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12-01-2022, 05:11 PM - 1 Like   #1
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Focus Issues :( Particularly with screwdrive lenses.

I just received a k-3 iii, and it has focus issues. Out of the box, I took the lens off my k-5 iis, in a dark room (dim light at night). The new camera hunted and failed to lock about twice as much as the k-5. This is w/ my old DA limited screw drive lenses, and newer lenses. The k-5 is always faster and more often locks.
Then today I took some shots to check for focus, and they are not in focus, with screw drive lenses. I bought a couple new lenses, the 55mm DA*, and the new 11-18mm DA*, which have motors. They are better... Not perfect.. I need a better setup to fix them. My screw drive lenses, however are really bad. They all need -7 in the focus fine adjustment. They all seem to be the same. While on my k-5, they're perfect w/out any adjustment.

My current setup for testing isn't great.. I need to get a sturdier tripod and stand for the target. And more light.. But w/ my rough setup today, it's obvious there's an issue.
Is it acceptable for a new camera to be off by -7? I mean.. they do say they give us that adjustment for people who want sharper focus than they check for in the factory. But it's obviously a body issue, since all screw drive lenses are the same.


I had a bad experience w/ a k-7.. Thought it was bad.. but occasionally had a good shot. I was new, and kept blaming myself. Warranty expired.. Then I had a chance to try a different camera, and it was obvious, I had a bad k-7 the entire time. Then I got the k-5 which was perfect out of the box. Now this new one, which was much more expensive.. Is supposed to have a better focus system.. And it's not as good as my old camera. I don't want to be stuck w/ a bad one again!!



What do you all think? Is it OK to need to adjust a new camera like this to get focus, or should I send it back? (Hate expensive internet purchases like this, but no local stores here sell Pentax).

12-01-2022, 05:33 PM   #2
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k3 iii much faster with da screw drive lenses compare to any modern Pentax cameras KP , K3 II by my experience .
when ALL LENSES require -7 fine adjustment it's something wrong with camera

Quick tip .
first update to the latest firmware .
Put camera on tripod in live view ( AFS - Spot ) and focus in something precise and wait for a focus confirmation but don't fire , after the focus confirm switch to OVF if you push the shutter release button and hear the focus confirmation
it's mean nothing wrong with your camera .
12-01-2022, 06:19 PM   #3
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QuoteOriginally posted by nixxo2002 Quote
k3 iii much faster with da screw drive lenses compare to any modern Pentax cameras KP , K3 II by my experience .
when ALL LENSES require -7 fine adjustment it's something wrong with camera

Quick tip .
first update to the latest firmware .
Put camera on tripod in live view ( AFS - Spot ) and focus in something precise and wait for a focus confirmation but don't fire , after the focus confirm switch to OVF if you push the shutter release button and hear the focus confirmation
it's mean nothing wrong with your camera .

When I put the lens adjustment at 0, I hear the motor for a split second when switching between live view and optical. When it's at -7, it seems to be on target.. But the live view photo still looks better.
12-01-2022, 07:03 PM   #4
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live view and ovf using different focusing systems . in live view focus 99.9% accurate .
did you update firmware ?

12-01-2022, 07:20 PM   #5
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Yes, I updated the firmware as soon as I unboxed it.

If any others are having similar issue w/ screw lenses, let me know..

The focus is hit or miss, too... from the same spot, on a tripod, on the same subject, one will be in focus, the next won't.

And the best shots aren't as sharp as my k-5... Is this sensor less sharp in general?

I did see this thread:

Comparison K5IIs & K3III: Pentax SLR Talk Forum: Digital Photography Review

unfortunately, his k-5 shots are better, too.. I was hoping it was an issue particular to him, but mine is quite similar. On his pics, if you zoom in on the power pole, you can see details on the k-5 image, which are not visible on the k-3.. I take technical macro photos, where zooming to see details is important.


Mirror shake seems to be worse than the k-5, too.. All the shots had motion blur, when the cam is mounted on my best sturdiest tripod, unless I use the electronic shutter.. (but then other features are disabled, like anti-shake if I'm shooting by hand). It is a lowish light situation here, and my shots are about 1/60 which isn't ideal for mirror shake. But the point is, the k-3iii is much worse than the k-5 iis.

---------- Post added 12-01-22 at 09:20 PM ----------

Well...
I had time to do some more testing.. They aren't all -7.. All my screw lenses are negative, but range from -1 to -9.. .. (-1, -7, -6 -9). And my two motor lenses are +1 and +4. I'm using an angled focus chart.
but what is strange, is all of them are perfect on my k-5! Same exact setup. On the k-5 w/ no adjustments, the focus is right in the middle.
Does this make sense for any reason? (I'm sort of expecting to do it again tomorrow, and find different results.. Which is what my old k-7 did..)
12-01-2022, 08:36 PM - 1 Like   #6
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send it back
12-01-2022, 09:49 PM   #7
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Shutter shock could be involved in the lack of sharpness. Try a much slower and much faster shutter speed. As for the adjustment- until you are clear about shutter shock I’d wait to fine tune them. Make sure it’s in good light.

12-01-2022, 10:49 PM   #8
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QuoteOriginally posted by ramseybuckeye Quote
send it back
Yeah, maybe so.. I checked, and they have a no questions exchange/return policy. Guess I should start w/ an exchange to see if it has the same issues. I'm afraid it might end up as a return, tho.. after reading through some other posts from technical people. (people using their photos for technical things where they need sharp focus zoomed in)

(off topic, but I don't want to only complain.. the new lenses are great! (DA* 11-18mm and DA* 55mm). Although the 11-18 is huge! I laughed when I opened it.(my other lenses are all prime DA limited (and old film manual lenses I rarely use)))

Last edited by wicked1; 12-01-2022 at 11:14 PM.
12-01-2022, 11:05 PM   #9
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There are lots of stack up tolerances involved especially so when some of our lenses are very old.
Lens/camera flange thickness, lens focus limiter tolerances, AF module tolerances, etc...
We don't even know if Pentax still keeps the same golden unit for checking/establish these tolerances in the factory.

I've seen this need for adjustment (and even for my MF lenses) when I moved from K7, K5, K30, K1
The K3iii is supposed to be better for AF, but that does not mean lenses built in 2000 is to the exact match to the camera tolerance.
In many ways, the camera is 'within spec' since it can AF adjust to your lenses. (I have some that even a +/-10 won't work, but works fine on my K5/K30 )
I've also had some lenses don't AF well on my K1, but no issues on my brother's K1.


Try to send back the camera and see if a new one works better, but imho, its hard to totally fault the camera.
Its just the nature of things with new cameras and old/er lenses. (unless its CDAF or hybrid AF )
12-02-2022, 05:33 AM - 1 Like   #10
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I had this with my K-3 Mark III as well. Whatever I tried, I felt it was not as sharp as my KP. I made pictures of the same outdoor scene with one lens and changed bodies. The KP gave the better results and was quicker in focusing. I explained it to the seller and I returned the kit to them. It was send to Ricoh and they refunded the seller and the seller refunded me. So I lost my K-3 Mark III kit with 18-135.... They could get a new one and but could not offer it me for the same price I had payed just weeks before.
As for the K-7 I had sort of the same experience as Wicked1, till I found out that worked fine when in (very) good light. Indoors not such good results, but outdoors not a problem as long as the light was good.
12-02-2022, 07:12 AM   #11
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For what it’s worth my own experience with focus fine tuning on 6 different Pentax bodies and 25+ lenses is that focus adjustments of up to +-10 are not uncommon. What is unlikely is for all your lenses to need the same adjustment or no adjustment at all on your K5. That is very suspect to me and while there may very well be something wrong with your K3iii there is almost certainly something wrong in your focus adjustments. Every lens to body pairing has 2 completely unique metal surfaces pressed together not to mention that the position of the elements is never perfectly precise inside each lens. That combination means that yes it is entirely possible, in fact likely, for lenses on a new camera body to need -7 adjustment. I found that with careful tuning I can get consistent results even at F1.4 though all my screw drive lenses are less consistent than all my dc/sdm lenses.
12-02-2022, 07:45 AM   #12
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The focus adjustment is done to make up for inconsistencies in lenses and camera bodies. If it's doing that, the camera is functioning properly. If you had a lens you couldn't adjust for, I'd be worried. That's when you send the camera back. That you can adjust the camera so the lens works properly is a sign everything is working pretty much as designed. It's when you get a lens that goes beyond those parameters that you need to worry.
12-02-2022, 08:00 AM   #13
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QuoteOriginally posted by normhead Quote
The focus adjustment is done to make up for inconsistencies in lenses and camera bodies. If it's doing that, the camera is functioning properly. If you had a lens you couldn't adjust for, I'd be worried. That's when you send the camera back. That you can adjust the camera so the lens works properly is a sign everything is working pretty much as designed. It's when you get a lens that goes beyond those parameters that you need to worry.
A few caveats…

1) it seems that despite tuning the results aren’t that sharp compared to the older models this user owns.

2) it also seems that the af tuning results are inconsistent; this suggests that either the method of tuning isn’t working, or the camera isn’t focusing consistently. If all of the lenses are using no af fine adjustment on one camera (effectively a 0 adjustment); if these same lenses need many different adjustments on another camera, that suggests inconsistent af - although if comparing a 16mp to a 26mp a need to bear in mind the enhanced detail may allow fine evaluation of focus due to enhanced detail captured.
12-02-2022, 08:18 AM   #14
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QuoteOriginally posted by UncleVanya Quote
although if comparing a 16mp to a 26mp a need to bear in mind the enhanced detail may allow fine evaluation of focus due to enhanced detail captured.
Thanks, you understand the situation. But... There is less detail in even the best 26mp images, than the 16mp ones. Basically, I'm taking photos in my house at the moment. On the k-5, I can see the grain detail in my wood chairs on the other side of the room, when zoomed all the way into the image. (I'm going to 200% zoom). Even with perfect focus, the k-3iii images are missing this detail.. It's just smooth brown. (I am looking at the raw images on a computer.. not jpegs on the camera)(I am shooting manual. Same settings on both camera. Same lens I'm swapping back and forth. Same tripod).

This is admittedly an extreme situation, and people aren't generally looking at photos this way.. But like I've been saying.. The point is, this camera is supposed to be better.. it is not. I'm sure it's fine for 98% of people just taking shots of one subject which fills the screen. But if you have a need to zoom in and have sharp details.. it's not working. And why make excuses for Pentax. If this is their flagship camera (for this sensor size), it should take clear, sharp images.. It shouldn't be a step backwards from my 10+ year old camera. I was kind of hoping a bunch of people would say no, theirs are sharp as a tack, and show me super clear examples, etc.. But the more I dig in here and other forums, all the people w/ high image quality demands are having similar complaints. Maybe the focus on this one I've got is truly broken.. But I think even w/ perfect focus, this camera sensor is not as sharp as its predecessors.


Well.. I'll have time for a few more tests this afternoon... Then got to decide if I exchange it, or just send it back for refund.
12-02-2022, 08:39 AM   #15
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QuoteOriginally posted by wicked1 Quote
I was kind of hoping a bunch of people would say no, theirs are sharp as a tack, and show me super clear examples, etc.. But the more I dig in here and other forums, all the people w/ high image quality demands are having similar complaints. Maybe the focus on this one I've got is truly broken.. But I think even w/ perfect focus, this camera sensor is not as sharp as its predecessors.
You've posted this thread in the wrong subforum which may be why K3III users aren't answering. I'll move it for you.

FWIW I get exceptionally nice results, more dynamic range, better low-light performance, and faster focus lock on my K3III than on my K70. I had a KP previously that as I recall was not giving me sharper results than the K70 so I'd consider them comparable for this discussion. It's been a long time since I had the K5II so I have nothing to compare to there.

Bonus: the K3III drives the lens SDM motor with more authority and quite to my surprise resurrected a DA*55 that the SDM has died on, or so I had thought it died.
Now that said, I have found a need to fine-focus lenses on the K3III that had not been needed on previous Pentax bodies, or at least hadn't noted a need to. In my own use, the new Pentax seems less tolerant of imprecise lens calibration.

Last edited by gatorguy; 12-02-2022 at 10:10 AM.
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