gorann

Set up very ready but not in action yet. Supposed to be clear but it is not, so I am waiting for the terrain to follow the map🥱. Double RASA8 rig with a Samyang 135 piggybacking and an Evostar 72ED as guide scope. all on a Mesu200. Three ASI2600MC waiting for photons, each one with its own laptop to be on the safe side.

If you have taken a dark image with an ZWO ASI071MC and stretched it you will see a clear "amp glow". The 071 comes with the older generation Sony chips, the newer ones sold by ZWO that do not show "amp glow" are the 533, 2400, 2600 and 6200. The 183, 294, 071 and 1600 all have amp glow, but it is easily handled by subtracting darks.

Really nice but I am also a bit distracted by the very red and rather big stars. I would try to only add Ha to the galaxy to highlight its Ha regions rather than the whole image and see what it looks like.

Impressive image Steve! It reminds me to put my Samyang 135 as piggy-back on my double-RASA rig. I recently gave an old Canon FD 200mm f/2.8 (bought cheaply on ebay) a try as piggy-back but its stars were nowhere close to what the Samyang gives.

Sh2-126 is one of the largest Ha objects in the Sharpless catalogue, so this image just shows a part of it, the part containing the dusty nebula LBN437. The data was captured during an hour before clouds ended the imaging night. However, with the double RASA-rig this gave me two hours of data which can be enough for a RASA at f/2 to get a reasonably good image of relatively bright objects like these. So, 2 x 20 x 3 min = 2 hours with two RASA 8 and ASI2600MC (gain 100, offset 30, -10°C) on a Mesu 200 in my home obsy. Processed in PI and PS. No filter used so the is RGB and not HaRGB - the set-up is quite good at picking up Ha.

Stars are excellent Olly, I think you have that problem solved👍, but I suspect there is more colour and structure in your data to be brought out, especially in the dust. At least I found a bit more in my attempt on the shark with a similar integration time: https://www.astrobin.com/6s82qb/C/ That came at the cost of more star halos so maybe try the Starnet approach on the dust? (which I have not done yet)

Really nice capture Steve with great detail in teh galaxy! Olly initially compained about a dark sky but now in your latest version I find it a bit too bright. Maybe also try to soften the red around some of the stars and there is a dark centre in your bightest star. Probably something created by these fancy programs, would not happen in PS😉

Yes, that is the one our Swedish friend in the video got inspired by. Will probably give Olly's version a try when the clouds are back.

Yes, after thinking more about it I came to the same conclusion. I will see if I have an old cupboard I can take apart and make one of the Olly design.

One to be very proud of Martin!

Nice image! I looked for a HaRGB image on Astrobin and found this one: https://www.astrobin.com/298177/ I attach a crop of it. It shows that same star but very red so presumably a lot of Ha. So it is there but why you have a ring around it beats me. Cheers, Göran

I actually worried less about your large set-up where the top and bottom must be quite parallell than that of Daniel Sundstöm in the video. He says nothing about how he made sure it was all parallell. Any tilt in the screen where the laser spots are seen (or in the holder of the camera) will cause a circular movement and be interpreted as a tilt in the sensor even if there is none.

And a rug is neccessary if you drop things!

Interesting Olly, I thought of it but never tried superpixel binning my RASA images. Wonder why your stars suddenly got a blue rim from that. Should give one of my data sets a try. But tonight I will be busy collecting data.

Tonight will hopefully be third light for my dual RASA8-ASI2600MC rig. Hope for clear sky until midnight. Cheers, Göran

Olly, I think your stars look as good as could be expected from such a fast instrument with a wider than recommended sensor so I would be happy and do like you say: just get on with it. I aslo usually downsample the images I put out, both because it makes the files smaller and more managible (still usually around 8 Mb as jpg). Most often I found 4000 x 3000 pixels or even a bit less to be sufficient to present all the details that really matters in the image.

Nice one Olly and you seem pleased with what the rig can accomplish, which is reassuring. However, I agree with Vlaiv that it would be interesting to see it in higher resolution to peep at your corner stars. If they are perfect or nearly so it may convince me to make that sensor-tilt-adjustemnt set-up you just described in another thread. It is great that we both went for the ASI2600MC that has a built-in tilt plate. I have been following a thread about the cheaper competitor (Touptek sold under various names) with the same sensor but without tilt plate, and with that camera some have experienced tilt and can only adjust it by adding a tilt plate and there would be no space for that on a RASA8. Cheers Göran

Very interesting! If you get an improvement I may try the same. Just one question, is there no risk of damaging the sensor by shining a laser at it? Also, I assume the top and bottom plate of that plywood construction must be completely parallell.

At least it is a sodium light that have a very narrow band width that should be taken out with light pollution filters and there are probably specific filters for sodium. If they change it do broadband LED (which they may very well do soner than later to save energy) there is no way to filter it away as far as I uderstand.

Thanks a lot Olly, much appreciated as allways. I agree that the first image is a bit more attractive and shining than the second one, but I who can blame a nebula for beeing at bit dull if you have a magnitude of 16 and a surface brightness only 23😉.

Very clever, I may try that if airplane mode does not help. I do have the computers set to never turn off when on a charger and that seems to work. In this case it had not gone to sleep but had rebooted (so I had to type in my password) which makes me suspect a forced update.

I just posted these images on the equipment post I started but thought they may also have a place on the Deep Space Imaging page with a bit more info. Cheers, Göran About the first image. This is only from one of the RASAs since the laptop for the camera on the other one apparently decided to update Windows after grabbing three subs. So 83 x 2 min with a RASA8 and ASI2600MC (gain 100). LBN (Lynds Braight Nebula Catalogue) 603 is located in Cassiopeia and appears to be rarely imaged. Abouth the Second Image: Now all laptops in airplane mode to stop updates. This is 2+2=4 hours (RASA8+ASI2600MC gain 100, 80x3 min). The prominent central structure is LBN438, which is catalogued in Lynds' Catalogue of Bright Nebula, but it is quite dim and demands rather deep data and stretch. Its magnitude is 16 and the surface brightness only 23. It is 30 arc-minutes long.There are more LBNs in the image including 435 and 440 and quite a few galaxies from the PGC and UGC cataloges. The nebulosity is part of the Lacerta Molecular Cloud. The annotated image shows a myriad of galaxies. I could only find relatively few images of LBN438 on Astrobin and none as wide field as this one. Gary Imm has as usual done his research and written a very interesting description of LBN 438 that I can recommend to those that want to know more: https://www.astrobin.com/8iq7ay/

Finally I got my first two images with the rig. The first night I aimed at LBN603 and to be safe I had one laptop for each camera and a third running the mount and PHD2. But in the morning I found that one of my laptops had probably decided to do a Windows update so I only got about three hours from one of them (first image below) - still better than none so an unforseen advantage of a dual rig. The second night I had all laptops in airplane mode and got 2 + 2 hours on LBN438 (second image below). I could have got a bit more if I had done a flip but I prioritized sleep. Still 4 hours gets me rather deep with these light buckets. Stars were not perfect in the corners but could be fixed reasonably well with processing. I suspect that like @ollypenrice found just rotating the cameras could affect this and I may try some of that first, or just live with it. By the way, I noticed no problems with flexure. Cheers, Göran

Yes, as @wimvb says I have not so far seen any reason to use flats, since as you also found Olly, there are no visible dustbunnies and a very even field illumination. A dose of Gradient Exterminator is all it takes. I also do not use darks with the ASI2600 as I cannot see any notisible effect of them. So for me it is Debayer -> Star alignment -> Image integration. By the way I just got the first image from the double rig last night. However, when I checked it this morning one computer had stopped and logged out so I only got three frames from one of the RASAs. Still, the advantage of a double rig was that I at least got data from the other one. So here is this seasons first light. about 3 hours on LBN603: Cheers, Göran

Moved the rig over to the Mesu. New season so I started with polar alignment tonight but then clouds decided to cover the whole sky... Will give it another try tomorrow.