Saturday, July 2, 2011

Experimenting with Neutral Density filters

I purchased a neutral density filter that contains 8 stops within it just by adjusting the filter once it is screwed on the lens.  I did this after seeing and becoming very interested in the effects produced by being able to shoot at a longer shutter speed in daylight.  Often the shots of water at the ocean or streams are shot with an ND filter (graduated or not) to enable longer shutter speeds than possible without the filter. While you can get similar effects in post-production, who wants to spend all that time on the computer when you can do it in the field.
My subject for the experiment were flowers on the deck.  I kept the lens length the same (105mm), changed the f-stop and shutter speed to see what the camera would record.  Interestingly I had white balance set on Auto (where I normally shoot it), and all of the photos came out with a different temperature!  I also found that color noise was quite pronounced at f/22 at a 30 second shutter speed, not quite as noticeable at f/19; 30 sec; and non-existent at f/22 for both a 10 sec and a 15 sec exposure.  Additionally, the color shift was quite pronounced between the 15 sec and the 30 sec exposure at f/22.

Where does this all lead?  For me, I am learning.  I want to take longer exposure photos of landscapes with water in them, and the more I know about how the photos will probably turn out the better equipped I will be to get what I want in the camera.

Here's the photos so you also can see the difference - other than cropping, I've applied no alterations to them: Tomorrow I will post one of these after I have worked with it.

0.5 sec at f/6.7, ISO 200

10.0 sec at f/22, ISO 200

15.0 sec at f/22; ISO 200

20 sec at f/22; ISO 200 - why is this so dark when the 30 sec one below is lighter?

30 sec at f/22; ISO 200

30 sec at f/19; ISO 200

No comments: