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1/2 step zoom steps

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1/2 step zoom steps
« on: 15 / September / 2011, 20:04:42 »
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question. I have got the "zoom shoot"by Keoeeit script up and running on my sx10. I got it to do 128 zoom steps taking a picture at each step. My question is can the zoom steps be 1/2 which would double 128 and make for a more smooth zoom if I use say a ".5" step? I am wanting to use it as a time lapse that zooms.

Re: 1/2 step zoom steps
« Reply #1 on: 15 / September / 2011, 20:25:52 »
Did you really get 120 zoom steps ?  The code in core/kbd.c suggests the SX20 really only has 8 zoom steps.

(Also - please don't post the same question in multiple threads.)

UPDATE :  maybe it does - http://chdk.setepontos.com/index.php?topic=5722.msg60076#msg60076
« Last Edit: 15 / September / 2011, 20:32:42 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

Re: 1/2 step zoom steps
« Reply #2 on: 15 / September / 2011, 21:14:13 »
pretty sure about the 128 steps, I'll double check after work tomorrow. Sorry for multipost. How do I delete the other post. I realized after posting that this is a script related question. I looked for a way to delete. Thanks. Can fractions be used as variables in scripts such as .5 or .3?

Re: 1/2 step zoom steps
« Reply #3 on: 15 / September / 2011, 22:14:51 »
pretty sure about the 128 steps, I'll double check after work tomorrow. Sorry for multipost. How do I delete the other post. I realized after posting that this is a script related question. I looked for a way to delete. Thanks. Can fractions be used as variables in scripts such as .5 or .3?
Don't worry about the multiple posts - my note was more an FYI that the people who might be able to help usually read all new posts (for every thread).

Meanwhile,  both the CHDK scripting languages use integer variables only.  Some general ways to work with that limitation are posted here :  http://chdk.setepontos.com/index.php?topic=1452.msg13206#msg13206

However, that won't help you much.  I'm afraid the zoom_step code works in fixed integer increments, which is okay for most CHDK cameras that only have zoom steps between 6 and 15 or so steps.  Apparently the SX20 megazoom has a continious mode.  To get finer control,  I suspect you would have to rewrite the core CHDK code.  Not too hard if you can program and have the time to setup a development environment.  Otherwise,  unless someone else has a better idea, you are probably out of luck.

And BTW - some of us would line to have "only" 120 zoom steps.



« Last Edit: 15 / September / 2011, 22:16:28 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16


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Offline SkyWalker9

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Re: 1/2 step zoom steps
« Reply #4 on: 16 / September / 2011, 13:23:54 »
Did you really get 120 zoom steps ?  The code in core/kbd.c suggests the SX20 really only has 8 zoom steps...
Just for clarification, the S-series of Canon PS have 129 steps (0-128). I've used this capability when scripting on my SX20, i.e. http://chdk.setepontos.com/index.php?topic=6149.msg65352#msg65352

I've zoomed my SX20 camera when shooting HD video and I've found the zoom to be very smooth, and when I've scripted a similar zoom from 0 to 129 it appeared to be about the same speed. People who have become accustom to HD on other video devices may not find 129 steps adequate on their camera.

Regarding zoom in half steps, when scripting I've always used integer values between 0 and 128 to avoid problems with the camera operation, i.e. "lock ups" or premature shutdown of camera while shooting.

Hope this helps.

 

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