infinity focus and setting higher ISO for evening shots on A490 - General Help and Assistance on using CHDK stable releases - CHDK Forum

infinity focus and setting higher ISO for evening shots on A490

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I've got CHDK build 0.9.9-1444 with an intervalometer script working on my A490, main purpose being as a camera to snap pictures every 2 seconds from my aerial platforms.  At first I was added the set_aflock 1 line to the script so the autofocus would be disabled, trying to remember to aim the camera at something far as the script started. However that did not work well for me and I was getting a lot of blurred shots so I took the line out and seem to be getting better results although not as many shots per flight because of the focus lag, but it's a good trade off.  Is there such a thing as a setting to just set the focus to infinity at the start, or at such a point that anything from say, 20' and further away would always be in focus?

The other thing was I noticed this camera sets what it thinks is the best ISO for the conditions. I notice that my lower light flights are producing 80% blurry shots, even when aimed at fairly bright backgrounds like the setting sun.  I just did a series of shots from 150' in the air of the sun setting and did not get one usable shot.  The camera seemed to be exposing for the foreground instead of the background and was obviously using slower shutter (flash is disabled from camera menu)

Is there a way to either push the ISO to get faster shutter speeds, or alternatively force a faster shutter speed somehow?  I suppose I could manually set the shutter speed to x, but I'd sooner have the camera just deliberately underexpose the foreground and calc the shutter speed on the background (sunset)

Is this doable or is it just restrictions I have to live with with a lower end camera like this?


thanks

Re: infinity focus and setting higher ISO for evening shots on A490
« Reply #1 on: 27 / July / 2012, 06:58:14 »
Is there such a thing as a setting to just set the focus to infinity at the start, or at such a point that anything from say, 20' and further away would always be in focus?
Take a look at this :
http://chdk.wikia.com/wiki/CHDK_scripting#set_focus_.2F_get_focus


Quote
Is there a way to either push the ISO to get faster shutter speeds, or alternatively force a faster shutter speed somehow?  I suppose I could manually set the shutter speed to x, but I'd sooner have the camera just deliberately underexpose the foreground and calc the shutter speed on the background (sunset)
This might help :
http://chdk.wikia.com/wiki/CHDK_scripting#set_iso_.2F_get_iso


A handly place to find this sort of thing :
http://chdk.wikia.com/wiki/CHDK_Scripting_Cross_Reference_Page
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline srsa_4c

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Re: infinity focus and setting higher ISO for evening shots on A490
« Reply #2 on: 27 / July / 2012, 09:21:17 »
I've got CHDK build 0.9.9-1444
It might also be a good idea to upgrade to a current release: http://mighty-hoernsche.de/

Re: infinity focus and setting higher ISO for evening shots on A490
« Reply #3 on: 30 / July / 2012, 12:57:35 »
thanks for the replies - I am getting a little better results now by playing with the Auto ISO settings and setting a min shutter speed - also updated to the newer firmware so I'm not sure what did what, but getting higher percentage of usable shots is the main thing.


 

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