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Welcome to 2013, Nikon Fans!

Discussion in 'Open Discussion' started by ijm5012, Oct 8, 2018.

  1. ijm5012

    ijm5012 Mu-43 Legend

    Oct 2, 2013
    Pittsburgh, PA
    Ian
    It seems as if early adopters of the Z7 are realizing that just because there is on-sensor PDAF, does not mean that it does not need to be focus tuned. Of course, a company like Reikan was already aware of this.

    Apparently, many people thought that because the PDAF was on-sensor, gone were the days of having to calibrate your lens/camera combinations. How wrong they were... Of course, owners of either of the E-M1 camera bodies know the importance of fine tuning the autofocus accuracy when using a focusing mode that relies on PDAF, as we've been doing so for the past 5 years.

    It just made me laugh when I read the thread and people were saying "What do you mean I need to calibrate my focus? The PDAF is on-sensor!"
     
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    • Informative Informative x 1
  2. tkbslc

    tkbslc Super Moderator

    Seems like it would be easier to just educate people rather than berate them. There's plenty that I don't know, so who am I to judge?
     
    • Agree Agree x 5
  3. ijm5012

    ijm5012 Mu-43 Legend

    Oct 2, 2013
    Pittsburgh, PA
    Ian
    I’m not berating them. It’s just funny to look at the threads and see people realizing that despite the PDAF being on-sensor, there is still some adjustment that needs to be made.

    I wonder if Sony’s or Fuji’s have this same option, since they would need it given their focusing set-up (OSPDAF).
     
  4. Growltiger

    Growltiger Mu-43 All-Pro

    Mar 26, 2014
    UK
    I admit ignorance. I would love to understand why with PDAF on sensor, calibration is needed.
     
  5. ijm5012

    ijm5012 Mu-43 Legend

    Oct 2, 2013
    Pittsburgh, PA
    Ian
    I agree, I don’t fully understand why it’s necessary myself. However, having owned a few E-M1’s and E-M1 II’s, there most definitely is a difference in AF accuracy after fine-tuning the AF for use when shooting with C-AF.

    It seems that this is no different with the Nikon cameras either.
     
  6. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    Houston
    FYI---------------------------EM1 Micro Focus Adjustment - Why and How to Perform
     
    • Informative Informative x 2
  7. ScottinPollock

    ScottinPollock Mu-43 Top Veteran

    Because PD tells the lens to focus to a distance, and CD goes back and forth until it gets it right.

    While it's true that alignment issues with off sensor PD don't exist with on sensor PD, lens variations can cause the focus plane to be different than the distance it was told to go to.
     
    • Like Like x 2
  8. I'm ignorant when it comes to fine tuning focus on m43. It took me 2 days to tune all my lenses to my Canon 7Dmkll and 6D as they all had back/front focusing issues from new. I would have thought though, that with the forgiving nature of DOF in m43, that you would have to be well off front or back to need a tune? Am I mistaken?
     
  9. ScottinPollock

    ScottinPollock Mu-43 Top Veteran

    Depends on focal length, distance, and aperture. Sure m43 has more DOF than full frame, but there are still instances where it can be razor thin (macro for instance).
     
  10. Phocal

    Phocal Mu-43 Hall of Famer

    Jan 3, 2014
    Houston
    I regularly shoot where DoF is very thin...………..

    This shot it is actually kind of large at 1.0 inch
    39035626775_7ed978ba79_o.
    E-M1    OLYMPUS M.300mm F4.0    300mm    f/4.0    1/3200s    ISO 200

    Tricolored Heron 011 - Final Edit that I printed
    by Phocal Art, on Flickr

    Here it is .8 inches
    39146617674_e4f3927eeb_o.
    E-M1    M.300mm F4.0 + MC-14    420mm    f/5.6    1/2000s    ISO 200

    Tricolored Heron 006
    by Phocal Art, on Flickr

    Here it is .5 inches
    37593562501_f1a6e7994f_o.
    E-M1    M.300mm F4.0 + MC-14    420mm    f/5.6    1/1000s    ISO 200

    Green Heron 017
    by Phocal Art, on Flickr

    I know I have more that are under .5 inches but these are what I found on a quick search.
     
    Last edited: Oct 8, 2018
    • Like Like x 1
    • Agree Agree x 1
  11. Growltiger

    Growltiger Mu-43 All-Pro

    Mar 26, 2014
    UK
    I still don't understand. I see that the lens can go to the wrong place, but the next time it will do better until it is perfect. If the lens is at 2m and needs to go to 15m, it certainly isn't going to get it exactly right first time. But with the measurement on the sensor, why doesn't it very soon get perfect focus?
     
  12. barry13

    barry13 Super Moderator; Photon Wrangler Subscribing Member

    Mar 7, 2014
    Southern California
    Barry
    Hi, you're describing CDAF. PDAF doesn't work that way... the camera doesn't know if the image is in perfect focus and wouldn't know what to do about it.

    And PDAF, if calibrated, is supposed to be near-perfect the first time, and not need any refinements on each shot.
     
    • Informative Informative x 1
  13. Growltiger

    Growltiger Mu-43 All-Pro

    Mar 26, 2014
    UK
    If the focus is only slightly out, surely PDAF can tell? Otherwise how would it make a small adjustment? And if it can tell, why doesn't PDAF keep measuring and adjusting?
     
  14. ScottinPollock

    ScottinPollock Mu-43 Top Veteran

    That's just not the way it works... and why it is faster, and not as accurate as CD.

    Some of Sony's cams have a hybrid autofocus, where it does the initial focus with PD, and if there's enough time, double checks it with CD. This is the best of both worlds, but it doesn't use this under all circumstances.
     
    • Informative Informative x 2
  15. gnarlydog australia

    gnarlydog australia Mu-43 Hall of Famer Subscribing Member

    Feb 23, 2015
    Brisbane, Australia
    Damiano Visocnik
    I have no idea how this PDAF works ( I mainly use manual focus lenses) but does that mean each AF lens has to be paired to a certain camera?
    Is then possible to use said lens on a different body and still have perfect focus, or does each lens need adjusting for each camera?
    If that is the case having two bodies sharing the same lens is not that great?
     
  16. Ross the fiddler

    Ross the fiddler Mu-43 Hall of Famer

    I'm surprised to see that from you! Come on, the lenses aren't calibrated for nothing. No, it is the lens that can be out & why micro adjustment is necessary when we use DSLR lenses on the E-M1 models & thankfully there is provision for those adjustments.
    That's part of the frustration when trying to adjust for a particular lens. One thinks they have it right, but then it isn't always spot on. Then again, I don't think it is all about the inconsistency of a lens, but subject detail & micro distance too.
     
    Last edited: Oct 8, 2018
    • Informative Informative x 1
  17. barry13

    barry13 Super Moderator; Photon Wrangler Subscribing Member

    Mar 7, 2014
    Southern California
    Barry
    Hi, since the calibration is done (and stored) in the body, it's solved already.
     
  18. Ross the fiddler

    Ross the fiddler Mu-43 Hall of Famer

    For example, if I'm using a 12-60 SWD lens on my E-M1 & Mk II I have to adjust the micro adjustment at wide angle & tele ends of the lens. Also, there is provision to have different adjustments across the focus target screen, which might be useful for wide angles. Also, if I'm adjusting for the 50-200 SWD lens, I can store that, but as soon as I attach an EC14 I then have to do those adjustments again & that is then stored as separate data (which is recalled for those lens combinations).
    If you have two bodies sharing that same lens, then putting those settings into the second body may be correct, but then it should be checked (when updating the FW for one model & saving its setting, I think these settings may be saved too & then can be transferred to another camera if needed).

    Some advocate making adjustments for a M4/3's lens when using C-AF, but I'm not so convinced of that because both CD-AF & PD-AF (on E-M1 models) are combined & I think CD-AF is the final focus lock, perhaps.(?)
    000085030.
     
    Last edited: Oct 8, 2018
    • Informative Informative x 3
  19. gnarlydog australia

    gnarlydog australia Mu-43 Hall of Famer Subscribing Member

    Feb 23, 2015
    Brisbane, Australia
    Damiano Visocnik
    OK, so the calibration is done on one body but if I then attach said lens to a second body I need to perform calibration on the second body too?
    So a lens must be tuned for each body?
     
    • Agree Agree x 1
  20. ijm5012

    ijm5012 Mu-43 Legend

    Oct 2, 2013
    Pittsburgh, PA
    Ian
    Correct. I just did this with both of my D500's. It is specific to the exact lens/body combo.
     
    • Informative Informative x 1
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