Dragging the Shutter Pt.2

In my last post I talked a little about long exposures and what I am trying to achieve with them. I usually reserve long exposure photography for my trips to the coast - occasionally I'll do some long exposure images if I have a nice sky and fast moving clouds, it can add to cityscapes and architectural type images.

As I touched on in the last post my aim when doing seascapes or coastal photography is to add blur and a sense of movement to water (it is equally applicable to waterfall images), typically for me this involves the breaking waves and capturing the water as it pulls back into the sea.

I'll include the exif data underneath each image to give an idea of my settings. Unless otherwise stated they were all shot with a 3 stop ND (Neutral Density) filter and a 0.6 GND (Graduated Neutral Density) filter. The ND to give me a longer shutter speed and the GND to balance out the sky with the foreground.

NB: I'm of the opinion that exif data is completely meaningless - this information is only relevant to me at that particular point in time. If you were stood next to me at that precise second in time you would probably have the same image as me but even then it's not guaranteed. It is more meaningful to use the information as a guide, to see how I juggled the individual camera settings in order to achieve the final overall setting I desired - in this case a shutter speed of around 1 second whilst exposing correctly for the scene in front of me.

Rattray Rush [50mm/1.0sec/f11/ISO 160]

Rattray Rush [50mm/1.0sec/f11/ISO 160]

For this image I was working close to the surf line - mainly to give variations on the foreground as the water receded back across the sand. Having sat and pondered the scene in front of me I subconsciously decided on my shutter speed. I knew I didn't want to end up with a shutter speed that would run into 10's of seconds or minutes as this would render that fantastic sky into a blur. losing all the wonderful detail in the clouds. A shutter speed of that duration would also render the waves as a smooth, flat blend of white and bottle green.

I wished to keep structure and detail in the sky and I wanted a sense of the power and energy in the waves that were breaking along the beach. With all this in mind I set up and adjusted my camera for aperture (f11), base ISO (100) to start and then added a 3 stop ND and 0.6 GND to achieve my desired shutter speed and to balance the sky and foreground respectively. This setup gave me a shutter speed of around 1.6 - 2.0 seconds which was just a little long for the effect I was after and, despite the camera saying this was the ideal exposure, I felt the images were a little dark. If I chose to go to a shutter speed of 1.0 second at this point without doing anything else this would result in an even more underexposed image. In order to rectify my exposure and give me my desired shutter speed I had two options;

1. I could open up the lens aperture (but I was happy with f11) or,

2. I could increase the ISO a little.

I chose to increase the ISO to 160, so a rise of 2/3 of a stop from the base ISO of 100. This gave me my 1.0 second shutter speed and a better exposed image and after a couple of test frames I was keeping the detail I desired in the waves.

Now, this might all seem a lot, and it probably is if you are new to this or photography in general. However, on this occasion it all passed through my subconscious in the space of a few seconds as I watched what was happening in front of me while dialling in the settings. In fact, it's taken far, far longer to write it all down for this blog!!

Awash [24mm/1.0sec/f11/ISO 160]

Awash [24mm/1.0sec/f11/ISO 160]

Having spent a bit of time with the camera in portrait orientation I flipped back to landscape to vary the composition and give a different perspective. This image was taken at 24mm and you'll note from the exif data that nothing else was changed. The light levels hadn't changed much, I was happy with my shutter speed and that was it. Just keep shooting. The wider aspect gives more room in the composition for the sand with the waves occupying a smaller area in the middle ground. The sky was still fantastic and I still wanted to keep the detail in the clouds. 

The key to this second image was the piece of seaweed. I wanted to capture the white water/foam as it pulled back down the sand. Patience is the key to this, waiting for the right combination of waves to roll far enough up the sand, embrace the seaweed and then return to the sea. Again I could have varied the shutter speed as I had a fair bit of leeway in my exposure, the histogram was clumped around the centre so I could have pushed it further right but, and this is the key to this type of image, that would have meant losing detail in the water. Doubling the shutter to 2 seconds or maybe a bit further to 3 or 5 would have reduced the impact of the breaking waves.

Timing is key and in the age of digital cameras the images are free, when practising this technique do not be afraid to take as many images as you feel are appropriate. If you so desired you could fill a memory card and then sort through the hundreds of resulting images to find 'the one' or maybe a dozen or so that you are really happy with and wish to tweak in post.

Ripples [33mm/79.0sec/f16/ISO100]

Ripples [33mm/79.0sec/f16/ISO100]

For this last image I wanted to use the patterns in the sand as my subject and leading line - the gentle 'S' curve to the left of the frame pulls you through with the textured sand giving the interest. As I was now pointing along the beach I had the clouds moving in line with the camera, they were moving overhead from behind me. I still had the wonderful detail but, as I had the texture an detail in the sand I was happy to use the strong wind that was blowing the clouds overhead and turn them into a nice smooth blend of greys.

In order to achieve a sufficiently long exposure I adjusted my camera settings - the two that I had control over again were aperture and ISO. Shutter speed would be determined by the other two setting. Wanting as long a shutter speed as possible I reduced the ISO to 100, so making it less sensitive to the incoming light, and reduced my aperture to f16 (thus making a smaller hole for light to pass in to the lens). My choice of aperture was driven by two factors; I wanted to reduce the amount of light entering the lens and I also wanted to increase my depth of field for this image. Using an aperture of f16 allows me to have more of the image in (relatively) sharp focus, both in front and behind my chosen focal point (approximately a third of the way into the frame). these base settings gave me a shutter speed of 1/13 of a second for a properly exposed image - nowhere near long enough to capture any movement in the clouds.

As you can see form the exif data under the image I had the shutter open for 79.0 seconds, in order to achieve this I placed a 10 stop ND filter, along with my 0.6 GND, in front of the lens. This had the effect of increasing my exposure time by 10 stops - to work this out I use an app on my phone. You enter the initial shutter speed and strength (3, 6 or 10 stop etc) of the ND filter and it will calculate the time required to have the shutter open in order to properly expose the image. This can result in a bit of trial and error if you have rapidly changing light conditions - and can be a pain if you're doing exposure that are several minutes long. Most DSLR or CSC cameras also have a limit on their native shutter speeds, this is typically 30 seconds at the slow end of the scale. In order to use shutter speeds longer than this the camera typically has a bulb mode, marked as 'B' on the mode dial wheel. In order to use this you require a remote shutter release that can be locked out for the duration of the exposure.

If you haven't already seen my video where I explain this on location you can find it by clicking here. If you have any questions about what you have read above then please feel free to leave them in the comments below and I will do my best to answer them.