ASIAir Video mode & MicroSD card buffering?

[CraigD1986]

Hi All.

I'm just getting into planetary imaging and have noticed that when I start recording a video, the frame rate often drops from around 100fps to 10fps after a few seconds. Is this buffering as the file is being written to the SD card or something else?

[Elp]

Likely, not buffering as such but skipped frames as the bandwidth isn't there to transfer and write to the SD card.

Why aren't you saving to the internal memory, or are you using a gen 1 (video isn't possible with the 1) or 2 (pro)?

Have you also decreased the resolution or region of interest (ROI) before recording, it'll give slightly better FPS.

When I tried usb 3 connection between the camera and air the plus and mini (mini doesn't have usb 3 ports, the plus does) it didn't make any difference to the FPS, using usb 3 does make a difference on astroberry however and I assume on pc too.

Edited December 28, 2023 by Elp

[LaurenceT]

1 hour ago, Elp said:

Likely, not buffering as such but skipped frames as the bandwidth isn't there to transfer and write to the SD card.

Why aren't you saving to the internal memory, or are you using a gen 1 (video isn't possible with the 1) or 2 (pro)?

Have you also decreased the resolution or region of interest (ROI) before recording, it'll give slightly better FPS.

When I tried usb 3 connection between the camera and air the plus and mini (mini doesn't have usb 3 ports, the plus does) it didn't make any difference to the FPS, using usb 3 does make a difference on astroberry however and I assume on pc too.

Perhaps I haven't read this right but my Asiair Pro has video mode.

[Elp]

1 hour ago, LaurenceT said:

Perhaps I haven't read this right but my Asiair Pro has video mode.

"(Video isn't possible with the 1)" probably should have added gen 1 or first generation asiair.

Yes, the Pro is the bare minimum asiair to have all the software features that are also in the superseding models.

Edited December 29, 2023 by Elp

[bosun21]

11 hours ago, Elp said:

Have you also decreased the resolution or region of interest (ROI) before recording, it'll give slightly better FPS.

How do you reduce the ROI with an AIR? They haven't got this function.

[Elp]

It's on the LHS of the video mode screen, but the resolutions are preset limited and can't be customised like you can in firecapture.

[CraigD1986]

I'm using an ASIAir Plus but have always recorded to an SD card so I can take the card out and transfer the files easily afterwards. I'll try recording to the internal storage next time. The Frame rate improves at lower resolutions but my FOV is tiny (Skywatcher 190MN and ASI662MC) so it would be good to be able to take 1080p lunar videos.