[mmbrombe]

Greetings,

I have recently purchased a Pentax K70, which I am enjoying tremendously. My previous camera was mirrorless so I never dealt with having to (or not having to) adjust lenses for focal accuracy (or whatever this procedure is called). I've read multiple articles regarding this topic and it seems that there are two extreme camps: Those who never bothered with this adjustment (and never had an issue), or those who absolutely, positively swear by it, whose lenses were all completely out of whack requiring significant tweaking. I'd like to hear from Pentax owners' experiences regarding this adjustment to see if I should invest the time and effort to try to investigate my lenses. By the way, I am no pro, I bought my K70 with the kit 18-135 and have purchased a 35mm 2.4 prime that I love. Will likely buy many more in the future. Thanks.

[UncleVanya]

Start by just taking shots. If you see some focus misses then see if you see anything consistent. So for example if you shoot at a wide open aperture and the eyes of your subject aren't quite as in focus as the ears... and this keeps happening and you are sure you put the focus mark over the eyes - you may need to adjust things.


That's my take.
Many opinions.

[Adam]

If you experience issues with focus/softness, that's when I'd start worrying about AF adjustments. Usually wide-aperture lenses are more picky than slower zooms.

[Keith23]

Used Pentax (four bodies; many lenses) for years and have never had a focus issue (except my own poor focusing skills with manual lenses). Just take photos!

[brightseal]

AF adjustments

What exactly is auto focus adjustment?

[Adam]

What exactly is auto focus adjustment?

See:
Fixing Front and Back Focus - Introduction - In-Depth Articles

[Kozlok]

HERE is an article on the forum about focus adjustment.

I adjusted most of my lenses, and found slightly better performance on my F4 and slower lenses, and noticeable improvement below F4. You only have 2 lenses, so shouldn't be much trouble. Note that I have used a proper focusing target, but in a pinch, I'll photograph a knot on a pine board that's about the same size as my focus target, and take the shot at a shallow angle. If I take 4 or 5 shots and compare them, if they all front or back focus, I adjust a bit until my keeper rate is 3 out of 4. No focus system is perfect. Go take 10 portraits of a friend at wide open, focusing on the eye. Compare all the shots, is the nose tip consistently better focused than the eye? The front of the ear? Do this when you're not trying to actually photograph something important so you don't feel the need to get the rest of the shot right. And also, do it in the light you plan on shooting in. Focus calibration is different for natural light vs. artificial.

[brightseal]

nevermind