gorann

I thought about that sometimes, especially when I had to crudely crop some less well planned, or rather unplanned, mosaics, just to have them fit into the usual square that squareheads enjoy😄. I think your mosaic is great and very useful!

Thanks! Very nice mosaic Adrian, I will save it for reference! But, yes, it is on a few wide field images too, including SDSS (Aladin) where I spotted it, but I bluntly decided these would not count😉.

Thanks a lot boys! Yes, I just had a look at them on my mobile phone, and there the second one looks blown out, but not so much on one of my computer screens, especially earlier today when the room was quite bright. So here is a compromise:

This very rarely imaged object from the Sharpless catalogue is located about 2.5 degrees north of the Lobster Claw and Cave Nebulae. I can only find one other image of it on Astrobin. Quite strong in Ha but no Oiii to be found by the NBZ dual-band filter. Imaged over two nights since nights are getting very short up here, so this willl be my second but last image for the season (I can say that since I have collected the data for a final one). So, dual RASA8 and ASI2600MC (gain 100) with IDAS NBZ dual-band filters (Ha+Oiii) on a Mesu 200 mount. 90 x 5 min, so 7.5 hours. Procesed in PI and PS . I have posted an A and B version, the latter brighter and more contrasty. I realized that my preference depends on what screen I see it on, and comments most welcome! Cheers Göran

Would not the double encoders on the Mk1 mean that it will automatically stop if there is a mismatch between the encoders, like if you have a cable snag stopping the movement or the scope hitting the pier? With only encolders on the motors they may just continue running. But what do I know...... In any case, the old Mesu Mk1 I recently bought from Olly had a pre-Sitech system so it is now with Lucas to be upgraded and I decided to play it safe and go for the Sitech II (1000 USD compared to 500 USD for the Sitech I) to be able to use all encoders. Another reason being that my present Mesu200 Mk1 came with the Sitech II and I imagine I will be running into less nocturnal confusions if they both work exactly the same.

All great images Rodd👍, maybe except the last one where you were not too kind to the stars...

Grand finale indeed Wim! Lovely colour and details. Darkness is gone for us up here so time to prepare for late August. I assume isolating your obsy is first on the list.

As I understand it Lucas got rid of the encoders in Mesu 200 mk2 so then the more advanced Sitech II was no longer needed.

Sh2-140, Sh2-145, Sh2-150 and PK107+7.1 in Cepheus I continue my hunt for galactic dust until the bitter end, which will be soon since astrodarkness is rapidly disappearing up here now. This two-panel mosiac was imaged under a full moon with my dual-RASA rig over two nights. Again the IDAS NBZ dual band (Ha+Oiii) filter made it possible even with the moon at full force. Sh2-140 is rather commonly imaged, but this is not so much so for the other two Sharpless objects in the image. The Ha emitting sphere in the top right corner is the faint but rather large (15') planetary nebula PK 107+7.1 So, caught 16-17 April 2022 with RASA8 and ASI2600MC (gain 100) with IDAS NBZ filter, on a Mesu 200. 193 x 5 min, so about 17 hours. Processed in PI and PS, including Star Xterminator to stretch the nebulosity separately from the stars. Cheers, Göran

This two-panel mosiac was imaged under a full moon with my dual-RASA rig over two nights. Again the IDAS NBZ dual band (Ha+Oiii) filter made it possible even with the moon at full force. Sh2-140 is rather commonly imaged, but this is not so much so for the other two Sharpless objects in the image. The Ha emitting sphere in the top right corner is the faint but rather large (15') planetary nebula PK 107+7.1 So, caught 16-17 April 2022 with RASA8 and ASI2600MC (gain 100) with IDAS NBZ filter, on a Mesu 200. 193 x 5 min, so about 17 hours. Processed in PI and PS, including Star Xterminator to stretch the nebulosity separately from the stars. Comment most welcome as allways Cheers, Göran

You are perfectly right - the ASI1600 was maybe on pair with CCDs like the 8300 and won at the time by being cheaper but it suffered from amp glow and microlensing artefacts, but the new generation CMOS has since then left the CCDs behind. But I can see that the low second hand prices on what used to be very expensive CCDs are tempting.

Not sure I agree Steve, and you have much tighter stars in the CMOS image, although that could hardly be down to the camera😉

Good thing is that I am not in a town, so no lights to dim😁

Roof off and the dual-RASA8 rig up and running, with a Samyang 135 piggybacking. To play it safe I've now got one lapttop per camera and another running the mount. Aiming at Sharpless 140 and I just wish that annoying moon was on the other side of the planet, but my IDAS NBZ filters are hopefully doing their best to ignore it. This will be one of the last sessions for the season - only 3 hours of astro darkness at night now here at 60°N🥴 Apparently my smartphone camera produces oval moons😄 Cheers, Göran

Something I really like with CMOS (like the ASI1600) is the virtually instant downloading time, which makes framing or focusing so much easier.

Interesting! Never thought about it but from here on tape it will be in case the light gets in the wrong position when I rotate the camera.

That looks very promising! Now you can just go for it and any slightly oval corner stars can allways be fixed in processing. One thing you could think about is organizing your cables in a semi circle so you do not have to deal with odd star spikes. There are plenty of threads about it. This is how I did it (curved steel wire inside and electric tape to secure the cables to it):

Mesages on this thred are getting shorter and shorter for a good reason: Peltier every time! I do not understand why Altair keeps on trying to sell their fan cameras. If you just have a fan you cannot hold a stable temperature and get appropriate calibration frames like darks, so essentially you cannot calibrate the subs.

As Robin pointed out you really need a dew shield for the RASA. The good thing with that is that the camera then produces enough heat to keep dew away so you have no use for a dew heater. I would first try to set focus carefully as Olly points out. If that does not work for the corner stars try to fiddle with the sensor distance (the sensor lies 6.5 mm or 17.5 mm into the ASI1600 without or with the 11mm extension ring that came with the camera). One thing to check is that a defocused bright star really looks symmetrical. It has to be spot on, and if not you need to collimate (using a small camera and the CS adapter that came with the RASA so you can reach the screws. When you get the RASA8 to work, a very different and very deep imaging world will open up!

Thanks a lot! Yes, I cannot find any other visual image of it. But the Ha and Oiii signal is really needed. I made a gif (https://ezgif.com/maker) to show the difference between the RGB image and RGB+HaOiii (it jumps between the images in 5 s intervals:

In late March I stumbled on these faint blue (Oiii) and red (Ha) filaments in Camelopardalis by accident when I imaged this area using the NBZ dual band Ha+Oiii filter. After some searching, and with the help from friends, I realized that this was the first visual light image of the SNR G150.3+4.5 described by radio astronomers in 2014. (https://www.aanda.org/articles/aa/abs/2014/07/aa24128-14/aa24128-14.html). I have now combined about 18 hours of HaOiii data with 4 hours of RGB data (ASI2600MC without filter). I get the feeling that the dark nebulosity and other dust are obscuring most of the SNR and that we just get a small glimpse of it through a hole in the dust clouds. So, caught with my dual RASA8 rig and ASI2600MC on Mesu 200. 212x5 min with IDAS NBZ filter and 49 x 5 min without filter, so totally about 22 hours. Processed in PI and PS. Cheers, Göran

Supernova remnant G150.3+4.5 and LDN 1400 & Co in HaOiiiRGB In late March I stumbled on these faint blue (Oiii) and red (Ha) filaments by accident when I imaged this area using the NBZ dual band Ha+Oiii filter. After some searching, and with the help from friends, I realized that this was the first visual light image of the SNR G150.3+4.5 described by radio astronomers in 2014. (https://www.aanda.org/articles/aa/abs/2014/07/aa24128-14/aa24128-14.html). I have now combined about 18 hours of HaOiii data with 4 hours of RGB data (ASI2600MC without filter). I get the feeling that the dark nebulosity and other dust are obscuring most of the SNR and that we just get a small glimpse of it through a hole in the dust clouds. So, caught with my dual RASA8 rig and ASI2600MC. 212x5 min with IDAS NBZ filter and 49 x 5 min without filter, so totally about 22 hours. Cheers, Göran

Interesting Wim! For a resident of that dwarf galaxy, what would the Milky Way look like?

I like the image a lot. The galaxy stands out nicely on my screen. Great processing!

Just found this thread so I may have missed something, but when you now in 2022 decide to upgrade why would you look for an old CCD when virtually everyone are going for CMOS? CCDs for amateur astrophotography are not produced anymore and I am happy that I sold my ATIK460 in time, about two years ago, when I still could get some money for it. With the new generation CMOS cameras you have more sensitivity, less noise, less dead pixels, no dead columns, and immediate downloads, so you can focus and frame in real time. And large sensor sizes are no longer astronomically expesive.