Sigma 105 - aperture puzzle.

For some time I have been frustrated by the apparent overly shallow depth of field when photographing at 1:1. I dropped some of the worst shots into PhotoMe and found to my surprise that all of those taken using the lens aperture ring were shown to have been taken at f2.8. I had made a note of the (manual) aperture settings used and they ranged from f8 to f16...the camera would have been set on aperture priority. The lens seems to be working fine on the 'A' setting.

Am I doing something wrong?

I remember shortly after buying the lens, posting on the forum about my disappointment with the results obtained from this lens. I was persuaded that due to my lack of experience with macro photography I needed to try harder

Perhaps I need to look again at some of the earlier shots...

I am puzzled by this and would appreciate advice/comments.

When using the aperture ring the automatic functions of the camera stop to work so you need to work in manual and use the stop down metering (green button) to get the correct exposure.
Better to leave the lens just on A i think.

Thank you Stefan - on reflection I am sure you are right, why I thought there was any advantage to be gained by using the aperture ring I can't imagine.

Another senior moment I suspect

Roger