Aperture Elph 115

hokiespurs

Aperture Elph 115

« on: 22 / April / 2015, 17:38:03 »

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Hi, I'm running some intervalometer scripts on an Elph 115, and am having trouble with the aperture not staying fixed. The pictures were being taken outside on a bright day with an exposure fixed at 1/2000, iso of 100, and the ND filter state fixed as "out". The pictures were being taken from a moving vehicle and the first picture was taken at f/3.2 (which looked good), and all subsequent pictures were taken at f/9.0 (which was dark). I've read online that the Elph 115 only has an aperture range of: f/3.2 (W) - f/6.9 (T) (taken from http://www.usa.canon.com/cusa/consumer/products/cameras/digital_cameras/powershot_elph_115_is#Specifications).

Any thoughts on what might be going on? Is there a way to set the aperture in a script? I tried using the set_av96 command, but am not sure I implemented it correctly. Thanks!

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waterwingz

12038

Re: Aperture Elph 115

« Reply #1 on: 22 / April / 2015, 17:47:31 »

Quote from: hokiespurs on 22 / April / 2015, 17:38:03

I've read online that the Elph 115 only has an aperture range of: f/3.2 (W) - f/6.9 (T)

Your Elph115 does not have a variable aperture. The reported aperture only changes when you either adjust the zoom position or the ND filter is inserted. The spec f/3.2 (W) - f/6.9 (T) only gives you an indication of how the aperture changes with zoom position. This is not something you can set.

Quote

The pictures were being taken outside on a bright day with an exposure fixed at 1/2000, iso of 100, and the ND filter state fixed as "out". The pictures were being taken from a moving vehicle and the first picture was taken at f/3.2 (which looked good), and all subsequent pictures were taken at f/9.0 (which was dark).

Where you using CHDK to set the Tv and ISO values? If so then the camera must have inserted the ND filter even though you told it not too with the CHDK menu item.

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Any thoughts on what might be going on? Is there a way to set the aperture in a script? I tried using the set_av96 command, but am not sure I implemented it correctly. Thanks!

You can't set something that is not there so the set_av96() command will not help.

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hokiespurs

Re: Aperture Elph 115

« Reply #2 on: 23 / April / 2015, 10:18:18 »

Thanks waterwingz!

The iso=100, shutter speed=1/2000, and ND filter='out' were set in the "enhanced photo operations" menu.

So it sounds like even though it was set to not drop the ND filter in, the camera still determined that it should use the ND filter(it was a very bright day), which resulted in the F9.0 (ND Filter In).

Is there a better way in CHDK to lock the ND filter out?

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