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SX10 Shutter Speeds

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SX10 Shutter Speeds
« on: 28 / August / 2009, 12:27:14 »
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I have been playing with the shutter speed overrides with my new SX10.  I am able to get the extended long exposure times, however, I can't seem to get shutter speeds faster than the base camera ones like I could previously with my S2 and A570.  I have tried both through scripting and through the override menus.
Has anyone else with an SX10 been able to get faster shutter speeds?

Re: SX10 Shutter Speeds
« Reply #1 on: 02 / October / 2009, 15:40:33 »
I have been playing with the shutter speed overrides with my new SX10.  I am able to get the extended long exposure times, however, I can't seem to get shutter speeds faster than the base camera ones like I could previously with my S2 and A570.  I have tried both through scripting and through the override menus.
Has anyone else with an SX10 been able to get faster shutter speeds?

BUMP!

Has anyone else been able to verify this?  The fastest shutter I can seem to get is 1/3200 which is the same as the standard limit.
Is the physical limit really 1/3200 (or perhaps done intentionally by Canon)?  Or is there something wrong with the build?
I am currently using 103A, build 811.
As stated above, I had no problems getting better speeds on my S2 and A570 (1/16,000 verified, possibly better).

-tgq

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Offline reyalp

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Re: SX10 Shutter Speeds
« Reply #2 on: 02 / October / 2009, 18:07:09 »
Overrides on the SX10 work the same way as on other builds. If extra high shutter speeds don't work, then it's something different about the camera.
Don't forget what the H stands for.

Re: SX10 Shutter Speeds
« Reply #3 on: 02 / October / 2009, 18:22:51 »
I've just had a play with my SX10 and cant seem to see it changing anything. I've been trying to find some docs to explain what I should see but cant find any. Can someone please explain what should happen or point me at some docs so I can check to see if it is working or not?

Ta  Stuart


Re: SX10 Shutter Speeds
« Reply #4 on: 03 / October / 2009, 11:16:08 »
Overrides on the SX10 work the same way as on other builds. If extra high shutter speeds don't work, then it's something different about the camera.

I do understand that.  What I would like to find out is why.
- Is the camera simply not physically capable (I wouldn't think this, that it could go from 1/32000 capability to 1/3200 in one camera model)
- Is the camera further disabled so that CHDK no longer has permission to change these settings (Canon is on to us!)
- Are the software references moved/changed so that CHDK is no longer take advantage of the proper ones (ie propcase change or something like it).  I don't know enough about the dumps and code to check this out.

I do find it suspicious that the overrides are limited to only those available normally. With the exception of F11 and some of the ISO values, but these actually show up on the Canon interface when used as if they are part of the normal function (ie, the camera displays F11, ISO 4000, ISO 40, etc, not just the CHDK interface)
As opposed to the previous overrides that would work but would show up as something different on the Camera interface (1/16,000 would work but show up as 1/2000 or whatever the software limit was)

-Any thoughts by anyone, especially those who have the SX10 and did the porting for it?

-tgq

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Offline fudgey

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Re: SX10 Shutter Speeds
« Reply #5 on: 04 / October / 2009, 09:58:25 »
First, note that for these faster-than-M-mode-fastest-Tv exposures, in-camera PLAY mode EXIF view will not show the correct exposure and JPEG EXIF exposure time fields are incorrect as well. Only the resulting photo (by its lack of light) and the Canon MakerNotes section in the EXIF tag will reveal that you've actually achieved a short exposure time.


Does CHDK Tv override work in the camera's built-in Tv range? You mentioned you achieved extra long exposures, but that's a bit different from normal exposures. I'm asking this because RaduP is struggling with Tv overrides in his port, and it appears possible that some new cameras use a previously unknown propset.

Set Tv to something normal like 1/500 s and shoot (if you're in Tv mode or M mode, set in-camera Tv to something else such as 1/10 s, or if you're in a fully automatic mode, make sure you aren't in bright light and during half shoot check that the camera didn't select Tv 1/500 s).

For that photo, enable Canon builtin EXIF display in PLAY mode and check Tv. It should be 1/500 s. If it isn't, Tv override is broken (or you're doing something wrong). But if it is, Tv override works and there's something different in sx10 regarding short exposures.

You could also try shooting at 1/10000 and then check JPEG EXIF MakerNotes:ExposureTime (exiftool -MakerNotes:ExposureTime *.JPG). If that shows something close to 1/10000 (I get 1/9955 on my a570is), CHDK is working as it is on other cameras. If it doesn't, either something is different or you're not doing it right.

If makernotes exposure time indicates you successfully attempted a short exposure but your photo doesn't match that setup, it's likely that your camera just can't go that fast. The limit could still be something slightly faster than 1/3200, especially with a narrow aperture (such as F/11). Zoom could affect this limit as well.




Re: SX10 Shutter Speeds
« Reply #6 on: 04 / October / 2009, 11:18:52 »
I'll do a few more checks like you mentioned.
I do know it isn't getting the shoreter shutter speeds as I have done comprison checks of the final images for exposure levels.  Everything beyond the camera limit is identical in exposure level.

I do think the overrides are working generally as I use them in scripts I run no problem (but only within normal ranges).
I am hoping it may have something more to do with a changed propcase or something like that rather than general camera limitation or disabling.  Perhaps I'll try some propcase scans.

-tgq

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Offline reyalp

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Re: SX10 Shutter Speeds
« Reply #7 on: 04 / October / 2009, 17:25:58 »
I'll do a few more checks like you mentioned.
I am hoping it may have something more to do with a changed propcase or something like that rather than general camera limitation or disabling.  Perhaps I'll try some propcase scans.
If it works in the normal range, it's not a propcase problem.
Don't forget what the H stands for.


Re: SX10 Shutter Speeds
« Reply #8 on: 04 / October / 2009, 19:54:36 »
I'll do a few more checks like you mentioned.
I am hoping it may have something more to do with a changed propcase or something like that rather than general camera limitation or disabling.  Perhaps I'll try some propcase scans.
If it works in the normal range, it's not a propcase problem.
yeah, it doesn't seem to be.  I tried some simple tests.  I can assign procases outside of the range and they register as the set propcase, but the exposure is still the same.  I'm supposing it is either deeper in the build/port code which I am not up on or that it is inaccessable and virtually disabled by Canon either by design or by coincidence.  Some day when I get time to learn all about the CHDK code and firmware dumps, I may look deeper, but that would be a lot of learning and time that I don't have to spare right now, so if anyone who is familiar with the coding and SX10 port/firmware can offer further insight it would be appreciated in the meantime.

Also, what is different about the long exposure ability relative to how shutter speeds are set?  Is there something in that area that can be of help?

Are there any other cams where this is a known issue?  I would imagine the SX20 is/will. 

Re: SX10 Shutter Speeds
« Reply #9 on: 04 / October / 2009, 21:02:46 »
Some further minor info.  I thought to check at intermediate, non-normal shutter speeds to make sure that the shutter speed setting is not just using pre-indexed ones.  Canon built-in shutter speeds are at 1/3EV steps, so I stepped through a series at 1/6EV steps and the results appeared correct, the intermediate shutter speeds (ones at non-normal speeds) were of differing exposure level.  So the setting appears to be implementing correctly in this respect.

 

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