Pentax K-m: Manual focus lenses

Using old manual focus lenses with the Pentax K-m is rather difficult compared to modern mirrorless cameras.

1. It is very difficult to focus accurately through the optical viewfinder. It was not an easy task even with the Pentax *ist Ds/K10D, while the viewfinder of the Pentax K-m is even worse (it is pentamirror and has lower magnification). And, of course, there is no Live View.

2. There is a focus indicator, but it is slow and inaccurate. It is confusing and distracting.

3. The Pentax K-m with Pentax K/M-series lenses in the Av mode only shoots with the aperture wide open (it doesn't even try to close the aperture). It is like all Pentax DSLRs.

4. For other aperture values, you should use the M mode. You can force the shutter speed to be set automatically by pressing the Av button. Then the camera briefly closes the aperture to meter the light.

5. A disadvantage of using the M mode is that AutoISO is disabled. You should select ISO manually.

6. AutoISO works in the Av mode, but with lenses that don't transmit the focal length (including A-series lenses and all non-electronic lenses), the longest shutter speed is always limited to 1/125. I would prefer a longer shutter speed for wide angle lenses (especially with SR), but there is no way to change this limit.

7. The good thing is that Shake Reduction (SR) works with all lenses. Of course, you should choose the focal length. A dialog appears when the camera is turned on (or you can call it up from the menu). And in my opinion, SR of the K-m is more effective and useful than SR of the K10D (which I really disliked because it ruined images).

After the Sony a7c (where I don't have any problems with manual focus and AutoISO), I am very disappointed with the Pentax K-m.

Now I understand why I shot a lot with the average DA 18-55/3.5-5.6 AL (first version) on the K10D, even though my Pentax K/M/A series lenses are much better (and I can see it on old photos). Just because of the autofocus. The DA 18-55/3.5-5.6, the DA 14/2.8 (which is too wide for universal use), and the F 35-80/4-5.6 were the only Pentax autofocus lenses I owned.

In general, I dislike DSLRs with their optical viewfinders and overly complicated designs. And of course, many interesting lenses cannot be used with DSLRs because of their long flange focal lengths. That's why I didn't buy the Pentax K-1. I prefer mirrorless cameras for manual focus lenses.

Now I only have one autofocus lens for my Sony a7. And I do not use it very often.

See also related notes:

• "Zoom View Finder 1.08-1.60x": Using for the Pentax K-m (2024-08-20)
• "Zoom View Finder 1.08-1.60x" magnifier. (2024-04-11)
• Pentax DA L 18-55/3.5-5.6 (K) (2024-02-15)