KP82

The eye-relief is measured from the top surface of the eye lens. So if that piece of glass is recessed in the housing of the eyepiece, the actual useable eye-relief will be much less than quoted by the manufacturer.

I agree with @Louis D that you may want to post some pics of your husband's current scope, so someone might be able to help you get it working while you're waiting for the stock of the SW 200P to come back. I've got a 22 years old department store Tasco 60mm f/15 refractor and it's working perfectly fine after I fixed its tripod and replaced the stock .965 focuser with a 1.25 unit.

Feb 2021 will be the earliest date when these SW and Bresser dobs are back in stock. It's been quoted by many suppliers including FLO. Unless someone absolutely must have the scope before Christmas, he/she shouldn't be paying for the extra premium charged by astroshop.eu

Press the "Rate" key and then select the slew speed using the numpad, 1 being the slowest and 9 being the fastest.

Excellent choice. The Bresser is an overall better kit than the SW and you're lucky that it's in stock where you're at the moment. The finder shoe on the Bresser/Explore Scientific scopes is incompatible with the standard SW format found on many aftermarket finderscopes. Therefore I'd recommend replace the stock finder shoe so you can use a readily available RACI finder instead of the plastic 6x30 toy that is bundled with the scope. The stock 25mm SPL eyepiece is actually pretty decent. You can price in an 8mm BST Starguider eyepiece for high power views.

Well if you're going to take short exposures (1 - 2 mins per sub) with an ED80, you can probably get away without guiding provided you properly balance your setup. As for a good low cost guiding setup, the SW 9x50 finderscope w/ C mount adapter + ASI120MM-S is a decent option: https://www.firstlightoptics.com/guide-scopes/sky-watcher-9x50-finder-adapter-zwo-asi120mm-bundle.html

The SW 200PDS newt can indeed be used for both visual and ap, but the heq5 pro (being one of the best beginner AP mounts) will probably struggle with the weight of the OTA depending on how heavy your imaging kit is. If you've already got a DSLR, you will need to pick up a guidescope, a guide camera, a coma corrector and collimation tools (either cheshire ep or laser). Starting your journey of ap at 1000mm focal length with a fast newt could be quite challenging, therefore I'd also recommend the two scopes approach, 8" dob for visual and ED80 + EQ5 for ap.

The Orion 130ST you've quoted costs £265, so I'd assume your budget is about £250 - 300. For that amount of money, I'd recommend this one: https://www.firstlightoptics.com/bresser-telescopes/bresser-messier-6-inch-planetary-dobsonian.html The dobsonian mount is much more user friendly for beginners than an Equatorial one especially with a newtonian reflector. The bresser comes with a solar filter, so you can even use it to view the Sun. And if you would like to go further in the near future, you could purchase a separate motorised equatorial mount and attach the scope to it to take pictures of the moon, planets and some deep sky objects with your DSLR. The major problem you (in fact for anyone who's looking to buy their first telescopes for Christmas) have is that astronomical equipment are in short supply everywhere due to covid, so it is very likely you wouldn't be able to get hold of one before Christmas unless you look into the "Used" market.

The latest EQ6-R and AZ-EQ5/6 have built-in FTDI chip, so you can just use a regular USB cable. However they will still show up as a COM device (serial).

Theoretically dithering every sub is optimal if you can. However with inexpensive mounts most of us have, doing so would waste huge amount of time. Therefore I normally set dithering to every 3 subs if my total light subs isn't likely to exceed 50. If I go for more shorter exposures, then probably dither every 5.

The Olympus 8x40 DPSI is probably the best binoculars for £55. The only thing to remember is that it isn't sealed, so if your brother uses it during a cold winter night for stargazing, beware the water vapour could build up inside when he brings it into the warm living room.

SW Heritage 76 is probably one of the only very few beginner scopes that would fall in your price bracket. Honestly you would be better off turning that £50 into gift vouchers (e.g. FLO vouchers) and give them to your brother so he can use them for his future scope purchase.

Nice shot! The shape of the stars shows a little bit of trailing, so shorter exposure to minimise tracking errors would be a good idea. The optimal ISO (ie the one that yields the best dynamic range for that particular sensor in your DSLR) depends on which camera you have. Here is the link for Canon: http://dslr-astrophotography.com/iso-values-canon-cameras/ . You can find links for Nikon and Sony on the page. As for optimal exposure you want the peak of the luminance histogram to be about 1/3 from the left. If you're using a camera lens, you can adjust the aperture to achieve this since your choice of exposure time is limited in order to minimise tracking error. If you're actually using a scope (fixed aperture), you might not be able to achieve it until you add guiding into your setup. 80 flats are kind of excessive. 20-ish would be enough. Also since you're using pretty short exposures, I'd recommend you take more darks to minimise the noise in the master dark frame.

I agree with the others a small 4 - 5" mak is probably your best option. That Celestron refractor looks very much like the Skywatcher Startravel 80. It's ok for widefield sweeping of the night sky and terrestrial viewing, but will struggle with high power lunar and planetary views due to strong CA.

The physical length of the Megrez 72 is about 300mm and its focal length is 430mm. If you also factor in the length of the 2" and 1.25" adapter on the focuser drawtube, it is highly unlikely to have enough backfocus distance for the binoviewer without any GPC.

If you're going for an apo frac with your binoviewer, make sure you get a 1.25" diagonal rather than a 2" one (with 1.25" adapter) and preferably prism over dielectric. Prism diagonal consumes less backfocus distance compared dielectric. And 1.25" can save you somewhere between 35mm to 45mm backfocus distance compared to 2".

I remember I've read somewhere the ZERO could run Astroberry but the performance was extremely poor. Otherwise it would have been perfect in terms of both size and power consumption. Well let's hope the ZERO will be updated with the pi4 hardware soon. Yes I'll be using the GUI unless the KStars on Android can be used to platesolve remotely. I want this electronic finderscope to be self-contained and powered by the same battery as the mount. I'll only be using a tablet or phone to manage it. No laptop.

Has anyone tried to run Astroberry on a Pi 3A+ rather than the usual 3B+ or 4? How is the performance with the limited 512MB RAM onboard? The reason I'm asking is that I'd like to combine a spare SW 9x50 straight-thru finderscope, C mount adapter, rpi and a rpi HQ camera into a self contained electronic finderscope for my iEXOS-100 portable visual setup. I can then control the mount remotely with a tablet or phone through INDI, and perform more accurate PA with polar drift align and GOTO with planetarium software + plate solving (much better than ES ExploreStars app). The 3A+ is cheaper, smaller and draws less power than 3B+/4.

If this Celestron Li-ion battery is anything like my Celestron LiFePO4 battery pack, the 12V tip positive socket acts as both input and output. If your EQ6-R came with a stock 12V cigarette plug, you will need an adapter from here: https://www.firstlightoptics.com/power-accessories/lynx-astro-silicone-21mm-dc-jack-to-female-cigarette-socket.html

If you could minimise the thermal difference (e.g. no heating, windows wide open to let the room temperature be acclimatised to the outside), I think it would work for certain bright DSO targets. Yes you can certainly polar align indoor with drift align. However your window of capture will be limited while your targets are still low near the horizon which means more atmoshpere interference.

Filter removal is enough for leveraging the the amount of Ha captured by the sensor. If you actually go for full spectrum, you will need your own IR/UV filter or else your stars will be bloated.

For £600, Celestron NexStar 6 SLT should fit your bill for planetary and lunar imaging: https://www.firstlightoptics.com/slt-series/celestron-nexstar-6-slt.html Planetary imaging is normally done by capturing a video sequence of the target and then stack the individual frames in software to produce the final result. Since the Celestron comes with an alt-az mount, there will be field rotation. So you need to limit the length of your video sequence.

This is where I got my 600D modded: http://www.astronomiser.co.uk/

I've never owned any GOTO version of a dob myself, but one of our local astro club members has that exact SW 300P GOTO model. Despite the flextube design it is still very heavy (outside my comfort zone, that's why I stopped at 8"). The alignment process is just as easy as any other synscan mounts and the GOTO is pretty accurate. But the noise of the motor is fairly loud. He's had it for several years, so I don't know if it was as loud when it was new.

If you haven't already got another scope and you have ample amount of funds + previous experience with observing, I'd recommend a large 12" dob + a 3-4" ED frac combo over an SCT. The dob will get you as much if not more light as the SCT while the frac can be a nice grab'n'go with wide fov. You could even squeeze in a decent EQ mount for dabbling into imaging if you wish. Those TV eyepieces will come in handy with the fast newt and provide a space walk effect with the frac. The SCT being slow doesn't really take advantage of those expensive eyepieces (ES 82 or Baader Morpheus would do if you want wide afov). SW 300P flextube: https://www.firstlightoptics.com/dobsonians/skywatcher-skyliner-300p-flextube-dobsonian.html Vixen SD81S: https://www.firstlightoptics.com/vixen/vixen-sd-81s-76146-apo-refractor.html SW AZ GTi (GOTO Alt-az for visual): https://www.firstlightoptics.com/skywatcher-mounts/sky-watcher-az-gti-wifi-alt-az-mount-tripod.html or ES iEXOS-100 PMC8 (for lightweight imaging): https://www.firstlightoptics.com/explore-scientific-mounts/explore-scientific-iexos-100-pmc-eight-equatorial-mount.html All of these combined are still well within your budget if you were going for the CPC925 or 1100. You will have plenty amount of funds left for eyepieces and other bits and pieces.