As is happening regularly on Thursday nights in recent weeks, last Thursday evening I found myself with time to kill and a camera bag over my shoulder. I was en route to week 4 of the Commercial Photography course that I am doing at the Light Exchange in Rathmines. With 5 minutes to spare as I passed The Barge pub at Charelmont, and rain just beginning to fall, I stopped briefly to try to grab a shot of the pub with the canal gate in the foreground.
The canal that runs along in front of The Barge is the Grand Canal, and parallel to it runs a busy road. Between the road and the canal is a low wall, and it was this wall that acted as my tripod for this shot, allowing me to get a sharp exposure at a slow shutter speed.
There are two reasons why the shutter speed is slow – it’s not that I was trying to achieve an artistic effect by slowing it down, but I was trying to minimize noise by using a low ISO, and trying to keep the light sources in the frame as small as possible, by using a small aperture. Because it was dark it followed that I would need a slow shutter speed to ensure adequate light hit the sensor in the camera. In this case that took 20 seconds.
The lighting of the pub was difficult to deal with because parts of the building are spot lit, including the entire three-storey section at the right hand side. It turned out that this area of the frame was receiving 5 to 6 stops more light than the darker areas of the frame, meaning retaining detail in a single exposure would be impossible.
I didn’t have time to take multiple 20 second exposures and wasn’t certain that if I did I would manage to not move the camera during the time it would take to get them all, so I had to rely on trying to recover detail from the RAW file processed at three different exposures (-2 stops, 0 stops, +2 stops) and merged in Photomatix.
The colours in the image that resulted from this processing were over-saturated in the highlight areas (and looked very unnatural) but a monochrome conversion suits the image quite well and I’m happy with the results.
The eagle-eyed might notice a few spots of flare – these are due to the rain that was falling more and more and was, of course, another reason not to spend another 5 minutes taking a series of exposures for a proper HDR shot.
Relative newcomer to your blog. I’m enjoying it a lot
I suppose it is diffraction through the small aperture that’s responsible for the “starbursts” round the bright lights, so I’m intrigued to know what you mean by:
“trying to keep the light sources in the frame as small as possible, by using a small aperture”?
Hi Graeme… welcome to the blog! Yeah it’s probably not the clearest statement in the world but what I mean is exactly what you thought – that by using a small aperture, any pin point light sources will become starbursts in the final image due to the shape of the aperture when it is closed down. Had I used a wider aperture (e.g. f/5.6 or f/8) the light sources would have been softer and appeared a bit larger in the final image.
Ronan, an absolutely BEAUTIFUL photograph! i am a b&w addict… and this photo is just gorgeous! i am green with envy!