This topic contains 85 replies, has 24 voices, and was last updated by Gabriella 9 hours, 39 minutes ago.
April 5, 2006 at 6:11 pm #175603
Is this for Canon hardware only? Any chance that other digital cameras with (hopefully standard output formats) could possibly work?April 5, 2006 at 7:00 pm #175614
There don’t seem to be many cameras that comply to a standard in this regard. A standard would be PTP (Picture Transfer Protocol), which many cameras support – but only for downloading images. A camera that is said to support PTP is not automatically remote controllable over that protocol and the commands sent to the Canon cameras on top of PTP seem to be Canon specific. Also, I don’t think I have ever before had a camera that can send the viewfinder image over USB. This doesn’t seem to be a wide-spread feature from my experience. But as the usual spec sheets and reviews don’t often tell us these things, I don’t know for sure.
MirkoApril 5, 2006 at 9:15 pm #175656
Mirko, I am sorry to hear that the Canon’s ability to be somewhat remote controlled is rare. Based on what I’ve seen, I can confirm that my PowerShot A70 can send the viewfinder image over USB as well as a full camera capture, but the controls for adjusting white balance etc. are Canon-specific extensions atop PTP. With Saul’s pointing it out, I’ve used ptpcanon to do this, a Canon-specific fork of ptpcam. (Canon does support its own completely proprietary protocol in addition to PTP).
A plea to all interested parties: write to the camera manufactures and ask them to support open standards, such as PTP, for controlling cameras from a computer, and ask them to publish details on how to do this using their cameras. If you buy a camera that is controllable from a computer, consider letting the manufacturer know why you chose their model.
Just an FYI, there is an IEEE1394 standard for aquiring images from still cameras and adjusting brightness etc, called IIDC or DCAM, supported in Linux by Coriander. Coriander states IIDC is used by industrial and scientific cameras; I am unaware of any cameras that use this. This is in addition to the 1394 standard for acquiring DV over 1394 (the Linux drivers refer to it as AVC, not sure of the official name), but as far as I know it does not support any commands to control a camera (aside from a few to play or rewind the tape in a camcorder).
P.S. Thanks for the screenshot.April 5, 2006 at 10:22 pm #175674
“eventide” wrote: Based on what I’ve seen, I can confirm that my PowerShot A70 can send the viewfinder image over USB as well as a full camera capture, but the controls for adjusting white balance etc. are Canon-specific extensions atop PTP. With Saul’s pointing it out, I’ve used ptpcanon to do this, a Canon-specific fork of ptpcam. (Canon does support its own completely proprietary protocol in addition to PTP).
Yes, ptpcanon is what I have tried, too, but I haven’t done much more testing than that.
This is the third camera I’ll be using for brickfilming. I have had an Olympus C-5050, which can be controlled almost entirely from gphoto2 using a proprietary protocol, but apparently has no preview over USB (and it turns off the LCD when you connect the USB cable, which means you cannot really focus manually). A Nikon Coolpix 885, which supports PTP (for which I bought it) but could take pictures with neither ptpcam nor gphoto. And no preview, I suppose. The A70 looks promising, though. I have no idea how complicated ptpcam is, but I would assume controlling the cam from software is not that difficult, if one just looks at ptpcam’s code.
Just an FYI, there is an IEEE1394 standard for aquiring images from still cameras and adjusting brightness etc, called IIDC or DCAM, supported in Linux by Coriander. Coriander states IIDC is used by industrial and scientific cameras; I am unaware of any cameras that use this.
Here is a list of (mostly industrial) firewire cameras, the table also states whether they support IIDC. Most of the usable ones seem to be >=$1000, though. I believe a consumer camera is more value for the money (though a c-mount would be cool).
MirkoApril 6, 2006 at 7:29 am #175759
A problem with manual focus might be, that you never know whether you are in focus or not until you actually capture a frame. So manual focussing would not be very useful, BUT I would like to be able to restore the af-state, in case something unpredictable interrupts your shooting.April 6, 2006 at 4:42 pm #175822
A new screenshot…
Now I have controls for shutter-speed, aperture, white-balance and autofocus-mode. And a button to start the auto-focussing-process, not to mention a zoom-slider It’s not continuos but has 7 zoom-settings. Another limitation of the SDK, I think.April 6, 2006 at 5:30 pm #175831
According to the reverse engineered commands here, the zoom is set by a command that can only take parameters from 0-10 (0-6 being optical zoom settings). This seems to be not just a limitation of the SDK, but either of the camera hardware (can you choose more than six settings with the lever on the camera? I’ll have to check this tonight) or at least the command set of the remote interface.
MirkoApril 6, 2006 at 6:08 pm #175844
I just happen to have my camera here at work with me. Yes, zoom goes all the way in to all the way out in 6 increments.
I don’t think using zoom yields very good results for macro-style shooting, though. In order to get proper focus, it’s better to use macro mode or install macro lenses. Or both, which is what I did for some shots in System Reboot.April 7, 2006 at 7:17 am #176092
Ok then it’s the the camera, not the sdk. I wonder what about the S2 for example. It has 12x zoom… in 7 steps ?!
The QC4000 has no zoom at all, so 7 steps are a big improvement.
Autofocus is poor in tele-macro, you can’t get closer then about 30cm… but distortion is much higher in wide-macro.April 7, 2006 at 9:05 am #176097
“Haukinger” wrote: The QC4000 has no zoom at all, so 7 steps are a big improvement.
I guess there is nothing wrong with 7 steps. I didn’t even notice the zoom is not continuous until I read your post, but what RevMen says is true: I cannot zoom from wide to tele in more than 6 increments on the A70 either. Zooms in film are probably better done in post production anyway.
Autofocus is poor in tele-macro, you can’t get closer then about 30cm… but distortion is much higher in wide-macro.
The most important thing for me is to have wide-angle in macro mode (not possible with the C-5050, e.g.). I believe it is more natural to get closer to the object and use wide-angle, as a tele lens from farther away tends to look like you’re observing the minifigs through binoculars.