SharpCap Forums

I am trying to find out if there is a maximum exposure length for live stacking, I want to be able to use the saved frames rather than the stack but someone suggested that live stacking may only be suitable for shorter exposures, basically I'm after dithering with 3-4 minutes exposures. TIA

Hi,

there's nothing to stop you from using long exposures in live stacking, but it does tend to mean that the key feature of live stacking (seeing the image appear and build up and improve in front of your eyes) is far less compelling as the image will only update once every few minutes.

Also, make sure that using long exposures is actually beneficial – you will typically only get benefit from very long exposures when one of the following conditions is satisfied

1) imaging in a very dark location with low light pollution
2) using narrowband filters
3) using a CCD or CMOS camera with very high read noise (8e or more).

You will find lots of discussions elsewhere on the forums about how the minimum sub length for deep sky astrophotography should be calculated from measurements of your light pollution, sensor read noise and other information. SharpCap Pro has this calculation built in as part of the 'Smart Histogram' functionality.

Cheers, Robin

Thanks very much for your reply, I use the smart histogram feature and will be trying the MDR as well as the unity gain setting that I have been using up to now if I ever get a clear night again. I have just got a mono camera to use with NB filters so hope the smart histogram works as well as it has done for my OSC.
Mark