DSUSB and Canon 40D

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Guy Campeau
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DSUSB and Canon 40D

Post by Guy Campeau » Fri Jul 31, 2009 6:23 pm

Hi Doug,

I have bought some time ago a DSUSB for my Canon 350XT. (Which wokrs perfectly)
Recently, I have had the opportunity to upgrade to a Canon 40D.
Then I discover that my DSUSB would need a new cable in order to be used with the three pins connector of the 40D,
so I have order that cable from Shoestring (of course), an extension cable has also been bought at the same time.

I have read previous threads about this set up and I can't find the answer clearly, this is just not working :(

My Canon 40D is set a manual, bulb is selected, the DSUSB check is positive and the DSUSB device starts the exposure with no problem, but holds it for just one seconds. If I choose 30 sec instead of bulb, the exposure will go to the 30 seconds marks (the 30 sec exposure is selected with DSLR shutter at this time also)

Then I set the Canon 40D at bulb and tries a 35 sec exposure with the DSLR SHutter, no success, a one second exposure is made.

To be clear, when set to bulb, in manual mode, with the DSLR shutter, my Canon 40D is able to take only a one second exposure.
I have tried this with and without the extension cable, with the same results.

What is the problem and ...the solution to it !

dpanderson
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Re: DSUSB and Canon 40D

Post by dpanderson » Sat Aug 01, 2009 4:42 pm

In DSLR Shutter, under the File menu, there are a choice between "No AF Signal", "AF pulse at start", and "AF during exposure". Have you tried all three of these choices to see if one of them works?
Doug Anderson
Shoestring Astronomy
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Guy Campeau
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Re: DSUSB and Canon 40D

Post by Guy Campeau » Mon Aug 03, 2009 10:48 am

Hi Doug,

I have tried what you have suggested and the last option called ''AF during exposure (Nikon D200) just works fine, so thanks you.

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Re: DSUSB and Canon 40D

Post by dpanderson » Mon Aug 03, 2009 11:04 am

That's good news. Thanks for getting back on this.
Doug Anderson
Shoestring Astronomy
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okhoydal
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Re: DSUSB and Canon 40D

Post by okhoydal » Thu Jan 07, 2010 4:23 pm

Hi,

I have the same problem, and using DSLRshutter the trick with setting "AF during exposure" works well.
But when controling the camera from Nebulosity there is now way to obtain exposure times longer than 30s. When setting exposure longer than 30s, the shutter only stays open a fraction of a second. I have tried all possible solutions I've seen posted on the forum, but nothing works.

I also own a 450D, and when using that (with a 3.5 to 2.5mm jack cable) there are no problems at all.

I use Nebulosity v.2.2.1 and the firmware of my 40D is also the latest (v.1.1.1)

Regards,
Odd Hoydalsvik

dpanderson
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Re: DSUSB and Canon 40D

Post by dpanderson » Thu Jan 07, 2010 6:21 pm

This sounds like a problem with Nebulosity. Please contact Craig Stark at www.stark-labs.com
Doug Anderson
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okhoydal
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Re: DSUSB and Canon 40D

Post by okhoydal » Fri Jan 08, 2010 11:47 am

Hi Doug,

Maybe that is so, but I just wanted to examine the behaviour a bit closer, so I dowloaded DSUSBCheck and performed some tests. Here are the results:

Initial check of functions:
------------------------------
Open Shutter: Shutter opens and closes again immediately, no preview shown after shutter closes :(
Close Shutter: Preview image is displayed on camera screen
Assert AF/Wakeup: Camera wakes up, and focusing if lens is in AF mode :)
Deassert AF/Wakeup: Nothing happens
LED Green: Led turns green :)
LED Red: Led turns red :)
LED On: Led turns on :)
LED Off: Led turns off :)
--------------
Then after trying a lot of key-pressing sequences I found the following behaviour:

Case 1:
--------
press 'Assert AF/Wakeup', Close shutter, 'Open shutter': Shutter opens and remain open
press 'Close shutter': Nothing happens
press 'Deassert AF/Wakeup' : Shutter closing and preview displayed

Case 2:
--------
Press 'Assert AF/Wakeup' 'Close shutter', 'Open shutter: Shutter opens and remain open
press 'Deassert AF/Wakeup': Shutter closing and preview displayed

In both case 1 and 2, I can expose more than 30 seconds.

To me this seems like a rather strange behaviour... The good thing is that it is repeatable.
So the question then is: Is this the normal behaviour of EOS40D, and something Nebulosity should have to deal with? Or is it something wrong with DSUSB?

Regards
Odd

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Re: DSUSB and Canon 40D

Post by dpanderson » Fri Jan 08, 2010 5:32 pm

Some cameras require both the AF/Wakeup and Shutter signals be asserted. Sounds like the 40D falls in this category. Craig will know how to deal with this in Nebulosity.

Your DSUSB is working fine. It is a fairly dumb box, it depends upon the application software to tell it exactly what to do. This provides more flexibility than having a DSUSB that is hardwired to respond in only one manner.
Doug Anderson
Shoestring Astronomy
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okhoydal
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Re: DSUSB and Canon 40D

Post by okhoydal » Mon Jan 11, 2010 2:55 pm

The solution is to NOT use the DSUSB, but to let Nebulosity control the camera directly via the USB cable.
Set the DSLR long-exposure adapter Preference in Nebulosity to "DIGIC III onboard" before connecting to the camera. That works fine.

Regards,
Odd

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Re: DSUSB and Canon 40D

Post by dpanderson » Mon Jan 11, 2010 3:20 pm

Ah, so the 40D is one of the camera models that does not suffer from the 30 second exposure time limitation. Unfortunately, I'm not well versed in every model of camera.
Doug Anderson
Shoestring Astronomy
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