QH5YL-ii fuzzy view & newton rings

[Purplehayze104]

Hi All

again.....just another quick question

with regards to solar imaging with a QH5YL-ii, i've recently been trying to image again some solar disk mosaics with my small lunt35, now im not to sure why this happens, but any capture software I use tends to show quite soft almost blurry screen shots, ive spent ages trying my get it focused as best I can so I can sort of count that out (almost), managed to sort the gain & shot speed (m/s) as to get the best image I can on screen too, (cant get rid of newton rings either) soooo..... would it be of any use trying a IR blocking filter on the cam at all ? or being a solar scope I shouldn't need one, or... just get a more suitable cam & keep the QHY for guiding

also the helical focuser is a bit pants, fine for visual, but moves slightest touch or knock of a cable an has no locking screw to stop It rotating, anyone have any quick fixes or ideas.

any help much appreciated.

kind regards

john

[michael.h.f.wilkinson]

I used to have an LS35, and did not find it necessary to use an IR block filter. What could be a problem is reaching focus, I  found. Some cameras (DMK21) clearly needed a Barlow to reach focus, others (ASI130MM)  were borderline at prime focus.

[JamesF]

The shape of the QHY camera should make it easier to find focus I'd have thought.  If there's insufficient travel you could just move the camera in or out a bit (within reason).

I'm sure I read in another posting recently that someone was using flats to get rid of newton's rings but I'm really not sure.  I'll see if I can find the post again.

James

[JamesF]

Found a mention of it here, though I'm not entirely sure how the process works for Ha imaging.

http://stargazerslounge.com/topic/246932-zwo-asi174mm-bands-on-image-normal-or-a-problem/

James

[michael.h.f.wilkinson]

Flats can certainly help sorting out Newton rings.

[Purplehayze104]

Hi James thanks for reply & link will give it a read

I can get focus, its just the image on the screen I have to use to focus tends to be like looking throu tracing paper, tends to look very soft, captures alright get upto 52fps in firecapture, then when I convert to tiff then try combining in most processing software tends to only partially do it with other images ramdomly attach but not to mosaic, gets a lil frustrating.

regards

john

[Purplehayze104]

hi michael

curious as how to do flats with a solar scope, not had much experience in producing them

[michael.h.f.wilkinson]

My ASI130MM had patter noise which required flats and darks to correct. Without that it would not work. That camera has the same sensor as the QHY5-II, but not the same one as the QHY5L-II. It would help if you could show us an image

[michael.h.f.wilkinson]

hi michael

curious as how to do flats with a solar scope, not had much experience in producing them

I make flats by covering the objective with a few layers of cling film and recording the image while the scope points to the sun. In my case 4 layers works best, although I do need to triple exposure time

[Purplehayze104]

will post a few images later to show how theyve come out just at work at the moment & no way of posting any

but thanks for the info on flats will give that a go next time I get chance

kind regards

john

[JamesF]

I make flats by covering the objective with a few layers of cling film and recording the image while the scope points to the sun. In my case 4 layers works best, although I do need to triple exposure time

That genuinely made me laugh, Michael.  Where did you get the idea for using cling film?

James

[michael.h.f.wilkinson]

That genuinely made me laugh, Michael.  Where did you get the idea for using cling film?

James

On SolarChat. It is the only piece of H-alpha imaging paraphernalia that is cheap

[Purplehayze104]

well i finally got a full disk mosaic from my images the other day, thanks to michael, autostitch worked its magic an combined them without a problem, its a bit rough as had no flats to add and some processing no work of art, will try another trick which was mentioned to see wot i can do about the uneven illumination ive got. Also there is a lot of banding across the whole disk which was also on the avi's not sure if this is an artifact of the camera or newton rings hopefully someone will be able to tell me.

ive added a stacked image of before anything was done forgot to mention these were taken around 6.45pm with clear skies maybe something to do with the quality of the image maybe

regards

john

7 - Jup_191744.bmp

[JamesF]

There's another thread running at the moment talking about the banding and newton's rings on solar Ha images that's probably worth a read.

James

[JamesF]

This one: http://stargazerslounge.com/topic/247530-quark-and-zwo-newtons-rings-and-bands-problem-solved/

James

[Purplehayze104]

thanks for the link James, sounds a good idea that, be interesting to see some shots of it, curious to see if it would work with the lil lunt..

regards

john