Originally posted by 35mmfilmfan I intend to purchase a bottle of red wine tomorrow to facilitate the fine tuning of my lenses, having tried other methods with indifferent success. I look forward to revealing the results of my investigations. I may even mention how I get on with the lenses.
With all the interest being expressed in my "wine bottle autofocus tuning method"
I thought I would give a pictorial demonstration of it's capabilities.
These two pictures were taken with the K1 + DFA* 85mm at f1.4 from a distance of about 4 feet. Central single AF point used centred on the B of Beaujeu. The first was shot with the calibrated +7 I have set up for this lens. The second taken with the AF/FA turned off.
You can see the backfocus evident without any adjustment. If I was taking a close portrait shot at wide aperture the difference is glaring and would ruin the shot.
Because I know my K1 has backfocus without adjustment, this quick and easy method of using such a wine bottle label works well for me,
especially as I always have a steady supply of wine bottles to hand although I have to go to the store to get one