Hi all Discovered an apparent anomaly with regard to dirt on the sensor array in the Canon EOS1Ds. Been out shooting pretty pics of poppies growing in hedgerows today. At one point cloud obscured the sun so I paused...the cloud pattern was interesting as the sun tried to break through so I took a couple of frames then resumed shooting the flowers.
I knew there was some dirt present on the chip (isn't there always?) so having processed all images I looked at the sky shot first. As I expected the clear areas of blue exhibited black dust marks, most noticeable near the left and right sides of the sensor (which is where you sweep it when trying to clean the chip) with just a few in the middle. At 200% on screen some fifty plus clicks of the healing brush were required to render the image clinically clean. Then moved on to the flower pics. Any dust on the chip would be partially obscured in the foliage background however one picture is really interesting. Back-lit close-up of poppy with out of focus background. All of the background is totally out of focus green/yellow tones, similar to the sky in it's random nature but just a different colour range. There is not a single dust blemish anywhere on the image. No cleaning was required at all. This picture was taken with the same lens moments after the noticeably dirty sky picture. Most of the flower pictures (all close-ups with shallow depth of field and predominantly green) are virtually dust free. The sky picture (obviously mixed blue/grey tones and close to infinity focus) shows every spec of dust on the chip. Something I suspect related to depth of focus and possibly colour content at the array. Would councils wiser than myself care to comment? Regards -- Mark M Sykes Mark Sykes Photography =============================================================== GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE
