Huge circle in Solar images

[SaraG]

Hi,

When I am taking a solar image now with a barlow (3x Televue) I get a huge circle in the middle like glare, I also have an IR Cut and Continuum filter, I suspect it is light bouncing off those.

I also got the same with my 2x Revelation astro barlow on the moon.

Has anybody else seen these?

I blame the filters on the camera nose piece boucning the light off them. Should I put the filters further up the optical path?

I only seemed to get it now and then, the barlows work fine otherwise.

The reason I think its the filters is I only get it when up close and in green light with the IR cut on it on the sun.

I am using a DSLR (1100d) and the lenses are very clean ( I cleaned em with baader fluiid lol)

[Macavity]

I have most certainly experienced the problem - With a Baader solar continuum filter (white light, MAK 150 etc.) plus IR/UV cut. I had also attributed it to some sort of "internal reflection", off the mirror-like filter. I never did work on a solution though...

I assume it is exacerbated by high levels of light, but might also happen with other (dichroic) filters, under night skies? Somewhat worrying... And doubtless to be revisited here.

[SaraG]

I never used to get it, only when I tried a new IR Cut filter to try to get better focus.

I blame the IR cut filter.

I did get it on a daytime 2x moon with no filters though. That I blamed on the Revelation Astro 2x barlow being cheap.

I even tried swapping the order of the filters, no dice.

I wonder if a ND filter in the front would help?

[markt]

The problem is the order you have all these elements stacked: Make sure all filters are screwed on the end of the barlow not on the camera nosepeice.

[SaraG]

Hmm I will have to try that.. thanks...

So which order is best? IR | Continuum > Barlow > Nosepiece?

In maybe 3 weeks when I see the sun again.

[markt]

In maybe 3 weeks when I see the sun again.

You may be lucky if you're in the UK, i'm hoping for some sun over the weekend...