michael.h.f.wilkinson

I was at work, so only had the 60mm Coronado at my disposal, but the view was stunning

Very nice indeed!. Had a look in H-alpha over lunch, and the seeing was great here as well. Those two bright lines in H-alpha almost looked like two parallel scratches in the surface, revealing the heat inside

Same here. I haven't tried my other laptop, but I very much doubt that would change anything, especially as the ASI183MM-Pro works flawlessly. I have replaced the rather flimsy flat USB3 cable supplied with the camera by a quality cable (actually, I tried two different ones), but no change in results. Again, everything works neatly in all my other ZWO cameras (ASI183MM-Pro, ASI183MC, ASI178MM, ASI174MM). All sockets on the PC are USB3 in this case. I will contact the supplier of the camera. It looks like it is going to be a very clear night tonight. I will go for the ASI183MM-Pro, and see what I can get. I am not wasting any more precious imaging time on this camera for now.

I have now tried a better power supply, run NINA, APT, and ASIstudio (both planetary and DSO modes) and all have problems getting the image from the camera. I have installed new drivers, changed USB speed settings, but nothing seems to work. I guess the camera must be faulty.

It almost sounded like double the sensitivity, but given the 85% maximum QE of some sensors, that isn't possible. A higher well depth is very nice, of course. It would benefit the sensors with small pixels most, I suppose.

Very nice indeed. Crisp but not over-processed. Great stuff

The Brightsky version seems to have very nearly the same specs as the earlier Apollo variant. That suggests they are essentially the same bins, making them BA-8 series (like Helios Apollo). The Helios Apollos I had (15x70 type) were great. The Helios LightQuest (16x80 in my case) are even better, but if these Omegons are indeed variations of the Apollos, they should be fine. You will need a sturdy support. I can hand-hold my 16x80s, but they are lightweight (2.4 kg) compared to the Omegon 22x85 (4.8 kg)

Might try that. Closer inspection of the ASIimg tool's results suggests that on occasion, this also drops subs. two darks out of a run of 30 120s exposures are 4 minutes and a bit apart, which suggests something was dropped. Maybe I need to increase pauses between shots? I would have thought the frame buffer in the ASI294MM would act as a cache, so the next exposure could start whilst the previous is sent to the computer

Just noticed the power supply might be a bit too weedy (3A vs recommended 5A). This does not explain why everything seems to work fine in the ASIimg app from ASIstudio (and at a higher ambient temperature at that)

Thanks for that. Just finished a perfect run of 60 s darks at gain 120 and -10 in the ASIimg tool. No frames dropped at all. I am beginning to suspect the USB settings

My ASI294MM-Pro seems to have constant problems with my capture software. FireCapture won't recognise it, whereas my ASI183MM-Pro works just fine on it. Yesterday I spent a frustrating evening trying to get it to work together with APT. It does recognise it, but live view stutters and jams, making focusing a near nightmare, single shots may or may not appear on the screen, cooling may or may not work (sometimes failing to cool, sometimes reporting temperatures that are WAY off (+32 deg C, or -19.6 deg C), and dropping loads of subs once you thought you had everything running smoothly. Only 17 subs out of 29 were actually saved to disk (they were crap, as the spacing was off, so no great loss, but it's the principle that counts). I tried running a plan for darks, but it also dropped 2 frame out of 8 before I pulled the plug on it. My ASI183MM-Pro works just fine using the same software. Really frustrating! I have replaced the cables, updated drivers and software, FireCapture still cannot connect, I tried creating a dark library with APT, which first refused to cool properly, then seemed to be OK, then failed to store the first 6 out of 7 darks I tried to shoot. I am now running ZWO's own ASIimg software to create darks, and that seems to work fine. However, that doesn't have nearly as many features as APT. Are these known issues with the ASI294MM or is my one faulty in some way?

Very nice collection!

Amazing collection. I really need to get my ASI294MM attached to the Samyang 135mm F/2

Grabbed 240 60s subs with my latest toy, capturing the Heart and Soul Nebulae together with the Double Cluster. I used my modded Canon EOS 550D with Optolong L-eNhance filter. Stacked the result in APP, with 30 darks, 50 flats, and 64 bias frames. Apart from the automatic stretch and gradient removal in APP, all I did in GIMP was a little crop. Very pleased with the initial result

An unexpected treat: clear skies. Quickly set up the Great Polaris mount with Canon EOS 550D, Optolong L-eNhance filter and 135mm F/2. Shooting the Heart and Soul Nebulae with a side-order of Double Cluster Over an hour of data captured, and the skies stay clear

Tonight was the first decently clear night in ages, so I set the alarm for 4:30 to pick up comet Leonard. I noticed a high haze was obscuring the comet in my suburban garden, so I drove out of town, to just north of the hamlet of Dorkwerd. Skies were much better now, and I picked up Leonard with the Zeiss 10x42 binoculars easily, by hopping downwards and to the right of alpha Coronae Borealis. I switched to the Helios Lightquest 16x80s and was treated to a much better view, with the tail clearly in sight. I would estimate the tail spanned at least a degree. I then switched to Churyiumov-Gerasimenko, easily spotted by hopping upwards from M44 (itself an easy naked-eye object here, but hardly visible from my garden). The comet was quite an extensive fuzzy blob, but no hint of tail. I switched back to the Zeiss 10x42, and could make out the comet, but the 16x80s gave a much better view. After a quick look at both comets, waving at Rosetta and Philae in the case of the latter comet, and quick looks at M45 and the Double Cluster, I drove back home with two more comets bagged. Around 6:30, I tried Leonard again from the garden, as it had risen higher, and could make out the coma, but no hint of tail. Dark skies and big aperture clearly win.

It must have been early 1996, or perhaps late 1995 More recent results using a modded DSLR and much smaller scope are definitely much better but then of course, several hours of data beat 15 minutes any time (just like the QE of a DSLR beats that of even the most sensitive film by a huge factor)

Not sure I have posted this before, but here goes my first M42 This is a scan of a slide. A single 15 min exposure, manually guided. Camera: Contax RTS II Lens: 8" F/10 SCT, Method: prime focus with focal reducer to f/6.3, Celestron LPR filter used to reduce light polution Exposure: 15 min on 1600 ASA Fujichrome Sensia film Focus was slightly off, alas.

Just got one of those 135 mm lenses myself. Fingers crossed for first light Wednesday night

Treated myself to a new Samyang 135 mm F/2 which was going cheap (Cyber Monday deal). Feels very solid. Much to my surprise, it was quite clear last night, but of course I had to work late. By the time I was done clouds were rushing in, and I only got a quick look at a couple of Messier objects with the Helios LightQuest 16x80 binoculars. Clouds are now here for the foreseeable future, so normal service has been restored

Some astronomy students recently wanted to do some measurements of limb darkening on the sun in different wavelengths, so came to me as resident solar imager (the 16" RC of the observatory is NOT the instrument of choice here). Last week we were lucky with one sunny day, so I helped them get the data they needed with my solar rig

Welcome to SGL. I agree with the above comments that the EQ2 mount is too flimsy for the SW 130. I had a similar mount with a 115mm F/4.3 Newtonian and that was too much for the EQ2. I only bought the combo because I wanted to use the optics and rich-field scope, and the combo was going dirt cheap because the store was discontinuing its astronomy gear. I later replaced the legs of the tripod by hardwood, removed the mount, and built a P-mount for binoculars on top. If you want to get into imaging, an EQ3-2 is the bare minimum I have used successfully. If you don't want to get into astrophotography, get a Dobsonian

Some lovely detail there. The combination of F/2.8 and Bortle 2 skies really works well. I really should get my 6" F/5 Schmidt Newt to a dark site and gun for this object again

Interesting EP, with quite good eye relief for such a wide-angle EP. The only ES EPs I have are the 12mm and 17mm 92 deg, which are excellent. What scope will you be using?

As far as simulations are concerned, there are different algorithms (and different models). The idea that something that is not directly visible is exerting a gravitational pull on matter and light is well established by many different observations (like H-I velocity profiles mentioned before). Inferring the exact distribution from observation is quite a tricky (or ill-posed) inverse problem, and small perturbations in the input can cause large differences in the output, i.e. the results may change with more, and better data coming in. We will have to wait and see