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Thread: Pentax K-5 Auto focus... hmmm...

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    Pentax K-5 Auto focus... hmmm...

    I find the AF of the Pentax puzzling so far. Seems like a firmware patch must be coming up. I have been able to autofocus fairly fast on some difficult subjects and "it gets it" but something as simple as a parking sign seems slightly out of focus (DA70 at 2.4).

    I tried the lens adjustment and whatI have found is that some subjects seem spot on with no correction but a few then go one way or the other. Seems like say a parking sign with red letters like "No Parking" with Parking hours in letters and words will benefit from an adjust, but some other subjects are spot on. I tried using another AF point and it was similar.

    The live view AF is pretty spot on. I can focus using manual focus it seems often (which is good since I find virtually all digital SLR's here as not very good using the OVF).

    I still don't quite understand, but the focus seems really good for some truly difficult subjects and on some basic stuff it can go off the wrong way.

    Seems like Autofocus has been for many brands an issue (phase detection). in different ways. I understand Pentax is working on a firmware update for Tungsten light, as it as found by Pentaxeros I think it is, that 25 bodies had the same problem. in tungsten.

    - Raist

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    Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by raist3d View Post
    I find the AF of the Pentax puzzling so far. Seems like a firmware patch must be coming up. I have been able to autofocus fairly fast on some difficult subjects and "it gets it" but something as simple as a parking sign seems slightly out of focus (DA70 at 2.4).

    I tried the lens adjustment and whatI have found is that some subjects seem spot on with no correction but a few then go one way or the other. Seems like say a parking sign with red letters like "No Parking" with Parking hours in letters and words will benefit from an adjust, but some other subjects are spot on. I tried using another AF point and it was similar.

    The live view AF is pretty spot on. I can focus using manual focus it seems often (which is good since I find virtually all digital SLR's here as not very good using the OVF).

    I still don't quite understand, but the focus seems really good for some truly difficult subjects and on some basic stuff it can go off the wrong way.

    Seems like Autofocus has been for many brands an issue (phase detection). in different ways. I understand Pentax is working on a firmware update for Tungsten light, as it as found by Pentaxeros I think it is, that 25 bodies had the same problem. in tungsten.

    - Raist
    I owned a K10D in 2006 and experienced much the same problem with both zooms and primes. The 43/1.9 was a fabulous lens but the inconsistent focus drove me to drink. It's surprising to learn that Pentax's AF system is still afflicted by poor focus consistency some 5 years later. My K10D was calibrated twice by CR Kennedy (the Australian Pentax distributor) but it never came good. The K5 is definitely on my radar and I'm keen to see how this focus issue pans out if/when a FW update is released.

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    Workshop Member ptomsu's Avatar
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    Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by raist3d View Post
    I find the AF of the Pentax puzzling so far. Seems like a firmware patch must be coming up. I have been able to autofocus fairly fast on some difficult subjects and "it gets it" but something as simple as a parking sign seems slightly out of focus (DA70 at 2.4).

    I tried the lens adjustment and whatI have found is that some subjects seem spot on with no correction but a few then go one way or the other. Seems like say a parking sign with red letters like "No Parking" with Parking hours in letters and words will benefit from an adjust, but some other subjects are spot on. I tried using another AF point and it was similar.

    The live view AF is pretty spot on. I can focus using manual focus it seems often (which is good since I find virtually all digital SLR's here as not very good using the OVF).

    I still don't quite understand, but the focus seems really good for some truly difficult subjects and on some basic stuff it can go off the wrong way.

    Seems like Autofocus has been for many brands an issue (phase detection). in different ways. I understand Pentax is working on a firmware update for Tungsten light, as it as found by Pentaxeros I think it is, that 25 bodies had the same problem. in tungsten.

    - Raist
    You seem to be exactly where I have been a week ago

    I could not rely on that AF, it was not even just in low light, or Tungsten Light, it was in general unreliable. Sometimes focus spot on, sometimes just miles away.

    I finally was not willing to fool around with that, as I do not want to adjust to a camera's flaws but rather to work with it flawlessly! It reminded me very much on my issues I had with the Olympus E3 - was also AF not working and one could not even fine adjust lenses with the E3.

    Same thing happened to the E3 - just sold my 43 system as I did now return my Pentax K5. If a camera does not work properly, then the best lenses do not help, as the best features, the best DXO results etc etc , ......

    Time is simply to precious to waste on such issues. My advice - just return the camera and go for something which works

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    Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by ptomsu View Post
    You seem to be exactly where I have been a week ago
    Not exactly. I actually think that the K-5 has great image quality and I find myself able to manual focus :-) But maybe we have a 50% overlap :-)

    I could not rely on that AF, it was not even just in low light, or Tungsten Light, it was in general unreliable. Sometimes focus spot on, sometimes just miles away.
    I am not getting the miles away but certainly there's a a few subjects I have tried that it should just "get it spot on." I see that's not quite the case for me still trying a few more things.

    I finally was not willing to fool around with that, as I do not want to adjust to a camera's flaws but rather to work with it flawlessly! It reminded me very much on my issues I had with the Olympus E3 - was also AF not working and one could not even fine adjust lenses with the E3.
    That's understandable but I want to make sure it's not something I am missing here, particularly with the lens calibration. If the lens calibration can do it I am fine with that, even if it's a little bit of work.

    Same thing happened to the E3 - just sold my 43 system as I did now return my Pentax K5. If a camera does not work properly, then the best lenses do not help, as the best features, the best DXO results etc etc , ......
    I certainly had my back focus issues with the E-3 also.

    Time is simply to precious to waste on such issues. My advice - just return the camera and go for something which works
    Well the problem is that "what works" is also a combination of needs and wants. For example, I certainly don't want to carry around a Nikon D3.

    - Raist

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    Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by raist3d View Post
    For example, I certainly don't want to carry around a Nikon D3.

    - Raist
    Could be a D700 as well, which is much smaller and lighter

    Or try the D7000 - I have a friend who bought one and he is VERY happy. Played a bit around with it and I could not find any issues (in that short time) but I would not dare to discuss final IQ between D7000 and K5, although I am sure it is pretty close.

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    Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by ptomsu View Post
    Could be a D700 as well, which is much smaller and lighter

    Or try the D7000 - I have a friend who bought one and he is VERY happy. Played a bit around with it and I could not find any issues (in that short time) but I would not dare to discuss final IQ between D7000 and K5, although I am sure it is pretty close.
    I tried the D7000 briefly. The ergonomics seemed a bit better than I expected, the auto focus in a the very little but challenging test I did seemed spot on and secure. I prefer the K-5 size, feel and JPEG color. Nikon doesn't offer a DNG option, nor "pancake primes" to keep the system small.

    It could still be a consideration but certainly only "business stuff."

    - Raist

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    Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by raist3d View Post
    I find the AF of the Pentax puzzling so far. Seems like a firmware patch must be coming up. I have been able to autofocus fairly fast on some difficult subjects and "it gets it" but something as simple as a parking sign seems slightly out of focus (DA70 at 2.4).

    I tried the lens adjustment and whatI have found is that some subjects seem spot on with no correction but a few then go one way or the other. Seems like say a parking sign with red letters like "No Parking" with Parking hours in letters and words will benefit from an adjust, but some other subjects are spot on. I tried using another AF point and it was similar.

    The live view AF is pretty spot on. I can focus using manual focus it seems often (which is good since I find virtually all digital SLR's here as not very good using the OVF).

    I still don't quite understand, but the focus seems really good for some truly difficult subjects and on some basic stuff it can go off the wrong way.

    Seems like Autofocus has been for many brands an issue (phase detection). in different ways. I understand Pentax is working on a firmware update for Tungsten light, as it as found by Pentaxeros I think it is, that 25 bodies had the same problem. in tungsten.

    - Raist
    I've started seeing something similar, but it may not be an auto focus problem. In my case it looks more like the SR mechanism not working properly and producing a blurry image. Perhaps about 20-30 pct of the shots. Need to lock the camera on a tripod and turn off SR to clear this up. I hope this is not an SR problem because I bought this camera so I wouldn't have to drag a tripod around.
    Carl
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    Re: Pentax K-5 Auto focus... hmmm...

    So I tired a few subjects at 0 lens adjust with my DA70mm....

    •One street sign of the San Francisco transportation was spot on. My e-620 actually back focused that one even if I adjusted the Olympus focus sensitivity to be a smaller area (you have two areas in the Olympus recent cameras).

    •Both were good for a liquor store title in white and a yellow area

    •The 620 seemed to handle better the liquor store area that has neon/led lights

    •The k-5 picked up and did fine in a poster a bit down below

    In all of these the K-5 focuses noticeably faster.

    When trying a brick wall of a building the autofocus was pretty good, but again using live view revealed yet a hair more contrast making the shot look more detailed.

    I was able to manually focus 5 out of 5 attempts I tried. That's really good news, I have found digital SLRS a complete pain to auto focus.

    Lens used in all of this was DA 70 Limited at F2.4.

    One thing to note is that when comparing with 4/3rds, the 4/3rds has nearly one stop more DOF so any slight back focus or front focus- like what I mentioned in the brick wall vs live view, wouldn't show up.

    So so far it seems that:

    •Objects that have homogenous colors even if mixed say with white and letters, in red, seem that it will be a notch off autofocus.

    •Objects in lower light in tungsten will front focus sometimes badly (known issue)

    •Objects in lower (daylight) light seem to front focus a notch but not bad

    •Objects focused at an angle- like say letters in a poster that is on the ground, it will front focus sometimes a little. I have notice the Olympus 620 has issues with this too. Could be that the sensor picks "whatever is closest" in that perspective.

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    Re: Pentax K-5 Auto focus... hmmm...

    if it is about manual focus I find the finder of the K5 not that bright compared to other cameras. I believe the AF needs to work to use this camera to my taste. For me MF is not an option with the K5 viewfinder.

    I havent figured out yet how much of my AF problem is user error/fine adjustment and how much a problem of the K5.

    I havent given up on the K5 but then again I am tired of having to experiment and optimize to get reliable focus.

    I also start to feel weird because I find problems with all kinds of cameras instead of being a happy photographer using a new tool.

    Still I came home twice where I thought to have some nice images taken with the K5 and was disappointed to see how many for misfocused.
    This is not about hait splitting focus test but coming home and seeing unsharp images.

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    Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by t_streng View Post
    if it is about manual focus I find the finder of the K5 not that bright compared to other cameras. I believe the AF needs to work to use this camera to my taste. For me MF is not an option with the K5 viewfinder.

    I havent figured out yet how much of my AF problem is user error/fine adjustment and how much a problem of the K5.

    I havent given up on the K5 but then again I am tired of having to experiment and optimize to get reliable focus.

    I also start to feel weird because I find problems with all kinds of cameras instead of being a happy photographer using a new tool.

    Still I came home twice where I thought to have some nice images taken with the K5 and was disappointed to see how many for misfocused.
    This is not about hait splitting focus test but coming home and seeing unsharp images.
    I started today with the GH2 and 14-140. I tried AF in really bad light.

    The difference to the K5 is that the GH" will just not focus if it cannot get the focus right. So then you can jump in with MF.

    Should not be too good and exact some would say? Especially with the EVF?

    Well, this EVF is a very different capable breed of EFV. In my eyes much better compared to the very much praised hybrid VF of the A55. And I was able to nail some 70% of the MF shots with that EVF. Which tells me something. And all that with the 14-140, which at f5.8 at 140 (280) is not really fast.

    Colors and noise are very good (low) when you shoot in RAW, which I do exclusively! And the GH" with 14-140 is a really small combo giving you 28-280 coverage!

    When attaching my 2.8/17 the whole AF low light issues went away. This lens is marvelous on the GH2. Will get the new 2.5/14 later this months.

    PS: all AF and of course also MF was done without AF Assist Lamp! If you use AF assist, then focus is no problem at all with no lens.

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    Re: Pentax K-5 Auto focus... hmmm...

    Peter I have to admit that while my x1 was at leica for repair I borrowed my wifes 20/1.7 lens and put it on the E-P2. While the high ISO NOISE is much worse than the K5 the lens is over 1 stop faster then the 35/2.8.
    Let me know how you further like the GH2 vs the K5.
    Regards, Tom


    Quote Originally Posted by ptomsu View Post
    I started today with the GH2 and 14-140. I tried AF in really bad light.

    The difference to the K5 is that the GH" will just not focus if it cannot get the focus right. So then you can jump in with MF.

    Should not be too good and exact some would say? Especially with the EVF?

    Well, this EVF is a very different capable breed of EFV. In my eyes much better compared to the very much praised hybrid VF of the A55. And I was able to nail some 70% of the MF shots with that EVF. Which tells me something. And all that with the 14-140, which at f5.8 at 140 (280) is not really fast.

    Colors and noise are very good (low) when you shoot in RAW, which I do exclusively! And the GH" with 14-140 is a really small combo giving you 28-280 coverage!

    When attaching my 2.8/17 the whole AF low light issues went away. This lens is marvelous on the GH2. Will get the new 2.5/14 later this months.

    PS: all AF and of course also MF was done without AF Assist Lamp! If you use AF assist, then focus is no problem at all with no lens.

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    Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by t_streng View Post
    Peter I have to admit that while my x1 was at leica for repair I borrowed my wifes 20/1.7 lens and put it on the E-P2. While the high ISO NOISE is much worse than the K5 the lens is over 1 stop faster then the 35/2.8.
    Let me know how you further like the GH2 vs the K5.
    Regards, Tom
    Tom,

    sure I will let you know, so far I am happy with the results and the performance of the GH2 and the 14-140. But I was in the beginning also happy with the K5, well I must say when I got the K5 I did not have much time to test, but the GH2 I put through some of the ugly tests already the first hours

    I will be in Shanghai and Nanjing the next 2 weeks and will take the GH2 with me as my "one and only" cam. I will definitely put it through some extensive tests and then be able to do a more serious report.

    If it only performs as my EP2 performs (which is guaranteed already) it is a clear winner

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    Smile Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by ptomsu View Post
    Tom,

    sure I will let you know, so far I am happy with the results and the performance of the GH2 and the 14-140. But I was in the beginning also happy with the K5, well I must say when I got the K5 I did not have much time to test, but the GH2 I put through some of the ugly tests already the first hours

    I will be in Shanghai and Nanjing the next 2 weeks and will take the GH2 with me as my "one and only" cam. I will definitely put it through some extensive tests and then be able to do a more serious report.

    If it only performs as my EP2 performs (which is guaranteed already) it is a clear winner
    been following the thread for a day or 2 now, just like to say thanks for your honest opinions and also Shanghai and Nanjing are very photogenic, and very beautiful at night, a pity when I went a few years back I didnt have a camera - be sure to share your photos
    Vince

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    Re: Pentax K-5 Auto focus... hmmm...

    Quote Originally Posted by vincechu View Post
    been following the thread for a day or 2 now, just like to say thanks for your honest opinions and also Shanghai and Nanjing are very photogenic, and very beautiful at night, a pity when I went a few years back I didnt have a camera - be sure to share your photos
    Thanks for the update, I will share for sure. Hope to have enough time for photography besides doing business

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