Trig. Canon point n shoot camera via CHDK and Merlin shutt. interface  

Everything you need to motorize your head
no avatar
TomNai
Member
 
Topic author
Posts: 16
Likes: 0 post
Liked in: 0 post
Joined: Sun Jul 17, 2011 3:34 pm
Location: Munich
Info

Trig. Canon point n shoot camera via CHDK and Merlin shutt. interface

by TomNai » Sun Jul 17, 2011 4:25 pm

Hi everybody, I am new to this forum and I am trying to operate a Canon SX200is on the Merlin mount.
The camera doesn't have a remote shutter input, however the Canon Hack Development Kit CHDK provides a solution.

The approach is to trigger the camera via the USB port - as described here: http://chdk.wikia.com/wiki/USB_Remote_Cable

A Lithium and an alkaline cell provide a supply voltage of about 4.5 V.
If this voltage is applied to pins 1 (red) and 4 (black) of the USB cable the camera (which is running a CHDK script in and enless loop) is triggered.

This works well if I manually close a mechanical switch.
I understood that I can in the same way use the Merlin electronic shutter as a switch.
However, nothing happens when I use the Merlin for triggering the camera.

I have a few questions:
Is there a problem in this approach, can it work in principle?
What type of switch is used in the Merlin -"Auto-imaging"-Interface (thats how its called in the manual...)
Does anybody know how to make the Merlin Mount triggering a Canon camera via the CHDK?


Best regards
Tom



Asus EEE PC/ Papywizard / Ursa minor Bluetooth interface Version 1 / Merlin Mount / Canon SX200 is
Panoduino, Lumix FZ200, Lumix FZ28
Merlin, Papywizard, Powershot G9

User avatar
fma38
Moderator
 
Posts: 5850
Likes: 2 posts
Liked in: 2 posts
Joined: Wed Dec 07, 2005 6:21 pm
Location: Grenoble, France
Info

by fma38 » Sun Jul 17, 2011 5:25 pm

Did you try to reverse the wires from the Merlin? The internal 'contact' is an opto-coupler, so it may block in one direction...
Frédéric

no avatar
mediavets
Moderator
 
Posts: 16415
Likes: 2 posts
Liked in: 130 posts
Joined: Wed Nov 14, 2007 2:12 pm
Location: Isleham, Cambridgeshire, UK.
Info

by mediavets » Sun Jul 17, 2011 6:02 pm

There have been rare instances where the Snap connector of the Merlin mount is not connected internally or internal conector to the circuit board has become disconnected.
Andrew Stephens
Many different Nodal Ninja and Agnos pano heads. Merlin/Panogear mount with Papywizard on Nokia Internet tablets.
Nikon D5100 and D40, Sigma 8mm f3.5 FE, Nikon 10.5mm FE, 35mm, 50mm, 18-55mm, 70-210mm. Promote control.

no avatar
TomNai
Member
 
Topic author
Posts: 16
Likes: 0 post
Liked in: 0 post
Joined: Sun Jul 17, 2011 3:34 pm
Location: Munich
Info

by TomNai » Sun Jul 17, 2011 9:59 pm

fma38 wrote:Did you try to reverse the wires from the Merlin? The internal 'contact' is an opto-coupler, so it may block in one direction...

Great, thats it! I reversed the wires and it works. Thank you ! :)

Well, it works almost. The camera is focusing now, but it doesn't take a photo yet.
I realized by using a mechanical switch that the camera is making an image if it gets two subsequent pulses. Is it possible to do this with papywizard?
Maybe the Camera (CHDK) can be programmed to be triggered with one pulse?
Panoduino, Lumix FZ200, Lumix FZ28
Merlin, Papywizard, Powershot G9

no avatar
mediavets
Moderator
 
Posts: 16415
Likes: 2 posts
Liked in: 130 posts
Joined: Wed Nov 14, 2007 2:12 pm
Location: Isleham, Cambridgeshire, UK.
Info

by mediavets » Sun Jul 17, 2011 10:39 pm

TomNai wrote:Well, it works almost. The camera is focusing now, but it doesn't take a photo yet.
I realized by using a mechanical switch that the camera is making an image if it gets two subsequent pulses. Is it possible to do this with papywizard?

Try checking Mirror Lock up - see screenshot - I think it may do what you need.

Alternatively does the camera offer a manual focus mode, if so perhaps that will require a single trigger to operate the shutter?

A common problem if using autofocus is that many (most?) cameras will not trigger the shutter if they fail to get an autofocus lock, which will frequently be the case if shooting scenes with plain blue skies at a longer focal length.


Andrew Stephens
Many different Nodal Ninja and Agnos pano heads. Merlin/Panogear mount with Papywizard on Nokia Internet tablets.
Nikon D5100 and D40, Sigma 8mm f3.5 FE, Nikon 10.5mm FE, 35mm, 50mm, 18-55mm, 70-210mm. Promote control.

no avatar
sparks60
Member
 
Posts: 17
Likes: 0 post
Liked in: 0 post
Joined: Sat Dec 05, 2009 2:45 am
Info

by sparks60 » Mon Jul 18, 2011 11:34 am

TomNai wrote:Hi everybody, I am new to this forum and I am trying to operate a Canon SX200is on the Merlin mount.
The camera doesn't have a remote shutter input, however the Canon Hack Development Kit CHDK provides a solution.
The approach is to trigger the camera via the USB port - as described here: http://chdk.wikia.com/wiki/USB_Remote_Cable
Does anybody know how to make the Merlin Mount triggering a Canon camera via the CHDK?

Hi Tom
I have used a Canon a620 P/S with a usb shutter trigger and SDM which is a more sophisticated version of
the CHDK and used for stereo cameras but works just as well on a single camera.
http://stereo.jpn.org/eng/sdm/index.htm
As i did not want to connect the usb (3v in my case ) directly to the Merlin i made up a small box with a Picaxe chip which senses the
trigger pulse of the Merlin and fires the camera, this works perfectly.
One thing i found was that the pulse from the Merlin was too short to start with and i had to increase it in the camera tab on
Papywizard for a reliable trigger.
I would say that although you are using a different setup it could be that CHDK needs to see a longer pulse to trigger
the camera so i would try increasing that and see if it makes any difference.
If in the end you cannot get it to work reliably and want a permanent solution for that camera then i can supply all the details
for making a Picaxe trigger which is quite simple if you can solder, it does not cost much for the bits either and can be made
quite small.
http://www.techsupplies.co.uk/PICAXE

Hope this helps
Steve

no avatar
sparks60
Member
 
Posts: 17
Likes: 0 post
Liked in: 0 post
Joined: Sat Dec 05, 2009 2:45 am
Info

by sparks60 » Mon Jul 18, 2011 2:43 pm

TomNai wrote:Well, it works almost. The camera is focusing now, but it doesn't take a photo yet.
I realized by using a mechanical switch that the camera is making an image if it gets two subsequent pulses. Is it possible to do this with papywizard?
Maybe the Camera (CHDK) can be programmed to be triggered with one pulse?

Hi Tom
After the last post i emailed my friend who is the founder of SDM to confirm that it would trigger with one pulse
as i could not remember, well it does so i would try SDM on your sdcard with these settings in the menu.

"In menu Bracketing\Overrides, set 'focus mode' to Manual.
The header at the top of the screen should indicate FAST mode.
It will take a photo as soon as USB is detected."
There is a version for your model camera on link above and you can still run your scripts and other stuff as with CHDK.
Let us know if it works out ok

Steve

no avatar
TomNai
Member
 
Topic author
Posts: 16
Likes: 0 post
Liked in: 0 post
Joined: Sun Jul 17, 2011 3:34 pm
Location: Munich
Info

by TomNai » Mon Jul 18, 2011 8:54 pm

Thank you for interestings infos.
I've just got it running :-).

Its necessary to use the mirror lockup.

However, the trigger still failed every three or so images.

I tried changing the pulse duration parameters - with no no success.
Then I realized that by default CHDK is set to RAW mode - my 1 GB SD-Card was full after 130 images.
After disabling the Raw mode triggering works perfect. Probably saving the raw images takes too long (had the same issue with my Lumix on my homebrew panorama platform....)

Another interesting thing: Remote shuttering in CHDK doesn't require running the remote shutter script (remote.bas). It works without starting the script (probably you have to enable the remote option Enable Remote in Micellaneous stuff:Remote Parameters). Actually, when the remote script is running it doesn't trigger.

Tom
Panoduino, Lumix FZ200, Lumix FZ28
Merlin, Papywizard, Powershot G9

User avatar
fma38
Moderator
 
Posts: 5850
Likes: 2 posts
Liked in: 2 posts
Joined: Wed Dec 07, 2005 6:21 pm
Location: Grenoble, France
Info

by fma38 » Tue Jul 19, 2011 9:51 pm

You can extend the Time Value param in Papywizard to match the RAW writing time...
Frédéric

no avatar
TomNai
Member
 
Topic author
Posts: 16
Likes: 0 post
Liked in: 0 post
Joined: Sun Jul 17, 2011 3:34 pm
Location: Munich
Info

by TomNai » Wed Jul 20, 2011 8:49 pm

Actually my next aim is to make the platform faster, since I am used to make panoramas from hundreds of images.
I have a homebrew platform which is pretty fast (3-4 s per image) - see here: http://www.youtube.com/watch?v=dIgWIq7W5Yg , mostly it works fine, but it fails a bit too often (but in regard to how shaky its built, the performance is not too bad).
Now if got a merlin which is much more robust, but I realized now is that the Merlin is also relatively slow. In this forum I found some posts saying that with the Merlin, a speed of about 4-5 s per image can be achieved. However, so far I didn't get it faster than about 9 s per image (at f=336 mm which I'd like to use with my powershot SX200) and 6-7 images at f=800 mm.


I guess that 4-5 s per image is only possible with a very large focal length? When the images get smaller (smaller angle) then the travel distance between the images gets smaller, and if the speed remains the same I can make more images in the same time.


To increase the speed I reduced the timing parameters as far as possible,
I am also aware that setting home position can slow down the merlin (is this still an issue with the latest versions of papywizard/firmware?)
Further I tried increasing the supply voltage (external battery pack with an up/down voltage converter) to 16 V, but I did'nt see an improvement.

According to Teleskop Austrias Homepage, I have firmware version 020781, and I am using papywizard 2.0.0

What else can I do?

Tom
Panoduino, Lumix FZ200, Lumix FZ28
Merlin, Papywizard, Powershot G9

no avatar
mediavets
Moderator
 
Posts: 16415
Likes: 2 posts
Liked in: 130 posts
Joined: Wed Nov 14, 2007 2:12 pm
Location: Isleham, Cambridgeshire, UK.
Info

by mediavets » Wed Jul 20, 2011 9:16 pm

TomNai wrote:I am using papywizard 2.0.0

Tom

I don't think it will speed anything up but you should use the latest development version of Papywizard because the version you say you are using has threading problems:

http://www.papywizard.org/wiki/Download#Developementversions

It is reported that the Merlin/Panogear mount runs faster with the T&C/Panogear Touch Controller instead of Papywizard:

http://www.typeandcolour.de/index.php?tp=Produkte&up=soft

http://www.kolor.com/buy/photo-hardware/accessories/controleur-tactile-autonome.html
Andrew Stephens
Many different Nodal Ninja and Agnos pano heads. Merlin/Panogear mount with Papywizard on Nokia Internet tablets.
Nikon D5100 and D40, Sigma 8mm f3.5 FE, Nikon 10.5mm FE, 35mm, 50mm, 18-55mm, 70-210mm. Promote control.


Who is online

Users browsing this forum: No registered users and 1 guest