1. Welcome to TalkEmount.com—a friendly Sony E-mount camera & photography discussion forum!

    If you are thinking of buying a camera or need help with your photos, you will find our forum members full of advice! Click here to join for free!

Intermittent AF issue

Discussion in 'Sony Alpha E-Mount Cameras' started by Petrochemist, Jun 12, 2019 at 4:27 PM.

  1. Petrochemist

    Petrochemist TalkEmount Regular

    45
    Oct 19, 2018
    North Essex UK
    Mike
    I've recently brought an A7ii and Techart Pro. During testing this combination works well with my lenses much of the time, but it's gone through periods of failing to even try focusing (taking a picture with a severely out of focus image), and sometimes even failing to show anything in the viewfinder!
    Any ideas on where the issue might lie? Is it the camera, the techart, or the user???

    I don't have any native lenses having been using adapted lenses on a Nex6 since christmas & on the A7ii for only the last couple of days. In that time I haven't seen the blank screen on either body when just using manually adapted lens on this camera.
    Powering the camera off & rebooting it has not always cleared the blank screen, but does seem to restore operations eventually.
    None of my local friends who're into photography have yet gone for e-mount, though between members of the workshop we have most other options covered. :( 
     
  2. AlwaysOnAuto

    AlwaysOnAuto TalkEmount Hall of Famer

    Feb 17, 2015
    I have never used my TAP on my A7ii.
    If I were to run into your problem myself I'd start by dis-assembling the lens and adapter from the camera and cleaning all the contacts camera/adapter/lens, and putting it back together again. If that didn't seem to help I'd then check the battery to be sure it's fully charged as the TAP uses it to get power for focusing. In fact, I might reverse the order of what I just wrote since the battery is the source and a very basic need for both camera and adapter.
     
  3. Petrochemist

    Petrochemist TalkEmount Regular

    45
    Oct 19, 2018
    North Essex UK
    Mike
    Thanks for the suggestions.
    The battery was fully charged just before I started my testing, so should still be good after ~50 shots at the end of it let alone by 10 shots when the issue first occurred, even with increased usage needed to power the TAP.
    The contacts are certainly a good possibility. I'll give them a thorough clean at work tomorrow.
     
  4. AlwaysOnAuto

    AlwaysOnAuto TalkEmount Hall of Famer

    Feb 17, 2015
    I'm not sure if they changed the programing in the TAP, but mine wore the battery down when I left it attached to the camera overnite the first time I tried it out.
    I think you might want to remove it completely from the camera when you're done for the day.
     
  5. Petrochemist

    Petrochemist TalkEmount Regular

    45
    Oct 19, 2018
    North Essex UK
    Mike
    Good point I'd forgotten about that!
    I've seen claims that the latest firmware solves the issue, but I don't know what version mine has.

    Fortunately the m42 lenses I can currently adapt to it didn't fit in my A7's bag so I'd taken it off anyway. When I get the LTM adapter I might be more liable to leave the TAP on the camera, but it's probably best if I don't.
     
  6. bdbits

    bdbits TalkEmount All-Pro

    Sep 10, 2015
    Bob
    I used a TAP on an A7ii until a few months ago. It was a great AF adapter for me, and I only sold it because I have been switching to almost all native lenses.

    Note that it will work sporadically at best on earlier bodies like the NEX-6, and I don't think Techart lists them as supported. This has to do with changes to the focusing protocols on later cameras (which made adapters like TAP work), or that is my understanding anyway. On the A7ii it generally worked pretty well and seldom glitched. If it does lock up on you, I'd recommend turning off the camera, dismounting and remounting the TAP, then turning the camera back on.

    There are physical limitations to how far TAP can move the lens, so it is a good idea to get it somewhat in the neighborhood of the in-focus position before using autofocus. Also there were weight limitations, I want to say the limit was 700 grams but not sure. Anyway if you are using heavier lenses you may want to try something lighter and see if the problems go away.

    You should ensure you have recent firmware (there are update apps for iOS and Android) as there were a lot of fixes over time. You can see the firmware by looking at the 'lens version' in one of the last camera menus. I think v5 was the last one for the A7ii, and v6 was only need for 3rd-generation bodies. Also as i recall, battery drain on later firmware was significantly less, but I know it did drain slightly if left on for several days. So if you will not be using it for a few days, I would probably dismount it.

    Hope these notes help you a little bit. As I said, for me it was a great adapter on the A7ii and I really enjoyed using it.
     
  7. Petrochemist

    Petrochemist TalkEmount Regular

    45
    Oct 19, 2018
    North Essex UK
    Mike
    Thanks for that @bdbits@bdbits
    The 700g limit is what I'd seen, which covers most of my lenses, until you take the sub adapter into account The LM-M42 one I've got is 74g on its own.
    Surprisingly the 400mm I tried last night weighs less than the 35mm flektogon...
    I'll have to check the firmware version, and will get one of the kids to upgrade it for me if required, they're much quicker with phone apps than me!
    The Nex6 isn't listed as supported, but I'm sure I'll end up trying it at some point anyway. If it works slowly that could still be an advantage.
    The reset procedure you recommend didn't work every time, but I don't think it ever needed more than 2 attempts.
     
    Last edited: Jun 13, 2019 at 4:43 AM
  8. Petrochemist

    Petrochemist TalkEmount Regular

    45
    Oct 19, 2018
    North Essex UK
    Mike
    I couldn't find the contact cleaner but a little work with a pencil eraser on the TAP seems to have cured the issue. It was even able to autofocus my modified Soligor which is nearer to 200mm than the original 105 (the rear group was so badly fogged I ended up removing it & adding extension to compensate).
     
    • Like Like x 1
  9. AlwaysOnAuto

    AlwaysOnAuto TalkEmount Hall of Famer

    Feb 17, 2015
    That's good news. Were the contacts visibly dirty?
     
  10. Petrochemist

    Petrochemist TalkEmount Regular

    45
    Oct 19, 2018
    North Essex UK
    Mike
    Yes, I think they still are!
     
  11. christilou

    christilou TalkEmount All-Pro

    Nov 26, 2012
    Surrey, UK
    Christina
    I also tried it and found it's focus to be bit sporadic and information on how to use it a little sketchy. If you're having to move the lens manually into the rough ball park focus zone then I didn't see the point. Although there were times it focussed really well, there were plenty of others where absolutely nothing happened and so I returned it. When it worked though it was great :daz:
     
  12. bdbits

    bdbits TalkEmount All-Pro

    Sep 10, 2015
    Bob
    For me, getting it part way there only meant not expecting the TAP to immediately go from near MFD to at/near infinity. Otherwise, in normal scenarios, I seldom had to manually adjust focus. I thought it was great, but others not so much.

    From the FAQ I just found, 4.5mm is the limit I could not remember that it can move the lens. More info on all thing TAP over there.

    FAQ
     
  13. Petrochemist

    Petrochemist TalkEmount Regular

    45
    Oct 19, 2018
    North Essex UK
    Mike
    How close you need to get focus is very much a function of focal length, with lenses less than 50mm it can handle all normal distance without touching the focus. When playing with the 400mm I had to get reasonable close to right - but it then gets it spot on, something that's tricky to do manually.

    A few of the weirder lenses I've tried it with it had little effect on the focus distance - the 28.8mm microfische lens (adapted via M42) could only focus within about a foot, & the focusing movement only made an inch or twos difference, nut it did get a sharper shot than my previous quick trials with that lens.
     
    • Agree Agree x 1
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.