I have just gotten back from a fantastic week away in Margaret River, in the south west of Australia. All in all I had a fantastic trip, in which despite some terrible weather I was able to get some pictures that I am really happy with!!!!
However I was going through some of my pictures when I noticed this............
Bloody Catastrophe! All my long exposure mages are contaminated with this awful pink and green noise. I was attempting to use a long exposure type shot in bright sunlight, in this instance using a 10-stop ND filter to achieve a slight bit of blur in the fast moving water.I was using a shutter speed of around 5 seconds-ish for these shots and for some reason all this noise is present.
So why am I getting this noise?
Light leak! This is a very strange and uncommon effect, where light enters the camera through the viewfinder and contaminates the image by adding unwanted light noise to the sensor. Although the mirror will flip up whilst the image is being taken, some light, just like water or dust, will find its way into the camera body and spoil the image.
Normally this wouldn't be an issue, as a typical photographic exposure lasts anywhere from 1/50 to 1/1000 of a second this light contamination is so minimal it cant be noticed. However when using a 5 second exposure, the effect is amplified significantly. This is an issue I had read about before but never experienced in the field, likely because most of my long exposures in the past have been in the afternoon/ night time where background light is low, as opposed to these images take in glaring sunlight.
So how do we fix it?
Well it's very simple really. We need to ensure that if we are taking long exposure images in bright daylight, on in a situation where we run the risk of light leak we need to make sure that the eye hole is covered. This can be achieved with a thumb, some duct tape or a little handy piece of plastic that slots over the viewfinder. Anything that prevents light from entering the camera should work, just try and keep something like that handy in your kit bag next time you venture out!
Another way that would appear to work, is to convert the affected image to black and white as the colour cast is not then relevant...............
Anyway, all the best till next time.