nfotis

I guess that satellites like the Starlink will be visible at dusk and dawn only, since they'll be inside Earth's shadow when I observe/image. Being low Earth orbit, these must enter the cone of darkness quicker than a medium orbit satellite like OneWeb. Airliners must be a bigger problem, because they cause atmospheric disturbance and often use navigation lights. N.F.

It' s my understanding that above APS-C size there's too much vignetting on a C8 and C9.25 N.F.

I think that I'll delay my DSO camera purchase for a year, to see if the current generation of CMOS sensors will yield a monochrome version. Then we'll be able to see a head-to-head comparison and decide if the higher cost for the special order sensor and filters/filter wheels will be acceptable... Comparing a current OSC sensor with a decade-old monochrome sensor isn't very enlightening. Cheers, N.F. (living under a Bortle 8 sky)

Waiting for my 462 as well for my C9.25. IR/UV cut is needed for focusing, according to FLO (I bought also a IR-permitting filter at 850mm, which should be useful) I guess that a 2x Barlow is enough for it and the C11 (that's f//20, a bit oversampled I suppose, but not as big a deal as a clear atmosphere) If you check the ZWO FB page or Astrobin, you should see many people shooting planetary photos with a similar setup (ASI290 , 2x Barlow and a medium to large SCT). It seems that an ADC is a good tool to have if the planets are quite low on the horizon, too. N.F.

Thanks for the report. I gather that you are using the mount visually for now? What made you select this mount Vs the CEM60 or similar? Availability, specs, or ...? It's my impression that the software part is still immature? N.F.

Returning to the subject matter, I think that the current pinch on supply will take a long time to get relieved. So, second hand market it is... (and the looming deadline of 31 December means that we in EU will have to contend with import taxes from UK and vice versa). N.F.

A note: programs like Backyard EOS etc when shooting planetary imaging video, they capture the live view of the camera in approximately 5x zoom (they receive the video stream to the back screen directly). This is approximately the same size as a planetary imaging camera (similar to ROI). N.F.

On paper, the Synta and Bosma 150mm Maks look quite similar. Would like to see a comparison test between them (let's hope that Bosma will make a 7 or 8 inch Mak as well). (Update: there was a 200mm Mak from Bosma in the past: https://www.cloudynights.com/topic/369569-info-re-bosma-mk24020-2002400mm-mak/ ) N.F.

The C9.25 is approaching the limit of what can be carried by a single person. I have carried mine in an IKEA shoulder bag, so it's feasible (I am 1.80 meters, and not that athletic). My HEQ5 mount can be carried with its tripod over a short distance without counterweights. An EQ5 mount or similar is (I think) the lower limit in stability and load capacity for visual observation. This mount might be usable, if you want Alt-Az http://skywatcher.com/product/az-eq5-synscan-wpier-tripod/ N.F.

I was eyeing the Skymax 180 myself, but I stumbled upon a used C9.25 XLT. The larger aperture should be an improvement in light gathering (and with f/10, it should be easy to use a Barlow for planetary imaging). I suspect that it's more a matter of the particular implementation, though. Both types have a large overlap in optical quality, as it seems (these are mass production items, and I guess that a good Skymax 180 will surpass an average C9.25, and vice versa). The Skymax seems to give better contrast to visual observation, while the C9.25 seems to hold an advantage in imaging thanks to the large aperture. Hope this helps, N.F.

Made by the same people who made Stellina. This one is with 50mm F4 quadruplet apparently, and IMX462 sensor. Looks quite nice on paper, and much cheaper than Stellina. N.F.

Note that programs like Backyard EOS and APT offer a live view video capture mode in EOS cameras. If you zoom at 5x when shooting planets via these programs (in "thethered mode", the computer captures native sensor resolution (or so) while capturing uncompressed video, at approximately HD resolution. And you can control focus, exposure etc from your computer. That's a way to imitate the small sensors like ASI290. Forget HD or even 4K video from a dSLR for planetary imaging, the planet will be too small for recording. N.F.

In general, planetary observation/imaging seems to require more focal length than a large aperture. Scopes like the Skymax 127 and 150 are quite popular for planets (the Skymax 180 is termed a 'planet killer', but it requires a mount HEQ5 class at least for good results). For planetary imaging, most small sensor used (like the ASI290/462) try to reach an f/15 or so for ideal sampling (that depends on atmospheric quality of course). N.F.

In general, for planetary observation and imaging, you need as much focal length as possible. Many use a 2x Barlow even with the Skymax 150 and longer scopes, in order to discern a disk with their camera/sensor. The Skymax 127 (or the similar Bresser) are OK for observation with a suitable eyepiece - a Barlow isn't really needed, except if you need good eye relief. Hope this helps, N.F.

Well, it's not only a matter of payload, but accuracy as well. It should be quite accurate when imaging, and you can easily add a focusing motor if you wish. An OAG and guider, a filter wheel and a cooled camera often reach 3 kg in total, so it might be a good idea to get a sturdy focuser. It's a bit heavy, though, I have to admit that. Cheers, N.F.

I bought a used dual speed focuser from TS for fitting to my Skymax 127 (unfortunately, it couldn't clear the original focuser). It looks sturdy enough: https://www.teleskop-express.de/shop/product_info.php/info/p781_TS-Optics-2--Dual-Speed-Crayford-Focuser-with-SC-thread-connection.html There's also a monorail version https://www.teleskop-express.de/shop/product_info.php/info/p4299_TS-Optics-MONORAIL-2--Focuser---Dual-Speed---M90x1-Thread-Connection.html Hope this helps, N.F.

I am surprised that you had to use a 2x Barlow with the C14. So, would a Luminous 2.5x Barlow be usable with a C9.25 XLT? Or should I go for a 1.5x Barlow? (I am thinking about the ASI462 camera myself) N.F.

I am wondering, would this sensor be useful as a planetary camera via a C mount to 1.25"? The dimensions are near an ASI290, but the resolution is higher. Quite an intriguing sensor, I have to admit, despite the tiny pixels. N.F.

Maybe an academic question, but today's Raspberry pi 4 isn't powerful enough for the required tasks? Since I have a HEQ5 mount, it was quite interesting to see it being used in such a compact implementation. N.F.

I wonder, would this Barlow be useful in planetary imaging with a C9.25? I am thinking about getting the ASI462 planetary camera myself. Adding the Barlow would raise the focal ratio to f/16 or so (and the focal distance). N.F.

Yeah, I meant a red+IR pass filter (maybe). I was trying to understand where the deep red and IR sensitivity of this sensor could be used... I suppose that we shall see a monochrome version of this sensor soon? N.F.

A bit off topic: This reminds me, if I get the ASI462 camera I'll need the UV/IR cut filter, right? I wonder, the extended red/IR range of this sensor might be useful with an L filter? Because I got an idea: use an L filter, keep the results as a monochrome image, then shoot RGB and separate each channel for an LRGB mix? N.F.

Quite an interesting project, I have to admit. It could be an interesting basis for a mountaintop remote observatory, provided that there's power and internet available. N.F.

I am in a similar situation, so I went first for a guiding mount (bought a used HEQ5) after I played with my used Skymax 127. Initially, I am just dabbling in photography using my Canon DSLR, and I may continue later with a dedicated camera. N.F.

There's a widespread stock replenishment problem, due to the surge in Astronomy and the production problems due to the pandemic. N.F.