gorann

Nice Wim! But maybe add some annotations so we know where to look;-)

It is fun to see that this question comes up regularly on SGL. I agree with @vlaiv that it is easy to get confused and I have to stop and think every time. I probably should put up a note about it in the obsy saying: "ADD 1/3 OF THE FILTER THICKNESS TO THE IMAGE TRAIN" since there usually are enough other things to think about there and then. But as someone said here, never trust what scope or flattener/reducer manufacturers claim should be the correct backspace - check corner stars and be prepared to adjust.

Just wanted to assure you that the Esprit 150 works fine with my full frame cameras using the flattener (at least for me). But I am quite sure you would get quite dark corners with a reducer. So the inexpensive way for you would be to use the ASI2600 you have with a reducer if you want to catch more of the FOV of your scope. the ASI2600 may actually be a better camera as it is 16 bit rather than 14 bit. Here are the FOVs you will get with the ASI2400 and ASI2600 with 0.77x reducer. So a bit bigger with the ASI2400: (made it with this free FOV calculator: http://astronomy.tools/calculators/field_of_view/) Cheers, Göran

Very nice, but yes you have (or had now) a radial gradient. Somtimes DBE or GradXT creates them if not set properly. Have a look at this image by @ollypenrice to see what the dust around M45 looks like. https://www.astrobin.com/a7j34x/

Yes, this is an outstanding achievement Lee, and what a great idea to capture all these goodies together! I assume you have a quite dark sky.

Interesting and convincing Steve! It clearly looks like the mono is capturing more detail. But then as @ollypenrice points out you may loose out on colour infomation, so maybe it depends on the target. Using the mono-OSC approach could be superior on bright objects like the jellyfish, but if you hunt for weak Oiii from a SNR, maybe two OSC would be better as you want to separate out as much Oiii as possible. Just speculating. But I am tempted to put my QHY268MM with NBZ on one of my RASAs. In cases where I know that I am looking for weak Oiii maybe I would use a Oiii filter on the mono camera, and add it to the blue channel. Fun with experiments but not so fun to remove the camera from a RASA as you never know what the stars will look like next time

Interesting Steve! A comparison you could make that could be convincing is to compare your mono data with a grayscale version of your osc data, using the same number of subs from the same times at night. I assume you used the dual rig so already have that data from the same night. Will the data from the mono camera show significantly more detail and depth?

Yes, a great improvement Francis! One comment: in the new version bright stars and the blue (and some yellow) areas around them have been blown out. There is more details in these areas in the first version. When that happens to me I try to select the best of each version. If you have PS, you can put the old version as an invisible layer on top of the new one and blend in some of the old with the brush tool where the old version is less blown out. Maybe as a luminosity layer (experiment with blend mode).

That is a great, and as @ollypenrice says, eerie image Wim! As you know I am at the moment escaping sub-zero Sweden on an island in the south Pacific. With Musk´s eerie Starlink as the only connection with the rest of the world I have not been on SGL as regularly as normally so I missed the posting of your dwarf galaxy. Have you tried the dark arts of BlurXT on it yet? If not you should. Also as you know I have an MN190 tucked away in a closet - got it a few years ago for 500 Euros from someone that did not know its true value . It seems to be as close as a deadly person can get to an 8" refractor, so I see it as an investment to play with during all those dark nights I expect to get once I retire😄.

Very impressive demonstration of what StarXT can do! I would experiment with reducing the blue a bit (using a curve on the blue channel) since much of the blue appear to be halos from the bright blue stars (so artifacts of the optics that can be suppressed with good conscience). That would also make the Ha signal less purple.

This is a busy area in Cygnus with both bright and faint delicate nebulosity, near Deneb, one of the brightest stars in the sky (the big one down to the right in this image). It took some taming of Deneb in processing to allow the extremely faint centerpiece, the very large supernova remnant Wetserhout 63 to come through. There are four Sharpless objects in the image, more LBNs and LDNs than I could count, and also the Propeller Nebula that has been missed by the famous catalogues. Over the last year or so I have been coming back to this area with my Samyang 135 and RASA 8, now all sitting together. When I a few days ago caught this wide field image with the Samyang 135 I thought I could use it as a nice frame to bring all the RASA8 images together, totally around 50 hours of f/2 data. So this image is a symbiosis of Samyang and RASA8 data.

He he! Thanks a lot Alan and Merry Christmas! CS, Göran

Sh2-126, the great nebula in Lacerta, here flanked by LBN438 (down to the left) and the Gecko Nebula (LBN437, upper right). This is a Samyang 135 image where I have added RASA8 data to the main features. I have my Samyang 135 piggybacking on my dual-RASA8 rig, so there is a bit of symbiosis in this image. Totally about 18 hours of data using IDAS NBZ filters and IMX571 OSC cameras. Processed in PI and PS, including StarXT. Happy holidays everyone!

Very cool Wim! Are there any other images of Leo A? I could not find any after a short search on Astrobin. There is a small area of bands just north of Leo A. Is that an artifact of something real (would be an odd artifact - banding are usually not that local). Cheers, Göran

Yes, it would be worth finding out if there is still a quality issue with the mirror of RASA8. There has clearly been a bad batch produced as @symmetaland others have been victims of.

My guess is that if you are into astrophotography long enough and take thousands of subs, a freak satellite event like this may eventually happen

My vote is on the RASA. I have an Esprit 100 and it clearly needs many times more integration time to get to the same depth as a RASA8. Not sure why you want a RASA11. Your camera fits well with a RASA8 and to get an equally large FOV with a RASA11 you need a full frame (24x36) sensor (like ASI6200). The RASA 11 is also very heavy and difficult to handle alone, as evident from this scary thread 😱 Cheers, Göran

PS Steve, maybe you could make a crop of each image to better show your point?

Interesting Steve! Is BXT rewriting theory? Keen to see what @vlaiv have to say🤔

After 7 years of astrophotography, I could maybe start a web page for advice, but it would only have one line: log onto: https://stargazerslounge.com

I am equally perplexed - why would someone that obviously (clear from this thread) has no experience and no clue about astrophotography start a web site and give advice? Who would it benefit?

Thanks a lot Steve! And yes, you are right about the sky!

Could be! This two-planel mosaic has a big overlap in the middle, to double the data on the SNR. The left part of the mosaic was captured two nights ago and combined with data to the right, including the SNR, that I captured two years ago and may have posted here, but then with less data so not as good.

Thanks Carole! Yes, a dark sky really helps for an object like this.

This SNR is another cool target for RASA owners! This is a two panel mosaic including the rather well known Propeller Nebula and the very large but faint supernova remnant (WC63 aka SNR G 082.2+05.3), which is possibly even more faint than the Squid Nebula. Captured with my dual RASA 8 rig with ASI2600MC and IDAS NBZ filter. 92 x 5 min. Processed in PI and PS using both StarXT and Noise XT, which really helps squeezing out that last part of faint nebulosity. ( I don't think BlurXT does much for an image like this with few delicate details).