Properly focusing DSO images within capture software

seaber

Hi all,

When prepping the shot for DSO captures, is there a trick to getting them properly focused within the capture software? I'm using Sharpcap with my ASI224MC

What I mean by this is say for example I'm prepping to capture M57. To get it to even show up on the computer screen you need to adjust the gain and exposure high enough to the point it lowers your FPS as a whole. Small focusing or movement adjustments makes everything on screen jumpy and hard to fine tune. Is this just the nature of the beast when prepping for a cap?

riklaunim

I use a Bahtinov mask to focus on a bright star. Then I move to the targeted area and recheck - on few-second exposure. For DS image focusing ability to clip preview image levels is very very handy. Nebulosity has it, don't know if Sharpcap can do it - it allows to see the DS object even on short exposures (easier framing) as well as the Bahtinov mask spikes.

To focus with Bahtinov I take an exposure, check the spikes, correct slightly, re-take the exposure, check spikes again... and done.

rickevans10473

This probably differs from orthodoxy but I focus on a nearby bright star without focusing aids, then center the intended target. Full disclosure I'm using a C8 SCT on an AVX mount. The camera is an ASI174MC-Cool To get to the target I use Precise GoTo which takes me to a bright reference star. I center that star then reduce the format maybe 320x240 and zoom the image to fill the screen thus magnifying the star image. I lower the exposure to make the unfocused star just visible. Then focus the star to minimize the point size. After focusing I return the format to the desired size and send the scope to the target DSO.

SeaBer wrote:
Hi all,

When prepping the shot for DSO captures, is there a trick to getting them properly focused within the capture software? I'm using Sharpcap with my ASI224MC