[MarkJerling]

I just noticed something. When I stick a manual lens on, the camera automatically goes to centre AF point only.

Is that a setting? Or will the K-1 only use the centre AF point with a manual lens?

[Not a Number]

It works the same way with all the crop bodies too. AFIAK there is no way to change this. Probably has something to do with lack of the "data" pin and any associated lens info.

[MarkJerling]

It works the same way with all the crop bodies too. AFIAK there is no way to change this. Probably has something to do with lack of the "data" pin and any associated lens info.

Thank you! You know, I never noticed it on the K-5! I blame the new stunning viewfinder display in the K-1.

[BigMackCam]

It's the same on my non-Pentax gear too, Mark...

For what it's worth, live view (and zooming / moving the area in view) works well.

If you're going to use manual focus regularly with your lovely K-1II, I'd recommend considering an LCD loupe. I use an inexpensive Matin loupe on my K-3 / K-3II, and it works wonders for manual focusing. It almost gives the same benefits as a modern EVF (albeit with lower resolution), but still allows you to remove it and go back to pure OVF DSLR elegance

[MarkJerling]

It's the same on my non-Pentax gear too, Mark...

For what it's worth, live view (and zooming / moving the area in view) works well.

If you're going to use manual focus regularly with your lovely K-1II, I'd recommend considering an LCD loupe. I use an inexpensive Matin loupe on my K-3 / K-3II, and it works wonders for manual focusing. It almost gives the same benefits as a modern EVF (albeit with lower resolution), but still allows you to remove it and go back to pure OVF DSLR elegance

Thanks Mike. I use LV on tripod, but when walking around I find I get OK focus through the viewfinder.

I don't know why I never noticed that it's centre point only on the K-5 too....

[stevebrot]

It works the same way with all the crop bodies too. AFIAK there is no way to change this. Probably has something to do with lack of the "data" pin and any associated lens info.

What they said ^ ^ ^

Its been that way, pretty much forever. Why that is has never been clear to me. I would be curious to know if the same is true for the Irix lenses where manual focus is paired with a functional data pin.


Steve

[KX-Digital]

I just noticed something. When I stick a manual lens on, the camera automatically goes to centre AF point only.

Is that a setting? Or will the K-1 only use the centre AF point with a manual lens?

The only solution to that is inserting a focusing screen that is actually suitable for manual focussing (matt or ground glass with or without microprism's and/or split-image). Currently I have a Canon Ec-L in my K200d but my next d-slr will get an Ec-A. The Ec-B has a normal horizontal split image, the S-type is plain matt. For those who prefer Nikon screens there are the F6-A, F6-J and F6-L which have horizontal split image, microsprisms and diagonal split-image respectively. I got mine from focusingscreen.com but there are other suppliers some of which make their own screens instead of adapting other brands.

If i ever buy another brand d-slr it will most probably be because of the focusing screen. It has always surprised me how bad the screens of my Z-1 and K200d were for manual focussing. I recently was given a Minolta 300si and although it too is an autofocus camera the screen is perfectly usable for manual focussing, contrary to my AF-Pentaxes.

[leekil]

It works the same way with all the crop bodies too. AFIAK there is no way to change this. Probably has something to do with lack of the "data" pin and any associated lens info.

Why does it need the data pin? Isn't it just focusing using the light coming from the lens where the focus point is?

[Not a Number]

Why does it need the data pin? Isn't it just focusing using the light coming from the lens where the focus point is?

Pure speculation. What is the major difference on the mount of AF vs MF lenses other than the data pin (and screwdrive and/or zoom contacts)? Identifying the lens could allow the AF to better handle lens distortion.

@stevebrot brings up a way to test the hypothesis, given there is any lens correction data for the Irix lens(es).

[leekil]

Is there any technical reason why it wouldn't work with manual focus lenses? Or is it an intentional crippling of the AF functionality to promote use/purchase of more modern lenses.

[MarkJerling]

The only solution to that is inserting a focusing screen that is actually suitable for manual focussing (matt or ground glass with or without microprism's and/or split-image). Currently I have a Canon Ec-L in my K200d but my next d-slr will get an Ec-A. The Ec-B has a normal horizontal split image, the S-type is plain matt. For those who prefer Nikon screens there are the F6-A, F6-J and F6-L which have horizontal split image, microsprisms and diagonal split-image respectively. I got mine from focusingscreen.com but there are other suppliers some of which make their own screens instead of adapting other brands.

If i ever buy another brand d-slr it will most probably be because of the focusing screen. It has always surprised me how bad the screens of my Z-1 and K200d were for manual focussing. I recently was given a Minolta 300si and although it too is an autofocus camera the screen is perfectly usable for manual focussing, contrary to my AF-Pentaxes.

I'm OK with not having a traditional microprism or split image focus screen. I find I can focus perfectly well without it, although a bit tediously!

[Not a Number]

Is there any technical reason why it wouldn't work with manual focus lenses? Or is it an intentional crippling of the AF functionality to promote use/purchase of more modern lenses.

If that were the case it would simply be easier not to support MF lenses. Why even bother with stop-down metering and such. It would make the cameras a lot simpler and cheaper to produce.

As for the technical reasons I'm no optical or electrical engineer, lens or camera designer. Best to ask someone at Ricoh. All I can do is make wild speculations and accusations too.

BTW: I just attached my Vivitar 2× Macro Focusing TC with KA mount (no data pin) to some of my DA lenses. The AF point gets locked to center.

[stevebrot]

All I can do is make wild speculations and accusations too.

I will make a wild speculation...

• It is unlikely that there is a design or engineering rational for limiting focus confirmation to the center point with non-AF lenses
• Comprehensive support for multiple focus points and automated point selection exists for AF lenses in manual focus modes
• It has been about 14 years since Pentax dropped its last manual focus lenses (Pentax-A 15/3.5, Pentax-A* 400/2.8, and others(?) discontinued in 2004)
• Additional enhanced manual focus capabilities beyond AF-lens support is not required to support current lens offerings. In short, focus confirm is a convenience feature provided for users of pre-2004 legacy lenses.
• Focus confirmation represents the most basic level of PDAF support, though with the highest level of sensitivity using the center point. That is pretty decent, IMHO, for a convenience feature.
• Development and QA effort to support the single center point is minimal and easily justified
• Support for additional fixed points would result in multiple use cases per point requiring analysis and testing. This is not trivial and is not as easily justified. I could generate a few use and test cases to illustrate, but the exercise would probably not be worth the trouble. It is enough to say that all possible permutations of use and camera state must be tested separate from the similar AF cases.
• Focus confirmation (e.g. electronic rangefinder) features on other brands have similar limitations

Steve

* AF lenses support the full range of AF point options in manual focus mode.

[Not a Number]

^^^-- All that @stevebrot said

If the intent is to make you buy AF lenses you can still buy plenty of the plasticky FA lenses on the used market. How does Ricoh profit from that? Why even support the K-mount with all the legacy lenses on the used market. Drop the K-mount and make you buy all new lenses seems like a better strategy if that the intentions were nefarious.

BTW: As stevebrot notes when I switch my K10D to manual focus mode with a DA lens I am still able to select focus points. Chances are probably better than even that an Irix MF lens with functional data pin and chip will have selectable focus points.

[stevebrot]

Chances are probably better than even that an Irix MF lens with functional data pin and chip will have selectable focus points.

What is it they call that mount variant, KA2?