Focus range? My focus plane is tilted.

jakubt

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Hi. I got my new Git1. It works pretty much as expected. My primary use is as dashcam so I prefer hyperfocal focus distance. I have noticed that focus plane is not aligned with sensor on mine. It is most noticeable in close focus. This is a still from video, about 15cm from 24 inch screen displaying my test chart that I use for DSLR lens testing:

distance-close.jpg

you can see right side is very sharp (even Bayer demosaicing and sharpening artifacts are visible). Left side is soft.
Left side becomes almost comparably sharp as right one at around 80cm distance.

At far distance this reverses: left side is very very sharp, right side is slightly soft, but still usable:
Crops from still from video (plate is about 9m from camera):
distance-9m-compare-web.jpg
Notice also how trees are softer on left side.

I'm considering to get a replacement. Local company I got it from advertises 24-hour replacements for faulty ones.
But I wonder: what focus range is on your's Git1?
 

Nigel

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You shouldn't expect it to be in focus much closer than 80cm, having good focus at 15cm suggests that it is focused a bit closer than it should be. The huge depth of field means that even if the lens is slightly out of alignment with the sensor, you should still be able to get everything from 80cm to infinity in good focus.

The difference in your second image looks more like the amount of sharpening used than the focus and that will depend on the exposure used as well as the focus, since it is 2 separate photos probably with different exposure it is hard to tell the difference in focus between sides.

If it was mine I would refocus it myself a little further away, it is just the 4 screws to remove and then twist the lens, maybe removing some of the locking glue first if it doesn't want to turn. Since it is only a 2MP sensor, you can focus it accurately using the HDMI cable to a 1080 monitor.
 

lacibaci

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Looks like the lens base is not seated correctly. Or the sensor was soldered on an angle.
 
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