Bad Pixel Notes - Canon CHDK User Manual

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Bad pixel notes

Bad, or hot pixels affect DNG images especially for long exposures. Using "
parameters
Main Menu > RAW
for your camera have been identified
directly while taking an image - this also affects any associated JPEG image,
pixel coordinates you need to capture a "dark frame" by shooting an image with the lens completely
capped. For shutter speeds longer than 1 to 10 seconds, it's wise to keep a collection of dark-frames on
hand for each exposure length that you will be using in the future, as more warm and hot-pixels appear
with extended shutter speeds. After that you can use this program:
Read more about this program & how to use it
http://chdk.wikia.com/wiki/CHDK_firmware_usage/AllBest#Hot-Pixel_Removal_.
28Build_100-16_and_later.29
From build 0.9.9 - 1039 a menu entry
menu, available if the camera has DNG support. This is a scriptless operation to create the
parameters
file (necessary to enable DNG), and overwrite any existing
"badpixel.bin",
Switch to record mode (there is a reminder dialog if still in display mode), Select "
the menu, press
RAW
will notice the camera takes 2 shots, the blue print LED will come on briefly during each shot, wait for
the process to complete, you will see a display of the number of bad pixels, - that number can be
disturbing to some, a figure such as 15,000 or even more is not uncommon. You can check for the file
with the File Browser.
Instructions
for BADPIXEL.LUA
(As of build 1039, this script is obsolete. Support for it will be removed in the future, use "
" from the RAW menu instead)
badpixel.bin
*
Q. When I select the script with
A. From fe50- Thanks
Ok, then follow me...
- power your camera on, half-press the shutter, to go to record mode
- press PRINT, then press
- select "Load script from file", go 2 steps down to the TEST/ folder, press
- select "BADPIXEL.LUA", press
- start the script with the SHUTTER !
- wait until you see "press SET to save....." (This may take 30 seconds or so, please be patient)
- press
FUNC./SET
- press to leave the
PRINT
- press , go to the "RAW parameters", enter it with
MENU
- enable the settings "Save RAW" , "DNG format" and "DNG file extension"
- press to leave the
PRINT
Now RAW saving in DNG format is enabled, transfer the DNG files with a card reader.
Bad Pixel Removal
Here we will briefly try to understand the meaning of the menu options of
Main Menu > Raw parameters > Bad pixel removal
menu, CHDK can remove them automatically, after the "bad" pixels
("badpixel.bin"),
"Create badpixel.bin"
, and the operation commences, taking approx. 20 to 40 seconds, you
FUNC./SET
script...
FUNC./SET
fe50
FUNC./SET
FUNC./SET
to store the badpixel.bin automatically in the right place (/CHDK/badpixel.bin)
mode, press PRINT again to enter
<ALT>
mode again
<ALT>
Use this option to remove defective pixels
http://ewavr.nm.ru/chdk/show_bad.zip
here:
is included in the
, nothing happens, How do I run it?
FUNC./SET
Bad pixel removal
To obtain this list of hot-
Main Menu > RAW
"badpixel.bin".
Create badpixel.bin"
Create
FUNC./SET
mode
<ALT>
[Off, Average, RAWconv]
" in the
in
in