K10D focus problems
Posted 18/01/2012 - 09:59
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The subjects you have photographed are not the best for demonstarting at 800px what is and isn't in focus. Try being at 45 degrees to a brick wall and mark a spot on the wall that you focus on. Then use the widest aperture and see what happens.
If you use a tripod you will eliminate camera shake. Don't forget to use the 2 second self timer so that the mirror locks up before the exposure, thus eliminating mirror vibration as well.
You should be able to see in the viewfinder what point (use centre point focus only) snaps into focus anyway.
If you have fiddled with the AF I suggest you reset factory settings before you start and go from there afresh.
If you use a tripod you will eliminate camera shake. Don't forget to use the 2 second self timer so that the mirror locks up before the exposure, thus eliminating mirror vibration as well.
You should be able to see in the viewfinder what point (use centre point focus only) snaps into focus anyway.
If you have fiddled with the AF I suggest you reset factory settings before you start and go from there afresh.
Best regards, John
Posted 18/01/2012 - 13:34
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This is not a camera shake issue. I have reset the camera through in camera software, is there another way?
Maybe these will help elucidate the problem (click for original size):
BTW, I typical point the center square between a contrast line (colour divide, skyline, etc):
Focused on the top of the faraway hills
IMGP5992 by eduardodourado, on Flickr
Focused on the tower and reframed (finger not lifted from button)
IMGP5998 by eduardodourado, on Flickr
Focused on the top of the hill just right of center
IMGP5997 by eduardodourado, on Flickr
Focused on the little hill in the center.
IMGP5994 by eduardodourado, on Flickr
During this trip I had not fiddled with focus correction but when I did I found it to be set at -20um, I had messed with it a long time before, most have left it that way.
On the other forum, some pointed to the mirror having been bumped.
My observations on that:
It is possible, but I doubt that is the issue.
No inclination is evident in the mirror and as I understand it a small one would skew the plane of focus from horizontal (as projected onto the screen) into oblique. That isn't perceptible either.
I still would not rule it out. However, in the optical viewfinder both at 55mm and 18mm the image seems to be in focus at the same distance of focus approximately. Meaning, when the object is ~1m away it appears to be in focus when the scale on the lens is at ~1m. With the correction I have dialled in right now, AF seems to work and match the physics from the scales at 55mm, but the AF sets a focus different focus distance for 18mm.
So I don't think there is anything clearly wrong with the physical path through the lens, mirror, focus screen and focus detector.
Maybe these will help elucidate the problem (click for original size):
BTW, I typical point the center square between a contrast line (colour divide, skyline, etc):
Focused on the top of the faraway hills
IMGP5992 by eduardodourado, on Flickr
Focused on the tower and reframed (finger not lifted from button)
IMGP5998 by eduardodourado, on Flickr
Focused on the top of the hill just right of center
IMGP5997 by eduardodourado, on Flickr
Focused on the little hill in the center.
IMGP5994 by eduardodourado, on Flickr
During this trip I had not fiddled with focus correction but when I did I found it to be set at -20um, I had messed with it a long time before, most have left it that way.
On the other forum, some pointed to the mirror having been bumped.
My observations on that:
It is possible, but I doubt that is the issue.
No inclination is evident in the mirror and as I understand it a small one would skew the plane of focus from horizontal (as projected onto the screen) into oblique. That isn't perceptible either.
I still would not rule it out. However, in the optical viewfinder both at 55mm and 18mm the image seems to be in focus at the same distance of focus approximately. Meaning, when the object is ~1m away it appears to be in focus when the scale on the lens is at ~1m. With the correction I have dialled in right now, AF seems to work and match the physics from the scales at 55mm, but the AF sets a focus different focus distance for 18mm.
So I don't think there is anything clearly wrong with the physical path through the lens, mirror, focus screen and focus detector.
Posted 18/01/2012 - 13:47
Link
Not the right sort of subjects I'm afraid, we need something more obvious at closer distances. Buildings, brick walls, etc lens themselves better, so we can see where you are focused.
Camera shake is always present without a tripod, and sometimes with. It is just vastly reduced as shutter speeds increase and is often below our threashold, but as it's a variable it should be elimnated properly with a sturdy tripod. Also, in these shots, you could have wind shake so out in the open.
Camera shake is always present without a tripod, and sometimes with. It is just vastly reduced as shutter speeds increase and is often below our threashold, but as it's a variable it should be elimnated properly with a sturdy tripod. Also, in these shots, you could have wind shake so out in the open.
Best regards, John
Posted 19/01/2012 - 11:31
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I agree with John and would add that atmospheric haze isn't going to help when you are focusing on such distant objects.
I did once have a problem with my K20D when it started back-focusing with every lens and I lost a lot of good images. It was particularly noticeable on portraits with sharp ears and soft eyes.
I took my heart in my hands and performed the 'HACK' and brought evereything back to normal. You might consider it because you can always put things back the way they were.
I did once have a problem with my K20D when it started back-focusing with every lens and I lost a lot of good images. It was particularly noticeable on portraits with sharp ears and soft eyes.
I took my heart in my hands and performed the 'HACK' and brought evereything back to normal. You might consider it because you can always put things back the way they were.
Ken
“We must avoid however, snapping away, shooting quickly and without thought, overloading ourselves with unnecessary images that clutter our memory and diminish the clarity of the whole.” - Henri Cartier-Bresson -
“We must avoid however, snapping away, shooting quickly and without thought, overloading ourselves with unnecessary images that clutter our memory and diminish the clarity of the whole.” - Henri Cartier-Bresson -
Posted 19/01/2012 - 11:45
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Gartmore, I have made the hack. Then I had the problem of huge deviations for different focal lengths.
I don't believe its any of that because my camera has had its failed focus and not so sharp images before. Not like these though.
When, as evidenced by the shot of the horses with the stone in the foreground and of the tower with the gorse and footpath in the foreground, the focus point is dozens or hundreds of meters away, but in the shot the plane most in focus is in the foreground, the answer cannot be haze, or camera movement, there must be something wrong with AF or the sensor position.
BTW, I've emailed Pentax Technical and am waiting to hear their suggestions. I'd be happy to hear its my fault and how I can fix it.
I don't believe its any of that because my camera has had its failed focus and not so sharp images before. Not like these though.
When, as evidenced by the shot of the horses with the stone in the foreground and of the tower with the gorse and footpath in the foreground, the focus point is dozens or hundreds of meters away, but in the shot the plane most in focus is in the foreground, the answer cannot be haze, or camera movement, there must be something wrong with AF or the sensor position.
BTW, I've emailed Pentax Technical and am waiting to hear their suggestions. I'd be happy to hear its my fault and how I can fix it.
Posted 26/01/2012 - 16:40
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Mailed Pentax explaining the situation and they said to send it to repair...
Does anyone have and idea of how much that might cost? Its not in warranty
Does anyone have and idea of how much that might cost? Its not in warranty
Posted 16/02/2012 - 15:42
Link
Got this resolved yet?
Posted 15/03/2012 - 22:19
Link
So I eventually got tired of this and sent the camera to Reflecta in Spain, which is the reference support for Pentax in its portuguese site.
A slow and opaque process followed (codes to track repair budgeting didn't work), I've gotten a quote for 314 Euros. "Main base cam dig" + labour + postage.
Not clear, but something massive needed replacing.
I asked the equipment be returned, because at that price I'd rather wait and live with the problem until a cheap alternative is found.
Its been 9 days since the quote and after two emails no acknowledgement has been made...
Not well impressed with the whole process.
A slow and opaque process followed (codes to track repair budgeting didn't work), I've gotten a quote for 314 Euros. "Main base cam dig" + labour + postage.
Not clear, but something massive needed replacing.
I asked the equipment be returned, because at that price I'd rather wait and live with the problem until a cheap alternative is found.
Its been 9 days since the quote and after two emails no acknowledgement has been made...
Not well impressed with the whole process.
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787 posts
18 years
Portugal
At first I thought it just focused on the wrong place, but then I realized it seems to be horrible front focusing.
These are consecutive images, both focused on the horse, both focused positively a second apart.
IMGP6026 by eduardodourado, on Flickr
IMGP6027 by eduardodourado, on Flickr
The sharpest photo from the day (only about 1.5m)... Testing out the new boots.
IMGP6039 by eduardodourado, on Flickr
This was focused on the lettering is actually isn't too bad, also focused at a distance
IMGP6046 by eduardodourado, on Flickr
No image from this walk is really sharp were it was focused.
I've tried another lens, cleaned the contacts, removed and replaced the focus screen, reset the camera and installed latest firmware.
I've tried to use focus correction in debug mode.
I've managed to get good results for 55mm focusing near and far, as well as with a 70-300mm, by using -450um as correction.
However, with this at 18mm, the lens will only focus very close and does not focus beyond ~3m (it also does not focus well).
In fact, looking at the focus scale of the lens, while at 55mm, the camera can focus on a spot at about 50cm distance and you'll read ~50cm. At 18mm focusing on the same spot at the same distance you'll read ~1m. It focused (beep, hexagon pops up) but its out of focus.
Here are pics from the tests (18mm pics are croped):
-100 um
18mm
IMGP6273 by eduardodourado, on Flickr
55mm
IMGP6274 by eduardodourado, on Flickr
-200 um
18mm
IMGP6275 by eduardodourado, on Flickr
55mm
IMGP6276 by eduardodourado, on Flickr
-300 um
18mm
IMGP6277 by eduardodourado, on Flickr
55mm
IMGP6278 by eduardodourado, on Flickr
-400 um
18mm
IMGP6279 by eduardodourado, on Flickr
55mm
IMGP6280 by eduardodourado, on Flickr
I don't know what I did to the camera, but if it is a FF issue I created, its unlike what other people experienced because when the compensate its ok for that lens... Mine doesn't even work within the whole range of the lens. Maybe because the compensation required is so large...?
As anyone have any ideas?