Tuesday, 7 July 2009

Canon G9 – test of image quality after “Lens error, camera restart” incident

In my last posting I worked through what I did when my G9 suddenly experienced a “Lens error, camera restart” incident – go here for more details. At the time I did a quick image quality test to check that all was well. I have now done a more detailed test and here is my experience.

I am about to go away for a week and want to take a compact camera with me and the G9 would be ideal, but after the recent incident I was only willing to do this if I could convince myself that the image quality had not been impaired by the fairly robust treatment I had had to give the lens to get it working again.

In order to do this I decided to try to replicate an image that I took a few months ago that I was happy with and which had printed up well. This is an image of a window from my local church which has quite a lot of fine detail all over the image – the original image is below.

I looked up the original EXIF data to replicate it; this was ISO 80, f5.0 with aperture priority, auto focusing with a focal length of approximately 29mm.

This afternoon I set out to replicate the image, which is shown below.

Apart from it being a different season (there are leaves on the tree now), totally different light conditions and a slightly shorter focal length (25mm vs 29mm) the image above is good enough for my test.

I synchronised the settings in Lightroom so that the same settings that might affect image sharpness etc were used on both; such as clarity, contrast, vibrance, sharpening and noise reduction etc.

I have looked over the whole of both images and found that the image quality on the post incident image is as good as the earlier one – in fact it may be better… I have checked centre to edge and the two 100% extracts of the same part of the image below show that there is no loss of detail in the post incident image and the auto focusing is working fine.


The G9 is behaving itself again and its image quality is as good as it was beforehand, so I shall be taking it with me on the trip.