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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

FT-lenses on E-M1 Mk II (1 Viewer)

Follow up to the selective focusing behavior.
I did some testing with both the Mark I (not yet sold) and the Mark II: Three AAA batteries with clear lettering and bright colors, two in front and one behind. The two in front were set just far enough apart so that the single focusing box (small sized on the Mark I) fit in between. All three batteries were well lit and set in the same position with the same lettering etc. facing the camera. I tested both my 50-200 and my Canon 400.
In such a scenario, there was no trouble with the Mark II because it saw no difference between the battery in the back and the front two. Both cameras locked on the same way. But when I replaced the rear battery with a small red plastic bottle with far less detail (practically none), the Mark II would refuse to stay focused on it and would always jump forward and lock onto the batteries. The Mark I did better, not 100%, but better for sure.
 
Interesting. For completeness and to test your theory of why, what happens if you increase the distance between the front batteries with 50% or 100%?

Niels
 
It doesn't seem to matter. Tried it. It just seems to be a mater of the detail of the subject.
Here is with the back battery about 20cm behind the front two, with the Olympus 50-200 at 200 on my Mark II. I have added the box to show roughly where it was placed. Unfortunately you can't show the focus point in any program other than PhotoMe and the thumbnail is too small and can't be copied out.
These should be self explanatory. Notice though, how the box even overlaps the front batteries and still locks onto the back one, but it has to be well centered with the vertical of the cross on the rear battery. Remember that the cross does not fill the box. Here in blue:
EM125908b.jpg
CDAF takes in everything in the box and looks for contrast edges. The PDAF only uses the what is under the cross for its calculations. With FT and adapted lenses we only have PDAF.
EM125908a.jpg EM125909a.jpg
Here with the red bottle (red is always difficult for AF systems) it refuses unless I get the cross off of the batteries
EM125912a.jpg EM125911a.jpg
 
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If I move the front batteries far enough apart that the cross does not overlap at all, it will nail the bottle. A little overlap and it jumps to the battery even though the vertical of the cross is still on the bottle.
EM125913a.jpg EM125914a.jpg
 
It may be the level of detail or it may be a built in assumption that usually people are trying to take images of the things that are closer rather than the more distant items.

Niels
 
I am sure that is part of it. The Olympus expert on the German Oly forum explains it roughly that the Mark II tries to evaluate the quality of the image in the field and concentrate on that, whatever "quality" means. More often than not, it will be the object closer to the camera. His examples show a nice sharp main object in the foreground and blurred objects in the background. So our problem goes against the way the camera "thinks", and we have to try and find ways to trick it into doing what we want it to.
That all said, I repleat that my mFT 75-300 II is not only blazingly fast focusing, it is also more selective because it uses both CDAF and PDAF, which gives us more freedom of choice. CDAF points can be made really small, and they still work, where PDAF points are crosses that have to cover a larger area in order to work at all. CDAF points are NOT cross type, they are just small areas of the image.
Here is his article on the subject:
http://pen-and-tell.blogspot.co.at/2016/12/e-m1ii-der-neue-af.html
Part way down, after the picture of the sprayer, is the crux of the mater. I will follow with a rough English translation after breakfast, though Google translate may do OK.
 
I am sure that is part of it. The Olympus expert on the German Oly forum explains it roughly that the Mark II tries to evaluate the quality of the image in the field and concentrate on that, whatever "quality" means. More often than not, it will be the object closer to the camera. His examples show a nice sharp main object in the foreground and blurred objects in the background. So our problem goes against the way the camera "thinks", and we have to try and find ways to trick it into doing what we want it to.
That all said, I repleat that my mFT 75-300 II is not only blazingly fast focusing, it is also more selective because it uses both CDAF and PDAF, which gives us more freedom of choice. CDAF points can be made really small, and they still work, where PDAF points are crosses that have to cover a larger area in order to work at all. CDAF points are NOT cross type, they are just small areas of the image.
Here is his article on the subject:
http://pen-and-tell.blogspot.co.at/2016/12/e-m1ii-der-neue-af.html
Part way down, after the picture of the sprayer, is the crux of the mater. I will follow with a rough English translation after breakfast, though Google translate may do OK.

Would you expect the pana 100-400 to work more like the oly or more like the canon lens in this respect? I am relatively sure that will be my choice but still contemplating oly vs pana camera to pair with it.

Niels
 
As it is a native mFT lens, I would assume that it uses both systems. From what I have heard, it focuses very quickly, so I think it is safe to say it would be more like the little Oly zoom in that respect. I myself am not wild about the IQ on the long end though, which is why I will stay with the Canon/Metabones setup, at least for now, in spite of the slow AF. If I had to choose between the PanaLeica and the Oly 300/4+ MC-14, it would be a no brainer as I seldom need the convenience of the zoom. It would get stuck at 400mm, which is where it is weakest.
What I would love to see Oly make would be a 200-500/3.5-6.3. No need for them to make a 100-400 unless they make it a LOT better, which means bigger lenses, more weight etc. The Canon 100-400 II is superb, but I found it to be too slow focusing with the Metabones. Optically in a class by its self.
 
Hi Dan, that's a great write up!
I have been holding back on purchasing the mk2
I am still with the mk1. I have also been using the meta/siggy 500f4.5 combo and it is great but heavy. I have arranged a test and wow for the mk2 to try it out with my OLY 300f4, which is super sharp! Like many other birders I have been frustrated by the focusing of the mk1 for BIF. Could you give me some settings for BIF with the Mk2. As your aware the test and wow is only 3 days so dont won't to spend a heap of time experimenting with settings. Is there a great difference between the mk1 and mk2 for BIF. And how would you rate it against the 7dmk2.
Kind regards Mike
 
Hi Mike,
I haven't had much chance to do BiF with the II yet because of the weather and lack of flying birds. But... I have basically the same setup, that is all AF points active, release priority off, 10fps normal with the I and 15 electronic with the II. The II has much less rolling shutter with the electronic shutter. Much more usable. IS-1, or IS-OFF if you have really good light. The biggest help though has been my action finder. With 400mm it is very hard to keep a bird in the VF, but very easy with the action finder. I point and hope ... er... shoot. ;) It will be easier with the 300mm.
ISO 400 to 800 depending, and anywhere from 0 to + 1 EV against the sky depending on whether it is blue or not. If the lens has a focus limiter, use it! Great feature on the Mark II! Let me know if anything isn't clear or if I can be of further help.
Sold my WE-M1 yesterday. Was actually a bit sorry to see it go. I have really enjoyed that camera!
 
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