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Terry Lovejoy | profile | all galleries >> DSLR's For Astrophotography - Tech Notes >> The 300D filter Modification >> Modified 300D and daylight Photography >> Adjusting AF tree view | thumbnails | slideshow

Adjusting AF

The replacement of the standard Canon IRcut/AA filter with the Baader high transmission IR/UV cut filter caused the focal plane to move forward. This was because the Baader filter is about 70% the thickness of the standard filter. Anticipating this the existing shims under the CMOS were removed during the filter replacement which also moved the CMOS 0.2mm forward.

The removal of the shims was still not enough to fully correct Autofocus, but by adjusting the AF screw at the rear of the shutter compartment autofocus is now spot on.

Please note that some people have reported that the screw cannot be turned and is locked. I will investigate this further....
Autofocus Fixed!
Autofocus Fixed!