tomato

Apologies Olly if I keep the Imaging Surgery theme going, but I wonder do you have any thoughts on my post 10 above on using channel extraction in Pixinsight to obtain RGB channels from a OSC image?

This is my final galaxy image for this season 😪, astro darkness almost gone from my location. It is unfortunately heavily cropped as attempts to make the rig less prone to sag introduced some camera miss-alignment which I decided not to correct and use the time to image instead. Captured with the dual Esprit 150/ASI 178 rig, data binned 2x2 so imaging at 0.94 arcsec/pixel, total integration 5.4 hrs L 58 x 3 min R 15 x 3 min G 16 x 3 min B 19 x 3 min Calibrated and stacked in APP, processed in APP,AP and GIMP. Apparently this galaxy is considered to only have a single spiral arm, but to my eye there is a hint of an second shorter inner arm at the base of the galaxy, but it is more likely to be my dodgy processing. Thanks for looking

This is my final entry, astro darkness almost gone from my location now. NGC 4725, captured with the dual Esprit 150/ASI 178 rig, data binned 2x2 so imaging at 0.94 arcsec/pixel, total integration 5.4 hrs L 58 x 3 min R 15 x 3 min G 16 x 3 min B 19 x 3 min Calibrated and stacked in APP, processed in APP,AP and GIMP.

Just wondering Olly, have you ever had a RASA imaging at Les Granges?

Brendan, sorry to hi-jack this thread but on Olly's point re channel extraction, I have loaded a OSC broadband stacked image into PI and using the Channel Extraction process tool, have created a Red, Green and Blue file, the images look to me like they have extracted the relevant data for each colour channel. Could I not now compose a LRGB image using these?

It will be a trusty KAF8300 taking Lum and a QHY268c taking the colour. Previously I have used two 8300 cameras, one taking lum and the other divided equally between RGB, so this is a ratio 1:0.3:0.3:0.3. I have used this capture ratio successfully on dual CMOS cameras but thinking about it the only project the dual CCD cameras has done to date was a M31 mosaic and the colour channels were a struggle on that one. As Olly says with the mono and OSC this will go roughly to 1:0.25:0.5:0.25, but the CMOS camera is quite a bit more sensitive than the CCD, so wouldn't that work in my favour? This set up has worked ok on NB with the CCD taking Ha and the OSC working with a dual band filter, but LRGB is a different kettle of fish. It won't be a big deal if it doesn't work, the OSC was purchased specifically for WF with a RASA, and it will be fun to try.

I plan to do this on my dual rig in the autumn. I will shoot Lum on one scope and use a CMOS OSC camera on the other to capture RGB. I can get very similar FOVs and resolutions by using a focal reducer on the Lum scope. I will process the data separately then extract the RGB channels from the colour data and combine these with the Lum, just as I would if I had captured separate RGB with a mono camera and filters.

I don't think they built really tall chimneys at the start of the Industrial Revolution, so most of the soot and dirt came straight back down, hence the Black Country name. The interstellar murk does create some wonderful opportunities for imaging but I think I prefer my space to be clean. That's why the Fornax Deep Field is my favourite HST image, nothing but the clean vacuum of space between us and the galaxies at the edge of the Universe.

A tiny hair on the sensor can produce a trail on the image that looks like a liquid drop that has run down.

I know the OP has gone mono but I don’t think the latest OSC cameras combined with the latest dual band filters are a non starter for NB targets. Here is a 1 hour integration with a RASA8/QHY268c OSC using the IDAS NBZ dual NB filter. I dare say a mono camera with separate NB filters will give a better result but this took an hour to capture and 20 minutes to process in APP, so I’d venture OSC NB imaging can be quick and reasonably straightforward with the appropriate equipment and software.

Another superbly crafted image Goran. Please don’t take this the wrong way, but aren’t large parts of the Cosmos just filthy with dust? I say this because the image reminds me of illustrations of the Black Country, which if you are not familiar with the name, described parts of the West Midlands in the UK characterised by the pollution from the Industrial Revolution. Don’t get me wrong, I’m from that region and am immensely proud of it’s heritage, there is a tenuous connection for me as the clouds of dust and smoke in your stunning image have their origins in Cosmic thermonuclear furnaces.

With the cost of those filters, I couldn’t see me putting them in more than once.☺️

Very nice, I’ll take two for my dual rig....😉

Great M13, you have NGC 6207 in there also. Good choice with the ASI 2600mc, I have the QHY version and have been mightily impressed.

Don’t be too alarmed by Sitech, I followed the excellent Steve Richards set up guide and although there are pages and pages of parameters to mess with in the Configuration file, I haven’t touched any of them. Sitech.exe links seamlessly to CDC, SGP, NINA etc, or you can use it stand alone like I did for the first few years. It comes with a comprehensive catalogue of objects so plenty to go at. The Sitech users forum is great, quite a few Mesu owners on there but I love the posts from the intrepid astronomers using the Sitech module to control a myriad of home made mounts of all shapes and sizes.

Looks great, Lucas has certainly given the mount a streamlined look, the Mk I is festooned with nuts and bolts. My Mesu is coming up to seven years old, on Friday night it was guiding at 0.35” total RMS, with about 100 kg all up load, with nary a belt mod or DFO tweak in sight.

Thread resurrection, I understand the nightly releases of NINA now support ASCOM compatible dome control, anybody used this successfully with the Pulsar dome control?

Probably no help but I have the Datacolor Spyder 5 Express model and after doing a bit of online research I use it with the DisplayCal free calibration software rather than the software bundled with the unit. This tutorial is pretty good: https://www.techspot.com/guides/2055-how-to-monitor-calibration/ I use a separate display monitor as I could never get used to how the display changed so much with the tilt angle of the laptop screen. I agree the green cast does not look right.

Wow, a branch of visual astronomy that hurts the wallet as much as imaging.

Fantastic detail and colour, really sharp. I never realised there was a gap in the tail between it and the galaxy until looking at this close in image.

How long to get “good” images? I think it all depends, I have seen first time images on SGL that look as good as some taken by renowned imagers with many years of experience. My first time images like most others I suspect, were not to this standard. However, I wouldn’t be hesitant about posting anything, I felt the same way as I had spent upwards of £5k on my initial set up and felt the quality of my images should reflect that level of investment. In the end I posted this image of M81 which should have been way better than it was if you took the kit used to capture it into account, but, hey, I thought it was pretty cool, but more to the point, I received nothing but encouraging feedback on this forum, and also many useful pointers on how I might improve on it.

Having spent the morning helping @Tomatobro install and commission the Pulsar supplied dome drive and controller, I must say I am very impressed with the simplicity of the process and the performance of the unit. For sure they aren’t cheap, but it delivers everything that is required with the minimum of fuss, if you aren’t into retro engineering and don’t have access to a fully equipped workshop then they are definitely worth considering.

I think in my very early days with the Mesu 200 I used the ST-4 port on the Sitech II controller with no issues, I’m assuming the Sitech controller shipped with the Mk II has an ST-4 port?

A very thought provoking post Olly. I accepted that a dual 6” refractor rig imaging at 1” per pixel was always going to be challenging on several fronts, and so it has proved to be. To be fair since @Tomatobro’s designed and fabricated top bracing plate, differential flexture has been managed to (for me) an acceptable level, but it does show up from time to time. To be fair, after this recent observation I checked and found both the bracing plate retaining bolts and the tube ring clamps looser than they should be, I will repeat the same imaging orientation and see if it improves after tightening. The AO solution sounds like an interesting and challenging project, I presume the SX unit would be the one to go for?

Here is my attempt, processed in Startools, and Affinity photo. Super clean data as usual, default workflow in ST, then adjustments in Levels, Curves and Selective colour in AP.