Yet Another Sunset Script (yass) v4.5

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Re: Yet Another Sunset Script (yass) v4.2
« Reply #50 on: 05 / June / 2014, 08:29:47 »
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Settings last night:
Shot Rate: 10"
Tv normal Limit: 1/4"
Tv low limit 12"
ISO default:  100
ISO Upper limit: 1250
Exposure ramp rate:  medium
Aperture setting: min_Av
Use ND Filter:  eneabled
Raw Enable:  Disabled
Those are pretty much the defaults other than the ISO Upper limit (changed from 400 to 1250) and Tv low limit from 10" to 12".  Should be okay.

One thing occurred to me immediately that I should probably have mentioned and it's why I wanted to see the log files.  My strongest suspicion is that this is related to the camera's ND filter engaging/disengaging.

When I tried using the versions of the script by the previous authors,  I would see a jump like that when my camera automatically introduced or removed the ND filter.  Cameras with adjustable apertures (i.e. user settable f-stops) do not tend to automatically engage the ND filter  - camera with fixed apertures (other than what changes with zoom position)  do. So I added code to control the ND filter and rather than just force the ND filter off,  I added logic to control it as part of the exposure adjustment code.

The catch here is that I assumed the inserting ND filter was the equivalent of changing by 3 f-stops.  That seemed to work well on the camera I was using at the time (A1200) and matched testing of the camera and my research on the forum.  I've since noticed some variation between camera models in that number and so you may need to "calibrate" the factor used by the script.

To change the factor today, you'd need to edit line 89 of the script where it says :
Code: [Select]
    nd96=288                -- ND filter's number of equivalent f-stops
Changing the 288 to 192 gives you 2 f-stops, 288 to 96 gives you one f-stop, and so on.

Or you can just disable the ND filter altogether using the available script parameter in the CHDK Script Menu.

All of the above is dependent on seeing if the ND filter position was reported as changed when the exposure suddenly jumped.

There are a couple of things I can do here.  First of all,  I should make the ND filter calibration factor something that can be set in the script parameters so future users do not have to edit the code.  And I can pretty easily provide a simple script that will provide the correct calibration factor.  I'll do those tonight regardless of what you find. (I suppose I could even make it an automatic part of the program that runs at the start for a few seconds if ND filter mode is enabled).



Ported : A1200  SD940  G10  Powershot N  G16*

Re: Yet Another Sunset Script (yass) v4.2
« Reply #51 on: 05 / June / 2014, 15:39:46 »
Sounds good to me.  I'll leave the ND settings as is to be able to replicate last nights results.  I'll provide you with the logs tonight. Thx.
« Last Edit: 05 / June / 2014, 15:58:44 by El Pistoffo »

Re: Yet Another Sunset Script (yass) v4.2
« Reply #52 on: 05 / June / 2014, 21:37:46 »
Sounds good to me.  I'll leave the ND settings as is to be able to replicate last nights results.  I'll provide you with the logs tonight. Thx.
Ok.

Meanwhile, here's a little script that will actually measure the correct offset value (in f-stops or apex96 units) of your camera's ND filter.  Useful if you want to adjust the script.

Update : note that the script becomes confused in bright light ( i.e. outdoors).  Works best in an indoor setting with normal lighting.
« Last Edit: 01 / November / 2014, 13:56:04 by waterwingz »
Ported : A1200  SD940  G10  Powershot N  G16*

Re: Yet Another Sunset Script (yass) v4.2
« Reply #53 on: 05 / June / 2014, 22:31:27 »
Sounds good to me.  I'll leave the ND settings as is to be able to replicate last nights results.  I'll provide you with the logs tonight. Thx.
Ok.

Meanwhile, here's a little script that will actually measure the correct offset value (in f-stops or apex96 units) of your camera's ND filter.  Useful if you want to adjust the script.

Even though I had logging enabled in the script I cannot find the log. It's not in the logs folder or anywhere else that I could find.  Rats! >:(

Tonight's TL had the same issue.  I guess I will try adjusting the ND filter as you suggested.  I'l try that little script tomorrow.  I might start off with the lowest ND setting to start.  Would disabling the "Use ND Filter" be an option?

I'll post link to tonights TL when ready.

Thx

Exposure pop at :28

http://youtu.be/DttL_m38_D0
« Last Edit: 05 / June / 2014, 22:55:07 by El Pistoffo »


Re: Yet Another Sunset Script (yass) v4.2
« Reply #54 on: 05 / June / 2014, 22:45:04 »
Even though I had logging enabled in the script I cannot find the log.  Rats! >:(
The log file is called yass4.csv.  It should be located in the root (top) directory on your SD card.  You likely won't be able to see it if you try to use a USB cable between your camera and PC.  You need to read the card with an SD card reader attached to your PC.

Quote
Tonight's TL had the same issue.  I guess I will try adjusting the ND filter as you suggested.   I'll try that little script tomorrow.  I might start off with the lowest ND setting to start. 
If you use the script,  it will give you an "exact" number to use.  Run it a couple of times to be sure.

Quote
Would disabling the "Use ND Filter" be an option?
Yes - but then we would not learn anything.
Ported : A1200  SD940  G10  Powershot N  G16*

Re: Yet Another Sunset Script (yass) v4.2
« Reply #55 on: 05 / June / 2014, 23:02:23 »
I always use an SD card reader.  I'll check the root directory more closely for that log.

Does your ND script need to be run with bright daylight conditions same as those used in the TL?

Thx.

Re: Yet Another Sunset Script (yass) v4.2
« Reply #56 on: 05 / June / 2014, 23:11:04 »
Does your ND script need to be run with bright daylight conditions same as those used in the TL?
It doesn't care much -  I tested it tonight with only my 60W desk lamp lighting some junk on my desk.
Ported : A1200  SD940  G10  Powershot N  G16*

Re: Yet Another Sunset Script (yass) v4.2
« Reply #57 on: 06 / June / 2014, 08:51:46 »
Log file from last night.

Thx



Re: Yet Another Sunset Script (yass) v4.2
« Reply #58 on: 06 / June / 2014, 10:05:25 »
Which image showed the jump?

IMG_8403.JPG ?

Log is interesting. Something I should have asked earlier - what version of the script are you running ?
« Last Edit: 06 / June / 2014, 15:13:11 by waterwingz »
Ported : A1200  SD940  G10  Powershot N  G16*

Re: Yet Another Sunset Script (yass) v4.2
« Reply #59 on: 06 / June / 2014, 16:30:55 »
Which image showed the jump?

IMG_8403.JPG ?

Log is interesting. Something I should have asked earlier - what version of the script are you running ?

The jump occurred on IMG_8795.jpg

Script version 2.6

Here is IMG_8794.jpg and IMG_8795.jpg:




« Last Edit: 06 / June / 2014, 16:53:42 by El Pistoffo »

 

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