DaveS

Oh no, yet another galaxy to image lol As for small targets I'm starting out on my quest to image as many of the HCGs as I can. I won't get all of them, but we'll see how many I end up with. I've already got my Trius 694 on the ODK 12 for a totally bonkers 0.46"/px. Regarding RASAs, given that you really want about 1000 mm FL with today's small pixel cameras, that implies a clear aperture of 500 mm. Anyone want to hazard a guess at how many figures in the price?

After a bit more thought, and considering Olly's point that 6" is about the limit for useful imaging, then I might replace the ODK12 with a TAK TOA 150. I'm still not sure about the camera, though I notice that QHY have a slightly more "affordable" IMX 461 camea.

I'm getting more than somewhat irked by the manifest distain shown to those of us who's astronomy pretty much depends on GOTO and plate solving. Apparently we are too bone idle to learn the sky, well when I was a kid I took every opportunity of a clear night to go out with my little Hamlyn astronomy book and learn at least one new constellation each night. I still know my way around. And we have the attention span of a ferret. Humph, believe me, getting even a high end automated rig running reliably enough that it can be left to its own devices takes the attention span of a Pak Protector, not a ferret. We also apparently want instant gratification. The nearest I get to that is carrying out a trial stack the next morning, most of my images take a lot of nights, some of them over 2-3 years. I don't know if you call that instant, I don't. And real astronomers haven't pushed their telescopes around for a very long time, more likely to be found sitting in warm, well lit control rooms on the top of mountains. Rant over.

I can see a Kessler Cascade coming, then nobody will be able to get to orbit.

Shortly after I moved here I pointed my little 180 Mak at the Leo Triplet. I only managed to get M65 and M66 in the FoV, but they looked like a pair of car headlights. Having a dark sky helps.

I've actually thought about this a lot, and in that disastrous event then I would likely replace my DDM 85 with a Planewave mount, as the cheapest ASA mount is now £25k or more (Depending on how much the pound has tanked), as for the telescope, I don't know. Not too happy with OOUK, maybe a Planewave as well. The camera and filters are even more problematic, but something with a Gsense 4040 sensor is the likely best choice.

100% GOTO plus plate solving. Imaging time is too precious in this dank swamp of a country to waste any of it faffing around trying to find your target. The "thrill of the chase" come later when the data is on the computer and you're trying to tease out faint tidal tails from the background.

The GTC would be nice if it comes up S/H. Who wants a miserable 10 metre telescope when the 39 metre E-ELT comes on line😂

The Musk-rat has a constellation, Bozo wants one too.

Just a token effort from me, Orion and friends rising across the road outside my house Edit: Handheld capture with my smartphone.

From my experience, I found that my images calibrated better without Darks, as they left more noise in the final stack then just Bias. I remember in the Trius manual Terry says the same thing. The next clear night (Yeah, right) i will try getting some Bin 2 RGB data to see how it compares with the Bin1 Liminance I already have.

Thanks Paul. The 294 is looking increasingly attractive, and would be a better fit for the ODK than the 533, plus it has a wider peak to the QE curve. However, the SX 694 has the advantage of being able to bin 2x2 in hardware (If I wanted 0.92 2/px) and only needing Flats and Bias frames. But the 294 has a significantly higher QE, lower noise (At HGC gain), and wider dynamic range. But like all CMOS is finicky over calibration amd has Amp Glow that needs calibrating out. Argh!

Well, the autofocus is now operating as it should, all I need to do is find out what's causing these spurious diffraction spikes and sort them out. At first I thought they were due to blooming, but the ABG should have taken care of them. As this is from 1+2 hours I think diffraction from a telephone wire would be eliminated by Sigma stacking. I think it has to be something in the imaging train. I checked for spider webs in the OTA but it's clear, and those spikes are suspiciously orthogonal. I will have to take the imaging train apart again to look. It's not on the filter as I can see them in a blue and red image. It's like playing blummin' whack-a-mole .

What sets ASA and, I think, Planewave apart is the combination of very high resolution shaft encoders, 0.02" per tick on the DDM 85, finer on the DDM 100, and Direct Drive with no backlash allowing a very stiff feedback loop. The encoders are read at 100Hz so any wind gust that might shift the OTA is immediately read and corrected.

I wasn't going to reply to this thread again but here is an image of the Coma Cluster. Red, Green, and Luminance are 10 min subs, Blue is 17.5 min. Luminance is 0.61"/px but seeing limited rather than guiding limited. North is to the left.

Do you want more photos of cloud ☹️.

Part of the Coma Berenice cluster of galaxies Hickson Compact Group 44, AKA the leo Quartet Hickson Compact Group 68. The blue streak is from a bright star out of the frame, reflected off of a poorly anodised adaptor The Owl Cluster Finally the Double Cluster in Perseus, presented as a two pane mosaic The other images I have done are 2-3 year projects.

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Damn, but that's wonderful. No, I can't afford another telescope though I've been tempted. I do love a field strewn with galaxies!

Well, it wouldn't but I've never had any problems even when imaging until dawn. Maybe I don't have very steep temperature falls. A note: If you are imaging several objects through the night then Sequence will, of course, make as many MLPTs. And now I'm out.

ASA support are right, their mounts don't need, nor would benefit from, a weather station. The software (Sequence and Autoslew) makes two sky models. The first is a whole sky model which is for pointing , taking care of polar alignment, collimation, wedge, etc, while the second, called MLPT is done for your exposure sequence. When you start a sequence Sequence wil slew to a focus star, carry out a synch, then it will step the telescope through the imaging path making exposures at each point, the step size of which is normally 15 mins but you can alter this. For each exposure it will plate solve and calculate the errors. Finally Sequence will calculate an overall correction for the whole path and begin the sequence. If a meridian flip is needed Sequence will know this and carry out a MLPT for the first part of the run, do the flip, tesynch and carry out a second MLPT for the rest of the run. This takes care of the parameters that a weather station is needed for to calculate eg atmospheric refraction.

Fabulous kit, not envious at all. Yeah, right 🤣. Actually the first time I've seen an actual real photo of the DDM100, as distinct from renders. I'm still holding on to my two DDMs by the way!

If you want 0.25" or better then find yourself a S/H ASA DDM. But finding hens' teeth might be easier. Unless you can afford a DDM100 at in excess of £25k

Yep, that would be a possibility, capture the RGB at bin 2 and 0.92 "/px, and the Luminance at bin 1 0.46"/px to pick up any detail that might be lurking below the bin 2 resolution.. The 533 does have some attractive features, but whether they are £1,149 attractive is another matter.

To expand on my previous post (From my phone), I have the 533 and the SX 694 in Stellarium and have been playing with the FoV. However, if the 694 at ~0.46"/px is silly, then the 533 at ~0.38 "/px is downright ludicrous. I could bin it at 2x2, but that would be 0.76"/px, at which point I might as well use the G3 16200 at bin 1 and crop. In any case, this is just a project to go after as many of the Hickson Compact Groups that are doable from here. It's not a major research project so probably not worth spending any money on. Again I thank all contributors for their posts.