Jonesdee

Interesting, that's exactly what my Rice Crispies told me!

Hi Vlad As you say, a fun exercise. some more info - it was shot with an FSQ85 plus Field Corrector (455mm) using ASI2600: Dave

Not sure if surveillance satellites can alter course, but if that were the cause, it must be pretty manoeuvrable! I think I agree with Enigma_RL - must be aliens

Yes, good thought @Tiny Clanger. It was a 3 minute exposure and a rocket could have passed over at relatively low level and registered on the sensor. Much more interesting than the Space-X stuff !

I wondered that too James, but these usually show multiple trails from the various lights on board. Possibly something flying very high?

While discarding poor subs last night, I came across this - plenty of trails from Mr Musk's toys, but what is the wandering object on the right? Anyone seen anything like this before? Dave

All Thanks for your input - I will start again from scratch and reprocess the data. Will post the results . . . Dave

Hi Stuart, thanks for your reply. Interestingly I cannot see the issue in either individual subs or the master flat. Good to know that you do not use the flattener as this points to an issue with the main optics of the scope. I will check with a torch as you suggested, however looking through the OTA at the sky seems clear.

In October I broke the piggy bank and bought an FSQ-85ED, which was supplied with the 1.01x Flattener. Given our rubbish weather, I have only had a couple of opportunities to use it, the first being with my ASI1600 mono. I had the flattener fitted for that session and was pleased with the results. In December I purchased an ASI2600 OSC and fitted that to the Tak without the flattener, first to save the aggravation of setting accurate back focus and secondly because it should not be needed for that sensor size (the flattener is supposedly only required to correct astigmatism with full frame sensors). I imaged M52 and IC1805 in the first session and noticed that the centre of the stacked image appeared to be very bright., despite being calibrated with flats, dark flats and dark frames. Using DBE in Pixinsight I was able to reduce the flare, but it returned quite significantly when noise reduction was applied to the image . Next clear night I imaged close to M81/82 with dark sky in the centre of the frame. Sure enough, there was a bright circle in the centre. Suspecting the ASI2600 to be faulty, last night I repeated the test with my ASI294, expecting it to be fine. Unfortunately the same bright patch was present, pointing the blame at the scope instead of the camera. Here is a (slightly cropped) screen grab of the ASI294 image. Subs were calibrated with darks, flats and dark flats, stacked and for quickness, gradients removed with ABE in Pixinsight. No other processing performed . The issue is very clear even in a low-res snip: Has anyone experienced anything similar to this? I wonder if use of the 1.01x flattener is mandatory with the latest FSQ85s, i.e. have the main optics been changed to better work with the flattener which is now supplied free of charge with the scope? Next test will obviously be to try one of the OSCs on the scope with the flattener fitted. Cheers Dave

I recently needed to make a couple of custom length power cables and purchased some of this: https://www.ebay.co.uk/itm/163699838807 It is extremely flexible and appears to be of the same quality as that used by commercial suppliers. Maximum current is 4 Amps, however it runs the coolers on my ZWO cameras without issue. I am not affiliated in any way to the seller, just wanted to share details of what I believe to be a very useful product for the DIYers amongst us. BTW I asked the seller if he had any 4 core in the equivalent material (for focus controllers) but that is not something he stocks. Cheers Dave

Canon 100D if they are still available. Very light weight, 18Mpx and do everything that's needed for astro via Backyard EOS. These days I mainly use cooled ZWO cameras, but keep the 100Ds for use with my Star Adventurer (I have 2 - one is fully modded, the other has just the IR filter removed.) Dave

You are absolutely correct - the Yongnuo is a 100mm f2 lens. My mistake, I was confusing it with a Canon 200mm that I have borrowed from a colleague (and sadly has to be returned). Value for money, the Yongnuo is great, however the autofocus is not brilliant if you want to use it as a general purpose lens. I focus it with the controls in Backyard EOS, or just do it manually. I will edit my original post!

I guide mine with a 60mm Altair Astro guide scope, GPCAM2 camera and PHD2 software. This setup also allows me to get fairly quick and accurate Polar Alignment using the PHD2 Drift Align Tool. Ten minute+ exposures are then possible (using a solid tripod of course). I control the camera (modded Canon 100D) via Backyard EOS, which can also enable dithering via PHD2. I bought my Star Adventurer to avoid the long setup time required by my full size scopes and am delighted with it, although since completing my observatory it doesn't get so much use. I mainly use Contax 50mm f1.8 and Yongnuo 200mm f2 lenses. The Contax is excellent quality glass with full manual control and can be picked up cheaply these days. Dave Cygnus.tif

Cheers Kev, I hope we get some decent weather soon to give it a proper try! Just to have the mount set up and ready to go is a massive benefit. Being a very compact obs, I can mount the scope through the shutter opening, so it is not necessary to climb inside too often. Next step will probably be a motor to rotate the dome, but I don't see that as a critical item yet. With the 80mm refractor, it appears to take around an hour to track from one side of the slit to the other Dave

Cheers Steve Yup, you just cannot have too many clamps! Being a keen woodworker for many years, I have aquired a good selection of tools to make a task like this relatively easy to accomplish. Also, being almost 70 now and recently retired, I have the time to spend on projects like this (certainly beats working!) Dave