M45 diffraction spikes, and M82 single exposure.

[Oslet]

Hi,

Just got in to AP. And this is my first post.  Now I've only had 2 decent nights, the curse of the sky where I live. Yesterday I focused on doing single frames to test a few targets. Equipment: 200PDS,HEQ5 and Canon EOS1300D, no coma corrector. My question is what is causing all the extra diffraction spikes around the stars, between the spider vein spikes?                                                                                               I have seen these on some other photos on this forum as well. Any way to reduce this?

M45 Iso 800, 60s:

M82 Iso 800, 75s:

[alacant]

13 minutes ago, Oslet said:

extra diffraction spikes

Hi. The mirror clips. If you don't like them, you could fit a 'donut' mask over the mirror to hide them.

HTH

[Oslet]

4 minutes ago, alacant said:

Hi. The mirror clips. If you don't like them, you could fit a 'donut' mask over the mirror to hide them.

HTH

Ah ok, then at least it's nothing wrong.

Thank you alacant

[AKB]

For interest, take a look at this thread investigating the same problem...

 

[Oslet]

1 hour ago, AKB said:

For interest, take a look at this thread investigating the same problem...

 

Thats what I've been looking for. Thank you.

I think I'll take out the primary and have a look at it today. It's causing some agony when focusing. I've also seen this visual and it's kinda anoying. 

[Oslet]

Ok, then a made a 3 part mask, and fixed each part under the mirror clamps. Used some black waterproof cardboard, just a thin rim around the edge of the mirror. Waiting for sky to clear again, and I'll post the after result picture as soon as i got one. Getting the tube fitted to the main mirror again is NOT EASY on the 200pds. Just a word of advice. I'ts going to be a while before i do that again. 

[RolandKol]

hmm  
I have 130PDS... not a 200 canon
but even so, I always fit Mirror onto the OTA, not vise versa

OTA stands quite nicely upside down

[Oslet]

1 minute ago, RolandKol said:

hmm  
I have 130PDS... not a 200 canon
but even so, I always fit Mirror onto the OTA, not vise versa

OTA stands quite nicely upside down

Yeah  But a lot of black something were pealing of the edges when I took it off  Did not want it in the tube when i re-fitted. But I guess thats just my paranoia  

[RolandKol]

So while Primary is off, 

check for the vacuum cleaner
I flocked mine, - and vacuuming the scope is quite usual for me

[Oslet]

Good tip. I'll do some householding next time ?

[Oslet]

Then I got some results after the mask was fitted to the primary mirror. And WOW, that was worth it.

Before:

After (twice the exposure time):