Olympus UK E-System User Group

Olympus UK E-System User Group (https://e-group.uk.net/forum/index.php)
-   Olympus OM-D E-M1 Mark II (https://e-group.uk.net/forum/forumdisplay.php?f=73)
-   -   AF Fine Adjustment on E-M1 Mk II (https://e-group.uk.net/forum/showthread.php?t=45384)

Ross the fiddler 23rd June 2017 04:03 AM

AF Fine Adjustment on E-M1 Mk II
 
EDIT: (Mon 26/6/2017) Please look here for a very good explanation of how the Mk II differs with AF to that of the E-M1 with a better understanding on how to use it. http://pen-and-tell.blogspot.com.au/...r-neue-af.html

I decided to try the 40-150 Pro with the MC14 on the new body when I heard some birds outside. Of course they weren't around when I had the camera, so I took some photos of static objects to try them out & I was disappointed with the results. I know this subject has come up before, but I feel it may need a fresh look. So I tried the lens combination on the E-M1 with fine results. After that I tried the Mk II with Magnified View select (through Fn2, MultiFunction), both with magnification on & off with much better results. My assumption with that was it was now just using CD-AF as the E-M1 was while normal AF (Mk II) was using PD-AF (S-AF). So my next move was to try AF Fine Adjustment at +10 & I got better results. From that quick & rough trial I would suggest it maybe is a good idea to now perform AF Fine Adj with all lenses since it uses PD-AF (+ CD-AF), particularly with lens combinations using a teleconverter. I will make further checks & adjustments to see if there are any differences, but if I suspect a subject is out of focus I can revert to Magnified View selection at +14 (but not with a magnified view though).

My feeling is, they gave us PD-AF with all lenses to perform like a DSLR & therefore it does perform like a DSLR; that is, needing AF Fine Adjustment as well, particularly with lens combinations. In other words, "You can't have your cake & eat it too". That is, AF Fine Adj. is needed on DSLRs & I think so does this camera (as it is provided for DSLR lenses as well as MFT lenses). While the Mk II claims Dual FAST AF system, so did the Mk I. I think a better understanding of when those Dual AF operations occur & when only one does (on each model) would result in a better AF outcome.

The following is quoted from the Mk II (Australian) web page here.
Quote:

High-speed AF system

A completely new AF system makes it possible to capture fast-moving subjects. With a Dual FAST AF system that uses the 121-point AF area for both On-chip Phase Detection AF and Contrast AF, the E-M1 Mark II delivers dramatic advancements in AF precision, tracking performance, and operability.

121-point All-cross-type On-chip Phase Detection AF

This E-M1 Mark II is equipped with an 11 x 11 121-point All-cross-type sensor. With an AF area that covers 75% vertically and 80% horizontally, subjects can be tracked across a wide range. All 121 points are cross-type focus points, making subject detection very accurate.

New AF algorithm

The new 121-point All-cross-type On-chip Phase Detection sensor and new TruePic VIII image processor significantly improve focus detection performance. The new moving subject tracking algorithm makes it possible to continue tracking various subject changes.
I welcome comments please.

blu-by-u 23rd June 2017 04:27 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
Don't understand.:( I am totally lost. Are you saying that we can select between Contrast or Phase on say the 40-150 pro? And in Phase, I can actually do fine adjustments?

If so, Please show the steps.

Thanks Uncle Ross.

Ross the fiddler 23rd June 2017 05:33 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
Quote:

Originally Posted by blu-by-u (Post 418393)
Don't understand.:( I am totally lost. Are you saying that we can select between Contrast or Phase on say the 40-150 pro? And in Phase, I can actually do fine adjustments?

If so, Please show the steps.

Thanks Uncle Ross.

I think normal S-AF shooting is done predominantly with PD-AF while the Magnified View function, that can be anywhere in the focus area on the screen & can be selected by touch I think is only CD-AF.

So my feeling is; PD-AF usually requires the lens to be calibrated, or adjusted with AF Fine Adj., in camera & this camera has that provision, for all lenses & lens combinations, so we should use it. EDIT: I may have to eat my words with making AF Fine Adjustment with MFT lenses because there is no adjustment amount shown when viewing the thumbnail with info in camera as seen with 4/3's lenses.

Ross the fiddler 23rd June 2017 06:43 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
I may have to eat my words with making AF Fine Adjustment with MFT lenses because there is no adjustment amount shown when viewing the thumbnail with info in camera as seen with 4/3's lenses. I will investigate further myself, but if anybody has any official information from Olympus, then I would love to see it.

bassman 23rd June 2017 11:13 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
Look forward to hear how you get on with this one, Ross. I have calibrated my lenses, where I felt they've needed doing, including 40-150mm 2.8 +MC-14. Purchased a Spyder Lenscal, used tripod etc and remembering to turn off the image stab'. Easy to get carried away with all this stuff but in my case, definitely worth doing ! All my current lenses are MFT(no 4/3's) and seem to remember I had fun working out how the camera function actually worked. For a zoom lens, you can adjust for the wide and tele end, on that same lens. Once confident how it worked, I was having great fun testing all my lenses and I found you can't spoil anything.... into menu, turn lens data off and you're back where you started.


Mark

OM USer 23rd June 2017 11:32 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
Its crazy that you need to make a manual adjustment for the lenses in this day and age. There is a sophisticated processor in the camera and all it has to do (provided it is pointed at the obligatory brick wall, graph paper, or high contrast design) is chunter through the focus range in CDAF looking for when each contast point is in focus and update the PDAF fine adjustment setting accordingly.

Ross the fiddler 23rd June 2017 11:48 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
Quote:

Originally Posted by bassman (Post 418431)
Look forward to hear how you get on with this one, Ross. I have calibrated my lenses, where I felt they've needed doing, including 40-150mm 2.8 +MC-14. Purchased a Spyder Lenscal, used tripod etc and remembering to turn off the image stab'. Easy to get carried away with all this stuff but in my case, definitely worth doing ! All my current lenses are MFT(no 4/3's) and seem to remember I had fun working out how the camera function actually worked. For a zoom lens, you can adjust for the wide and tele end, on that same lens. Once confident how it worked, I was having great fun testing all my lenses and I found you can't spoil anything.... into menu, turn lens data off and you're back where you started.


Mark

So you did do the AF Fine Adj in the Mk II then for those lenses? Great! I only took a quick stab at a +10 for the tele end of the 40-150 Pro & MC14. I'm familiar with using it on the E-M1 (Mk I) with the 50-200 SWD lens & EC14 etc. The Sigma macro lens & EC14 also need it too. I had some doubts about it when the adjustment figure doesn't show when reviewing the images though. I'll do meore checking tomorrow in day light again. Thanks for your feadback. *yes

Ross the fiddler 23rd June 2017 11:51 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
Quote:

Originally Posted by OM USer (Post 418435)
Its crazy that you need to make a manual adjustment for the lenses in this day and age. There is a sophisticated processor in the camera and all it has to do (provided it is pointed at the obligatory brick wall, graph paper, or high contrast design) is chunter through the focus range in CDAF looking for when each contast point is in focus and update the PDAF fine adjustment setting accordingly.

You must be thinking of the Nikon system then (or was it Canon?). ;)

DerekW 23rd June 2017 04:24 PM

Re: AF Fine Adjustment on E-M1 Mk II
 
I do not understand why a fine adjustment has to be made on a mirrorless camera as the focus sensors are on the same plane as the image sensor (actually part of the image sensor), I can understand why on a dSLR as the focussing device is away from the film plane.

Miketoll 23rd June 2017 06:01 PM

Re: AF Fine Adjustment on E-M1 Mk II
 
Quote:

Originally Posted by DerekW (Post 418459)
I do not understand why a fine adjustment has to be made on a mirrorless camera as the focus sensors are on the same plane as the image sensor (actually part of the image sensor), I can understand why on a dSLR as the focussing device is away from the film plane.

Me too Derek.

DanC.Licks 23rd June 2017 06:48 PM

Re: AF Fine Adjustment on E-M1 Mk II
 
Part of the problem is in the nature of CDAF and PDAF systems, and trying to combine them. One thinks closer is best and the other thinks further away is best, so when the camera tries to think and decide which AF system it is going to use for what kind of image (as I understand it it does not use both at the same time) it can get confused. According to the expert on the German Oly forum, there is never any need to fine adjustment when the camera uses CDAF, but it MIGHT need it with PDAF. Confusing...
That all said, a +10 adjustment is HUGE! My trusty old 50-200 has I think +1 on the long end, otherwise nothing. My Canon 400/Metabones is bang on every time on my thet chart. Unfortunately though, we don't buy cameras to take pictures of test charts, and real world situations are harder to manage.
It would not surprise me if there are improvements on the way via via firmware updates. Hope so...
It would be great if we could connect our brains to the camera via Bluetooth or something so it would know what WE want rather than decide for its self.

Ross the fiddler 23rd June 2017 11:42 PM

Re: AF Fine Adjustment on E-M1 Mk II
 
Quote:

Originally Posted by DerekW (Post 418459)
I do not understand why a fine adjustment has to be made on a mirrorless camera as the focus sensors are on the same plane as the image sensor (actually part of the image sensor), I can understand why on a dSLR as the focussing device is away from the film plane.

If the camera is using PD-AF it instructs the lens to focus at a particular setting according to the detected phase angle (or whatever it is detecting), & that may not necessarily be exactly in focus at the intended critical point because the lens may not be as accurately calibrated for PD-AF, so a fine adjustment stored in the camera can correct that. The difference here is understanding how the PD-AF is combined with CD-AF & when. I think that 'touch' AF (using magnification method) only uses CD-AF & may get around occasions where (PD-)AF can have anomalies.

DanC.Licks 24th June 2017 04:53 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
I have also heard that the AF works slightly differently depending on the mode selected. I only use S-AF (C-AF is useless with the Metabones/Canon rig, not to mention C-AF+Tr) so I can't say, but there was some discussion about just that on the German forum.
It is SO easy to become dependent on AF and once we have it, there is no going back, and we want it to work ALL the time.... surprise... :D

MJ224 24th June 2017 08:39 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
All double dutch to me...........

Either the focus works or not. Certainly did not pay 1700+ for the focus system not to work.

Well over my head..........................*chr

Ross the fiddler 24th June 2017 11:49 AM

Re: AF Fine Adjustment on E-M1 Mk II
 
Quote:

Originally Posted by MJ224 (Post 418534)
All double dutch to me...........

Either the focus works or not. Certainly did not pay 1700+ for the focus system not to work.

Well over my head..........................*chr

When I was trying to focus on an object using the 40-150 Pro lens with the MC14 TC that took more effort than it did on E-M1 then I wanted to find out why & what the differences were & how I can make it at least as reliable in those circumstances. I also didn't pay $2500 to be disappointed either. I'm not sure if anything I've done has really made any difference or not, but I will just be cautious when taking photos where I'm trying to focus on a small area in isolation to the surrounds & if necessary try the Magnification selection (at X 14 size AF box) if needed, in the hope that it may only use CD-AF (for S-AF), giving that further flexibility in the use of the camera.
On going back over the frames I believe IS was part of the issue too. Also, just for the information, I was using Anti-Shock Sequential Low drive mode.


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