Fine tuning a new acquisition, the TS Hypergraph 6 version of the Sharpstar 15028 HNT. All is good, I like it a lot, but have quite an annoying problem with starburst diffraction.
The image below shows two main problems
(1) The starburst itself (could live with it)
(2) Fading of the starburst on stars towards the edge of the frame, which seem to follow the vignetting profile of the scope (the vignetting is slightly off centre also).
Ordinarily, given it is symmetric in the centre, I don't really mind the starburst, but cannot deal with it being partially present on stars all around the edges and between the edges and centre.
This scope has a lot of shiny screws that were not blackened (I wish TS would do this, but maybe have an agreement with Sharpstar not to modify scopes?)
As there are no feature impeding on the aperture of the primary mirror, I must conclude this diffraction is caused before the light hits the primary mirror.
Here is what I see looking into the scope, many screws.
I don't see this effect on images produced by this scope elsewhere, so wondering what peoples thought are, especially if you have one.
This occurs even when the spacing and stars are in good shape beyond where the asymmetry in stars is seen.
Any help or insight appreciated, especially since the same screw density/location does not seem to do this to other people as far as I can tell.
CS, Colm
The image below shows two main problems
(1) The starburst itself (could live with it)
(2) Fading of the starburst on stars towards the edge of the frame, which seem to follow the vignetting profile of the scope (the vignetting is slightly off centre also).
Ordinarily, given it is symmetric in the centre, I don't really mind the starburst, but cannot deal with it being partially present on stars all around the edges and between the edges and centre.
This scope has a lot of shiny screws that were not blackened (I wish TS would do this, but maybe have an agreement with Sharpstar not to modify scopes?)
As there are no feature impeding on the aperture of the primary mirror, I must conclude this diffraction is caused before the light hits the primary mirror.
Here is what I see looking into the scope, many screws.
I don't see this effect on images produced by this scope elsewhere, so wondering what peoples thought are, especially if you have one.
This occurs even when the spacing and stars are in good shape beyond where the asymmetry in stars is seen.
Any help or insight appreciated, especially since the same screw density/location does not seem to do this to other people as far as I can tell.
CS, Colm
