Long exposure photography

In keeping with a previous post, I've been spending a bit of time working on long exposure shots. Mostly of moving water in streams and small cascades, as well as ocean shots at twilight.

It's trial and error, because the amount of exposure time needed depends on the water flow as well as whether the sun is shining or not. It's much better to have the sun behind clouds for these stream shots so you don't get harsh highlights and shadows.

Of course a tripod is a necessity. A good sturdy strong one. Water and cameras don't mix!

All these photos were taken with my Canon 50D body and 10-22mm EF-S lens. Using neutral density filters. The ISO was set at 100, but apertures and exposure times were really variable. From 3 seconds to 30 seconds! There's no easy way to work out what's the right exposure, though I do use the in camera light meter to give me a guide. After all, you're trying to create something that you can't see - a picture of light in motion - so only practice gets you there.

I'm working with two different neutral density filters at present. One is the Tiffen Variable ND filter which gives you a bit of flexibility in controlling the light coming through the lens, between 2 to 8 stops, which means you can try a bunch of different timed exposures to find the right look. I found this filter particularly useful for running water shots.

The second filter is the previously mentioned Hoya NDX400, which is one dark piece of glass, and awesome for those silky long sunrise shots over the ocean.

The final thing that happened not long after this shot was captured was a wave toppled my tripod and flooded/ ruined my camera. Perhaps I hadn't stabilised it as well as I thought I had - it was certainly a rather unpleasant surprise.

So I'll soon be the proud owner of a new Canon 70D!!

Using a Neutral Density Filter

Since my last post I have indeed been shooting exclusively in manual mode. I've played with changing the ISO, the aperture and the shutter speed to get a well exposed shot, and although I haven't taken any pictures worth bragging about, I have learnt a lot and believe I'm taking better exposed pictures as a result.

I can highly recommend going fully manual, you will really get to understand your exposures so much better.

Ever since I began trying to take long exposure shots of waterfalls I've been coveting a neutral density filter. The problem with taking longer exposures of white water is that although you get the silky look, the white tends to be over exposed. Which is where the neutral density filter comes in.

A neutral density filter is like a pair of sunglasses. It reduces the amount of light coming through the lens, therefore allowing a longer exposure - to get the silky movement - without blowing out the highlights. The filters come in various strengths, depending on how many stops down of light they block.

I have a variable ND filter on order, but at present am working with a Hoya NDX400 which is effectively a 9 stop filter. This filter is considered the grand daddy of ND filters and came with a hefty price tag, but hey, it's Christmas right? It's also summer, so no waterfalls anywhere near me at present. Lots of ocean and sunsets though.

I had to head up to Carnarvon for a teaching session, so I threw the swag in the car and headed north on Thursday, stopping in at Gladstone for the night. This is an old loading jetty on Shark Bay, now disused and falling apart, but the shallow waters of Shark Bay make for a good subject for my first attempt at a long exposure shot with the filter.

The following photo was taken at f/18 for 30 sec, ISO 100 using my EFS 10-22mm lens at 10mm. Without the ND filter this would just be white. I've done some post processing to bring out some of the colours.

Comments always appreciated.