CraigT82

Here is 2 hrs of O3 added to the 2 hrs Ha as HOO. O3 was 600s exposures but still didn't pick up much. Also the stars in all the O3 frames were all rugby ball shaped across the whole frames. Not sure why as the guiding was well under half the imaging scale throughout.

You definitely need NINA to drive the mount for the plate solving to work properly. Once it takes that first plate solve image and calculates how far off target it is, it will then command the mount to move to the right spot and solve again, and again, as many times as necessary to get onto target (as described in the framing tab), before starting the sequence. No prior star alignment is necessary at all other than PA. Just start from the mounts parked position. I have it set to a pointing precision of one arcmin and it usually takes two solves/moves (1 minute max) to get on target. I set it to 0.5 arcmin once and it took too long to get to the right spot so went back to 1 arcmin precision. Once it works properly you will never look back! It also means that consecutive nights imaging are all framed the same way and you need to crop very little of the stacked image.

Very nice! Such an interesting open cluster to the lower right too.

B seems to have a little more contrast in the nebulosity, but stars seem to be a little tighter in A. I'll go for A please Bob.

Great shots! Where did you get the prints done?! Always on the lookout for decent printing places

Did a little experimenting last night with 2hrs worth of shorter (300s) binned Ha exposures to avoid horizontal blooming on the 8300 sensor. Seems to have worked quite well with only a smidge of the blooming visible on the brightest star which disappears upon stretching. Definitely not getting as deep as id like though, compared with the 1200s used previously. Quick calibration and stack in APT, then levels stretch and noise reduction in gimp and exported as jpg. Slight tweak of brightness on phone using ps xpress as it appeared very dark on mobile device compared to monitor.

Thanks Vlaiv. I spotted that difference in the nebulosity myself after I exported the new image from PI and compared to the original, but at that point I had spent so much time on it I couldn't face going back to re-do it 😆. I will keep coming back to this one and see if I can make a perfect blend of the defined nebulosity of the first with the RGB stars of the second.

Thanks for your comments Adrian, your Flaming Star and Tadpoles widefield is a corker 👍. So far im not too sure on the methodology of adding the RGB stars to NB images, there is always more than one way to skin a cat and I don't think I used the right method considering the very limited RGB data I had to play with, but bat this stage I'm just trying to learn as much as I can about DSO processing. It is waaaaay more involved and time consuming than planetary/lunar processing!

I have spent an absolute age redoing my Rosette image from a couple of weeks ago, this time processing completely in PI rather than APP and adding 1 more hour of 03. I also replaced the stars in this narrowband image with RGB stars using starmask and pixelmath following a YouTube tutorial. I only had 5x30s for each of the RGB channels so not really much of an improvement to the image overall, but the whole exercise has helped me learn quite a bit more about PI so worthwhile so the same. This is 5x1200s Ha and 5x1200s O3, with 5x30s each for RGB for the stars. 200/1200 newt, atik 383l mono. Baader 7nm NB and RGB filters. (First image is the posted original)

Any imaging scope that has a moving primary mirror is best suited to an off axis guider like you say. This is so the guide cam is seeing the exact same movement that the imaging camera is seeing, which is what really matters when it cones to guiding. The upside is that there is less stuff and weight attached to the scope (as opposed to a separate guide scope), downside is they can be quite fiddly to get set up. Once set up though they will just work everytime as long as not disturbed. I've just started using an OAG... the ZWO one, which is quite nicely made, not top of the range but it works. I had some issues with the long threads of my T2 nosepiece fouling the prism stalk but 5 mins with a file sorted that out.

Instead of cotton wool you could get a box of zeiss optical wipes. Each wipe is individually packaged and so is clean and free from particulate contamination, and already impregnated with cleaning solution (Isopropanol & ethanol, a preservative mixture of : 5 - chloro - 2 - methyl - 2 H - isothiazol - 3 - one and 2 - methyl - 2 H - isothiazol - 3 - one (3:1). Currently less than £15 for a box of 200 online. I use these and gently drag over the mirror surface from inside to outside, fresh wipe for each drag (after blowing or rinsing all the dust and loose material off first).

Sorry I just re-read your OP, and the thread title, and it made perfect sense... don't know what I was thinking about when I read it through the first time! Are you wedded to refractors?

What you've said there is a little confusing to me... you say for relatively widefield imaging, which implies a relatively short FL scope, but then mention you want a longer FL scope? Longer than the z73 but still quite wide.. is that what you want?

some good info on this here.. https://www.cloudynights.com/topic/549132-how-to-protect-stars-when-doing-a-stretch-in-photoshop/ and here...

Very nice, I just love the bowshock around the star at centre of frame

Very nice image, this is such an ethereal target, with nebulosity literally everywhere in the frame! I think it should be called the seahorse nebula

Thanks for the processing info Steve. Since you mentioned this... I'm sure that the people over at the HOYS citizen science project would love to have some of your stacked and calibrated linear Ha data uploaded to their photometry data site, it's really easy to do and NGC2244 is one of the clusters they are looking at. Just thought I'd mention it in case you weren't already aware of the project.

Wow what a beauty that is, it's like looking through a tunnel of flame in zero G! If you don't mind sharing how did you get to that colour palette with a HOO combination?

That is absolutely stunning, the stars are just gorgeous 😍

Plane tickets to La Palma?! For whenever we are able to travel again of course 😉

That's a real beaut and a wonderful achievement, love the framing too 👍

Thanks Martin, very kind comment and much appreciated! I do have some more O3 collected waiting to go into it once I have received a new flat panel that's on order. I'm hoping this will allow me to vary the colour slightly and boost the blue.

I managed to get a some more imaging done with my 200p dob tube last week, following on from first light on IC1805 the week before. I shot Ha and O3 on the Rosette and combined as HOO Palette. 6x1200s Ha and 3x1200s O3. This shows some of the horizontal blooming effect of the 8300 sensor on the brighter stars, but I also shot some much shorter RGB frames, with the intention of uploading them to the HOYS project server, and they may also serve me further by being swapped into this image as substitute stars as they are nice and round. Not sure how to do that but it must be possible? After that I got 1hr Ha (3x1200s) data on IC434. I messed up the framing on this one and inadvertently included Alnitak in frame which I've cropped out of this image. There is all sorts going on with the stars in this one: Guiding was terrible at well over 1" throughout the session, but I also think I've got some deformation of the primary which is likely because it is glued into it's cell. I will tackle this issue and hopefully get some more data on this target (Hb perhaps) before it retires for the year. Also I may have just really cackhandedly processed it as I'm still at the stage of just clicking things and seeing what happens. 200mm f/6 skywatcher newt on EQ6, Atik 383L, Baader 7nm filters, ZWO EFW and OAG. No coma corrector.

I'm impressed the SW focuser copes with all that weight... very nice M51!

I love em! Growing up on Hubble imagery, for me an astro pic isn't an astro pic unless it has diff spikes 😂