I appear to be getting a thin red outline around high contrast areas in some of my pictures such as tree branches against a light sky.

This is more than likely due to a phenomenon called ‘bleeding’ on your image sensor. This is where light from one pixel bleeds over to an adjacent pixel which is designed to detect a different colour. This is a disadvantage to Bayer type sensors and the result is a thin red outline around dark areas …

My front element is chipped.

Small chips are unlikely to make any difference to picture quality and therefore is generally not worth any further action. Larger chips may cause flair under certain lighting conditions. If you feel this may be the case please contact us.

I have an old Sigma 70-300mm lens which I gather needs ‘re-chipping’ to work on my new Canon digital SLR. Can this be done?

The majority of lenses we can rechip. However there are a few older lenses which we are unable to re-chip due to parts no longer being available. In order to answer your question, we need to determine which 70-300mm lens you have. If you look at the lens, is the Macro switch held on by …