Second light CaK.

smerral

I'm still having trouble with Newton's rings in Ha. I've ordered a tilt adapter so that I can maybe eliminate them or at least reduce them. Meanwhile here's a CaK shot from today. This too has Newton's rings but they are less prominent.

~~And an example of the Ha through a double stacked PST and 1.5x barlow.~~

skywatcher

verry nice pictures !

the first image is a mosaic ?

have you try to make some flat to reduce the newton ring's ?

smerral

Yes Skywatcher the first image is a mosaic of 4 panels (I can do it in two at a push but it's tight).

I use a ST102 f.5 refractor and a Lunt B600 diagonal.

Yes I have tried taking a flat for the Ha - in fact I always use one anyway to reduce variable illumination.

Flats seemed to work well with the DMK31. But the NRs are more prominent with the ASI120 and flats don't seem as effective.

I've ordered a tilt tuner, so maybe that in combination with flats will do the trick.

However, by applying some blurring to the flat I did manage to almost remove the rings in a few captures.

Here is the result using a PST double stack and a 1.5x barlow.

Although the DMK gave me great results I think the ASI120 is definitely better - apart from the rings of course.

Sam@ZWO

simple amazing!

title-adjust definilty can solve newton ring problem!

smerral

Well that's my tilt adapter arrived! - I have it tilted with a 7mm gap. A bit of DIY with an old 35mm film tube to keep the light out and now it's all ready to go! Unfortunately there's no sun today! :(