2 replies to this topic

[Gbarr56]

Hi,

I've had these nagging reflections in my telescope. I shoot with the following:

 

TPO 8 inch Ritchey Chretien Telescope

SBIG STF 8300 Monochrome CCD
SBIG 8 Position Filter Wheel
SBIG OAG-8300 Off-Axis Guider

CCD Tele compressor (CCDT67) - Astro-Physics
Moonlite 2.5 inch Large Format SCT focuser

I can't figure out what is causing my reflections. See attached image. Maybe someone recognizes the patterns. The blue circled reflections are all over the image. The red circled reflections are always 2 in the images. I can usually darken the sky to get rid of them.

 

Does this look familiar to anyone?

 

 

 

[pyrasanth]

Those patterns look like diffraction patterns from a spider- I think you need to look at reflections/matt black paint and adequate shielding.

 

There also appears to be a failure of your flats or no flats are being used- not sure if you are using flats. I would start by investigating your flats and ensure that any of the optical components are adequately shielded from either stray light or reflective surfaces.

 

If the errors land in clear background you can clone stamp them out after removing the stars but you will need to find out the cause long term.

[lurking_grue]

As I recall, there's a video somewhere on you tube regarding reflections in RCs.  I would search there if you haven't already.  I am making NO claim to the veracity of the information - it simply clicked in my memory and thought you might be interested.  "RC telescope reflections" (my search terms).  It won't be the first result returned.