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Problems with infinity focus on A6000
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PostPosted: Wed Apr 04, 2018 10:02 pm    Post subject: Reply with quote
Eriksen wrote:
itsfozzy wrote:
Would you mind posting a picture of the lens attached to the adapter and camera please, this conversation is hurting my head and I wonder if we're missing something really obvious.

Another question, do you have another Nikon lens to try? it could be that your lens is at fault.

I`ve tried with a lot of lenses and different adapters with the same result. The only adapters and lens I can focus beyond infinity with is a Konica to Nex adapter which is 21.2mm thick and that is over 1mm shorter than it should have been, so because of that I know there must be something wrong with my camera.


You seem to have a logic defying problem, good luck!


PostPosted: Wed Apr 04, 2018 11:01 pm    Post subject: Reply with quote
Ate you manually focusing using the magnifying focusing aid?


PostPosted: Thu Apr 05, 2018 2:50 am    Post subject: Reply with quote
dnas wrote:
Ate you manually focusing using the magnifying focusing aid?

Yes I do use that aid..


PostPosted: Thu Apr 05, 2018 3:49 am    Post subject: Reply with quote
Eriksen wrote:
dnas wrote:
Are you manually focusing using the magnifying focusing aid?

Yes I do use that aid..

And when you use it, you can't focus to infinity, or is it only captured images that are out of focus at infinity?


PostPosted: Thu Apr 05, 2018 11:57 am    Post subject: Reply with quote
dnas wrote:
Eriksen wrote:
dnas wrote:
Are you manually focusing using the magnifying focusing aid?

Yes I do use that aid..

And when you use it, you can't focus to infinity, or is it only captured images that are out of focus at infinity?

The loss of sharpness is the same in both places.


PostPosted: Thu Apr 05, 2018 4:59 pm    Post subject: Reply with quote
Can you post a few pictures? with the lens focused at infinity mark, and MFD plus a few points in between, this should help us see how the lens is behaving and rule out a few thing.


PostPosted: Thu Apr 05, 2018 5:09 pm    Post subject: Reply with quote
Lightshow wrote:
Can you post a few pictures? with the lens focused at infinity mark, and MFD plus a few points in between, this should help us see how the lens is behaving and rule out a few thing.

A video showing focusing from mfd to INF will do.


PostPosted: Thu Apr 05, 2018 11:30 pm    Post subject: Reply with quote
Eriksen wrote:
...I can only reach 5-6 meters before the picture get unsharp.


You have puzzled us with the strangely put sentence. The "before the picture get unsharp" part should probably be left out. When you reach 5-6 meters picture is sharp. OK. Picture cannot change anymore since you have already focused to infinity on your lens.


PostPosted: Fri Apr 06, 2018 3:15 am    Post subject: Reply with quote
Pancolart wrote:
Eriksen wrote:
...I can only reach 5-6 meters before the picture get unsharp.


You have puzzled us with the strangely put sentence. The "before the picture get unsharp" part should probably be left out. When you reach 5-6 meters picture is sharp. OK. Picture cannot change anymore since you have already focused to infinity on your lens.

That´s right when the Nikon 28mm lens is set to infinity, the picture is only sharp at that distance. With some other lenses I can reach a lot longer, so it´s not the same for all lenses. But I think I shall take my camera to a photshop and have it compared with a similar camera in order to find out more. I think it will be very difficult to figure out this problem here on this forum since no other members have had the same problem and know how to fix it.


PostPosted: Fri Apr 06, 2018 5:51 pm    Post subject: Reply with quote
The problem is we can only go by a description that you provide us, where as a few pictures takes your point of view out of the investigation and we can see with our own eyes and can compare it to things that resemble it, whereas right now we are trying to solve a visual word puzzle, which isn't easy at the best of times.
This could be as simple as a bad adapter and dirty lens, or it could be a lens that has major issues, a description of each could sound the same.


PostPosted: Fri Apr 06, 2018 8:02 pm    Post subject: Reply with quote
I think the AF sensor plane has moved. AF lens focus range lets AF lens focus to infinity. How is manual focus of AF lens? What distance is indicated on AF lens when auto-focused at infinity? If lens scale does not indicate infinity, or appears beyond infinity, then AF detectors need adjustment.


PostPosted: Fri Apr 06, 2018 9:08 pm    Post subject: Reply with quote
visualopsins wrote:
I think the AF sensor plane has moved. AF lens focus range lets AF lens focus to infinity. How is manual focus of AF lens? What distance is indicated on AF lens when auto-focused at infinity? If lens scale does not indicate infinity, or appears beyond infinity, then AF detectors need adjustment.

Your comment doesn’t make sense , the AF sensor is the image sensor, how would it move? He has already said his AF Len works fine.
I don’t think the AF lenses have a physical distance scale, it’s a scale on the display, and I don’t think it’s tied to lens focu position but rather an estimate of focus plane distance.


PostPosted: Fri Apr 06, 2018 9:36 pm    Post subject: Reply with quote
Lightshow wrote:
visualopsins wrote:
I think the AF sensor plane has moved. AF lens focus range lets AF lens focus to infinity. How is manual focus of AF lens? What distance is indicated on AF lens when auto-focused at infinity? If lens scale does not indicate infinity, or appears beyond infinity, then AF detectors need adjustment.

Your comment doesn’t make sense , the AF sensor is the image sensor, how would it move? He has already said his AF Len works fine.
I don’t think the AF lenses have a physical distance scale, it’s a scale on the display, and I don’t think it’s tied to lens focu position but rather an estimate of focus plane distance.


Sensor needs adjustment -- surely there is an adjustment. Sensor needs to be moved at least 1mm toward lens.


PostPosted: Sat Apr 07, 2018 12:06 am    Post subject: Reply with quote
Pancolart wrote:
Eriksen wrote:
...I can only reach 5-6 meters before the picture get unsharp.


You have puzzled us with the strangely put sentence. The "before the picture get unsharp" part should probably be left out. When you reach 5-6 meters picture is sharp. OK. Picture cannot change anymore since you have already focused to infinity on your lens.


I too think there is something amiss.

Eriksen: There have been a number of things said that lead me to believe this is your first experience with adapted lenses. Is that true? You made a comment: "I can`t reach infinity. With the Nikon 28mm I can only reach 5-6 meters before the picture get unsharp." as well as other comments about focusing with different apertures. You should always focus at the widest aperture. Also 5-6 meters may very well be where infinity kicks in with a 28mm lens. So I want to ensure that our terminology is matching up with your understanding.

When using adapters, infinity may no longer occur at the point where the lens has indicated on the distance scale. That also means that if you turn the focus ring to its max where it hits a hard stop, you may have exceeded infinity. Infinity isn't a marking on the lens so much as it is where all comes into focus before going out of focus again. Most lenses will focus past that point when using adapters. So if this is the misunderstanding, you simply focus to the point just before it goes out of focus and that is infinity. It will occur before the focus ring hits its hard stop.


PostPosted: Sat Apr 07, 2018 12:11 am    Post subject: Reply with quote
The sensor is shimed at the factory, there is no easy way to adjust the register of the camera, it’s very unlikely to have the sensor move from its position, far more likely that the adapter or lens is not right.


PostPosted: Sat Apr 07, 2018 12:47 am    Post subject: Reply with quote
Missing piece then. About 1mm thick. You have parts diagram? Smile


PostPosted: Sat Apr 07, 2018 4:22 am    Post subject: Reply with quote
Maybe lens mounting plate (part of camera) is not fully seated against camera body, or something got in between. I'm pretty sure Eriksen's intuition is correct -- the register distance is off; longer than it should be by about 1mm.


PostPosted: Sat Apr 07, 2018 8:47 am    Post subject: Reply with quote
visualopsins wrote:
Maybe lens mounting plate (part of camera) is not fully seated against camera body, or something got in between. I'm pretty sure Eriksen's intuition is correct -- the register distance is off; longer than it should be by about 1mm.


I'm struggling with your logic here, because if the sensor has moved, then it will not function correctly with a native AF lens. A native lens will not magically correct a misaligned sensor.


PostPosted: Sat Apr 07, 2018 1:28 pm    Post subject: Reply with quote
itsfozzy wrote:
visualopsins wrote:
Maybe lens mounting plate (part of camera) is not fully seated against camera body, or something got in between. I'm pretty sure Eriksen's intuition is correct -- the register distance is off; longer than it should be by about 1mm.


I'm struggling with your logic here, because if the sensor has moved, then it will not function correctly with a native AF lens. A native lens will not magically correct a misaligned sensor.


If native lens has enough focus travel past infinity to achieve focus at infinity...while the adapted lenses do not have enough travel past infinity to reach infinity focus because of the increased register distance. I.e., put 1mm extension tube on known good body; the native lens still reaches infinity but adapted lenses cannot.


PostPosted: Sat Apr 07, 2018 1:39 pm    Post subject: Reply with quote
visualopsins wrote:
itsfozzy wrote:
visualopsins wrote:
Maybe lens mounting plate (part of camera) is not fully seated against camera body, or something got in between. I'm pretty sure Eriksen's intuition is correct -- the register distance is off; longer than it should be by about 1mm.


I'm struggling with your logic here, because if the sensor has moved, then it will not function correctly with a native AF lens. A native lens will not magically correct a misaligned sensor.


If native lens has enough focus travel past infinity to achieve focus at infinity...while the adapted lenses do not have enough travel past infinity to reach infinity focus because of the increased register distance. I.e., put 1mm extension tube on known good body; the native lens still reaches infinity but adapted lenses cannot.


Thanks for that, I see the point you're making. It seems highly unlikely to me that Sony would have built in that much redundancy, but stranger things have happened!


PostPosted: Sat Apr 07, 2018 3:11 pm    Post subject: Reply with quote
No sense in continuing the discussion unless Eriksen participates and responds to my comments.


PostPosted: Sat Apr 07, 2018 4:34 pm    Post subject: Reply with quote
I think I will go to a photoshop with my camera first and find out more and come back in this discussion when I´m sure what is wrong. I know that the focus of my lenses don´t reach beyond infinity cause it works properly with the Konica adapter which is over 1mm shorter.


PostPosted: Sat Apr 07, 2018 5:16 pm    Post subject: Reply with quote
Eriksen wrote:
I think I will go to a photoshop with my camera first and find out more and come back in this discussion when I´m sure what is wrong. I know that the focus of my lenses don´t reach beyond infinity cause it works properly with the Konica adapter which is over 1mm shorter.


Please define "works properly".


PostPosted: Sat Apr 07, 2018 6:32 pm    Post subject: Reply with quote
Eriksen wrote:
I think I will go to a photoshop with my camera first and find out more and come back in this discussion when I´m sure what is wrong. I know that the focus of my lenses don´t reach beyond infinity cause it works properly with the Konica adapter which is over 1mm shorter.


And if the other adapters were 1mm too short the register distance would be correct.

Therefore either the sensor is 1mm deeper into the body or the lens mounting plate has 1mm gap between itself & body.

Photoshop can verify. Smile


PostPosted: Sat Apr 07, 2018 8:54 pm    Post subject: Reply with quote
My attempts have been to clarify what I think is a misunderstanding. We know that infinity is a point where the distance is in focus and that point is before the distance falls back out of focus. I suspect Eriksen thinks of infinity as the point on the lens' distance scale where the focus ring hits its hard stop.
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