DaveS

Impressed that you've got so much of the tidal structure in NGC 3718, those are *very* faint and a real test.

QHY600 could be quite nice, bin 2x2 for a slightly dodgy 0.73"/px, or 3x3 for a more sensible 1.1"/px. But I don't like the 3:2 ratio, and my 2" mounted filters would vignette.

No, the QHY 461 is *not* a sensible option.

I could be very interested in this if the price is right. It's something I've been wishing SW would make for a while now, combining the strengths of the SA and the AZ-GTi.

But I *do* wish SW would ditch that god-awful torture saddle. I just hope there is / will be a suitable ADM replacement.

FLO have an announcement

Re: Earendel

And inevitably

Thanks, yes I saw that image, partly it's what got me thinking.

I'll try to put my HCG 44 to bed before thinking about swapping cameras for the smaller targets. Copeland's Septet, HCG 57 might be doable.

I try to get a healthy amount of RGB using G2v calibration so that the levels are at least approximately the same in the three channels, and in Bin 2. I keep the processing of this relatively "soft" without trying to use deconvolution or unsharp mask. For my ODK / 16200 system I found I needed 1.75x as much blue as red or green, but your system will have its own ratios. I will also attend to any colour balance adjustments and final gradient reductions here. The workflow (In AstroArt 8 will be (For each channel): Stack > Crop alignment edges > Gradient Reduction (Usually Adaptive Subtract) > DDP > Save FITS. During the DDP I will keep all the stacks open with their histograms which I will endeavour to match. Then import the three FITS files and combine in Trichromy. Again crop any alignment edges, and possibly another gradient reduction before sorting out aany wonky colour, usually it's just a matter of touching up slight imbalances. Finally save the RGB FITS.

For the luminance I try to get as much as I can without running into diminishing returns, or until I get fed up, usually at least 6 hours and preferably more, in Bin 1, just in case I have any detail below the 1.2"/px of my bin 2. This will get the full works of deconvolution, denoising, unsharp mask etc.

I will then upscale the RGB by bicubic interpolation before combining with the luminance into the LRGB. I will probably need to raise the saturation after the LRGB combination.

Hope this is of some help.

Yep, I saw that thread but it isn't real imaging.

I *could* I suppose put my old Trius 694 on the ODK but that would mean imaging at a crazy and spurious 0.46"/px.

Dunno? Give it up as a bad job?

I found This list of HCGs from Wiki. Think I'm gonna need the GTC to get anywhere.

With my ODK rig?

I've been working on HCG 44 for the competition And that got me thinking about other HGCs

Looking around in Stellarium I see a few, but they all look a lot smaller than HCG 44, Copeland's Septet, HCG 57 looks to be the nearest, so I was wondering...

...Has anyone done any beyond the obvious ones? Any ideas / strategy I might use to get something beyond a tick "been there, done that" sort of collecting obsession?

Yep, I know. Buy a humongous telescope and move to a mountain in the Atacama.

Yep, some good signal, but agree with Shibby, just needs the BG pulled down a touch and shift the colour balance a little.

Guess we'll just wait until @FLO announce availability .

Looks like it's built for the job, rather than just repurposed from an Alt-Az. A more robust wedge / cradle than the SA or the AZ-GTi. I could be interested if it's not *too* expensive.

I have to say that I do like the ODK 12 . When I was at Astrofest I visited the OOUK stand and had a chat with John after looking at the spot size data, which made it look like the 12 was the sweet spot. He agreed, and said they had computed the 12 originally and scaled the others from that. I promptly put down a deposit there and then!

Now I just have to quell a ruinously expensive hankering after a FLI 4040  .

This miserable effort is the result of last night's imaging. I had set up for 9 Bin 2 subs RGB in G2v calibration, but had multiple borkes before I did a hard shut down 🔨 and restart, losing around 3/4 of an hour from an already marginal run. Not unexpectedly the last Blue subs were trashed by cloud, leaving only 6, barely useable.

Well, after much application of the "Mechanic's Moto"* This is the result. 9 x 600 sec Red, and Gree, 6 x 1050 sec Blue. Sigma Stacked with full calibration, Crop, Gradient Reduction, DDP, Deconvolution, Trichromy and excess green removed. Saved at PNG

* "When in doubt, use a bigger hammer"

Yep, looks good to me, the colours aren't overblown (Very easy to do with galaxies) and you've worked the H-alpha in very well.

Well, you asked for a galaxy cluster so...

...I offer you the Coma Cluster (Or part thereof)

Captured 18 subs each RGB in Bin 2 G2v calibration (Red  and G, 600 sec, B 1050 sec) and 36 x 600 sec Bin 1 Luminance, but there was some trailing so not all the subs made it into the final stacks.

Capture in Maxim DL6 / ASA Sequence with the ODK rig, Stacking (Sigma Add. full calibration) and bashing around a bit in AstroArt 8. Saved as a JPEG (The PNG is nearly 80 MB)

North is up. I could, perhaps have framed this a bit better, but it is what it is.

Sounds about right, a big blob of yellow over me, and visibility is poor, with a blood red sun.

Just a quick first bash at the Coma Cluster This was supposed to be 9 subs each RGB in G2v calibration (Actually BGR as the moon would be rising towards the end) but 3 of the Blue subs had trailing. Sigma Add stacking, Crop, DDP and a bit of fiddling.

Will try and get more data tonight, though the transparency might be poor.

I think I could have framed this better, but it is what it is. Captured with the ODK rig.

The "Good to Stargaze" app has transparency and seeing. How accurate they are may be debatable.

Wow, a lot of tangled fine detail there!

Well, at least for the time being .

Last night I managed to get another 9 RGB subs in G2v calibration and Bin 2 to add to the 9 I had collected earlier. The whole 18 were stacked, cropped and gradient removed before DDP.

After Trichromy the saturation was boosted and a *very* slight adjustment of the hue. The RGB plate was then upscaled (Bicubic) before LRGB synthesis with the synthetic luminance I captured last year.

Although there are a couple of H-alpha jets I have found adding the H-alpha to be problematic. So unless I feel masochistic and grab a shed-load more H-alpha I'll leave this here.

I found a battery pack not really enough to run mount, cameras, dew heaters and computers, both a mini PC on the tripod (For mobile imaging) and laptop.

Just for reliability I feel much better with mains power.