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10-25-2014, 06:22 AM   #16
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I use a DA 15-50. A bit heavy but covers all my needs when I don't need to go into macro or tele so it is my all around lens.

I don't understand how this could harm the lens. Off course if I turned the focus wheel when also having the AF work could be bad,but why would anyone do that?

This problem is rare, but not very rare. I can't figure out what situation it happens in so I can not trigger the fault for error checking.

When it does happen, the image in the view finder is visibly out of focus, and still the camera don't AF. No hexagon in the view finder at those times.

10-25-2014, 07:31 PM   #17
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QuoteOriginally posted by FilipWessman Quote
I use a DA 15-50. A bit heavy but covers all my needs when I don't need to go into macro or tele so it is my all around lens.

I don't understand how this could harm the lens.
I assume you mean the DA* 16-50/2.8. That lens has quick shift and the rules are somewhat different. If you are using quick shift to defocus, it would appear that the image was already in focus so there was nothing to do. That is why I asked if you have a green hexagon.

QuoteOriginally posted by FilipWessman Quote
but why would anyone do that?
Good question, though every once in awhile somebody complains that it is too hard to overcome to manually focus when AF is turned on. Go figure...

QuoteOriginally posted by FilipWessman Quote
When it does happen, the image in the view finder is visibly out of focus, and still the camera don't AF. No hexagon in the view finder at those times.
Now we are getting somewhere! Is your lens still on warranty? It is possible that your SDM motor is having problems.


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10-26-2014, 01:32 AM   #18
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I have owned it for more than 2 years. Warranty depends on what the documentation of my purchase says. I guess I may have to dig it up from somewhere.

This problem is of the kind I really do not like, it happens so rarely I cant test things to figure out what is wrong, but still often enough to be a problem.
11-08-2014, 12:13 PM   #19
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Try if lens is working on live mode. I had similar issue with my 17-70 sdm lens. It's vierd cuz it works ok in live view but in normal mode it refuse to auto focus.

11-09-2014, 10:45 AM   #20
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K-3 autofocus is tricky

K3 autofocus is tricky this is my case:

Precision about my last post.

1st it is a big difference between the functionning of phase detection autofocus and constrast autofocus (using live view) , the contrast autofocus is very sharp and quick that is not the case with phase detection autofocus.

2nd If tried to calibrate the autofocus for my Sigma 30mm f1.4 lens, I can not find a setting for phase autofocus, but with contrast autofocus in live view focus is sharp and fast. The version of this lens I own, use the body motor to focus, not the HSM!

3th With my Pentax lens DA* 50-135mm f2.8 focus is sharp but slower in phase than in contrast mode ?

4th with my Pentax lenses 17-70mm f4 and DA* 16-50mm f2.8 same thing but phase focus do not work near the longer focal length (70mm for first and 50mm for second), the focus is also not very sharp.

5th focussing with my Pentax 15mm f4 prime lens has problem.

This case is very disapointing because my older pentax camera do not have these problems. I do a lot of show photos and the live view isn't a way acceptable to shoot shows.

If Ricoh-Pentax can produce a firmware update that will correct these auto focus problems it will be a great advance for ricoh-pentax users

Mario Groleau
11-09-2014, 11:30 AM   #21
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QuoteOriginally posted by mario_tr Quote
K3 autofocus is tricky this is my case:

Precision about my last post.

1st it is a big difference between the functionning of phase detection autofocus and constrast autofocus (using live view) , the contrast autofocus is very sharp and quick that is not the case with phase detection autofocus.

2nd If tried to calibrate the autofocus for my Sigma 30mm f1.4 lens, I can not find a setting for phase autofocus, but with contrast autofocus in live view focus is sharp and fast. The version of this lens I own, use the body motor to focus, not the HSM!

3th With my Pentax lens DA* 50-135mm f2.8 focus is sharp but slower in phase than in contrast mode ?

4th with my Pentax lenses 17-70mm f4 and DA* 16-50mm f2.8 same thing but phase focus do not work near the longer focal length (70mm for first and 50mm for second), the focus is also not very sharp.

5th focussing with my Pentax 15mm f4 prime lens has problem.

This case is very disapointing because my older pentax camera do not have these problems. I do a lot of show photos and the live view isn't a way acceptable to shoot shows.

If Ricoh-Pentax can produce a firmware update that will correct these auto focus problems it will be a great advance for ricoh-pentax users

Mario Groleau
I think most here will tell you phase detect AF is faster. Have you tried the AF micro-adjustment routine to see if you can improve the sharpness?
11-10-2014, 04:55 AM   #22
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QuoteOriginally posted by IchabodCrane Quote
I think most here will tell you phase detect AF is faster. Have you tried the AF micro-adjustment routine to see if you can improve the sharpness?
Oh Yes, I passed many time to try this option with the Sigma 30mm f1.4 a great lens I own since many years, The surprise was to find that the micro-adjustment was not constant, sometime the result was back focus sometime it was front focus, but with the live view focus, the focus was already ok.

Thank you for your post.
11-10-2014, 05:37 AM   #23
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I am sure that most of the posters in this thread are aware of what I am about to point out but, just in case. Phase detect auto focus is faster but often less accurate than contrast detect autofocus. Phase detect can get out of alignment with different lenses and lead to front and back focus problems. Contrast detect does not have that issue, at least not as severely. Sony attempted to use both systems by incorporating phase detection into its sensors. As I understand it the camera would use phase detection to get the focus close so that contrast detection could then fine tune the focus. With the A6000 this system had become almost as fast as DSLR phase detection.

11-11-2014, 03:03 AM   #24
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For the OP I have a DA*50-135 that focuses just fine with a K-3. Did you determine if perhaps the SDM system may be at fault?
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