[Gian]

Hello All,

my K3-II is my fourth Pentax DSLR, and I always felt that my shots were a tad less sharp than I was used to in the old film days.

Ok, I am older now, and that could be taken in account.

I never went deep into the AF adjustment menu, and the other evening I wanted to test my Limited primes.

I used an aluminum ruler placed at 45 degrees, and was totally amazed to see how much they all were out of focus.

I had to set the 50 macro and the 70 to +10 (wasn't enough for the 70!), and the 15 and 21 to +5.

I wonder why the user manual doesn't state that AF tuning should be done OUT OF THE BOX.

If the feature is hidden deep inside the user manual, it's looks like something optional.

On the contrary, my experience shows that it is a fundamental process to perform, before you start taking pictures.

Too bad that I get it only now, after thousands of shots...

-Gian

[Pentax Syntax]

While I agree that the AF adjustment feature is not highlighted, it is not really buried. Many users not requiring the pin-point accuracy needed for macro may never touch this feature. In addition, there are numerous methods out there argued to be the "best" way to do the adjustment. By shooting the ruler, you have chosen a very useful method for macro photography where the depth of field is tiny and focus is critical. For a landscape photography, a different method might be better. Among the many shortcomings of the Pentax owners manuals, no guidelines exist for how to really do this adjustment. For anyone reading this thread, I would suggest that each photographer use this feature to optimize the AF function of any lens/body combination if it becomes necessary. Like you, I do it for all of my macro lenses and at the long end of zooms likely be used for macro. Thanks for bringing this issue up!

[Gian]

Depth of field and focus is also critical with portrait, and I was always disappointed by the 70 Limited.

Now I know why!

[Theov39]

While I agree that the AF adjustment feature is not highlighted, it is not really buried. Many users not requiring the pin-point accuracy needed for macro may never touch this feature. In addition, there are numerous methods out there argued to be the "best" way to do the adjustment. By shooting the ruler, you have chosen a very useful method for macro photography where the depth of field is tiny and focus is critical. For a landscape photography, a different method might be better. Among the many shortcomings of the Pentax owners manuals, no guidelines exist for how to really do this adjustment. For anyone reading this thread, I would suggest that each photographer use this feature to optimize the AF function of any lens/body combination if it becomes necessary. Like you, I do it for all of my macro lenses and at the long end of zooms likely be used for macro. Thanks for bringing this issue up!

Good advice but HOW do you adjust the AF?

[savoche]

Good advice but HOW do you adjust the AF?

You mean, which buttons to press? Or the whole methology involved for properly finding out if you need adjustments?

If the former, it's described in the manual (p.45 for K-3, p.47 for K-3 II). If the latter... I have seen lots of ways to do it, all depending on what you what to find out. I find the easiest being to place five AA/AAA batteries upright on a flat surface at a distance that makes sense to shoot at with that lens, placing the batteries on a diagonal with the left most one closest to the camera and the right most one furthest away, then focus on the one in the middle and see what you get.

Like this (image stolen from this forum thread at fredmiranda.com)

[Grimmus]

If you use the User settings on the mode dial, make sure to go through and save the AF Fine Adustment setting in the custom menu to each of the user modes you have set up....otherwise, somewhat surprisingly, settings will remain on the default each time you select the user setting again.

I was also surprised how much adjustment was required with all lenses needing +8 to +10.

[JimJohnson]

If you use the User settings on the mode dial, make sure to go through and save the AF Fine Adustment setting in the custom menu to each of the user modes you have set up....otherwise, somewhat surprisingly, settings will remain on the default each time you select the user setting again.

I was also surprised how much adjustment was required with all lenses needing +8 to +10.

Good tip - however, when ALL lens need that much AF correction and all in the same direction, I suspect your camera body needs some shop time.

[brightseal]

Too bad that I get it only now, after thousands of shots...

Don't feel bad, took me a year and 12,000 shots to get a clue. Thanks for the info.

[Prakticant]

Great advice, I did not notice that before

If you use the User settings on the mode dial, make sure to go through and save the AF Fine Adustment setting in the custom menu to each of the user modes you have set up....otherwise, somewhat surprisingly, settings will remain on the default each time you select the user setting again.

[TheOneAndOnlyJH]

If you use the User settings on the mode dial, make sure to go through and save the AF Fine Adustment setting in the custom menu to each of the user modes you have set up....otherwise, somewhat surprisingly, settings will remain on the default each time you select the user setting again.

I didn't think much of this before because I had done the AF adjustment before I set up my user modes but I remembered it when I calibrated a new lens/camera combination, so I thought I'd clarify on this a little.

The custom setting #26 AF Adjustment to Off / Apply All / Apply One is stored in the User modes, but individual lens adjustments made under "Apply One" are global. If you change the "Apply One" AF adjustment for a lens in any mode, the adjustment for that lens will also be changed in the U1, U2, U3 User modes when set to AF Adjustment - "Apply One".

Initially I thought this would be a great way to have different adjustments for my zoom lens that needs different correction at short and long ends, but it turns out that's not quite so simple. If one of the AF adjustments is near zero you could set one user mode to turn AF adjust off, but my lens needs something like +3 and +6, so it's not an option for me.