Olympus Capture & E-M1 PDAF Calibration

Discussion in 'Olympus Cameras' started by tradesmith45, Jun 1, 2015.

  1. Yes

    3 vote(s)
  2. No

    6 vote(s)
  1. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Had time on my hands w/ my E-M1 & ZD 300mm f2.8 so tried several ways to do AF calibration. Thought some of you might benefit from my waste of time. Your C&C is welcome.

    Caveats: I'm a 1st time PDAF user so this will be old news for those of you who have been down this dark winding road before.

    These results apply to a well used ZD 300 f2.8 both w/ & w/o EC14 & EC20. This produces the smallest DOF of all the 4/3 lenses. This lens could have worn AF drive components. However, I have no evidence of wear or slack in the AF drive components.

    *AF calibration is very time consuming & very technically demanding IF you try any of the slanting ruler/scale methods because its so difficult to interrupt the results. Don't waste your time & $$!
    *Points In Focus has it right, using teathered shooting software is the only way to go & it's still demanding: http://www.pointsinfocus.com/learning/cameras-lenses/auto-focus-micro-adjustments-using-live-view/
    *PDAF variability may be 1/3 to 1/5 DOF at these FLs so random variation is a huge challenge.
    *On the E-M1, fine tuning is so fine its really hard to tell if you've nail focus!!!! I recommend you test in increments of 3 to 5 steps only. Using smaller steps, at least on the ZD300, will require you to use very large sample sizes - >12 captures per setting.

    After much frustration w/ all other methods, tried Olympus Capture w/ 10x-14x mag Live View using the old Air Force resolution target to determine when I had achieved good focus. This produced the clearest & fastest results for AF calibration. YMMV!

    EDIT: First adjusted focus using MF to get max image sharpness & noted the smallest group of lines clearly in focus at max aperture. This became my benchmark. I set the camera to S-AF+MF mode & would manually focus the lens to infinity before half pressing the shutter & wait to get the confirmation beep. Then check for for max sharpness. Then repeat by moving the focus to closest focus distance before again half-pressing & checking. This procedure can be repeated to check for consistency.

    I learned lots from all this. First is what a waste of time this is. Unless something is really different about your camera/lens many other factors will degrade your focus accuracy more than AF calibration. Here are 3 100% crop images from the E-M1 w/ ZD300+EC14 @ -20, +20 & 0 AF fine tuning settings:
    18363598041_48b9a648f9_o.jpg _5190001 - 2015-05-19 at 15-46-22 by tradesmith45, on Flickr
    17739432184_7a1ab482dc_o.jpg _5190008 - 2015-05-19 at 15-49-42 by tradesmith45, on Flickr
    [​IMG]_5190061 - 2015-05-19 at 16-11-41 by tradesmith45, on Flickr

    Yes the 2 extremes are slightly out of focus but only a little & they both triggered the focus confirmation light & beep from the E-M1 (firmware 3 more on this later).

    Many sights recommend doing AF calibration at about 50x the focal length. The problem that imposes is the need for outdoor space. That brings w/ it thermal turbulence - trust me this is a big problem! So I used indoor space & artificial light at 15-20x the FL.

    Olympus Capture use gave me a few challenges that some of you may know a way around. You will have to go back & forth from the computer controls & on camera controls. In fact you'll have to unplug the camera from the computer to input new AF fine tuning settings. And you're forced to use camera buttons to invoke mag view - before you start assign mag view to a button. I won't give lengthy discussion here because you can figure it out faster by trying it.

    When I was all done, the default lens data worked fine for the ZD300 alone & w/ the EC14. The EC20 required about a +5 setting Using Olympus Capture & about 30 min. I spent hours finding I should use +2 or -2 or +7 for these using other methods & I had ZERO confidence in the results. The several posts at PointsInFocus recount similar experience he had w/ Canon & Nikon DSLRs.

    All my testing indicated there was no difference in AF calibration among the 37 PDAF points on MY E-M1. YMMV!

    Scrolling through many images showed me that atmospheric conditions play a significant role in successful AF on moving subjects in addition to the various AF settings & shooting technique. I shoot BIF w/ the ZD300+EC14. Even w/ all 37 AF sensors selected, its really hard to keep a bird w/in the AF sensor zone!! I succeed about 75% of the time or less for really fast erratic birds.

    I will start another thread about AF-Lock settings based on this work.

    Hope you find this helpful-:)
    Last edited: Jun 2, 2015
    • Like Like x 1
  2. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    I have to disagree that doing the micro adjust is a waste of time. I believe you are wasting your money on those expensive lenses if you are not checking the accuracy of your lens. The camera companies would not waste their time and money providing the ability if there was not a need. As to which method is the best, easiest, most accurate I have no idea. I used the Focus Tune system and was very happy with it, it was not that difficult to set up or a problem to use. To test my 150 with no TC and with both TC's, took me maybe an hour.

    When I got my 50-200 SWD and took it out the first time it seemed to nail focus perfectly. Considering my first test of the lens was an airshow I was pretty damn happy. From then until now it as always seemed to perform perfectly, even when using in a macro/closeup mode. I have yet to run it thru the Focus Tune system due to lack of time since getting the system, but I plan on doing it just to see how things shake out when I get some spare time.

    With my 150 I noticed the focus was off right from the start. Having already talked with @faithblinded@faithblinded about the Focus Tune system I knew which way I was going to go. I actually got pretty close by photographing a bird and using my eyeball to judge, but it was not as close to being perfect as it is now.

    I like the Focus Tune system because the software (not me and my not perfect eyeball) analyzes the shots and does a pretty little line showing the average of the focus points for each setting. Then it has a focus consistency check you can perform, which I also did for all three combinations of my 150. It made a huge difference in my photographs with the 150 from what I can tell so far, have not had it that long and still need to do more testing. Between the 150 and 50-200 (and both TC's) I have around $2,800 invested (and plan on getting several more of the SHG lenses) and can not see why I would not run this procedure on my equipment. I buy the best quality lenses that I can afford, why gimp them by not making sure they focus at the correct point in space?

    No, I did not run the system on each focus point individually. But, I have spot checked the extreme ends of the sensor area and found no noticeable changes between them.

  3. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Thanks Phocal, I was hoping to hear from you :biggrin:. One small correction, I think fine tuning w/ anything less that good software and for these long FL, a really good place to test is a waste of a whole lot of time - just too much variability. Even if it wasn't free, Olympus Capture is pretty dang good for calibration. The other factor I saw is the really major role thermal turbulence has on IQ/focus at these long FL. I knew it could be a problem but this time I saw just how bad it can be. And the conditions I had we pretty good compared to some of my shooting locations. I'm certain that thermals can move the AF far more than anything we can do in calibration. So after we've done all this work (hopefully less work w/ FocusTune), those wily wabbits are throwing our focus off. Of course shorter FL lenses are a completely different story.

    I started my most recent calibration thinking w/ a good target & big tripod, it would be pretty easy. My post reflects how frustratingly wrong I was until I tried Oly Capture.

    That said, I'm strongly considering FocusTune v3 & hope you can answer some questions for me that I was unable to find on their support site. From what I read, the software automatically log the lens adjustment data used for each image so no need to use sticky notes or sort or change file names as you work through the various lens correction settings. Does it do that for the E-M1 files? I'd buy the software for that alone!! The 600mm, ZD300+EC20, requires almost 100' to the target. Do you know how big the downloadable Gen3 target is when printed? I'm thinking I'll use FocusTune w/ Olympus Capture to shot & manage the file downloads. Did you try that? Every thing work ok? Did you do a MF series to get a base line?

    One reason I'm considering FocusTune is I lost confidence in my gear after trying several difference calibration methods. The author of PointsInFocus blog had the same thing happen to him. Hoping FocusTune provides the repeatability needed to get my confidence back or shows me there is something wrong with my gear.

    Thanks again.

  4. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    The setting is actually saved in the exif data, will even display that information when looking at the photos on the camera.

    I did not download anything from them. At the end I will include photos of what they sent me and what I used (have a ruler in the photo so you can see the size of it). I also did not do a manual focus test prior to starting.

    When your lenses focuses it does not always focus on the exact same spot. There is error because of the mechanics in the lens and probably because of the environmental factors and small changes in distance no matter how much you have stuff anchored down. So, you take multiple shots at the same setting (5 actually and defocusing after each). The software finds an average for each setting, which is what you use to determine where it should be set. You can also do a focus consistency test by taking a bunch of shots and letting the software group them into 5's or 15's (believe that's what the settings are) and giving a percent consistency based on the average of those groupings. I used 100 shots and tried both groupings for the shots, results were more or less the same. I actually tested this prior to doing the test and after, there was a huge difference in the accuracy. I went thru a lot of double checking everything and doing it multiple times as well as doing focus consistency before and after. I also did focus consistency at the setting above and below the setting the software determined. In other words I really did not trust the system and did everything I could think of to make sure I got good data and results. I am a firm believer in the results.

    Next I need to run my 50-200 thru the software and see what I end up. I will post up my results and do a post about my thoughts on the software after I do. I have 8,634 photos on my computer taken with the lens (probably taken closer to 12,000 with it) and firmly believe the lens is spot on with or without the EC-14. So, if I run the test and get anything more the 2 or 3 off I will suspect the whole thing.

    View attachment 92067 View attachment 92068
    • Informative Informative x 1
  5. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Yeah, I'm in!

  6. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Thanks for the info really helpful.

    Watched the videos about FocusTune. Tried several rulers already. Don't see any value in slanting rulers given the variability & difficulty interpreting what part of the ruler is sharpest even w/ the assistance of the software.

    I get the impression that the downloadable Gen3 target fits onto the LensAlign so must not be very big. I'll print several so I can cover all 37 AF points at once.

    I look forward to seeing your results for the Z.D50-200. You mentioned having a problem w/ calibration of the Z.D150 f2. What happened.
  7. Clint

    Clint Mu-43 Hall of Famer Subscribing Member

    Apr 22, 2013
    San Diego area, CA
    I do not bother checking a lens unless I see consistent problems. Typically this will only be at the widest apertures with relatively close focusing distances for the focal length of the lens, say with depth of fields less than 4 inches.

    As an example with an 85mm f/1.4 at 6 feet and f1.4 it becomes very simple to see an issue, but closing down to F/2.8 can mask the problem. Out of a couple of dozen professional level lenses over the last decade I’ve only 1 that benefitted from focusing tuning. An 85mm f/1.4 and only on one camera body.

    There are more variables involved than one would think and your setup needs to be stable and very accurate if checking more than 1 focus point. There are other lens issues that may lead to false assumptions about micro adjustments or why your results are not obtaining what you hoped. Keep in mind the micro adjustment you make might only change 1mm (39/1000 of an inch) for each point of MF fine tuning as only one example. So setup accuracy is important!

    Consistency and repeatability is how you can verify your changes before you go out and put it to real life testing. If your finding are not consistent and repeatable then your test are not valid.

    Pixel peeping at 100% is not a valid way to verify what your real life photos may exhibit. What you see on the screen when viewing your entire photo or printing photos to the largest size you might print (which really does provide different results than viewing on a screen) and very valid. Otherwise you may drive yourself crazy trying to get accurate, consistent, and repeatable results.

    I believe Lens Align and FocusTune are the easiest, most accurate, quickest, and repeatable means to perform test. An alternative might be FoCal. In either case you will have to make your lens micro adjustments manually during the test. The number of changes required can be significantly reduced.

    You can shorten your test by several means. One method is run a test of 3 shots test at each adjustment point of 0, +10, +20, -10, -20. Then pick a 9 point spread based on your results and test at a middle point with plus and minus four points each side of the middle point. At this point you might have enough data to make an adjustment that gets you pretty accurate results. Then some photos of real objects.

    The only other thing I can add is that focusing tuning can cause unnecessary anxiety. In almost all issues I’ve helped somebody with, it primarily came down to their set up, focus targets being used, and/or pixel peeping. There are other lens issues that may lead to false assumptions about micro adjustments or why your results are not obtaining what you hoped!!! Just more reasons for a very accurate setup!
    Last edited: Jun 4, 2015
    • Agree Agree x 1
  8. johnvanatta

    johnvanatta Mu-43 Veteran Subscribing Member

    Aug 5, 2014
    Oakland, CA
    Fine adjusting PDAF is a royal pain. Something that isn't mentioned very much is that PD isn't really all that accurate at focusing*. I found on my Nikon 300/4 that the variance in the focus was about as large as the adjustment required, which meant it took a long time to get things correct. I used both ruler test shots on a tripod and field shots to eventually get a value of 7mm, which I don't consider negligible at all. There was a marked improvement in my hit rate once I got it dialed in, so it was worth the trouble to have a higher chance of getting the gleam in their eyes. But I don't relish having to do it again.

    Crossing my fingers that the Oly 300/4 and CDAF will mean I never have to.

    *CDAF accuracy is one of the biggest unsung advantages of m43.
    • Agree Agree x 1
  9. barry13

    barry13 Super Moderator; Photon Wrangler Subscribing Member

    Mar 7, 2014
    Southern California
    So if the ZD 70-300mm is 'CDAF optimized', does that mean it doesn't need calibration?

  10. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Depends on what your shooting it on - E-M1 vs others. If memory serves, attaching any 43 lens via adapter to the E-M1 forces the camera to PDAF & I don't recall a way to over ride that so it might need calibration on that camera.

    Of course, mount any 43 lens on another m43 camera & you'll be in CDAF - no calibration.
    • Like Like x 1
  11. barry13

    barry13 Super Moderator; Photon Wrangler Subscribing Member

    Mar 7, 2014
    Southern California
    Yes, I'm using my E-M1 with the mmf3, and frequently the EC-14.

  12. Ross the fiddler

    Ross the fiddler Mu-43 Hall of Famer

    Unfortunately, you're stuck with PD-AF on the E-M1. I wish there was an option to revert to CD-AF only with "Live View" optimised 4/3's lenses because taking a photo of hazy scenes in the Blue Mountains (NSW) with my 14-54 II lens it just struggles in PD-AF on the E-M1 (not a problem with twin cross PD-AF sensors in the E-30) whereas it focusses fine on the E-M5 with CD-AF (albeit slightly slower). I used to use the 70-300 on the E-M5 before I got the M75-300 lens & have only recently tried the 70-300 lens on the E-M1 just for a test for someone here.
    • Like Like x 1
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