There has been a thread about this in the past, but this is still an ongoing issue.
In short with a Canon EOS M100 running Ekos using either the Canon DSLR and Gphoto drivers if you take an exposure longer than 300s the camera shutdown when downloading.
Anything bellow 300s no problem.
In a previous thread someone mentioned that setting the mirror lock to 10s solved the issue which is not true.
While this is true that the camera will no longer shutdown for any exposure length, the exposure is locked out and no pixel are illuminated... even though the shutter is working correctly (I checked). I saw a post from the gentleman who thought he found the fix on facebook stating that he was still having the issue to this day...
I'm really hoping there could be a solution. Gphoto works perfectly with the camera at any exposure length. Another app called Cascade also works perfectly., so the issue seems to be with Ekos implementation of the Gphoto drivers. (I'm running Kstars on a RPI4 with Stellarmate OS 1.5.9)
I'm tried different USB hubs, no hub at all, different camera USB cable, different USB power supply, battery only= ... with the same result
I would really love to solve this issue. I'm not expecting a straight up solution but if any of you have any idea about the type of parameters or troubleshooting method I could play with in Ekos to get to the bottom of this that would be very much appreciated!
For those of you with a Canon EOS M100 having the same issue, here is a work around. Jasem has been kind enough to remote in into my system and tried everything he could, tweaking the gphoto drivers etc... without success unfortunately.
However there is a work around that works well so far:
1) Set your mirror lock to the value of 10: The camera will lock up for 10s before the exposure starts
2) Set the capture format to NATIVE. This is very important. If you set it to FITS the camera sensor won't be illuminated and your picture will look like a dark frames... strange but that's the behaviour.
3) You can now use exposures as long as you want without issues that fully illuminate the sensor
Note: updating the camera firmware has no effect... so don't waste your time here. You will now get CR2 pictures opening in the FITS viewer. Those won't be stretched properly and will look strange compared to pictures taken in FITS (at least for me...!). However they look identical to fits in other processing software like Astro Pixel Processor, Photoshop etc... so don't be alarmed... what I do is take a 180s exposure in FITS at 800 iso to make sure everything looks good (that exposure length doesn't not shutdown the camera when downloading) then proportionally adjust the ISO for longer exposure length and quickly import the first exposure into APP to double check.
Why bother with a M100 anyway...? well its really cheap on the second hand market, I got mine for $100, with astro modification it ended up cost me all up about $350 which is pretty great. It has the same ASP-C sensor found in the Canon D80, which is a new generation low noise sensor. It's very light compared to regular DSLRs. Downside? Does not support tethering natively, unless you use Ekos, Gphoto2 or Cascable which are 3rd party applications.