SharpCap Forums

Hello!

I’ve tried a few times now to capture an all-night time-lapse using my fisheye lens (via the sequencer), taking a shot every 15 seconds. I’m using auto-exposure for this.
Generally, it works quite well; however, I’ve noticed that the exposure time never seems to exceed 5 seconds, even though the profile file specifies 15 seconds.

My goal is to capture the Milky Way, but that’s likely to be difficult with exposure times of only 5 seconds. It would also be ideal if the exposure time could be reduced—for instance, when the moon rises.

Regards,
StarFlea

Hi,

that's a ToupTek camera you're using there right? On that make of cameras (including all the derived brands with the exception of Altair) the autoexposure only runs up to 5s - it's a limitation of the camera SDK. The API to set the maximum autoexposure value will fail on those cameras if I try to use a value longer than 5s. Altair being the exception has a maximum of 60s - this seems to be for historical reasons.

Unfortunately there isn't really much I can do about this - the SDK imposes a hard limit and SharpCap doesn't do its own autoexposure except in limited circumstances (and what it does isn't suitable for this sort of use case)

sorry about that,

Robin

Hi Robin!

Thanks for shedding some light on this! That explains a lot, though it is naturally a bit of a letdown.

Is an automatic gain adjustment possible, perhaps?

Otherwise, I guess I'll just have to live with this flaw...
In that case, I'll try working with a fixed exposure...

Cheers,
StarFlea

Hi,

if I remember rightly, there is no 'auto gain' on its own, but you can enable auto gain with auto exposure. You'll find that down a few controls from the exposure and gain controls, where you can set 'auto gain with auto exposure' to either off or 'up to gain XXXX'. So for example if set to 'up to 1600', the automatic adjustment of the gain can be anywhere in the range 100 to 1600 while in auto mode. I'm not sure if that will really be sufficient for your situation though

cheers,

Robin