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rawopint settings

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Offline reyalp

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rawopint settings
« on: 24 / April / 2018, 23:19:50 »
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Posting here in reply to a pm from @andrewexeter
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if I used rawopint - what settings should I start with? I film/wait for 6 hours each time I would like to be using the best settings at the start.

I use a canon ixus 70 - it has an option to tick on a ND filter

Any suggestions of help to get me started?
Unfortunately, rawopint has a lot of options and "best" really depends on the situation. Some testing is probably the best way to get a feel for it.

I think the defaults should mostly be reasonable. A few suggestions of things I'd change from default:

Interval
If you want shots taken at a steady interval, this needs to be longer than however long it takes your camera to save a picture, plus the longest exposure you want to allow in "Max Tv".

Max Tv Sec/1000
How long an exposure you want to allow. The default is 1 second. If you want more exposure at night you can go longer, but your interval will have to get longer too. If you use long exposures (usually more than a few seconds), the camera will start using "dark frames" which double the shooting time. You can disable dark frames in CHDK options.

Min Tv Sec/100k
I'd suggest around 50, to avoid exceeding 1/2000th sec.

ND Tv Sec/10000
I'd use 10 or 20 or so (~1/1000 - 1/500th), to avoid very short exposures since they can cause flickering.

Bv Ev shift
If you use something like 30%, lighting changes like sunsets, clouds etc will look more natural, with the scene getting somewhat darker / brighter as lighting changes. If you do a lot in post processing, it may be better to leave this off.

B Ev shift Base Bv
You can leave this on "First" if you are starting in bright light. If your scene will start in low light and go to full sun, it should be something like 11.

Max ISO
Depends on how much noise you want. 800 might not look good on an old camera like ixus70. High ISO also affects processing time.

Display
Off, if you want to maximize battery life.
Don't forget what the H stands for.

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Offline reyalp

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Re: rawopint settings
« Reply #1 on: 25 / April / 2018, 16:43:07 »
Replying to another PM
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I have tried to read up as much as I can - tomorrow I with test for the first time.
my max seconds exposure will be 10 sec = Max Tv Sec/1000 this will be 10000, correct?
Yes. Sec/1000 means the number is interpreted as 1/1000ths of a second.

Unfortunately the menu system is quite limited, so a lot of the units are funny like this.

If you use 10 second exposure and a 20 second interval, the dark frames subtraction I mentioned above will keep you from getting a 20 second interval, because a second or two is required to process and save the file.

If you want the interval to stay exactly 20 seconds, you can force dark frame off in the CHDK menu: Enhanced photo operations->dark frame subtraction OFF, or set your max exposure to something a little shorter, like 8 or 9 seconds. If dark frame is off, you might notice a purple glow around the corners or more hot pixels.

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my interval is going to be 20 second = interval sec/10 = 200 , yes?
Yes.

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my ixus 70 has an automatic ND - do I need to make any settings for this anywhere?
The settings in my post above are probably enough. There might be a small jump in exposure when the ND is changed by the script if the ND value is not correct, but from the code for this port I think the default should be OK.
Don't forget what the H stands for.

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Offline andrewexeter

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Re: rawopint settings
« Reply #2 on: 27 / April / 2018, 01:37:21 »
Here is my  rawopint timelapse - 90 mins waiting time at 20 second interval. CVS included - final image with Lightroom and a digital amber grad filter. Cloudy and drizzly day.

Your feedback please - I do not really understand the CVS data and at this stage unable to make a graph.
To take the best timelapse videos I can with only inexpensive equipment. Ixus 70

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Offline andrewexeter

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Re: rawopint settings
« Reply #3 on: 27 / April / 2018, 01:47:27 »

A longer timelapse with rawopint - 8 hours filming.

To take the best timelapse videos I can with only inexpensive equipment. Ixus 70


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Offline reyalp

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Re: rawopint settings
« Reply #4 on: 27 / April / 2018, 03:24:11 »

A longer timelapse with rawopint - 8 hours filming.
These look quite reasonable to me.  If there's something you would have liked to be different, I might be able to make suggestions.

I'm not sure why things get so blue around :40.

There are some log messages about the Av value (like av 554 != cam 578) I'm not entirely sure what this is about, it might have to do with incorrect ND value, but I don't think it's causing any major problem.

Attached are a couple charts from the 8 hour csv. These are made with Libreoffice Calc spreadsheet program. The X axis is frame number.

-exp shows exposure related parameters.
over_frac and under_frace are on the right Y axis as %, everything else is on the left in APEX*96 (meaning that each "stop" of each is a multiple of 96).
sv96 is ISO
tv96 is shutter
av96 is aperture, but really it's just show ND in or out
meter96 is the average exposure of the image
bv96 is the real brightness
bv_ev_shift is how much the script would adjust exposure to reflect scene brightness, if not limited by other limits.

This looks like a pretty typical rawopint run. You can see the ND filter go out and back in around frame 100, and then go out around 250.

You can see under_frac affects the exposure a lot, with the darker corners of the screen keeping the exposure up until limits are hit. I might increase the value of "Underexp -Ev" to 5 or 5 1/2.

-bt plots battery voltage (left Y axis) and temperature (right Y axis)
The only oddity here is that the battery temperature is consistently higher than the sensor, and the sensor is identical to optical in the log (I didn't plot optical).

The battery behavior looks pretty normal. You might be able to squeeze out a few more shots by adjusting the "Battery MIN Voltage" option in CHDK OSD battery settings to closer to the point where the camera shuts down. However, you should keep it above the point where the camera actually shuts down, because if the canon firmware does it's own low battery shutdown, it can corrupt the SD card.
Don't forget what the H stands for.

Re: rawopint settings
« Reply #5 on: 27 / April / 2018, 05:21:50 »
I'm not sure why things get so blue around :40.

The white balance does not change and is set at the first shot. I sometimes see that in my recordings too.

 

The only oddity here is that the battery temperature is consistently higher than the sensor, and the sensor is identical to optical in the log (I didn't plot optical).

That cannot be really. I've never seen anything like it. Could they be exchanged?
I would next time replace a warm battery with a cold to see which curve jumps.

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Offline andrewexeter

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Re: rawopint settings
« Reply #6 on: 27 / April / 2018, 09:23:05 »
Thank you guys for your quick feedback - to give you a bit more background to these last two photo tests. Regarding the 8 hour test - battery is a Pb - lead battery in a little body warmer - maybe this is why the temps are different? The operating setting are your defaults and suggestions. Interval at 20 seconds and both cameras in waterproof housing - outside temp about 12 degrees C.

The shorter video, at 90 mins waiting time was shot with different settings - aimed at day to night - however the battery used was just a tiny camera battery Lipo, thus the short run - I have not managed to produce a graph of the CVS yet but thank you for your advice on how to do it. It will be interesting to see how different the battery shows on a graph. I used settings suggested by reading MB's from Canada tests, but this video is a failed test because the battery died before the object of the test - the day to night.

I am very pleased with the results so far, thanks to every one who has made these fantastic scripts.
To take the best timelapse videos I can with only inexpensive equipment. Ixus 70

Re: rawopint settings
« Reply #7 on: 27 / April / 2018, 09:34:47 »
Regarding the 8 hour test - battery is a Pb - lead battery in a little body warmer - maybe this is why the temps are different?

Then I wonder where the temperature is coming from. The dummy batteries usually have none. Will probably be entered a wrong value ...


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Offline reyalp

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Re: rawopint settings
« Reply #8 on: 27 / April / 2018, 13:35:37 »
That cannot be really. I've never seen anything like it. Could they be exchanged?
I would next time replace a warm battery with a cold to see which curve jumps.
My thought was that Canon actually only used the "optical" temperature sensor on this camera, and reports the same value for CCD. That doesn't explain why the battery is higher though, or why there is a battery temp at all with an external. It doesn't seem like a problem in the port, the Canon firmware has named functions GetCCDTemperature, GetBatteryTemperature etc which seem to be used correctly.

@andrewexeter:
How is the external battery wired to the camera?

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The white balance does not change and is set at the first shot. I sometimes see that in my recordings too.
Yes, I'm just surprised it got that blue from an initial daylight WB.
Don't forget what the H stands for.

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Offline andrewexeter

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Re: rawopint settings
« Reply #9 on: 27 / April / 2018, 14:14:39 »
I made a dummy battery and connected it to a lead battery directly with crocodile clips.

Reyalp if you have time would you make a similar graph from csv from the 90min timelapse video clip? It would be interesting to compare visually the two battery readouts.

Tests were made on two different cameras, but at the same time, different rawopint settings, both in a underwater case - one camera with a large lead battery while the other used just the small canon lipo battery.

Regarding the blue - the day was overcast - does the light change to blue in the shadows before dark?
To take the best timelapse videos I can with only inexpensive equipment. Ixus 70

 

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