A2400 porting thread

waterwingz

12140

Re: A2400 porting thread

« Reply #90 on: 26 / May / 2014, 15:29:25 »

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I assume it has something to do with where to hooks are placed in capt_seq.c. The fact that overrides work when the shutter button is pushed down without a pause at half-press for focus suggests multiple paths through the capt_seq task?

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AK

10
Canon A2400 IS

Re: A2400 porting thread

« Reply #91 on: 30 / May / 2014, 14:07:17 »

Sorry for the late reply, I had disabled IS when I bought the camera to save battery. But it was enabled when I had done the previous tests.
I tried the same test with ISO and shutter overrides this time with IS turned off completely. Sadly had the same results.
ISO or shutter overrides dont take effect when AF lock occurs but same behavior all works when I press the shutter button all the way down without waiting for AF lock.

Hope it helps.
I am not that good with the code and dont have much expertise in that but will give it a go and help if I can...

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AK

10
Canon A2400 IS

Re: A2400 porting thread

« Reply #92 on: 03 / October / 2014, 08:58:03 »

Hi Guys,

Still the same issue is present on the stable release version 3598 1.2.0

I cant use my camera with CHDK in manual mode to set the ISO or shutter speeds.
Basically my camera behaves similar to auto mode even in manual...

Any help would be appreciated.

Quote from: AK on 26 / May / 2014, 11:04:39

Thanks for the quick

I am using the camera in P mode.
I took two consecutive shots of the same scene, its pretty dim room.

1. With ISO set to 100 and Ev Step set to 1/40 I took a shot by pressing the shutter half way and let the AF lock followed by a full press to take the shot. I went to view the image and saw that the image details to be ISO 800 and shutter speed as 1/20
The image looked fairly bright as if I had taken it with auto mode.

2. With the same ISO set to 100 and Ev step set to 1/40 I took the shot this time pressing the shutter button all the way down without waiting for the AF to Lock and ended up checking the image details to show it had indeed taken a shot with the set ISO as 100 and shutter as 1/40. The image was pretty dark as expected.

I was initially confused too and double checked that I was using the camera in Auto or Program mode.
Also if it helps in any way I had tried the above test with the ISO set to auto, but the camera was still in Program mode.

Maybe I will try to set the ISO manually from the camera menu to some value. But I am not sure if thats the way I need to use CHDK ISO override. Please correct my understanding if Im wrong, irrespective of the Auto ISO I expect the CHDK setting to override it. But just to be clear I tried all the above with the camera in Program mode only.

Quote from: waterwingz on 26 / May / 2014, 15:29:25

I assume it has something to do with where to hooks are placed in capt_seq.c. The fact that overrides work when the shutter button is pushed down without a pause at half-press for focus suggests multiple paths through the capt_seq task?

« Last Edit: 03 / October / 2014, 09:00:53 by AK »

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srsa_4c

4451

Re: A2400 porting thread

« Reply #93 on: 03 / October / 2014, 16:14:27 »

Quote from: AK on 03 / October / 2014, 08:58:03

Still the same issue is present on the stable release version 3598 1.2.0
I cant use my camera with CHDK in manual mode to set the ISO or shutter speeds.
Basically my camera behaves similar to auto mode even in manual...

Do you, by any chance, have "servo af" enabled in the Canon rec menu?

My a3400 (same generation, as already mentioned) does this (Canon settings: P mode, ISO1600):
servo AF not enabled:
- half press -> AF -> full press: overrides seem to be respected
- fast full press: overrides seem to be respected, exif gets wrong ISO (200 instead of 100)
images seem equally exposed

servo AF enabled:
- half press -> AF -> full press: shutter speed is not respected, ISO shows as 200
- fast full press: overrides seem to be respected, exif gets wrong ISO (200 instead of 100)
1st image is brighter, 2nd gets same exposure as in the previous experiment

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AK

10
Canon A2400 IS

Re: A2400 porting thread

« Reply #94 on: 04 / October / 2014, 02:05:12 »

Hi srsa_4c,
Thank you for the quick reply...

Exactly same behavior as you mentioned...!!

With servo AF disabled it works fine both ways, shutter half press or fast full press.
With servo AF enabled while taking a shot with shutter half press, overrides are not respected. Fast full press overrides are respected.
Although I have not confirmed the exif data (I don't know how, don't have photoshop to check RAW image properties. I'll confirm later)
But I'm pretty sure that it behaves exactly as you said, similar to the A3400.

« Last Edit: 04 / October / 2014, 02:07:01 by AK »

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srsa_4c

4451

Re: A2400 porting thread

« Reply #95 on: 04 / October / 2014, 18:37:41 »

Quote from: AK on 04 / October / 2014, 02:05:12

With servo AF disabled it works fine both ways, shutter half press or fast full press.
With servo AF enabled while taking a shot with shutter half press, overrides are not respected. Fast full press overrides are respected.

Thanks for confirming.
Making overrides work with servo AF would require some research (and the result isn't guaranteed), which may or may not happen. I also tried another camera (sx280), servo AF has the same influence on it, so the issue likely affects newer cameras.
For the time being, switch servo AF off when overriding exposure.

Quote

Although I have not confirmed the exif data (I don't know how, don't have photoshop to check RAW image properties. I'll confirm later)

No need for Photoshop, the camera itself can display these picture details in playback mode. Many image viewer programs can display exif data BTW.

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AK

10
Canon A2400 IS

Re: A2400 porting thread

« Reply #96 on: 06 / October / 2014, 00:54:32 »

For now I guess I can live without servo AF.
I did check the ISO values on the camera itself. It does show the proper ISO values which I had set while taking the picture with Servo AF enabled.
For example, I had set ISO override to 100 and when the overrides were respected (fast full press) it did show up as 100 in the playback mode. So I guess this is one this less to worry about in A2400 unlike the A3400.

Let me know if I can help with anything.

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