How Long is “Long Enough”?

New Zealand’s beauty and diversity of land and seascapes make it a world-class location for long exposures. The Bay of Plenty on New Zealand’s North Island is named by Captain Cook for having a vast abundance of everything. There are a variety of different beaches and more waterfalls than you can shoot in a weekend including two “Hot Water” waterfalls.

I tutor on all kinds of workshops and tours, two of which, that showcase the Bay of Plenty, are the Bay of Plenty Seascapes Weekend Workshop and the Kaimai Waterfall Photography Weekend Workshop.

These weekend workshops are designed to help students understand the difference between the dynamics of the sea and the lineal movement of a waterfall. Each length of exposure has its time and place, choosing the right one is relevant to the subject and a desire to tell the “Visuall Story” of what happens at that location.

All too often on social media, I see the wrong exposure used in the wrong location, the rush to use a ten stop to create an effect at the expense of the beauty and dynamics of the location. For me, a really long exposure is best used for landscapes that do not have a dynamic element, ie. calm seas, lakes, jetty and a slow-moving sky with plenty of definition. Here we want to smooth out the sea, lake, remove the wind chopped ripples and get that lovely silky effect and movement in the sky. My colleague and fellow tutor, Richard Young, is very adept at “long exposures.” Anything in the range of 2 – 8 minutes and he is in his element.

I tend to operate at the other end of the scale, 1/4 – 1 second. These are still considered long exposures because you can’t handhold the camera. That’s not to say that I don’t do longer exposures, it is about having enough knowledge to deal with what nature throws at you.

 

Seascapes

Presented with a sea with little or no water movement and I will be into a ten stop in a flash. However, most of the locations in the Seascape Workshop have dynamic water movements, such as movement over rock ledges and small offshore islands. These environments suit the shorter more explosive exposure. Repeatedly we find this falls into the 1/8 – 1/2 second shutter range to precisely capture the wave movement as it hits a rock or spills over the edge and drains away to reveal a white water pattern. This is my approach for an “incoming” wave that has an explosive element.

Something that I have used to great effect is a composite of multiple waves based loosely on a time-lapse. This allows me to capture the visual story over about 5 seconds made up of multiple shots of a 1/4 second each.
Presented with a sea with very little action, one small wave would look uninteresting, so I figured that if I shot each wave that came in and then reassembled the image in Photoshop to create the visual story, then I could walk away with a credible image from that morning. The B&W image from Otarawairere is made up of 5 separate wave shots. I had never seen these rocks before, they have always been underwater on previous visits.

So, how long is “long enough”? This is a phrase I use all the time and simply means that the exposure only needs to be slower than the speed of water to capture an effect, anything longer than this is up to your own personal preference.

With an explosive sea that’s moving fast the 1/4 second seems to be the magic length, in the image of “Kaikoura Limestone Blast” the sea is surging in at quite a pace, any longer on the exposure and we would not capture the blast against the rock.
(Image Kaikoura Likestone Blast)
However, waves that are drawing back need a longer exposure to capture the white water run trail, this tends to lean towards 1 – 2 second.
(Image: Wainuiomata Dawn Rush or Kaikoura or Kaikoura Limestone Drift)

A contradiction to what I have said happened one morning while shooting a seascape at Cathedral Cove looking towards “Sail Rock” this was about 5.30 am, the natural light at that time was giving me a 15-second exposure, which was all good until the sea picked up pace and started surging into the cave. 15 seconds was turning it to mist and not conveying the wave exploding on the one lone rock. A wild guess at creating a precise exposure during a long exposure paid off. I lit the front edge of the wave with a high powered torch and followed it as it moved across the mouth of the cave.

One of the things that I have learnt with dynamic seascapes is to read the waves, waves build in a cycle of seven of which 1 and 2 tend to be flat, 3 starts to build, 4, 5 and 6 are where the action is and seven could give you a bath! So always be aware of the size of the sea. As the sun comes over the horizon there is a natural increase in the wave pattern which intensifies through sunrise, when you think you have the wave pattern don’t become complacent, watch out for that seventh wave as it can be bigger than the rest and give a rogue wave. So stay safe.

 

Waterfalls

The Kaimai Waterfall Workshop is designed to instruct and practise reading the speed of water movement in waterfalls. I tend to refer to this as a running tap or a lineal movement that falls consistently and unbroken, unlike the sea which is variable.

Waterfalls are one area where I see many photographers shooting “too long” an exposure. The longer the water runs the more it overlaps with itself, thus losing any secondary detail. An example that I show students is to scribble on a piece of paper with a pen, here is a light scribble (1/4 seconds) and you will see all the gaps in the water flow, a longer scribble (1 second) and we have nice flowing water and secondary detail, an even longer scribble (5 seconds) and now we have completely overwritten any detail and have a black mess. Think of this example in reverse: as white water, 1/4 second is not long enough to give smooth water. 1 – 2 seconds are perfect for smooth white water, having defined secondary detail, and revealing a vortex (Image: Kaiate “The Scream” vortex). With 5 seconds you have lost all secondary detail and ended up with shaving foam. The answer always lies in the 1 – 2 second area and is relative to the volume and speed of the water.

We visit the Tarawera Falls a lot on workshops, it is 65m high and has a huge volume of water. One of my students (A hydro engineer) said that it was moving at ten tonnes a second, so a 1-second exposure is long enough.
With big waterfalls we also have to be mindful of wind movement generated by the fall, this can mean that there is a lot of foliage moving in the shot, we don’t want the viewer to think that the whole image is soft.

So, I ask you once again, “how long is long enough”? Well, that is up to you based on the image you want to convey, but don’t let the story be overwritten, a ten stop is not always the answer. From Serene to Dynamic, your job is to visually tell the story of that location.

Ken Wright
Tutor at NZWP

Join us in the Bay of Plenty

Inspired to capture your own long exposure seascapes? Bay of Plenty Seascapes Weekend Workshop.
Inspired to capture your own long exposure waterfall shots? Kaimai Waterfall Photography Weekend Workshop.

 

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