Focus Checking

I'm often frustrated by the lack of focus sharpness when I use the 500mm lens. I am sure a lot of it is down to my technique but when I saw a Spyder Lenscal tool for sale at a good price I decided to invest.

These are my first test shots. Admittedly the light could have been better (the ISO and slow shutter speed atest to that), but I think it indicates the narrow margins of success when shooting wide open with a long telephoto.

The lens was set on a tripod and locked down as best as possible. I used a remote release and the mirror up setting. The target was 4.5 metres away. I used single centre auto focus on the centre of the large squares and tried to make sur the target was parallel to the plane of the sensor.

p.s. You may have noticed that this is yet another way of saying, emergency blip!