Sunday, 2 June 2013

Know Your Camera (Guernsey style)

Just starting to work through some of the pictures I took during my recent trip to Guernsey.  Much of the time was spent giving workshops, including the first full day when Ann and I ran a Know Your Camera day for beginners.  As part of that day I took a series of images to illustrate certain points, and I thought it was worth reproducing them here.

The first set shows just how much latitude is available in a RAW file.  I shot the same scene ranging from two stops underexposed to two stops overexposed, and then hit the "Auto" button on each within the RAW converter.  Apart from a small amount of shadow noise in the underexposed shots and a slight colour shift in the overexposed shots, there was precious little to choose between them.  In all cases the image on the left is the equivalent JPEG straight out of the camera, and the image on the right is the automatic conversion.  Talk about RAW being the ultimate Get out of jail free card...

Another sequence attempted to demonstrate the difference between images which are unsharp due to poor focusing and those where there had been camera movement - usually because of too slow a shutter speed.  It's amazing how many people cannot distinguish between the two when shown a picture which is "soft".

The final illustration was to show the effects of Image Stabilisation.  In the example below, the same shot was taken hand-held at 1/15s with a 200mm lens, with and without IS.  The left hand image, without Image Stabilisation, unsurprisingly shows large amounts of camera shake - despite attempting to hold the lens as still as possible.  The right hand image shows the effect of the turning on Image Stabilisation on the lens - absolutely astonishing, as the image was critically sharp even at 100%.  The manufacturers claim 4 stops for the modern IS systems, and my rough experiment seems to back this up.