Reflections when using MPCC and NB filters?

[tooth_dr]

My Baader mark III MPCC loaner arrived today - courtesy of FLO and Baader - cheers!  I ran off some flats this evening and the results show a significant improvement.  I am using a Baader 7nm Ha filter with a QHY268M, on a SW 250PX

 

 

[Skyline]

On 22/04/2021 at 20:30, tooth_dr said:

No filterwheel, just a drawer.  Trying to find a new MPCC now 

That camera looks huge.

[tooth_dr]

43 minutes ago, Skyline said:

That camera looks huge.

It's roughly the same size as the ZWO 2600MC.  Here is it on the scope:

[javi89sv]

On 30/06/2021 at 23:19, tooth_dr said:

My Baader mark III MPCC loaner arrived today - courtesy of FLO and Baader - cheers!  I ran off some flats this evening and the results show a significant improvement.  I am using a Baader 7nm Ha filter with a QHY268M, on a SW 250PX

 

 

hello, i have the same problem, i get a white circle in the middle of my frame light. I am using a baader mpcc mark III and Asi 294 mc pro. Did you get any fix?

[tooth_dr]

12 hours ago, javi89sv said:

hello, i have the same problem, i get a white circle in the middle of my frame light. I am using a baader mpcc mark III and Asi 294 mc pro. Did you get any fix?

The MPCC III improved it but did not completely eradicate the issue. 

[rnobleeddy]

On 30/01/2023 at 18:46, javi89sv said:

hello, i have the same problem, i get a white circle in the middle of my frame light. I am using a baader mpcc mark III and Asi 294 mc pro. Did you get any fix?

With the MPCC III I didn't really have any issues - you could still see the issue if you stretch the raw data, but it was generally well corrected using flats. 

Don't know which filters you have, but check if they have a direction and if so, if you've got them the right way around- this helped a little with Baader filters.

[javi89sv]

20 hours ago, rnobleeddy said:

With the MPCC III I didn't really have any issues - you could still see the issue if you stretch the raw data, but it was generally well corrected using flats. 

Don't know which filters you have, but check if they have a direction and if so, if you've got them the right way around- this helped a little with Baader filters.

I usually use the CLS filter, but also when I don't use any filter I get that halo or reflection in the center of the image, which is not capable of correcting the calibration with flats

[rnobleeddy]

13 hours ago, javi89sv said:

I usually use the CLS filter, but also when I don't use any filter I get that halo or reflection in the center of the image, which is not capable of correcting the calibration with flats

This issue was specifically when using by narrowband filters with the older (gen 2 or gen 1) MPCC filters.

So this sounds like a different problem. 

Have you tried ditching the MPCC to confirm that's 100% the cause?

[javi89sv]

13 hours ago, rnobleeddy said:

This issue was specifically when using by narrowband filters with the older (gen 2 or gen 1) MPCC filters.

So this sounds like a different problem. 

Have you tried ditching the MPCC to confirm that's 100% the cause?

Yes, I have to do a test without cc and another with cc. The image on the left is without and the right is with, and as you can see with cc I have the donut or ring effect. The photo below has ABE applied to highlight the problem.

[rnobleeddy]

9 hours ago, javi89sv said:

Yes, I have to do a test without cc and another with cc. The image on the left is without and the right is with, and as you can see with cc I have the donut or ring effect. The photo below has ABE applied to highlight the problem.

I assume you've corrected flats on both images with flats taken with/without the corrector accordingly?

At this stage, if possible, I'd try out another MPCC III. You may have a bad example. 

Or perhaps someone else has some other ideas. Probably worth a new post- this may have the same impact, but the cause is different. I didn't have this happen with my MPCC II or III with broadband filters.