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General / Re: Compact Canon CDHK RAW & Lens Distortion
« on: July 28, 2013, 04:00:42 PM »
Thanks for this Chad.
I just reviewed where I had been trying to go with CHDK - that now a few months ago. It was really to try and develop a very large mixed point&shoot / DSLR system.
While I got some level of understanding I got sidetracked and now [just after having read my post on the chdk forum] can't even remember what some of my own post meant
However, if we keep it simply focused on a total point&shoot / CHDK solution I wonder if [within a powered USB hub network] a first switch [say SWITCH1] could be inserted in the final USB connection to the computer and a second switch [SWITCH2] be inserted in between mains supply and the USB hubs.
CHDK Shutter Operation would then require:
(i) initial conditions - SWITCH1 and SWITCH2 OPEN
(ii) CLOSE SWITCH2
(iii) Wait a second [or so] for all camera's LED lights to say they're ready to shoot
(iii) OPEN SWITCH2 [i.e capture the images]
What I don't understand is whether large propogation time delays are created throughout a USB hub network via hub transfomers etc
(iv) CLOSE SWITCH1 and SWITCH2...use reyalp's alternative ptp client to transfer the images [but since that's a 40 page 392 post topic i'm sure there's a few things to be aware of
]
I got involved at post #12 here but quickly got distracted and left it in mid-air...
http://chdk.setepontos.com/index.php?topic=9420.0
And as a ref:
http://www.flickr.com/groups/stereo/discuss/72157603947882001/
"The way it [SDM] works is that the camera loads software from the card that adds some new camera menus and controls. one of which is a "sync mode." When this mode is activated, it enters a loop that constantly checks for a voltage on the USB port. When you press and hold the momentary contact switch, it's wired to just deliver power from the battery to the USB's regular power and ground pins. When the software in each camera detects that voltage, it executes the camera's built-in programs to focus, set preflash, etc., and then it executes another loop that just keeps checking for the power to drop. When it detects the power drop, it triggers the final firing sequence. So, you just press the button, wait a second or so for both camera's LED lights to say they're ready to shoot, and release the button to fire both cameras. The sync is very good because that "tight" loop means both cameras detect the voltage drop at very close to the same time, and the firing process after that is fairly "deterministic" (not subject to a lot of randomness), so it happens in both cameras very nearly simultaneously."
I just reviewed where I had been trying to go with CHDK - that now a few months ago. It was really to try and develop a very large mixed point&shoot / DSLR system.
While I got some level of understanding I got sidetracked and now [just after having read my post on the chdk forum] can't even remember what some of my own post meant
However, if we keep it simply focused on a total point&shoot / CHDK solution I wonder if [within a powered USB hub network] a first switch [say SWITCH1] could be inserted in the final USB connection to the computer and a second switch [SWITCH2] be inserted in between mains supply and the USB hubs.
CHDK Shutter Operation would then require:
(i) initial conditions - SWITCH1 and SWITCH2 OPEN
(ii) CLOSE SWITCH2
(iii) Wait a second [or so] for all camera's LED lights to say they're ready to shoot
(iii) OPEN SWITCH2 [i.e capture the images]
What I don't understand is whether large propogation time delays are created throughout a USB hub network via hub transfomers etc
(iv) CLOSE SWITCH1 and SWITCH2...use reyalp's alternative ptp client to transfer the images [but since that's a 40 page 392 post topic i'm sure there's a few things to be aware of
]I got involved at post #12 here but quickly got distracted and left it in mid-air...
http://chdk.setepontos.com/index.php?topic=9420.0
And as a ref:
http://www.flickr.com/groups/stereo/discuss/72157603947882001/
"The way it [SDM] works is that the camera loads software from the card that adds some new camera menus and controls. one of which is a "sync mode." When this mode is activated, it enters a loop that constantly checks for a voltage on the USB port. When you press and hold the momentary contact switch, it's wired to just deliver power from the battery to the USB's regular power and ground pins. When the software in each camera detects that voltage, it executes the camera's built-in programs to focus, set preflash, etc., and then it executes another loop that just keeps checking for the power to drop. When it detects the power drop, it triggers the final firing sequence. So, you just press the button, wait a second or so for both camera's LED lights to say they're ready to shoot, and release the button to fire both cameras. The sync is very good because that "tight" loop means both cameras detect the voltage drop at very close to the same time, and the firing process after that is fairly "deterministic" (not subject to a lot of randomness), so it happens in both cameras very nearly simultaneously."
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