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Manual Focus @ Infinity not working

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Re: Manual Focus @ Infinity not working
« Reply #140 on: 01 / December / 2015, 10:40:01 »
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I would of course happy to say yes.... but with some reserves.
first of all i never did it with this last "recent" camera putting infinity at 1/2m
for the others i've tried many times to find a reliable method using set_focus. (even setting focus before each shoot) this has never  proved to be reliable enough having some unstable results. passing many hours trying to correlate resultats with all possible actions during kap session. even at wide angle. I would say that results were more unreliable at wa ! something we are not used in kap: longer the focal, sharper the pics !!
so after many attempts i came back to AF script (with an automatic reshoot if get_focus <> -1) with these cameras, results are quite OK, even for reshoot pictures. that's the only trick i can humbly do.
but this does not work with the last camera as for this one, as infinity is 1/2 meters it always reshoots !
I hope i'm clear.

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Offline reyalp

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Re: Manual Focus @ Infinity not working
« Reply #141 on: 14 / December / 2015, 22:41:28 »
if of interest here are typical results
here are 2 pics from this testing session. JPG direct from camera.
Looking at the embedded "CanonSi Makernote" information in the image shows the AF image with a subject distance of 100.  Same result as srsa_4c! The MF image shows it's subject distance as 6553.  Exactly what CHDK tries to set it to 
FWIW, I a similar thing on g7x, obviously without CHDK.

Setting MF to the max distance at full wide results in very out of focus images, FocusDistanceUpper = 65.53
Reducing the focus distance until the Canon UI distance bar shows one tick less then infinity (which is ~5 clicks of the dial) results in much better focus, FocusDistanceUpper = 15.92

The last numbered mark in the canon UI is 5 meters.

100% crop examples:

65.53 https://app.box.com/s/juy47hquntkm8kiu8f18hfs1eqns3h99
15.92 https://app.box.com/s/w2ps5bl3f72f1nquhhxjixnt333bkdh2

The big tree is ~100 meters away.

Don't forget what the H stands for.

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Offline eponymous

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Re: Manual Focus @ Infinity not working
« Reply #142 on: 15 / December / 2015, 15:00:37 »
Unfortunately, I cannnot run the MF mecha test3 script. I get a message
:60 attempt to index global 'capmode" (nihil value).
The chdk installation is not completed. You need the file CHDK/LUALIB/capmode.lua. Download the complete CHDK package for your camera and copy all files from the zip file to the sd card.

msl

Thought I'd try this out on my A4000, but I'm getting the same error, and the capmode.lua file is definitely on my SD card.

CHDK 1.5.0.
John

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Offline reyalp

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Re: Manual Focus @ Infinity not working
« Reply #143 on: 15 / December / 2015, 15:54:57 »
Thought I'd try this out on my A4000, but I'm getting the same error, and the capmode.lua file is definitely on my SD card.

CHDK 1.5.0.
It appears there is a bug in the script. It does not load the capmode module. If the file were missing, it would give a different error.

You could add capmode=require'capmode' at the top, but considering it can't run as written, it may not be the script waterwingz intended to post.

On the broader topic of the thread:
It occurred to me that you could use raw op to detect contrast and generate a camera specific calibration. The user would need aim the camera at an appropriate stable, distant target.
Don't forget what the H stands for.


Re: Manual Focus @ Infinity not working
« Reply #144 on: 15 / December / 2015, 19:36:06 »
It appears there is a bug in the script. It does not load the capmode module. If the file were missing, it would give a different error.  You could add capmode=require'capmode' at the top, but considering it can't run as written, it may not be the script waterwingz intended to post.
That was over a year ago - I think I tried to say in the post that the script was not actually tested.  No idea why so I fixed there bugs and reposted it :  focus3.lua.   

As mentioned a couple of weeks ago,  I've been playing with a script that builds a calibration table that can be used to set focus at infinity by other script at various zoom positions.  Waiting for a clear sunny day to field calibrate several of my cameras with a distant object to see how well it works.

Quote
On the broader topic of the thread:
It occurred to me that you could use raw op to detect contrast and generate a camera specific calibration. The user would need aim the camera at an appropriate stable, distant target.
Neat idea.  But I think that's basically what the "half press" focus ( and set_aflock(1) ) commands already do?
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline reyalp

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Re: Manual Focus @ Infinity not working
« Reply #145 on: 15 / December / 2015, 20:48:05 »
Neat idea.  But I think that's basically what the "half press" focus ( and set_aflock(1) ) commands already do?
If it works that would certainly be simpler and faster. I had the (possibly mistaken) impression from earlier discussion that reading back the SD from Canon AF didn't give usable values. Maybe that was due to confusion about the different CHDK and propcase values.
Don't forget what the H stands for.

Re: Manual Focus @ Infinity not working
« Reply #146 on: 15 / December / 2015, 21:18:38 »
If it works that would certainly be simpler and faster. I had the (possibly mistaken) impression from earlier discussion that reading back the SD from Canon AF didn't give usable values. Maybe that was due to confusion about the different CHDK and propcase values.
I've tried to reread the last 18 months of set_focus() threads & posts and confess to be confused. And mostly by my own posts I'll confess  :-X

We now know that trying to set focus at full wide angle zoom is problematic. But that may have seemed worse at the time because we did not understand that a SD of 1 or 2 meters would actually give sharp focus at infinity at full wide angle for some cameras.  We just didn't believe it and made wrong decisions based on that.

My current assumption is that if you let the camera focus at a distant object, you can get a valid SD and/or mecha position that will work for each zoom step.  The exact value may vary from shot to shot as the lens mechanism is not very precise and acceptable focus at infinity can occur over a range of settings - especially at maximum wide angle.    But there should be a set of values that will work for any particular camera at any zoom step setting and focus at infinity.

I'm still working on proving this - will likely take me a couple of weeks to find time to finish my testing. It would help if I owned one of the really bad cameras but I'll depend on some of the forum regulars for that.

Ported :   A1200    SD940   G10    Powershot N    G16

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Offline eponymous

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Re: Manual Focus @ Infinity not working
« Reply #147 on: 16 / December / 2015, 13:51:47 »
If it works that would certainly be simpler and faster. I had the (possibly mistaken) impression from earlier discussion that reading back the SD from Canon AF didn't give usable values. Maybe that was due to confusion about the different CHDK and propcase values.
I'm still working on proving this - will likely take me a couple of weeks to find time to finish my testing. It would help if I owned one of the really bad cameras but I'll depend on some of the forum regulars for that.
I have an a4000, which might qualify in that category. :) Let me know what I can do.

Edit: Tried it out with AFL on and the focus stayed the same within every zoom setting. Switched to MF or None and it then changed with every shot. Sadly, the sun had set by the time I figured that out, so more after sunrise!
« Last Edit: 16 / December / 2015, 17:20:07 by eponymous »
John


Re: Manual Focus @ Infinity not working
« Reply #148 on: 16 / December / 2015, 15:10:21 »
Quote
My current assumption is that if you let the camera focus at a distant object, you can get a valid SD and/or mecha position that will work for each zoom step.  The exact value may vary from shot to shot as the lens mechanism is not very precise and acceptable focus at infinity can occur over a range of settings - especially at maximum wide angle.    But there should be a set of values that will work for any particular camera at any zoom step setting and focus at infinity.

I'm still working on proving this - will likely take me a couple of weeks to find time to finish my testing. It would help if I owned one of the really bad cameras but I'll depend on some of the forum regulars for that.

I hope your assumption is correct, but from my perspective, even monitoring the mecha position during kap session, I never had reproductible results (although i recognize my approach is by far less structured)
I'll be happy to test on a couple of delinquants S100 if this is not driving me crazy again ;-)

Re: Manual Focus @ Infinity not working
« Reply #149 on: 26 / September / 2016, 18:57:01 »
Any news on this topic?  Having encountered problems with MF (Canon UI) pre-set/'locked' to be around 2m I encounter soft images.  I can get satisfactory results (focus) when stationary but when trying taking pictures while running/jogging the results are poor.  I've recently acquired two more S100 with the intention of comparing them and have already discovered that A and B differ significantly in focus accuracy and image quality but appear to have the similar problem when running.  (All exposure settings are manual, IS is off, as are MF assists.)

I am looking to CHDK to analyse and solve the problem but after reading this thread am concerned that variability between cameras/lens settings/shooting circumstances will prove too complex.  Is anyone out there having reliable success with KAP using a S100? (It seems similar to my task of relibaly taking a shot (instantly) with pre-set focus
   

 

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