Shot Histogram Request - page 47 - CHDK Releases - CHDK Forum

Shot Histogram Request

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Re: Shot Histogram Request
« Reply #460 on: 23 / December / 2013, 02:34:08 »
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Arrrg...here in the hospital...firewall. I'll admire the sledcreations when I get out of here. Could see the pics-very very nice. I've spent a bit over 6 weeks in the PNW exploring here and there. You are blessed in location.
Now should I add the G1X?
I'm hoping to create a lightweight backpackable astro kit...the G1x + Ioptron Skytracker + Berlebach Mini.
CHDK removes the need for the external intervalometer and I'm thinking once I can really dive into the CHDK threads I'll find a script what honors bulb ramping (or something close).
All that is left is to figure out how you did the external battery (or did you yet).
I see the ongoing quest to defeat the manual focus lost to autofocus once the screen is turned off BUT with the lightweight nature of lithium batteries why not just give in and carry the extra larger external battery and be done with it?
p.s. the plastic bag trick for weather proofing was brilliant!

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Re: Shot Histogram Request
« Reply #461 on: 23 / December / 2013, 08:24:54 »
Now should I add the G1X?

I'm hoping to create a lightweight backpackable astro kit...the G1x + Ioptron Skytracker + Berlebach Mini.
CHDK removes the need for the external intervalometer and I'm thinking once I can really dive into the CHDK threads I'll find a script what honors bulb ramping (or something close).
CHDK scripts can go a lot further than bulb ramping. In addition to directly setting the shutter time, a script can set the ISO, aperture, and control the G1X built in ND filter.

My CHDK mods also can measure the brightness of an image while it is still in the camera and use it to set the exposure of the next shot. I call it shot metering.
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All that is left is to figure out how you did the external battery (or did you yet).
I used this battery: http://www.bixnet.com/mumiexbapaki1.html
It was about 1/2 discharged after powering the G1X for 10 hours on my last trip
Quote
I see the ongoing quest to defeat the manual focus lost to autofocus once the screen is turned off BUT with the lightweight nature of lithium batteries why not just give in and carry the extra larger external battery and be done with it?
p.s. the plastic bag trick for weather proofing was brilliant!
reyalp and philmoz figured out how to turn the display off from a script without losing autofocus. My script turns the display on and off when you press <set> on the G1X. It would be useful to trigger this with a shortcut key outside of a script, but this hasn't been implemented yet.

It started to rain pretty hard at about 2:30 a.m. so I got up and took the camera into my tent. There was some water on the screen that got through the "weather proofing".  I wrapped the camera in plastic wrap in a hurry on my lap in the tent, so I don't think I did the best job. Next time, I'll wrap it at home first.
EOS-M3_120f / SX50_100b / SX260_101a / G1X_100g / D20_100b
https://www.youtube.com/user/DrLapser/videos

Genius applied
« Reply #462 on: 23 / December / 2013, 15:15:06 »
OK, close to 3 hours invested in sponging through the forum(s).
You Lapser, Waterwingz, Philmoz are all genius level.
I've toyed with Magic Lantern on a 6D....the overall presentation of CHDK=in how to approach it, get it, load it, use it is beyond ML. This site is far more user friendly; in organization, accessibility, and most importantly the approach to the noobie.

The battery you link too-sweeet. As a backpacker/cyclist/paddler first thing I looked for was weight ? Does double duty via USB power, nice. 10 hour shoot at 1/2 power=could run two cameras.

If you are bored (somehow I doubt that), a timelapse from my Sony days (last year, just sold all my Sony alpha mount stuff), just to show I love timelapse....sadly nothing close to a Holy Grail, and obviously something I learned as I went:
12,000 Pictures in 7 Minutes

Yep the G1X is in my future....
I assume your refined script is included in the latest builds for the G1X? and the non-genius simple minded end-user (ME) only has to enable scripts when running CHDK?


Re: Shot Histogram Request
« Reply #463 on: 23 / December / 2013, 16:07:09 »
Just watched the two vid you posted above. Watched not as a photographer nor anyone doing a critique but as someone worn out from work needing a therapeutic release--both vids provided well! In fact many many of your vids on youtube timelapsing provide something for the soul=Orion passing by, shooting stars, the ISS, the always beautiful clouds-esp the pink ones scalloping over Eugene.
I swore I was over timelapse after my 'big' one, many miles hiked to get to some of those spots; not counting the driving and the fear of amassing so many shutter clicks BUT you don't seem worried with multiple thousands of clicks on your G1X.
So looks like I'm back in when I add the Powershot.
Pulking? Yep we tried, here 20 secs in me with a pulk in tow (turn down music or the bagpipes will ruin your hearing):
RoanTheHighKnobHangWinMed
We decided that the Appalachian Trail overall was too steep/rocky/rooty for pulking :(


Re: Shot Histogram Request
« Reply #464 on: 23 / December / 2013, 16:37:45 »
.. and the fear of amassing so many shutter clicks BUT you don't seem worried with multiple thousands of clicks on your G1X.
I tend to believe that shutter clicks - even by hard core CHDK users - do not kill many P&S camera.  Dust infiltration onto the sensor,  lens errors from jammed gears, and the release of new&better models every year probably relegate more cameras to the back of the closet that actual wear and tear on the shutter.  And I do have a little experience to back up that statement.   So my advice is to enjoy these little machines as much as you can now and push them to their limits like lapser does - they are not a life-time investment.
Ported :   A1200    SD940   G10    Powershot N    G16

Re: Shot Histogram Request
« Reply #465 on: 31 / August / 2014, 14:15:47 »
Lapser,
I could only skim the thread but it looks like you've done some amazing work here.  I did notice you did some nice moon shots with your SX50 which I also do.  I have questions and tips for you;

-Did you ever get the histogram/metering features into trunk? If not, where can I get a build for SX50? Also your timelapse script.

-I'm interested in exposing the moon properly as it moves across the entire frame, so what I was orginally searching for is a way to get a histogram for the entire frame (based on the RAW buffer), and in fact I have no stuck pixels that I can detect so I want *every* pixel to be less than 3968 (the measured saturation on my camera)

-Your problems with whitebalance are easy to solve in an Avisynth script, I could make that for you.  Interpolation between white balances between start and end frames can be done with the animate command.

-You may also be interested in what I do further with my moon shots, it's called stacking, a common technique in astrophotography.  I find the simplest program is Astrostakkert!.  Basically drag the 25 shots or so of the moon moving across frame, and it lines them up, including pixel-by-pixel as it waves due to atmospheric disturbence.  The stacking accomplishes sharpening and noise reduction.  The result is quite amazing!

-There is also a planetcrop.avs script in Avisynth that centers each moon image, for some other stacking programs that have trouble locating the moon anywhere across the frame.

-Finally I'm interested in the full frame histogram to do extreme HDR, to make sure there's a shot with no blown highlights and some lower limit for the shadows.  At night I've had to exposure up to 8 minutes. (and I have no hot pixels).

-I'd also like a real normal daytime exposure mode that makes sure no highlights are missing.  As long as the sky is not in the shot :)  In fact in some cases I really hate the sky looking all white instead of blue.

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Offline lapser

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Re: Shot Histogram Request
« Reply #466 on: 01 / September / 2014, 21:42:47 »
-Did you ever get the histogram/metering features into trunk? If not, where can I get a build for SX50? Also your timelapse script.
Thanks for posting. Sorry, I've been pretty busy time lapsing and haven't posted much to the CHDK forum. If you'd like to catch up on what I've been doing lately, look at my YouTube channel, including the description section for the videos:

https://www.youtube.com/user/DrLapser/videos

I'm way behind on the latest CHDK updates, but you can download the custom CHDK build I'm using, and the Tlapser.lua script here:
https://drive.google.com/folderview?id=0B3woLhMB_tdqWmozT3hheXBzSms&usp=sharing
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-I'm interested in exposing the moon properly as it moves across the entire frame, so what I was orginally searching for is a way to get a histogram for the entire frame (based on the RAW buffer), and in fact I have no stuck pixels that I can detect so I want *every* pixel to be less than 3968 (the measured saturation on my camera)
I haven't gotten to the histogram processing functions in my CHDK build yet, but I'm planning to do that soon. But my current script has the ability to adjust exposure bias on the fly. What I do for SX50 zoomed moon shots is set a single metering area that covers the entire frame, so the moon is always in the metering area as long as it's in the frame. Then I adjust the exposure with the up and down arrow keys until it looks right on the screen. A histogram would be more accurate, but this way works pretty well, especially with raw files.

I used this method to time lapse the April 15 Lunar Eclipse:

https://www.youtube.com/watch?v=1C6zLG5os8Y

More recently, I was able to track the moon better and caught a close up of it setting behind a ridge (starts around 1:50):

https://www.youtube.com/watch?v=yv0TKcgiooA
Quote

-Your problems with whitebalance are easy to solve in an Avisynth script, I could make that for you.  Interpolation between white balances between start and end frames can be done with the animate command.

-You may also be interested in what I do further with my moon shots, it's called stacking, a common technique in astrophotography.  I find the simplest program is Astrostakkert!.  Basically drag the 25 shots or so of the moon moving across frame, and it lines them up, including pixel-by-pixel as it waves due to atmospheric disturbence.  The stacking accomplishes sharpening and noise reduction.  The result is quite amazing!

-There is also a planetcrop.avs script in Avisynth that centers each moon image, for some other stacking programs that have trouble locating the moon anywhere across the frame.
Many thanks for those ideas. I've been handling white balance by fading between two tracks in the final video.  Here's a good example where I faded from Milky Way white balance to daytime so the RV is white at the end:
https://www.youtube.com/watch?v=itwzU0UWVPs

I've been using VirtualDub with the DeShaker plugin for moon tracking. It doesn't always work well for the sun, since there are no features to match. Thanks for the tip with avisynth.
Quote
-Finally I'm interested in the full frame histogram to do extreme HDR, to make sure there's a shot with no blown highlights and some lower limit for the shadows.  At night I've had to exposure up to 8 minutes. (and I have no hot pixels).

-I'd also like a real normal daytime exposure mode that makes sure no highlights are missing.  As long as the sky is not in the shot :)  In fact in some cases I really hate the sky looking all white instead of blue.
I think I can do this once I get the histogram part done. I need to shift into obsessive programming mode for awhile. Right now, I'm in obsessive time lapsing mode, especially in the summer when the skies are clear. There's another total lunar eclipse on October 8-9 that I'm gearing up for, so I might try to do something before then. It would be nice to have histogram based metering of the moon with raw files on the SX50 for that eclipse. Lately, though, I've been working on getting the tracking right.
EOS-M3_120f / SX50_100b / SX260_101a / G1X_100g / D20_100b
https://www.youtube.com/user/DrLapser/videos

Re: Shot Histogram Request
« Reply #467 on: 01 / September / 2014, 22:42:33 »
Some follow-up references

Avisynth whitebalance
http://avisynth.nl/index.php/WhiteBalance
http://avisynth.nl/index.php/Animate

Avisynth Planetcrop
http://forum.doom9.org/showthread.php?t=165479

Planetary stacking
http://www.autostakkert.com/

Examples of stacking with SX50 - you can image Mars, Jupiter, Saturn, Venus with just a camera!
http://www.tool-box.info/blog/archives/1445-Saturn-near-opposition.html


 

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