tomato

Two very good renditions on the same data. Picking up on Olly’s comment on the dust, is the dark cross shaped region in the centre a clear ‘hole’ in the Hydrogen clouds, or is there obscuring dust there?

Thanks for the replies, I think I will give it a clean when it comes off the mount to make way for the refractors and the impending galaxy season.

This is the current condition of the corrector plate on my RASA8. I’m sure it is not impacting on the quality of the subs, but it’s bugging me as it looks dirty and uncared for. Plus I think there are some pollen grains on there which is not good. I have cleaned the objectives of my refractors when they were in a similar condition with Baader fluid and a clean microfibre cloth with no drama so perhaps I should just go for it?

Nice job! The Geoptik “stainless steel” might stay that way in New Mexico, but definitely not in Shropshire. I metal polish mine a couple of times a year but are quite pitted now after 3 years in the dome.

This has been done before, but with their relative close proximity in the night sky I have always wanted to capture M31 and M33 in the same image. This is a 6 panel mosaic using the SY135/IMX571c combination captured over the recent run of clear (but moon and atmospheric dust affected) nights. I had problems with flats correction and an uneven star density across the six panels about which I started thread in the Discussion section. The 'background' panels are each 30 x 2 mins with the galaxy panels being 80 x 2 mins and 120 x 2 mins respectively. The top right and bottom left panel received a partial stretch before combining to try and even up the star density, but you can still make it out. With both of these wonderful galaxies being about the same distance from us, I wonder what M31 and our own Milky Way would look like if you lived in a suitably orientated spiral arm of M33, and could an alien imager capture them both in the same FOV? It is a mosaic, so you can zoom in a bit, but each panel is already what I would call a widefield image. Thanks for looking.

I actually think the problem is that panels 2 and 5 are better quality than the rest, and so when I did star reduction work on the whole mosaic the smaller, tighter stars in these panels were minimised some way to invisibility. So I followed Olly's suggestion and applied a partial stretch to these panels before combining, not perfect but better, I think, than my first effort. I have posted the final version in the Deep Sky section.

I don’t make it complicated, QHY268c in DSO photographic mode, Risingcam IMX571c at gain 100, offset 768, same exposure times. I regularly combine these subs with no problem that’s apparent to me.

This was the only forum I frequented that didn’t have cute cat images, until now…

Great captures. The stack shot makes me glad we don’t have any Triffids growing in the garden…😉

Well, at least you now have more information on the issue than before you started the thread. Have you decided on a course of action? As you say, a replacement RASA could possibly have the same defect, but I suppose FLO could easily test it before shipping. The stop down mask is a quick and relatively easy fix but that solution would rankle with me on a scope costing in excess of £2K. A third option might be to obtain a refund and wait for one of the right vintage to come up on the classifieds, they do appear from time to time. The filed down mirror photo on CN does look rather grisly, but it appears to have reduced the flaring. It does look to me like poor tooling set up at the factory. Steve

Thanks Olly, I combined them in their linear state using APP, but I will have a go at individually stretching each panel then combining to try and achieve a more balanced result. This is the first time I have encountered this problem, last Spring I did a few galaxy mosaics over a number of nights in the Virgo region but had no such problems, but then the overall FOV was much smaller and they were captured with an F7 refractor.

Over the run of recent clear nights (but with Moon becoming increasingly intrusive) I attempted a 6 panel mosaic with the SY135/IMX571c to produce an image with both M31 and M33 in the same FOV. I had issues with flats correction which required a lot of artefact removal in the processing stage but the main issue is that it appears I haven't achieved a uniform level of star capture across the 6 panels. The star only image clearly shows a lower star density in the top right and bottom left panels. Each background panel was 30 x 2 mins exposures with the galaxy containing panels having double the integration time. Of course, the panels were shot at varying elevations and moon illumination and I think that's the root of the problem. I don't think it is background variation as the starless image (after much manipulation) is reasonably uniform. I can't see any way to fix this other than retake them or reduce the stars in the other panels, which I suppose would balance them up but is a bit counter productive...

Nice shark! You have to be impressed with the modern cameras, 5 or 10 years back the advice would have been don’t attempt objects like this when there is a moon up.

Conditions were good last night, my guiding was about 15% better than the night before.

I find StarXTerminator to give better results than Starnet most of the time, particularly when adding the stars back in. The latest version has an enhancement that works well with PixelMath, ~((~starless)*(~stars)).

Hi Alan, Attached is an image of Sadr (180 sec exposure)taken with my RASA8/QHY268c/NBZ combination, the scope was purchased from FLO in August 2020, the cables were in a circular arrangement. 2021-11-22_18-54-09_-20.00_180.00s_0009-crop.fits Crop

If you don’t have a robust focuser I wouldn’t recommend doing off axis guiding as this is more kit to put on the focuser. A small guidescope will be easier to set up and costs about the same as the Off Axis unit, both methods require a guide camera.

Here is my first image from 2014 with an astro camera, Atik 314 OSC, Altair 102mm APO, Mesu 200. No darks, no flats, no clue!

Really clear and crisp. There is a hint of red in the background, but that may be the iPad I’m using to view it.

It does look like a bit of moisture on the sensor window, what temperature were you running the camera at?

It would go on the Mesu (just) and it would be nice to own a bit of Spaceflight history, but I would have to sell all of my set up and then some to fund it.

AR, keeps you in control.

Love the tripod set up in the sand.

Hope the warranty repair goes OK, sending it back to China is the big downside to purchasing one of these cameras. I received mine back in December and it’s still OK at the moment.🤞 On the subject of head to head comparisons, I did a brief qualitative side by side trial of the Risingcam and QHY versions here:

Clutch tight on the RA drive?