Thursday, 26 November 2009

Project 49: Graduated Filters

This project had to be shot on an overcast day. There's plenty of those at the moment, but I chose to go to Cramond on Sunday (see previous post), and took a couple of photos with and without the graduated neutral density filter on. These sort of shots are very difficult to execute I find, and it appears that the foreground is a bit dark in the shot with the filter on, which is because I don't have one with a solid line, but instead its graduated from top to bottom. As a result these seascape type photos with a strong horizon present are harder get right. Anyway, the second photo is certainly more balanced and the sky much more interesting as a result of the filter.

The second lot of photos (apologies for the out of focus photo - the light all disappeared by the time I realised, but the effect is still there) are taken inside to show the effect of using a nd filter to balance the light from the window. It's not _really_ obvious in this case, but I do get the gist. Can anyone help me with why the nd is giving the colour cast in the indoor shots? The only light should have been coming in from outside, same in both photos...

Photo 1: No Filters used
40mm, f/11, 1/8sec, ISO200, tripod

Photo 2: Graduated Neutral Density Filter fitted
40mm, f/11, 1/8sec, ISO200, tripod, grad neut density filter

Photo 3: No Filters used
24mm, f/2.8, 1/4sec, ISO640, tripod

Photo 4: Graduated Neutral Density Filter fitted sideways
24mm, f/2.8, 1sec, ISO640, tripod

2 comments:

  1. Re "Can anyone help me with why the nd is giving the colour cast in the indoor shots?"

    In theory neutral should mean neutral so no colour shift but clearly there is more red when using the ND filter in this second shot.

    This may be down to the quality of the filter used. Not sure what you used but Cokin and Hoya tend to be associated with this issue. Lee and Singh-Ray seem to be better at not doing this.

    This should not be too difficult to fix in post processing by adjusting the colour balance if shooting RAW else make a level adjustment for the reds.

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  2. You know about ND grads but for other readers this post may be of some interest:

    http://astbury.blogspot.com/2009/10/landscape-project-34.html

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