Reduce delay between frames RPi4 w/HQ cam

[khobar95]

I have two Allsky cams running TJ's software, and both of them have a 6-7s delay between frames regardless of whether I set the delay to 5s or 1s. If I set it higher, like 10s, then I get a 10s delay between frames. I'd very much like to "fix" this, if I can.

I have auto everything turned off - no auto gain, no auto white balance, no auto exposure, etc.

I had experimented with saving images to USB3 flash instead of SD card - no difference.

I don't get any errors, and the system seems to work as advertised. I get the keogram and startrail images. Unfortunately, I have missed some really excellent fireballs as they've happened during the delay.

Attached is the support file for one of the systems. This was run yesterday or the day before trying to resolve a different issue though. Hopefully it is still valid.

Or I can run a new log tomorrow.

support-none-20250623135406.zip

[EricClaeys]

Please run allsky-config prepare_logs and after several images appear, upload another support log. Your current Debug Level of 1 doesn't provide enough information for troubleshooting.

Are you seeing this behavior during the day and night?

[khobar95]

Hi Eric.

The delay has shortened to 3-4s from 6-7s on the "newer" software. No other changes that I'm aware of.

support-none-20250629104720.zip

[EricClaeys]

Thanks @khobar95.
It's taking 3 seconds for libcamera-still to take a picture and save it to memory, even if the shutter speed is only 0.0001 seconds (basically 0 seconds).

On my Pi 4 running Bookworm instead of Bullseye, it takes about 4 seconds.
However, on my Pi 5 it takes about 1.3 seconds.

On your current Pi you're not going to get lower than 3 seconds per image. If you want anything faster you'll need to get a Pi 5.

I noticed your nighttime delay is 0. I'm curious how that works. After nighttime ends, would you please attach /var/log/allsky.log? I'd like to see if a 0 delay is giving any warnings.

[khobar95]

Ahh, okay. So it's the Pi and not the camera "causing" the delay. So, a USB cam wouldn't likely help then?

Here is the log:
allsky.log

[EricClaeys]

A ZWO camera would be faster.
Allsky talks directly to ZWO cameras so doesn't have the overhead of starting a program (libcamera-still)
having it write the image and the metadata to two different files which Allsky then has to read.

Don't quote me, but I think the "overhead" with a ZWO camera is less than a second on a Pi 4.

It would be cheaper to get a Pi 5 than to get a ZWO camera.

[khobar95]

Much appreciated!

I see Pi5's are now about $75 (4GB), so that is definitely something to think about. :)