Anatomy of a Shoot – Long Exposures

Anatomy of a Shoot – Long Exposures 

Long exposure shots are all the rage right now. You’ve all seen them; Pier, Cotton Candy Water, B & W. We are not just talking silkening the water with 10 second exposures on waterfalls. We are talking cotton candy, fog or mist look to water (or Clouds) of exposure for 5 minutes or even an hour. It’s the newest thing to catch on in landscapes so if you want to know how, follow me through a recent shoot.

 Now I’ve done long exposures before. Whether it was of the water to make for the cotton candy, or, doing star trails out in the desert. But I don’t do them often because; well quite frankly they are boring to do. You sit and wait for 5, 10, 20 minutes and then you get another shot.

In fact I spent one night from midnight to 4am getting just 4 shots of star trails only to have the in camera long exposure noise reduction determine the stars were noise and take them all out…so much for that nights sleep

But they can be great fun and really rewarding shots so lets give them a go 

What you need:

• A camera with B or Bulb mode (Bulb mode allows for holding the shutter open as long as you want)
• A locking remote control for your camera
• A Neutral Density (ND) Filter or a Graduated Neutral Density (GND) Filter as in this case
• A stopwatch, the timer in your smart phone works great
• A steady tripod

 Now we can get all fancy with this and if you find this is your thing, you may want to invest in remote controls that have timers built in and other niceties. We’ll keep it as simple as possible for now. 

The whole idea here is to get an exposure in minutes probably at least 5, probably more is better. So then we have to do what it will take to make possible a good exposure where the shutter speed is in minutes. If we try to do one during the day we are going to need a very strong Neutral Density Filter. 

What Neutral Density filters do is cut the amount of light that enters our camera through the lens and they do so without affecting the color of the image (hence the “neutral”) ND filters are rated in “Stops” form 1 to 3 to 6 to 10 and more or you can stack them to get what you need. If you wanted to do this during the day, most likely you would need a 10 stop ND filter or more. 

But for this shot I took an easier route and shot after sunset, in this case 30 minutes past sunset or into the Dusk period of day. For this time period there still is some light to the sky so in order to get a long exposure I needed to use a 3 stop ND filter. This brought me to about a 5 minute exposure for my first attempt. 

I set my camera up on my Manfrotto Tripod. Before I did anything I established my composition. I saw three rocks in the water that looked like stepping stones so I arranged my composition around them. I also at this point established my focus. Make sure you take care of both these things before you add any ND filters to your camera’s lens because the darkening effect will make it difficult for both you to see and your camera to auto focus so establish them first. In fact you may even want to set up before the sunsets so you and your camera can see better as it becomes very difficult after sunset. 

With my composition and focus established I put my 3 stop B +W ND filter on my lens. I set my camera to B or Bulb mode and plugged in my Canon RS-80N3Locking Remote into my Canon 5D and Canon 17-40L Lens. I set my ISO low at ISO 100 set the aperture to f/16 and decided to try a 5 minute exposure as a test. This resulted in a poor image. The rocks and water looked good but the sky was too bright and it was blown out.

 So I knew what I needed to do so I ran back to the truck to get a couple other items I didn’t have with me. A Cokin Pro Z  & 3 stop Graduated Neutral Density Filter and my Gossen DigiProF light meter. 

A graduated Neutral density filter is a split filter with a ND filter at top to cut back light and a clear bottom section to let through light normally. With this I could cut down the exposure on the sky while still keeping the exposure I wanted on the rocks and water. 

So now 15 minutes later I was ready for my second shot. This time I didn’t want to experiment I wanted to get a close to the correct exposure since I only had one more opportunity this evening as dusk was waning and there was no moon to light the scene 

So I had my camera now set to an even lower ISO 50 because I wanted an even longer exposure. Still f/16 and I set my Gossen meter to those settings and Measure the light of the rocks and water. It gave me a reading of 8 Minutes. The reason I didn’t measure the sky was that area would be covered by the 3 stop ND area of the filter and then that would mean I would need to do that “Math” stuff and figure out 3 stops  darker than the reading of the meter and I’d just rather not do any math when I am shooting even if I do quite often. 

But you do need to bear that in mind if you are using a hand held meter and a lens with an ND filter on it. You have to compensate for the filter. If you are using your camera built in meter you don’t need to compensate because it reads through the filter however you can only use your camera meter up to a 30 second exposure. Not near long enough for what we want. My hand held meter can read all the way to 30 Minute Exposures and from there, you can do the math if you need longer. 

So with the GND filterin place, the remote plugged in and my iPhone with stopwatch in hand. I set about to get an 8 Minute exposure, ISO 50, f/16. I pressed the remote and set the lock on it. 

And this was my resulting image

 And the same image converted to B & W

 Great exposure to the sky, great exposure to the rocks and water, foggy water. 

Now in post I did have to lighten the image slightly (about ½ stop). The reason for this is something else you have to take into consideration. IT WILL GET DARKER AS THE EXPOSURE GOES ON. 8 minutes later it was much darker than when I started the exposure. So although 8 minutes was a good reading at the time the exposure started, I need to compensate a little because it would be darker at the end of the exposure so probably a 10 to 12 minute exposure would have been perfect without any need to lighten in post.