Reflections or Refraction

[Paravision]

Hi All

This is my first post to Stargazers lounge so please be gentle 😊

I actually managed to get my first image of IC-434 (Horse Head nebula) the other night. I know it's not perfect, but it's a start. I've gone with kstars and Ekos, everything is communicating except for the Pegasus DMFC, So I've resorted to running parallels on the mac and use the dedicated focus software on windows at the same time! So focus isn't the sharpest! My new guide scope is in the post! So no guiding on the night. I took 20 Lights (lost one to a satellite), 20 Darks, 40 Bias and 40 Flats ( need to adjust exposure time slightly on Flats). But my main question is the reflections. My lights exposure was 2 min. at 300 iso 40 offset on an Altair Astro 294c Hypercam. Anyone with experience with reducing this effect? I live in Wales with lots of cloudy nights, so opportunities can be limited to go out. I do have the benefit of Bortle 3 skies though 👍.

[Swillis]

That is looking very nice. 

There was a post recently with a similar issue:

Conclusion was microlensing caused by the camera. But there may be something which can be done to post processing. 

 

[Anne S]

You don't need bias frames with cmos cameras, just darks, dark flats and flats. Can't comment on the reflections though that's a nasty bright star. Perhaps more, shorter exposures? I have an ASI533 but mostly use ccd cameras. Attached is with a ccd camera, lots of artefacts around the star.

It's very frustrating in Carmarthenshire too. Just 2 imaging sessions this season.  One hour on the Ring nebula and then a usb issue a few nights ago.

Anne

[scotty38]

8 minutes ago, Anne S said:

You don't need bias frames with cmos cameras, just darks, dark flats and flats.

That's not really correct, some CMOS cameras calibrate better with flat darks but plenty will use bias just fine.

[Paravision]

Thanks everyone for your thoughts. Definitely look into the micro-lensing. This is the first time I've seen this effect, so will investigate further when I get a clear night! I did use the camera with spacer ring for the first time this time. Previously I've used the camera via a diagonal. So will see if it makes a difference. You never know unless you try!