gorann

Interesting Olly with possible minute tilts in both the scope and camera. I have seen a bit of variability in star shapes and now you got me thinking that it has been the result of how the camera happened to be oriented (I often rotate the camera to get the best framing). Also interesting that it may be a good idea to focus on periferal stars, at least in your case. Will your autofocus allow you to pick any star in the FOV? I have no experience with autofocus.

PS @ollypenrice. Today I got my double RASA rig put together in the livingroom, after spending the day getting the balance point right for each piece of the equipment (you can see my pencil under the dual rig holder). I may be asking for trouble. The total weight is 29 kg so my iOptron CEM70 may struggle (32 kg max payload but as usual it is not stated if that is imaging or visual) and I may have to put it on the Mesu (although I have other plans for that mount). Got an Evostar 72ED as guide scope of one of them and to balance it a vintage Canon FD 200mm f/2.8 with an ASI2600MC as piggy back on the other. Cheers Göran

Hi Olly, you sounded very optimistic here, so what happened? It could now be a chip distance problem, but Vlaiv has a point, maybe it could be even better collimated.

I even convinced myself to buy a second one and I got no discount (but I didn't ask🥴)

Sorry if I am partly responsible for this RASA8 hype, but it is an amazing scope for wilde field imaging and my feeling is that it shows that aperture rules and cannot be overestimated. But then I am, as @wimvb says, at a dark site. I could in no way get as deep into faint nebulosity with my Esprit 150, but then I could never get as close to the finest detials with my RASA8 as with my Esprit 150 or 14" SCT, so it is all about what you are aiming for and if you want it all you need more than one scope.

Great news Olly! Eager to see the proper first light!

I saw virtually no IFN sgnal in the RGB so I thought there was litte reason to add it to the lum. However, I usually do not add 100% lum but use the slider to see where I get the lowest noise (just eyeing it). In this case I added the lum as 80% luminosity. Not sure what others do. The low IFN signal in the RGB means that it is virtually colourless in the image. With my RASA and ASI2600MC I do pick up quite a bit of colour in the IFN.

Here is my first version processed in PS and PI back and forth. As @ollypenrice also pointed out the lum data is great and virtually all the IFN signal was in the lum. Many choices to make, including colour saturation (more saturation seems to be in fashion so I saturated it a bit more than usual) and how much IFN to bring out is a main question. Right now I am rather pleased with this version, but I may think differently tomorrow. Cheers, Göran

Both my Artesky adapters came with a distance ring. It is 0.5 mm thick, goes over the T2 thread and looks like this. You can of course use any 0.5 mm ring. You use them when there is a filter (or glass window) in the image train. Göran

First take away the optical window on the scope. That was one of the first things I removed and the Artesky adapter seems to work well without it. If you have the window in or a filter then you should use the distance ring that came with the Artesky adapter. However, I do recognize the distorsion you get from my first attempt with my second RASA8 (although I had it in all corners) and the scope turned out to need some collimation and after that the corner stars looked much better, so another suggestion is that you check the collimation an a bright defocused star. First I thought it looked rather ok but not perfect, but I then had these odd stars in the cornes and thought that collimation may be needed and realized that in the defocused image needs to be perfectly symmetrical. Tilt is a possibility so try rotating the camera 180 degrees.

And with a RASA8 at 400 mm focal lenght, any guiding below 1" RMS is overkill😁

Since there is no backlash on a Mesu (being a friction drive) it is essentially all up to your guiding, and then mainly your seeing. Then of course a Mesu 200 can hold 100 kg of scopes.

It could also be seeing. My Mesu can give me 0.3 - 0.4" RMS on good nights but other nights I get 0.8". Both are usually ok for the pixel scale I work at. However, it is evident that I get better guiding when I use OAGs instead of a guide scope, but when I have a RASA on the mount OAG is not an option and then guiding is rarely better than 0.7".

A relief to hear that you made the right choice! But they should have a warning about the wrong one. We are now all eagerly waiting for your reports when skies get dark and clear!

Yes, astrophotographers must remeber to ask for the AR-coated version. My old ASI071MC had no built in IR filter so I always used it with a filter (like a Baader or ZWO lum filter). A bit akward with some set ups where it was difficult to fit in a filter.

That is a bit worrying - why would they sell an astro camera with an option that blocks out Ha? The ASI2600MC has a built in IR/UV cut filter on the sensor but it clearly lets a lot of Ha through.

Yes, very nice indeed, especially from a war DSLR! I had to Google UHC and concluded that it was probably not Universal Health Covearge but a Baader light pollution filter. I am fortunate enough here at Bortle 2-3 to be rather ignorant about those things😁

Not sure if this has been up for discussion here. I just heard of this and I have to say that I have severe doubts about it. I think that telescopes and high resolution cameras could be used for better purposes than chasing UFOs. Or can someone here change my mind? https://projects.iq.harvard.edu/galileo/activities

So maybe a few more details in my image is more related to my Mesu mount😉

Great image Wim and interesting info. I had a go at the same galaxies two years ago with my Esprit 150 and about the same integration time and the result was very similar to yours, so the MN190 is at least performing like a 6" refractor but at a much more reasonable cost. https://www.astrobin.com/394768/L/

Has that worked well with Spanish customs? I would worry that one may have to pay twice if the Chinese company has not done the paperwork correctly.

Interestingly I see that TS alone now sells four cameras with the IMX571 colour sensor. Seems to be an explosion of IMX571 cameras. The Altair one is a ToupTec so apparently identical to the RisingCam but more costly that the ASI..... Accidentally I noticed that TS include 25% VAT in the price. I thought German VAT was 19%, but maybe there are new EU rules saying they have to add my Swedish VAT that is 25%? EDIT: I now found out that there are new EU rules from 1st July stating that the VAT should be payed to the buyers taxauthorities, so no reason to shop in EU countries with low VAT anymore.

Found this informative thread on CN that may not have been mentioned here yet: https://www.cloudynights.com/topic/747251-risingcam-touptekaltair-imx571-sharpcap-sensor-analysis/

Amazing image Peter! Rogelio Bernal Andreo, who calls it Clouds of Andromeda, has a more popular article about it and also suggests that it is not Ha but wider emission that includes the Ha part of the spectrum. https://www.deepskycolors.com/archive/2017/01/01/Clouds-Of-Andromeda.html

There is also another graph for it in LCH mode (on the AliExpress site) so apparently it does not switch automatically at gain 100 as in the ASI camera. I assue that gives more flexibility. It will be interesting to hear about the first experiences with this camera - good that someone volunters to have a try!