Nikon D4, Sigma 120-300mm ƒ/2.8 DG OS HSM S, ISO 12800, ƒ/4, 1/2000

As we get older, we need to go to the eye doctor. People ages 20 to 30 should have an eye exam every two years unless visual changes, pain, flashes of light, new floaters, injury, or tearing occurs. Then, immediate care is necessary.

Yearly exams become essential in the late thirties when changes in vision and focus, along with eye diseases, are more likely to develop.

Your camera lenses are probably less likely to change in focus just from aging alone, but heavy use will affect the lenses.

After getting my new Nikon D750, I calibrated the lenses I own to the camera. I also decided to check one lens before the big Chick-fil-A Peach Bowl game on New Year’s Eve.

Just to remind you, anything in front or behind the book should be slightly out of focus. However, if the points in front or slightly behind are sharper than the book cover, this is when you need to make adjustments either to the lens or the camera fine-tune focus adjustments.

The Sigma 120-300mm ƒ/2.8 DG OS HSM S can be fine-tuned and calibrated for 16 different focus points using the USB dock and software you put on your computer.

This USB dock also lets you update the firmware on the lens.

So I took a couple of hours to shoot, make adjustments and then reshoot targets to get the lens in focus.

I then check all the cameras again with the camera.

Just like you need to see an eye doctor to adjust your prescription, take the time, check out your camera, and fine-tune focus the lenses. You will be surprised as to how sharp your lenses really can be.