Manual Focus @ Infinity not working - page 4 - Hello, I'm a NEWBIE - HELP!! (Newbies assistance, User Guides and thank you notes) - CHDK Forum
supplierdeeply

Manual Focus @ Infinity not working

  • 151 Replies
  • 56660 Views
*

Offline eponymous

  • *
  • 38
  • Canon A4000
Re: Manual Focus @ Infinity not working
« Reply #30 on: 30 / October / 2014, 12:06:40 »
Advertisements
OK, A4000, now with a short-distance set as well, about 6" from the camera.

AUTO: SD:0.1m mecha:760
AFL : SD:0.1m mecha:755
MF  : SD:infinity mecha:649


Again the first two images are good and the third is blurry (as expected, I suppose).
John

Re: Manual Focus @ Infinity not working
« Reply #31 on: 30 / October / 2014, 12:22:31 »
(which seems to start up in review mode?)
All versions of CHDK startup in review mode.

Quote
First, the script reports:
Code: [Select]
Focus Test 65.5m
AUTO: SD:1.4m mecha:663
AFL : SD:1.3m mecha:664
MF  : SD:infinity mecha:653
Strange - focus seems to be at infinity in the first two but the call to get_focus() is not returning that value.  And again,  the out of focus mecha value is farther out (lower number) than the two in focus.

OK, A4000, now with a short-distance set as well, about 6" from the camera.

AUTO: SD:0.1m mecha:760
AFL : SD:0.1m mecha:755
MF  : SD:infinity mecha:649


Again the first two images are good and the third is blurry (as expected, I suppose).
Did you changes the focus distance setting in the script parameter menu before you tried this?
« Last Edit: 30 / October / 2014, 12:27:13 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

*

Offline eponymous

  • *
  • 38
  • Canon A4000
Re: Manual Focus @ Infinity not working
« Reply #32 on: 30 / October / 2014, 12:33:38 »
(which seems to start up in review mode?)
All versions of CHDK startup in review mode.

<snip>

Did you changes the focus distance setting in the script parameter menu before you tried this?
That would have been good, huh?  :P

Once more, this time at ~30cm between end of lens and object:
Focus Test 0.3m
AUTO: SD:0.2m mecha:706
AFL : SD:0.2m mecha:707
MF  : SD:0.3m mecha:699


All images look good, but the DoF is around 10cm at this range, so that's not surprising. Not sure how big a deal the difference in lens extension is.
John

Re: Manual Focus @ Infinity not working
« Reply #33 on: 30 / October / 2014, 12:44:53 »
Not sure how big a deal the difference in lens extension is.
Part of the reason for my other test script is to characterize the mecha position vs reported focus distance vs requested focus distance vs zoom position.  Lots of data to wade through which is why I tried for simple first.

In testing so far, most of the mecha changes happen at close-up distances.  Once you get out more than 3 to 5 meters then everything tends to be in focus due to the depth of field of the little lens and the mecha setting does not change much with requested focus distance.
Ported :   A1200    SD940   G10    Powershot N    G16


Re: Manual Focus @ Infinity not working
« Reply #34 on: 30 / October / 2014, 12:48:41 »
log attached
Your log file shows the mecha position almost identical between the grouped shots so they should all look the same.   

And the second test shows that you did not change the focus distance setting in the script parameter menu when you shot the closeups.  But the camera tried to focus up close anyway - suggesting it is just ignoring the set_focus() commands.
Ported :   A1200    SD940   G10    Powershot N    G16

*

Offline eponymous

  • *
  • 38
  • Canon A4000
Re: Manual Focus @ Infinity not working
« Reply #35 on: 30 / October / 2014, 13:14:37 »
(which seems to start up in review mode?)
All versions of CHDK startup in review mode.

Quote
First, the script reports:

Focus Test 65.5m
AUTO: SD:1.4m mecha:663
AFL : SD:1.3m mecha:664
MF  : SD:infinity mecha:653


Strange - focus seems to be at infinity in the first two but the call to get_focus() is not returning that value.  And again, the out of focus mecha value is farther out (lower number) than the two in focus.
Yes, it is strange to me that the third one is fuzzy given the depth of field I'd expect. Any idea why that is?

I also turned on the DOF display (which I have in 1.2, but hadn't turned on in 1.3.0) and the pictures I took before weren't turning up with INFs. Not really sure why, since the house right in the middle is far enough away, but obviously the camera is taking other things into account.

So I changed the shot to something that did register INF across the board. Still the script reports something similar:

AUTO: SD:0.9m mecha:671
AFL : SD:1.2m mecha:668
MF  : SD:infinity mecha:656


Once again, the third shot is distinctly blurry and the other two are fine (attached screen shots).

Yes, weird that the distances reported are so short for the first two.
John

Re: Manual Focus @ Infinity not working
« Reply #36 on: 30 / October / 2014, 13:19:38 »
Could possibly be a coding error with where or when the script checks the current focus setting? I'll take a look later today.

Update : code looks okay
« Last Edit: 30 / October / 2014, 13:48:29 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

*

Offline philmoz

  • *****
  • 3450
    • Photos
Re: Manual Focus @ Infinity not working
« Reply #37 on: 30 / October / 2014, 15:26:44 »
I repeated yesterday's tests: one for infinity, other for a subject 30 cm closer (.3 m).
For the close distance testing, I used a ruler to make sure the distance between the objective and the subject was effectively 30 cm.
Log is attached.
DoF readings as follows:

1) Infinity test:
S/NL/FL-> INF/INF/INF
DOF/HYP -> inf/1.01 (before halpressing the shutter to get focus); inf/2.87 (after halfpressing the shutter)

2) Close distance test:
S/NL/FL-> .394/.346/.455
DOF/HYP -> .102/2.87

I did four consecutive runs for each subkect distance.

Both ran under Canon P mode, and Canon DoF "Mountain&Face" setting

As for the close distance test, the camera seemed to have missed the focus when in AFL and MF mode, when compared to the AUTO mode, as you can see from the pics below (from left to right, images in script shooting order)



For the close focus, where did you measure from - the end of the lens or the sensor plane?

The code is a bit messy; but I think CHDK assumes you are measuring from the end of the lens. It then tries to adjust the value sent to the camera to convert it to the distance from the sensor.

If you measured from the sensor then you can try checking the 'Use EXIF Subj. Dist (PC65)' setting (CHDK Settings -> OSD Settings -> DOF Calculator). This will turn off the lens to sensor adjustment.

Phil.
CHDK ports:
  sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
  g12 (1.00c, 1.00e, 1.00f & 1.00g)
  sx130is (1.01d & 1.01f)
  ixus310hs (1.00a & 1.01a)
  sx40hs (1.00d, 1.00g & 1.00i)
  g1x (1.00e, 1.00f & 1.00g)
  g5x (1.00c, 1.01a, 1.01b)
  g7x2 (1.01a, 1.01b, 1.10b)


Re: Manual Focus @ Infinity not working
« Reply #38 on: 30 / October / 2014, 15:29:58 »
Yes, it is strange to me that the third one is fuzzy given the depth of field I'd expect. Any idea why that is?
That's the point of the whole question. It's really hard to set out of focus a wide angle lens.
IMO the rear focusing point goes beyond the sensor because the focusing lens element* is setted wrongly too close to it. (*)usually a rear lens.
An alternative explanation could be that the middle lens group is setted into a wrong position.
Please WW correct me if i am wrong.
So i'm asking WW:
could we (I) set that mecha # via script? or that "FocusLensCurrentPosition" is a RO value we can get?

Re: Manual Focus @ Infinity not working
« Reply #39 on: 30 / October / 2014, 15:33:10 »
For the close focus, where did you measure from - the end of the lens or the sensor plane?

The code is a bit messy; but I think CHDK assumes you are measuring from the end of the lens. It then tries to adjust the value sent to the camera to convert it to the distance from the sensor.

If you measured from the sensor then you can try checking the 'Use EXIF Subj. Dist (PC65)' setting (CHDK Settings -> OSD Settings -> DOF Calculator). This will turn off the lens to sensor adjustment.

Phil.
This had come up before. As a matter of fact, I was just looking unsuccessfully for where reyalp and I discussed it.  It might explain the variation in closeup settings but not the "soft" focus some cameras see at infinity under set_focus ()?
« Last Edit: 30 / October / 2014, 15:35:10 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

 

Related Topics


SimplePortal 2.3.6 © 2008-2014, SimplePortal