your flash system and camera, occasional banding may still occur, especially at very fast shutter speeds. Speedlights have evolved to eliminate banding, but at the expense of greatly reduced output. Since I shoot a lot of my portraits though a large octabank, I use strobes to get the job done. I need lights with plenty of power and fast recycling.

Fort Collins, CO. portrait

Fort Collins, CO. portrait

If we choose to shoot at f1.4, my workflow goes like this. We scout the location before the client arrives, and take some sample exposures. I often walk around shooting at f1.4 with my 35mm to check backgrounds and bokeh quality. Next, I see what shutter speed is giving me the right exposure. If it is a sunny day, or partly cloudy, chances are good I will need my 5 stop ND to bring the shutter speed down below my camera sync speed (1/250). Next, we set up our strobe and large octabox and take a test shot. Since our strobes have over 1000 watts of power, we have the power necessary to compensate for the 5 stop ND filter attached to my lens. When the client arrives, I know I can shoot at a very shallow aperture using strobes and not worry about flash sync because I am using the 5 stop Mor-Slo ND filter to slow my shutter speed down.

Fort Collins, CO. portrait

Fort Collins, CO. portrait

The five stop effect. ND filters offer many creative options for photographers, and I never leave the house without a few in my camera bag. Whether it is photographing a massive waterfall in Iceland, or an Olympic skier on the slopes, I often use the five stop effect to get the results I need.

Tom’s website and workshops

Tom’s Pro Gallery page on this site