[Tired Old Man]

My legacy Tak M lens 135/2.4 & 50/1.2 with Pentax adapter ring will not focus at infinity on K-3.
I've tried AF Fine adjust in menu with not appreciable affect.
I configured spot AF with manual settings & can hear focus bell sound on distant subject in sunlight.
The kit zoom lens 18-135/3.5 does focus well at infinity, but I need the f2.4 on my Tak for gymnastic pics.
Please help with info if you can. I hope it's a procedure issue.

[Na Horuk]

Hey there! Maybe you can post a photo of the adapter or describe it a little? I think the problem is that the adapter you are using is flanged, and thus moves the lens simply too far from the sensor to reach infinity focus. You will not have this problem if you buy the genuine Pentax m42 adapter, or a flange-less knockoff (but again, these might be less than perfect, maybe even get stuck and so on). On these forums we usually recommend people buy the genuine adapter, its a worthwhile investment and is better quality than the knockoffs. You can buy a used one if you cannot find one from a store, as supplies of these adapters come and go.

[Adam]

I've tried AF Fine adjust in menu with not appreciable affect.

Those are for AF lenses. They have absolutely no effect on the focusing capabilities manual lenses.

As long as you have an adapter that supports infinity focusing (i.e. not one of the cheap ones with a protruding flange), you should be fine. Also, make sure the lens is screwed in tightly. This is what your adapter should look like. If it has a wider diameter on one side, you should replace it with the OEM adapter or a decent third-party adapter:



Are you able to get sharp images at infinity while focusing manually? If so, you should also be able to get focus confirmation, but bear in mind that there is always going to be a moderate degree of tolerance.

[Tired Old Man]

Thanks for your prompt replies. I'm still perplexed. Following is some more info on problem: can't focus at infinity.
I am using a PENTAX adapter (B&H $30.) that does not have extended flange, nor paint.
It looks identical to picture posted in your reply.
Embossed on adapter face are "PENTAX" and "Philippines".
I removed spring clip, and adapter sets slightly recessed into K-3 lens mount.
M42 Tak lens (f1.5/135mm full frame) screws firmly into adapter w/o play.
In Record menu, I set lens to 200mm (1.5x135), Manual exposure and Spot focus, Manual focus.
In optical viewfinder, the lens focus to a sharp image, but EV Preview shows slightly blur image.
I'm open to suggestions.

One post noted that menu: AF Fine Adjustment only applies to Auto lens - not manual lens like M42.

[Not a Number]

There's no need to remove the spring clip on the OEM Pentax adapters. I have two of the Philippines made ones and they install and remove from the camera mount without hitch.

When setting the focal length for manual focus lenses the recommended setting is to use the actual or next lowest length.

What is the history of the lenses? The previous owner may have adjusted the infinity focus setting to work on their camera.

[sterretje]

In Record menu, I set lens to 200mm (1.5x135)

Not related to your problem, but you should set it to 135mm (the actual focal length).

---------- Post added 13-02-15 at 06:26 ----------

I configured spot AF with manual settings & can hear focus bell sound on distant subject

The (PDAF) AF system has a range where it will indicate that a subject is in focus; you can easily experience this by (very slowly) slowly turning the focus ring till you hear the beep and next (very) slowly continue to turn the focus ring while observing the green hexagon. It will stay on for e.g. the first degree (or so) that you turn the focus ring.

It takes practice to find the exact point. If your camera supports live view, that can be an option to use. Alternative is to use a third party split prism screen (Katzeye, focusingscreen.com) or Canon EE screen; you might need to shim (calibrate) it.

[stevebrot]

In optical viewfinder, the lens focus to a sharp image, but EV Preview shows slightly blur image.

Image is optically sharp in viewfinder, but not on the captured image? (I don't know what EV preview is.)

Now a few notes:

• As noted above, there is no need to remove the spring clip from the genuine Pentax adapter
• While it is possible to use focus confirmation (green hexagon in the viewfinder using the AF system) with your Takumars, focus adjustment is not something you should be using with manual focus lenses. There is an explanation, but it is involved.
• Your optical viewfinder or live view are your manual focus options

Are you able to use live view to focus successfully?


Steve

[Lowell Goudge]

Some sample photos would be good. It's hard to judge what you consider as not sharp. Also when you say not focus to infinity, do you mean that when turned to the stop sign hey are out of focus, or when turned to the stop, the infinity mark is not lined up with the distance indicator on the lens, or do you mean infinity does not point straight up

The lens may have been played with or taken apart, and the focus collar misaligned, infinity focus readjusted for a flanged adaptor. Also note that witht he M42 adaptor it is not uncommon for lenses to sit a little off center.

One thing you can try, is with the lens set to infinity , slowly begin to focus closer while still pointing at a distant subject, does the image appear sharper? This would confirm focus reset for flanged adaptor.

Do the lenses work fine at closer distances?

Also, and not related to the issue at hand, but as others have pointed out there is no 135f2.4, or f1.5 as you have noted. And there is no M42 50mmF1.2 if you are reading these off the lens, they are not pentax lenses, or perhaps you are just mis typing?