KAP & UAV Exposure Control Intervalometer Script

OhSnap

32

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #740 on: 21 / February / 2016, 04:28:38 »

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Oh ok this was caused because the save RAW param was active (CHDK bug would always select it after changing other settings) , thus taking mutch longer to shoot a photo and often missing the next trigger. I guess this is what you were seeing.
What about the exposure issue? What do you think causes it?

Pixhawk triggers the cam by sending a 5v pulse through the usb.
This is how I set it up: http://www.tuffwing.com/support/pixhawk_camera_trigger_cable.html

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waterwingz

12139

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #741 on: 21 / February / 2016, 11:28:59 »

Quote from: OhSnap on 21 / February / 2016, 04:28:38

CHDK bug would always select it after changing other settings

AFAIK, this is not a bug that anyone else has reported. However, it is very easy to enable it accidentally while working in <ALT> mode - CHDK has an annoying keyboard shortcut feature that can't be fully disabled.

See : CHDK User Manual : Shortcut Keys

Maybe I'll add a warning at script startup if RAW is enabled. Either that or allow a script parameter to be used to let you specify if RAW should be enabled (and override the CHDK setting if necessary).

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What about the exposure issue? What do you think causes it?

Do you get the same problem when you shoot without RAW enabled?

To make things easier to diagnose, I can post a small test script that is basically an extract of the script's exposure logic.That would make it easier to determine if it's a script issue, a camera setup issue, or a CHDK port issue. If you can run some tests that would help.

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Ported : A1200 SD940 G10 Powershot N G16

OhSnap

32

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #742 on: 21 / February / 2016, 12:33:56 »

Ok it seems the RAW was getting enabled when I was accidentally pressing the debug button (it's a touchscreen).
The over-exposure issue happens whether with raw enbaled or not. Today did a couple of flights with exposure comp. set at -0.66 and that pretty mutch corrected it, but I'm worried it may alter the quality of the pics.

The second camera onboard running the NDVI filter (infront of sensor and behind lens) also had a serious over exp. issue and had to correct that by setting the exp comp at -1.

Also in both cases the camera seems to "think" that the over exp picture is OK, as the ISO levels are often high along with f values of 2.7.

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waterwingz

12139

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #743 on: 21 / February / 2016, 13:16:27 »

Quote from: OhSnap on 21 / February / 2016, 12:33:56

Ok it seems the RAW was getting enabled when I was accidentally pressing the debug button (it's a touchscreen).
The over-exposure issue happens whether with raw enbaled or not. Today did a couple of flights with exposure comp. set at -0.66 and that pretty mutch corrected it, but I'm worried it may alter the quality of the pics.

Correcting the exposure should only improve the "quality" of the pics.

Can you try the attached script ?? The script will take two shots - one with Canon's exposure setting and the other with the shutter speed and ISO both increased by one stop using the kap_uav.lua's exposure setting mechanism. Use it to shoot at anything outdoors.

The resulting two images should appear to be exposed exactly the same. Are they?

exp_test.lua (2.62 kB - downloaded 16 times.)

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Ported : A1200 SD940 G10 Powershot N G16

OhSnap

32

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #744 on: 21 / February / 2016, 13:54:55 »

I'll have to wait till tommorow, it's almost 9pm here.
So I only copy the script in the scripts folder and just activate it?

Here is the result after setting the exposure comp to -0.66 : https://www.dropbox.com/s/135par85djmm6f7/IMG_0181.JPG?dl=0

Also one more question, most flights are done between 40-60m do you think enabling focus at infinity would be a good idea? Some pics with default auto focus turn out a bit blurry.

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waterwingz

12139

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #745 on: 21 / February / 2016, 14:19:26 »

Quote from: OhSnap on 21 / February / 2016, 13:54:55

I'll have to wait till tommorow, it's almost 9pm here.

No problem.

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So I only copy the script in the scripts folder and just activate it?

Yes. Point the camera at something and launch the script. It will switch to shooting mode if necessary and immediately take the two shots.

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Here is the result after setting the exposure comp to -0.66 : https://www.dropbox.com/s/135par85djmm6f7/IMG_0181.JPG?dl=0

I was a little worried that the ND filter is not being handled correctly but the exposure comp needed would need to be a lot more than -0.66 if that was so.

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Also one more question, most flights are done between 40-60m do you think enabling focus at infinity would be a good idea? Some pics with default auto focus turn out a bit blurry.

I would definitely recommend using focus at infinity for KAP and UAV work.

However, you might want to test how well it works (even just shooting on the ground at a landscape). Some cameras don't focus well using that option - we don't really know why for sure. It's very camera dependent - my S100 works well for example but a few other S100's don't. But if it works for you, it will speed up shooting and lessen some "unsharp" photos where it can't quite find focus automatically.

There is a long thread about this here : Manual Focus @ Infinity not working

Edit : also Setting focus from scripts or menus if you are having trouble sleeping.

« Last Edit: 21 / February / 2016, 14:23:51 by waterwingz »

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Ported : A1200 SD940 G10 Powershot N G16

srsa_4c

4451

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #746 on: 21 / February / 2016, 16:29:27 »

@WW
The ixus240/elph320 port doesn't redefine CAM_MARKET_ISO_BASE. Could that be the cause of wrong exposure?

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waterwingz

12139

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #747 on: 21 / February / 2016, 16:47:50 »

Quote from: srsa_4c on 21 / February / 2016, 16:29:27

@WW
The ixus240/elph320 port doesn't redefine CAM_MARKET_ISO_BASE. Could that be the cause of wrong exposure?

Hmmm ... that would certainly explain it. The result of having that #define missing when it's needed would be a one f-stop overexposure when CHDK attempts to set the SV96 value. I was hoping to see something like that with the test script I posted but tracking it down without your hint here would have been hard!

The other camera that has been reported to overexpose slightly is the ixus255_elph330hs and it also does not have CAM_MARKET_ISO_BASE defined. Further, neither camera is reported as having been tested here : CAM_MARKET_ISO_BASE - please test

If the test script shows the one stop offset, or OhSnap can run the isobase.lua script (attached) we should be able to nail it down by changing that #define and rebuilding.

Thanks.

iso_base.lua (1.01 kB - downloaded 16 times.)

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Ported : A1200 SD940 G10 Powershot N G16

OhSnap

32

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #748 on: 22 / February / 2016, 04:40:55 »

Here are the results of running the test script on a bright sunny day:

https://www.dropbox.com/s/l2fnm1wx5hhqf82/IMG_0223.JPG?dl=0 - Photo 1
https://www.dropbox.com/s/bvyr7i4ye8i96fx/IMG_0224.JPG?dl=0 - Photo 2

I can clearly see a difference between the two, if that's what we're looking for.

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waterwingz

12139

Re: KAP & UAV Exposure Control Intervalometer Script

« Reply #749 on: 22 / February / 2016, 05:21:00 »

Quote from: OhSnap on 22 / February / 2016, 04:40:55

I can clearly see a difference between the two, if that's what we're looking for.

Thanks. That pretty much confirms a problem with the port. To confirm the source of that problem, can you please run the test script I posted above and report the results? Fixing the camera port will be easy if that confirms the cause.

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Ported : A1200 SD940 G10 Powershot N G16