Ags

I am in Bortle 8-9 and use a cheap RDF and a 50 mm RACI to star hop. But I have to start from a bright star.

More likely to be a weather balloon. Did you check in Stellarium?

Atacama Desert? Namibia? 😁 Welcome to the forum!

To be honest, I have been all over the place looking for a mount that tracks reasonably in EQ mode and can take something a bit heavier than a C6. I started out thinking of an EQ5 with an RA motor, on the basis that this option has the least to go wrong. The issues with it are no AZ mode and weight. That got me thinking about harmonic mounts, but I think realistically they need guiding which I really don't want to do. I have no doubt I can figure out guiding but I want to keep things simple with less to set up and fewer points of failure. Now I am thinking the new EQ-AL55I mount may be the best fit - it is over 2 kg lighter and smaller than the EQ5, and according to SkyWatcher can even take more load (10 vs 9 kg for the EQ5). It also partially supports ALT-AZ mode, unfortunately the firmware does not permit tracking in ALT-AZ, but you can still use it manually with motorized slow-mos.

You've got me thinking about the HEM15 again. It is more in my price range, and I like the weight. I'd really be interested in test exposures - say 5/10/20 seconds, if you have the time to try this out. In general how are you finding the mount? At the price differential I can live without EQ mode. In terms of scope upgrades, it would let me mount a C8 at least. That would be a nice bump up from the C6 for lunar observations and planetary imaging. I also see the mount can be trained with PEC...

I repeated the experiment with more ash and an hour of exposure. The camera and sharcap settings were right this time too. I counted 8 streaks and 4 possibles with the ash, and 5 streaks and 5 possibles without the ash... There is an element of judgement of course, and I am hardly experienced at streak counting... Anyway here are the two images - what I consider definite streaks are marked with a green dot, and the more uncertain ones are given a red dot. Control: With Ash:

Interesting. I had discounted the HEM15 partly because it has no at-az mode, but also because I understand unguided imaging is impossible with the non-EC Ioptron harmonic mounts. Have you ever tested this by any chance?

I think I found the reason and it is human error. I had forgotten Planetary Stabilization was enabled, meaning the images were randomy dithered.

That explains the noise difference between yours and mine. My stacks were of only 140 frames, and each frame was 7.5 ms. I think for finding best focus, the stacks will be 100 long or less. Note my jupiter is mis-colored, which is brcause I pushed up the saturation to make some details more visible.

@vlaiv i was doing a simple "maximum" stack. I wonder if my random noise got corrupted by debayering, which I thought I had disabled? I realised today I have a whole heap of ash in the ash vacuum machine we use to clean the pellet heaters. As combustion is much more complete in a pellet furnace, I am hoping that that ash will be a good, purer addition to Radiological Test Source A. Also the pellets come from scandinavian pine, which is the best location. I will shoot an hour each of darks, control and ash shots tonight. I'll also not be an idiot and make sure the camera is set to mono!

I am happy using 6s subs with my AZ-GTI. This works fine for DSOs. My question was more about the unguided performance of the harmonic mounts, as they are really designed for guiding but I hope to not use guiding as it is not needed for my supershort subs. The only reason for me to use longer subs is to reduce storage requirements and processing time. I would only use the AM3/5 in alt-az mode for visual and planetary imaging. Theoretically both these mounts could cope with a 10" newt, but they are so small I can hardly believe it.

Because granite is naturally radioactive? Not sure I have a lump of granite, but will try the experiment when I can. There is a village in Iran that is off-the-scale naturally radioactive. I have no plans to travel there to find out however 😀

Can you do short (6s-20s) unguided subs with these mounts at a focal length of up to 400mm? In alt-az mode can you point at a target and engage tracking. I don't use goto but do like tracking. What sort of scopes are reasonable for these mounts? I can never afford a large SCT so could either cope with 10" newtonian?

I decided my ash-stash might have reached critical mass, and inspired by watching Oppenheimer, I decided to try capture some death rays tonight. I shot darks as usual, and then a sequence of 8 one-minute subs of no-ash and 8-minute subs with the camera sitting on a cushion of ash. Then I stacked in DSS (no alignment, using Maximum as the stacking algorithm). I think i may have some camera or stacking settings wrong as the hot pixels came out as a characteristic pattern of six pixels...? But, the with-ash stack picked up a definite radiation trail! There were no trails in the no-ash stack. I don't think a single trail is proof my ash is the radiation source of course. I will collect more ash and do a longer stack, maybe 20 minutes. In the meantime while I hoard the ash I will try figure out why my hot pixels look funny.

It is clear here, but I am currently capturing some frames of a pile of wood-ash. I watched Oppenheimer tonight, so I decided to see if my fallout cam really works. I may need more wood ash, so this may only be a trial run...

I've tried fine sharpening on its own, and it makes the noise a lot worse. However, I have discovered since my last post that I can add in a degree of noise reduction without losing any noticeable detail. I think the image is dim as I was viewing the stack in darkness to mimic outside conditions. Also I capture using 1/3 to 1/2 of the histogram only. @PeterC65 how many frames in your stack? What was your sub length?

I will download it now. I did encounter a few crashes while playing with the feature. I found an older SER from a better night. This is the sort of thing I get using my C6: I guess there is an option somewhere to rotate the stream 180 degrees. This is with a short stack of 140 frames - enough to reduce the noise, but still keep a bit of the seeing variability. I have settled on these settings for now:

Yes I was thinking planetary stacking might be a good focus aid.

Great work! Whenever I try a color moon I find highlights turn green.

I did try out a few SERs with test cam 2 and got a reasonable result, but I think the conditions were limiting and my focus was not perfect. I'll try these settings on another night.

Is there something beyond the clouds? We may never know.

I think the sharpcap test camera can replay SER files, so I will play with the sequences I shot last night and see if I can get a pleasing view from live stacking.

Had a long look at Jupiter tonight. The moons were clustered close to the planet, making a pretty sight. Seeing was rubbish though, and colors were washed out by a thick haze. I tried out sharpCap live paletary stacking, but I think I prefer watching the unstacked video. I had a go at imaging the planet but this wasn't the night for it.

I tried it out tonight. The image is of course more stable, but I'm not entirely sure I prefer the stacked view. Watching the unstacked video is much more engaging and far closer to the visual experience, and I think the flashes of detail seen in the live stream surpass the results from the live stacking process.

Found this picture on forum.astronomie.de: