blinky

Hi, I got about 7 hrs of L and an hour each of R,G,B as well as an hour of Ha but for the life of my I cant get it to add the Ha properly to the galaxy! I get horrible colour casts, also my Ha seems noisy when stretched, tried to do a low stretch and just keep what I want by making the background black but that also does not work! Can anybody assist? I've attached the XISF files from Pixinsight, would appreciate a little help/advice 🙂 HA.xisf M31_LRGB.xisf

No – I dont think it looks like a Pelican either! Anyway, this was taken over 2 nights on the 27/28th August, totally around 7.5 hrs of narrowband 2 min (Ha/Oiii) and 5 min (Sii) data. Its taken a while to process, the data is good but I was not happy with the background so I cropped it in a bit. The scope was my William Optics ZS73 with an 0.8 reducer bringing it down to a pretty fast F4.7 (Its natively F5.9). Anyway, pretty happy with this, still getting used to narrow band processing as the colours are very subjective. This is in the Hubble Palette and has Sii mapped to Red, Ha to Green and Oiii to Blue.

Cool, pretty much what I thought - I think I need to go a mm or so further in but I like the idea of taking it out further to see what shapes they look like when its knowingly too far out

I think its now down to spacing - but I cant figure if its too far out or too close!

I emailed William Optics about this and they send an image of the focuser and said to tighten the screws. When I checked, one of them did need tightened, only about 3/4 of a turn, the others were tight but I gave them a little 16th of a turn to tighten them and its now looking a lot better 🙂

I'm really wondering if I need the focuser lock screw back in, I removed it when attaching the motor focuser and forgot to put it back in. To refit would mean removing the motor again as the bracket goes under the focuser and won't let me get the screw in. That might be today's job! One of the advantages of work from home.....

And just to check, the finder screws are the ones that are not countersunk in the image above? The ones on the side

Cheers, will order some and see how they go, could you feel the slop in the focuser? Mine to be honest feels rock solid!

I think I have a bit of focuser slop in my WO ZS73 - I get elongated stars in a couple of corners that move when I rotate the camera, so I believe this indicates is not the camera but the scope/focuser? Im wondering if its possible to tighten the focuser on the ZS73 and if so what screws? I have an electronic focuser connoted to the scope currently, and had to remove the focus lock screw for this to fit, I also cant feel any slop in the focuser but I assume that doesn't mean there is none as it only needs to be a fraction of a mm anyway

I watched that vid and it looks good, how does he build it though? I saw the video where he makes it but what's the 2" tube that he uses to hold the camera? I wonder if any Astro manufacturers would consider selling one of these jigs?

Great stuff

Ah! How obvious! I get it now and yes it works a treat.... Thanks

First time using Autostakket and Im a little confused! I load my image in, click analyse, get it to create alignment points but when I want to save, I want to stack the best 50% (Whats a reasonable % to stack? This is 2000 frames source file) - what are the 4 options for? Also, any tips on using wavelets in Registax? Never really done any planet imaging for years! I knocked up an IR filter with some film somebody gave me years ago and had a we go last night with my 8" SCT and ASI120mini Jupiter2.tif Saturn.tif

Thanks Alan - I strongly suspect I will adjust the flattener till I get to a point where I can live with it - Im not a pixel peeper! I also realise that this is not the worlds most expensive scope or camera and as such Im realistic in what I can achieve... Also, I think its the camera that has the tilt as it did follow it from top right to bottom left when I rotated the cam. Thanks for all your assistance with this, it has been really helpful

Bottom left still looks the worst - silly question, but do I determine what corner of the camera is bottom left to adjust tilt? I do have a tilt adjuster but Im not sure I can use it, due to the adjustment screws hitting off the filter wheel and knocking it out of tilt!

OK folks - how does this look? I think I might need to add a little more extension but t my eye it looks better - the tilt seems a bit improved as well, or will that become evident again once I add more space/extension?

Spot on BTW, 3mm, so I reduced the extension tube by 3mm down to 5.3

Thanks @symmetal, will go check things again before it gets dark and see how it goes tonight

So spacing should be 9.5 taking into account filter and ccd cover

Ignore the spacing in the last pic, that was last nights spacing!

@Davey-T @symmetal Can you confirm this is correct..... I measured from the front face of the camera case to the front of the OAG and i get 42mm (see the attached pictures for all these measurements) as I have a spacer in place already to give me the correct focus point for the guide cam. Add to that 6.5mm for the code and you get 48.5mm. 56.8 - 48.5 = 8.3mm which i have set on the reducer. I suppose this does not take into account the cover slip on the ccd or the filter depths, just away to see if I can find them now but does the above calculation sound good?

Ran the Pixinsight aberration spotter, loos like bottom left/right is tilted or not far enough out, would you agree?

Here we go - not perfect, I assume I have a little tilt somewhere? I wonder if I can get it acceptable in all corners by making the good one a little worse to make the bad corner better.... I do have a tilt adjuster but could never figure out how you are meant to adjust whilst its connected to the scope, is this possible?

Dawned on me earlier, I used the field flattener before and my ccd/filter wheel etc were setup to be the same as a DSLR, I.e. 55mm so adding the 1.8mm is what I need to do. I’ve never taken into account the thickness of filters etc but assume since the ASI1600 is a relatively small sensor it hopefully makes no discernible diffference.