gorann

That gives hope Stuart! Now it worked for a minute for me but then the fatal error message came back. I assume Salvatore is working on it.

When I try to open Astrobin for the last half hour I get this. I hope it has not fatally lost all the images again🥴

I have a lot of faith in a RASA 8 double rig with my ASI2600MC for dual band or RGB on one and an ASI2600MM for Lum on the other, except there is no ASI2600MM procued yet😰

Yes, miracles still happen - I am not a subscriber but I was promised to get a copy. I think ZWO owes Olly and me a camera each

Great! There is always new things to learn in this game

The draw back is of course that with 2 minute exposures one ASI2600 collects 30 x 52 Mb of data per hour, which after debayering becomes 30 x 313 Mb, so 9 Gb. Two of them will collect 18 Gb per hour. So stacking takes more time than collecting, so external hard drives are a necessity.

Ah, there we have what may save me Olly. The Light grasp combined with the new CMOS = short exposures. For this one it was 83 x 2 minutes. For the Squid I whent to the extreme and used 5 minute exposures😉.

But that is more than twice the FL - what was it Oddball said in Kelly's Heros about sending out them negative waves......

Good to know for anyone buying this camera. Hopefully you were intitally very unlucky.

PS. You bought an outstanding camera for sure, and lucky to get one in these times!

Ah, you are like me - getting into the buying mode when clouds settle in for too long

Nice images and good star shapes Dave! But a bit qurious why you whent for the Askar 200 f/4 from Sharpstar instead of the well proven and less expensive Samyang 135 f/2 with more aperture (twice the lightgrasp)?

That is really nice Tristan! With a RASA 8 you do not need many hours of clear sky (but over the last weeks I have not even got a minute). So far I have not found any need for using flats of darks with the ASI2600MC - maybe I was lucky with mine. Yes, there is a little bit of vignetting with the RASA 8 but that is why there is a DBE in PI or a Gradient Exterminator in PS😉

If I ever do it I will virtually bolt them together. Good thing is that there is no tendency for mirror flips in the RASA and the short FL and wide field makes them easy to align to a sufficient degree. And I would not be a pioneer. Just wish I have had a chance to tell him to arrange his cables better - he will get a mess of star spikes: https://www.dpreview.com/forums/post/62471743

I made some modifications to the Artesky adapter. In this image you see the side attaching to the scope. I have drilled two holes so I kan use a tool like the one in the image (found on ebay) to unscrew it safely from the camera since I realized that it could easily get stuck on the camera. Especially when I have a filter in there centrally I could not get a grip on it since the threaded ring from Celestron (not in this image) will just rotate freely (if you see what I mean). The second modification is the brown adhesive teflon tape (also ordered from ebay) that provides low friction so that the camera hopefully can be easily rotated. The tape is only 0.13 mm so it should not have much impact on the sensor distance. Further up in this thread you can see the wire ring I will introduce between the Artesky adaper and the threaded Celestron ring so that it cannot wobble sideways. Now I just have to get a clear night to test it all.....

Thanks Tristan! Yes, I have the same experience - focus remains spot on between days, and I have so far not lost a sub due to focus drift. The weak point is the sensitivity for sensor distance and any tilt, but that is probably inevitable for such a fast system.

Thanks Olly, I am equally surprised about the capacity of this scope and camera. It now struck me that the star colour situation can be improved with the usual PS methods: S-shaped curves in Lab Color and Increase Star Color in Noel's actions:

Yes, the problem as you know is that the outer edge of the camera adapter has to pass through the threads and then behind the threads there is space for it to move sideways. So this what I will try to use: a cirular piece of plastic covered steel wire to put in behind the threads in the Celestron attachment ring to force the camera to be centered. Have not tested it yet.

Thanks Steve. Interesting! For me it happened after midnight when I was done with another object (where the stars later turned out to be fine) and I had to rotate the camera to frame IC405&410. As you now the camera attatchment allows it to move sideways and I may have ended up with it quite uncentered. I hope that is the cause of the problem, but I need a clear sky to find out.......

Not sure what you mean about comparing RGB with NB. They are both NB and my image is a Ha Oiii image (IDAS NBX filter). Actually Rodd I like the soft fuzzy edges of the stars more than the round blown out ones, so it is on purpose and it is probably a matter of taste. However, maybe the stars were a bit too fuzzy at this scale so I now used curves on the stars to reduce them and the fuzziness a bit to make them a bit more descrete. But at a FL of 400 mm and a very aggresive crop I am here really working close to the pixel resolution. But this version shows a bit more separation of stars:

Thanks a lot Olly! Yes, if I had an RGB of it. This was taken while the moon was out and I had resided to do dual band imaging. Right now the sky prohibits any imaging.....

I never used a Hyperstar but from what I have read the RASA is something quite different especially when it comes to collimation issues. My RASA was perfectly collimated and have stayed like that. It is my impression that this is the norm for RASA. It also holds focus very well over the night. I think the Hyperstar concept is a bit of a compromise while the RASA optics are designed for fast imaging from the start. The RASAs (except the first generation of RASA 11) have a much better focusing mechanisms than the ordinary Celestron SCTs and there is no tendency for movements in the mirror. Apparently it is so good that a mirror lock system like I have on my SCTs is not needed and is not there.

Thanks Michael! Yes, I even contemplate over the possibility of having a double RASA 8 rig one day......

Impressive resolution Rodd! You got me inspired to do the same with my recent RASA 8 image of IC405 & IC410. Since I do not want to steal your thread with my image I post it separately.

@Rodd just posted a very impressive closeup of the Tadpoles in IC405. This got me inspired to do the same with my last image taken in November before clouds settled here, apparently forever. At this closeup the stars looks a bit odd, dimond shaped. I have not had that with the RASA8 before and think (or rather hope) it is due to a slightly off-centered camera (will plan to fix the wobbly attachment until next time) but it could also be some pinching of the mirror since it was - 4°C that night. Will find out next time it clears, whenever that will be. Still, I think it shows that the RASA 8 - ASI2600MC combo is quite good at picking up rather small details. 83 x 2 min subs (IDAS NBX dual-band filter), so totally only 2.7 hours. Here is the full frame (no it is not a mosaic): And here is the crop: