Trying some higher power shots of the sun

[DaveM]

A few experimental shots at 1800mm and 2700mm focal lengths to see how far I can push the mag. Unfortunately some newtons rings using the 3x barlow. I wonder if a different make of 3x barlow might not have the rings?

[sheeny]

Gorgeous, Dave! Gorgeous!

I tried to capture some today too, but gremlins stopped me then clouds and rain...

Al.

[DaveM]

Thanks Al,
As much as I enjoy having lots of cloud-free days to image over here, I'd trade a few for some rain and green grass...

[Merlin66]

Dave,
I sometimes get the Newton rings with my double stack SM60 when using the TV Powermates or the AE x4 imagemate.
I find they can vary in intensity with the tuning to Ha. They are also related to the cover plate thickness on the CCD chip itself and the pixel size of the camera...some cameras are worse than others.
The compromise for me is a x2.5 Powermate and the DMK21 camera.
I've just got a DMK41...so it will be interesting to see the results.
My seeing conditions don't really allow me to go much above f30 and f40 on a good day.
Ken

[DaveM]

I'm wondering if the 2.5x powermate might be worth trying. Trouble is I would have to buy it before I know if it gives rings or not on my setup. It may still be worth the risk though.

[Matt Wastell]

Hi Dave
Great images and nicely processed! The proms are awesome!
A 2.5 Powermate may be the go?
I do not think the rings in anyway detract from your work.