tomato

A couple of times on a large refractor I have “missed” the dovetail slot when rocking the heavy scope into position horizontally, because I haven’t opened the clamp sufficiently. I always look at the end of dovetail to check it has located properly before taking my hand away.

I agree SpaceX’s technological achievements are far in excess of the others, but from what I can see of Mr Musk, he isn’t short on ego so I am not surprised that the media has picked up on the story that to date he hasn’t gone for an orbital flight to go one better than Messrs Branson and Bezos.

Great M31, FOV adds to the image, galaxy is not too small but just enough space around it to put it into proportion. The colours look very similar to those put out by APP, what processing software did you use?

This is a combination of the LRGB channels from my 12 panel mosaic from last year taken with KAF8300 mono cameras and filters (about 4 hrs per panel total integration, took about 3 months to capture) and a 6 panel mosaic taken recently in one night with a KAF8300 taking Lum and a IMX 571 OSC (about 1.5 hrs per panel). The Pixel Peepers will have a great time with this one, there are hosts of distorted stars, duplicated stars and weird halos in many of the regions, but I’m frankly astounded how the software (APP and StarTools)is able to cobble the data together at all, given it’s diverse pedigree. But looking at the bigger picture, so to speak, I think it has more colour and Lum channel detail than the component parts, so for me it has been a worthwhile exercise.

A second hand Sony lens can be had for a bit less than the more popular Canon variety so after acquiring one of these, @Tomatobro machined up adapter plates to bolt it to my Moravian G2-8300 with integrated filter wheel. Initially, the spacing was calculated and some alloy spacers made to bolt up the lens to the camera body, but inevitably there was some tilt/spacing issues, so the spacers were replaced with nylock nuts on the other side of the lens flange, so adjustments could be made in-situ. I just need to make a soft light and dust exclusion collar to go around the outside.

Here is my version for a 16” flex tube dobsonian. The scope stays on the trolley permanently so it can be wheeled out of the garage and round to the back garden.

The banding became apparent in the Wipe module of Startools when trying to smooth out colour gradients in that quadrant associated (I think) with my mosaic panels not covering all of the reference image. As @Laurin Dave suggested, I think I will try to combine this data with the 12 panel mosaic M31 from last year, as I have now taken the refractors off the mount and put the RASA8 and SY 135 on there, to try my hand at some widefield NB imaging, gulp!

Thanks Dave, the saying about a bad workman and his tools comes to mind…

Good point Dave, here it is. The star shapes are inferior but that's not down to the sensor.

Well, here is the RGB only result. No contest IMHO, even with my inexpert processing skills. This is only 40 mins integration on each panel, remember. Guess I need to put together a decent sales pitch for my G2-8300. Hope nobody reads this thread...😆

I’m somehow pleased that they cannot currently print the Ford V8 to go under the hood…

I followed the recommendations of the script developer, namely produce Lum and RGB mosaics separately then combine these. Much as I have a soft spot for CCDs, the OSC data looks to me to be superior, I will produce an image today just from the RGB data to see how it compares. I have the dedicated SW Esprit 150 FR, I think it is a spacing issue. Ideally I would have a 268 mono camera on the other scope, but I went for the budget option of the FR and my existing G2-8300 sensor, alas my Astrophotography spend is not limitless. I could sell the G2-8300, but looking at the market it looks like folks are wising up about CCD cameras and are keeping their funds for the latest CMOS cameras.

I have checked an RGB channel combination image, there are no significant colour artefacts around the stars, so it may be due to the distortion manipulation required to combine the lum channel which has a different imaging scale. Wim, I confess I'm not familiar with your star mask fix, but there are other tools I can use.

I suspect the background artefacts which have distinct transition lines are due to the fact my mosaic panels did not cover the whole of the reference image, but I could be wrong. I will investigate the colour artefacts around the stars, but I have since noted that the star shapes in the corners of the Lum subs taken with the F/R are not as good as the OSC data... As for pixel peeping, I don't mind at all, the exercise can reveal shortcomings in the processing that can be addressed. And with 145 million of them, there is no shortage of opportunities.

Yes, keep those eyepieces in if you are after a relaxing, therapeutic experience. Imaging is laced with stress from start to finish, but in a good way. When you get some good subs on the drive in spite of everything, that’s entertainment.

And here is another one entirely processed in APP, no binning so fat stars at 100% scale but maybe turned the brightness down? I can do this all night...

I'm OK with both of 'em but I look forward to the quantitative analysis...

I succeeded in loading separate LRGB channels into Startools, my preferred processing package, so here is a version from there, software binned 35% to hopefully address the issues noted by Vlaiv. I note there is a theme developing with my image posts. Best to ignore the first couple or three versions I put up, the better ones tend come along after heeding all the good advice.🙂

Thanks Dave, I have been considering this, one for the next run of cloudy nights. I’m looking at @vlaiv’s comments, I’ve managed to load a LRGB file into Startools so will look at producing a version with a more sensible imaging scale.

I might add that I intended to software bin the image to 35% in StarTools, but alas I suspect the file size was too big as ST repeatedly crashed when trying to execute the operation.

Hi Vlaiv, I’m not at my processing PC so I can’t give you much in the way of numbers, but if I elaborate on my workflow this might help explain your observations. Lum data was collected with the 150/FR/G2-8300 @ 1.33”/pixel, RGB data (with the OSC camera @ 0.7”/pixel. A single night capture necessitated a 6 panel mosaic which resulted in a “letterbox” FOV of the galaxy. The Photometric Mosaic script requires a widefield image of the target as a reference, this is used to ensure smooth joins and minimal gradients as the panels are added. Inevitably, there were sections of background either side of the galaxy which were not covered by my mosaic panels, quite how the script deals with this I don’t know, but it returned no errors and the final image had a smooth, seamless background. The image size of the Lum mosaic was different to the RGB mosaic, these were registered in APP, using the dynamic distortion algorithm, normalised, then LRGB combined in APP. To give a more pleasing image I cropped it to the proportions of the widefield image (art intervening I’m afraid), then processed further in APP and AP.

Indeed, when you retire you need a hobby, swinging golf clubs never appealed.

Esprits have gone up a quite bit recently, but still cheaper than a well lauded Japanese brand. One is on loan from @Tomatobro, and the other I purchased second hand. Isn’t this why the government gave me access to my pension pot?

Here is M31, a 6 panel mosaic captured in a single night, 3rd - 4th October. Each panel is 40 mins Lum with the Esprit 150/0.77FR/G28300 CCD, and 40 mins RGB with the Esprit 150/QHY268c These were combined in Pixinsight using the Photometric mosaic script, then processed in Affinty photo. Its not terribly deep but the panels went together OK, better than my previous M31 mosaic efforts. The gradients were easier to manage but it was a super transparent night, for a change.

Sorry to hear it’s a hardware fault, I’ve been impressed (🤞) with my G2-8300.