Thursday 24 May 2012

Project 12: contrast and exposure

I think that the aim of this project is to examine the dynamic range of black and white and transparency film.  I remember the problems well from my film days but today, using digital cameras and raw capture it is not such a problem.  I think that digital cameras cope much better with high dynamic ranges anyway and raw conversion software enables us to compensate during post processing.  I use Adobe Lightroom where I am able to adjust the exposure and recover highlights as well as adding some fill light and recover the detail in the shadows.  It also enables me to adjust the brightness and contrast as well as the option of a built in ND grad to selectively reduce the exposure in the sky and recover detail.

For this project I selected an area of my local Nature reserve where an open area led into a woodland path providing areas of bright light and deep shadow.  I placed the camera on the tripod and set the expusre meter to spot metering mode.  I then took a reading from the shadow area which gave a reading of 1/25 @ f16.  The brightly lit grass gave a reading of 1/125 @ f16.  I then worked out the mid-range exposure at 1/60 @ f16.  I took two shots at this setting one black and white and one colour.  I gave them no post processing other than convert them to JPEGS. They are illustrated below.

 According to the histogram in Lightroom both images are slightly underexposed.  The sunlit area seems to me to be perfectly acceptable but both lack detail in the shadows.  At the time my eyes were able to see more detail in the shadows than the images show.  As the course notes suggest there does seem to be slightly more detail in the B&W image although, of course we are not looking at a negative.  It is marginal though.




This is my post processed colour image.  I have increased the exposure by half a stop and added some fill light to bring out the detail in the shadows.  I have also adjusted the blacks to help with this.  Finally I adjusted the colour temperature to warm the image up slightly.

No comments:

Post a Comment