wimvb

I think that this statement is significant. The mount is considerably different from your previous SW mount and probably runs a lot smoother. It would therefore need less aggression in the guiding pulses. And your description of large + and - deviations sugessts the same. What I would do is to hook up the mount to PHD on a laptop, create a new profile, and run the guiding assistant. Then use its recommended values as a baseline for AAP guiding.

If you attach the ring to the stems that hold the clips, you tighten the screws to the point where you still can slide a thin paper between the mirror and the ring (or clips). Any tighter and you risk pinching the mirror. Theoretically, you won't need any neoprene or cork. But in practice, any ring will warp slightly over time, and it's better to be safe.

I had a look at your data, and as I suspected, the only thing that deconvolution does is make the stars a little narrower and a little brighter. Since most of the nebulosity is in the midtones, deconvolution will only sharpen the brighter details, but at the cost of increasing noise in the rest of the nebula. Deconvolution works best on galaxy images and planets, where ther are bright details that need to be enhanced. Here is a before and after, with a soft STF applied Since I applied the same stretch to both images, you need to look very carefully. You will see a difference in the smaller stars, the diffraction spikes near bright stars, and in the brightes details of the nebulosity. Medium sized stars will also appear a little narrower. Imo, if you can see that deconvolution has been applied to a dso image, it's overdone. The real work will be done in the non linear stage with subtle enhancements of the deconolved image, like sharpening and local contrast enhancements. And in retrospect, here I overdid it a little. I had a version with 10 iterations and global dark deringing set to 0.05, which I think came out better. Here, the noise starts to show. This is the PSF that I used (extracted from low brightness stars), and the settings of the deconvolution process. deconvolution.xpsm With an image like this, I probably wouldn't collect any luminance at all, but only RGB and Ha.

It occurred to me that if you make a ring out of plastic, you don't really need the clips anymore. You replace them with the ring. As with tht clips, the ring should not press down on the mirror, or you get so called pinched optics.

Wow, I never examine the packaging this close

Conveniently unavailable.

… or skip the luminance and only collect RGB.

You have to look at filters as light blocking devices. Whatever light a filter blocks, will never make it to the sensor. But also, if you stack filters, you risk introducing reflections. Personally I would avoid it if possible.

Same with microsoft RDP. It turns on during startup and you can log in from any client that also has RDP installed. I use it to connect to a raspberry pi and to another windows machine.

https://www.sony-semicon.co.jp/e/news/2021/2021092901.html Sony just announced that they will start production of a UV sensitive cmos chip. I just wondered if this can have any applications in amateur AP.

Similar to what I had until a few years ago. I went from running Kstars indoors to running it all on the Pi on top of my telescope, because whenever I lost wifi connection to my setup, the whole imaging session would come to a halt. So now I have the whole data capture software, including Kstars and PHD, on one Pi on the telescope and I connect to that Pi with RDP. If I lose connection, any sequence will continue running. At the end of an imaging night, or the next morning, I transfer all image files with FileZilla to my laptop. If you PM me and send me the L master, I can have a look at it, and maybe come up with a recipe. But as I said earlier, deconvolution on nebulae won't always improve the image. And in your case, the diffraction halo around the bright stars complicate the process. If you don't mind tinkering, you could look into making a ring that sits on top of the mirror clamps, so that these are hidden. That way you can avoid the diffraction from the mirror clips. Cheers,

Very nice image. Imo, deconvolution on nebulae doesn't add much, other than perhaps reducing the stars a little. Just out of curiosity, how many Pis are a collection?

First of all, put an extension ring between camera and scope. This will give a more stable configuraion than having the focuser all out. Second, planets are bright and the 925 will collect a lot of light. You compensate by using short exposure times, measured in milliseconds rather than seconds.

”Bobbins.” As the guy in a youtube channel I’m following, would say. I was hoping to catch a few more galaxies in Pegasus and Andromeda before they disappear. But autumn is unfortunately also cloud season over here. (As are winter and spring, but autumn more so.)

the sleeve you use to hold the camera needs to be reasoably flat, so you don’t get any wobble there. Having the camera on a flat surface pointing down may actually help with that because you eliminate any distortions due to gravity. Fibre board from furniture is quite flat and won’t change over time, so works just fine.

Last spring I bought a new telescope (a refractor at that) for wide fields, but I couldn't test it then. So this is almost first light. I wanted to see what this telescope can deliver, and I must say, I'm not very impressed. The stars aren't round to the corners and there is a horrible blue bloat. The first night I collected data for this image, I didn't refocus before switching to the blue filter . (Hey, I'm a reflector guy. I'm not used to having to refocus.) The second night I refocused with the blue filter in place and collected new data. Even the green subs were below par and I used only 13 of 21 collected. For this reason I didn't even bother collecting luminance data. I created a synthetic luminance instead. What I am pleased with is the sensitivity of the ASI294MM which pulled out quite a few distant fuzzies from the limited data. TS 70EDQ ED refractor with built in corrector on AZ-EQ6 mount ZWO ASI294MM-Pro at -10C, gain 0 with Optolong RGB filters Red: 20 4 minutes Green: 13 x 4 minutes Blue: 30 x 4 minutes Total integration time, just over 4 hours with the moon at 80%. Processed in PixInsight (click on the images for larger versions) I have also used this scope together with a Star Analyzer 100 and have started playing with spectroscopy. I will probably use the scope for that and for wide field Ha objects. The Pelican nebula is very nicely framed with this scope and the 294.

Apart from all the math, there's a simple rule of thumb you can use. If the (fainter) stars in your image appear square and "blocky", you can try drizzle integration. Drizzle integration only gives a benefit when your images are undersampled. But as vlaiv wrote, that is seldom the case with amateur equipment. Undersampling occurs at shorter focal length and/or larger pixels. Furthermore "there ain't no such thing as a free lunch". Data that is used to retrieve information in the drizzle process, cannot be used to reduce noise (increase snr). In other words, drizzled images are noisier than undrizzled images of the same number of subs. That's what mathematicians call degrees of freedom.

Nice! I can see a ram coming out of the shadows. One big horn to the right. The one on the left is still innthe shadow. 😉

Software PEC is tricky, because it works by dead reckoning. As long as the mounts worm/motor is where eqmod thinks it is, it works fine. In theory. But in any mechanical system, over time, there is drift, and the two systems will differ. At that point, phd will need to undo eqmods pec pulses. Imo, just use phd predictive pec and forget about software pec. As long as the periodic error is smooth(-ish), phd can handle it.

AZ-EQ5, AZ-EQ6, EQ6-R, EQ8(?) have belt drive. The newer versions have usb connection.

Cable management. You forgot about cable management.

My guess about this product is that anyone who would consider buying one, would want high quality, detailed, full colour astro images withou any hassle. So why not put something like this on a stick (gold plated of course) https://en.wikipedia.org/wiki/View-Master

There is. Check out a Stellarmate instead.

@ollypenrice: yes, of course.

The explanation I gave you is when you look due South. When looking due North (as in your images), the celestial equator is below the horizon, by the same amount it is above the horizon when looking South. Dec is the angle from the celestial equator towards the polestar. If you are 51 degrees latitude, the cel equator is 39 deg below the horizon in the North, and a star with declination of 69 degrees, will be 30 degrees above the horizon. The Polestar is your latitude in degrees above the Northern horizon. Your 2nd image with HIP 47193 shows a declination of 81 degrees and an altitude of 21 degrees. The difference of 60 degrees is the amount that the cel equator is below your Northern horizon. This means that your location (latitude) is 90 - 60 = 30 degrees. When you look due East or West, the celestial equator crosses the horizon, which means that DEC and altitude will be the same. From this it follows that the altitude of an object with a given declination depends on the azimuth angle (compass direction). Did you do the phd calibration with your telescope pointing to the south and near the meridian (assuming you are in the northern hemisphere)?