File format changed to PNG part way through session

[Artemis]

This has happened a few times over the last 18 months, and before last night hadn't occured for quite a few months.

I have SharpCap set up for fireball observing, my capture settings are JPG output, 8 second exposure, and I set time limit to 1 hour and then set for a sequence of say 9 captures (at this time of year)

Results from last night are 2 folders with JPG files at the start of the night, as expected. Then the file format changed to PNG. It takes a lot longer to review PNG files, so I then transcode to an mp4 and review that.

This behaviour is very intermittent and I can't give any steps to reproduce it. I have been using my settings for all of this month with no problems.

The camera settings files show that the output format changed to Auto between one sequence and the next. Could this be a SharpCap issue? My other thought is that if the application focus is on the output format Auto button could its click event be activated somehow?

Sharpcap version: 4.1.14136.0
Camera: ZWO ASI676MC
OS: Windows 11 25H2

[admin]

Hi,

I see what you mean about the output format changing to auto and then that leading to PNG being selected. I will try to list the ways that I can think of for the auto to become engaged on the output format so you can see if any might make sense in your situation

* User input - if the 'Auto' checkbox is highlighted the pressing the space bar will toggle the check.
* Opening a camera if the setting to 'start cameras in auto output format' is enabled in the file format settings
* Loading a capture profile that has the 'auto' output format saved in it
* (Maybe) recovering from a camera glitch (camera disconnects and reconnects to USB) if the auto output format checkbox is enabled in the settings.

It's probably worth you trying to find and share the SharpCap log from one of the sessions where the problem happened - most of the above would leave info in the log that I could check for.

thanks,

Robin

[Artemis]

Hi Robin,

Thank you for the guidance. I have found the log file, and it does look like there was a problem with camera communication, at 21:43 in the attached log file.

I have turned off the 'Start camera with Auto' setting and set my preferred still format to JPG. Hopefully if I get another camera glitch it will stay as JPG output.

Kind regards
Artemis

[admin]

Hi Artemis,

yes, that looks like it is it - the camera obviously disconnects briefly and then reconnects. SharpCap is dealing with this, but it looks like the reconnect is resetting the 'auto' flag on the output format as if the camera had just been opened, which then sets PNG as the old (pre-disconnect) exposure is re-applied to the now re-opened camera.

I think that is a bug in the reconnection handling and I will see what I can do to fix it in a future update, but for now turning off the 'auto' setting will resolve the issue for you I think.

I must say that it is actually nice to see that the reconnection to the camera feature largely works in real-life usage. I spent a lot of time pulling out USB cables and then re-plugging them when developing that feature

cheers,

Robin

[Artemis]

I'm very impressed that SharpCap recovered so well after seeing the hardware disconnection messages, thats some very good work!

I'm not sure if this is relevant but I am using a BluStream UEX3C USB3.2 extender between my workstation and ZWO camera, about a 10m cable run.

Kind regards

[admin]

Hi,

USB extensions certainly add new possible ways for the system to fail, but I suspect that in a lot of cases these disconnections are down to the camera itself effectively rebooting after encountering some problem. I expect that if you paid several times more $$$ to buy an industrial grade camera with the same sensor then this sort of thing wouldn't happen - industrial cameras need to be rock solid over the long term, whereas a glitch on an astronomy camera is largely just accepted and dealt with. On the flip side, the industrial cameras don't have the astro related features like cooling and aren't nearly so well supported in SharpCap.

cheers,

Robin