#1353 Interval mode is misbehaving, alternating between intervals

[Enteq]

I am using interval mode. I set the interval to 1s. However, I now get pictures that are almost exactly alternatingly 2s and ~0.1s apart (see histogram from July 2026) This is broken since a recent update. Before that, it was constantly about 1.1 seconds (see histogram from March 2026)

Some example filenames including the number:
IMG_20260706_170728.402.jpg
IMG_20260706_170728.502.jpg
IMG_20260706_170730.546.jpg
IMG_20260706_170730.673.jpg
IMG_20260706_170732.674.jpg
IMG_20260706_170732.743.jpg
IMG_20260706_170734.772.jpg
IMG_20260706_170734.839.jpg
IMG_20260706_170736.876.jpg
IMG_20260706_170736.975.jpg
IMG_20260706_170739.015.jpg
IMG_20260706_170739.147.jpg
IMG_20260706_170741.135.jpg
IMG_20260706_170741.208.jpg
IMG_20260706_170743.239.jpg
IMG_20260706_170743.310.jpg
IMG_20260706_170745.342.jpg
IMG_20260706_170745.475.jpg
...

here some calculated differences in seconds:
0.1
2.044
0.127
2.001
0.069
2.029
0.067
2.037
0.099
2.04
0.132
1.988
0.073
2.031
0.071
2.032
0.133
1.998
0.102
1.995
0.079
2.023
0.145
1.989
0.102
2.0
0.132
2.0
0.074
...

[Enteq]

Note: This behaviour concerns autofocus on, and is broken since 1.56

When I switch autofocus off, the intervals are pretty close to 1.0s:
1.003
1.01
1.026
1.014
1.014
1.011
0.986
1.015
1.008
1.018
1.033

I think with enabled autofocus the new repeat interval logic that was introduced in 1.56 somehow oscillates between "wait pretty exactly 2.0s" and "take photo immediately with some autofocus-related delay of ~0.1s"

For now, I switched to contiuous autofocus as a workaround, which also seems to work.

[Anonymous]

Maybe it has something to do with

app/src/main/java/net/sourceforge/opencamera/cameracontroller/CameraController2.java

    private static final long autofocus_timeout_c = 1000; // timeout for calling autofocus_cb (applies for both auto and continuous focus)

[Mark]

Previously the interval timer was started when the previous photo was taken, i.e. after any delay to actually take the photo - so a 1s delay actually giving more like 1.1s.

Now it's measured from when the camera requests to take a photo, which in general should lead to more regular times closer to the requested interval. I think what's happening here is it's caught in a cycle where:

0.0s: request to take a photo
0.9s: photo took 0.9s
1.0s: request to take a photo
1.0s: photo taken immediately (0.1s since last photo)
2.0s: request to take a photo
2.9s: photo took 0.9s (1.9s since last photo)
3.0s: request to take a photo
3.0s: photo taken immediately (0.1s since last photo)

The variation may be taking time to focus for the one photo, but then the next photo is taken immediately due to already being focus.

So it makes sense this is connected to using autofocus mode - I'd recommend using continuous focus anyway these days unless there's a reason not to (most camera apps don't even expose autofocus as a separate mode these days).