pipnina

I do have a mischievous cat however even his powers of destruction haven't affected my telescope yet. No kids to speak of. I have only assumed so far that the mount or EKOS simply loses track of where the mount should be pointed... But why now after years of it working fine? Perhaps i need to look into mechanical issues as a struggling stepper motor or slippery clutch could maybe cause it to wig out? I don't know enough about the finder details of the skywatcher mounts under-the-hood operation, do the handsets act as the whole brain while the board inside the mount simply works as a stepper motor controller? If so It could be EKOS making alignment issues. If the brains are inside the mount then maybe I could plug my handset in and give it a factory wipe of some sort? I always power up my setup pointed at the pole star with the counterweight pointing as close to straight down as possible. Usually the first goto slew will be off by some ten thousand arcseconds or so but the first platesolve will bring it within a few hundred, and by 4-5 platesolves it's normally in the 20 second tolerance I have set in EKOS. I feel like I should have a security cam pointed at it (for multiple reasons) as I think many issues with controlling it from indoors would be solved if I could see it while controlling it!

Imaging was going well on M101 a few nights ago, but when it crossed the meridian EKOS/Indi or the mount itself had a wobbly performing the flip and it kept pointing in the wrong direction. I went outside a few times to right it back to home position after hitting park in EKOS. It messed up each time. Eventually i hit park for the final time and gave up. When I looked at it the next day I saw it like THIS! I had to perform a lot of careful maneuvers to get it out of there between the tripod legs! I have no idea how it managed it or how mount positioning could go so wrong... Could this be something to do with EKOS's alignment settings? I cleared them a few times when it was parked and also let it "sync" in the park position so it knew it was pointed at 88 degrees on DEC etc. It still refused to point properly.

First of all, my condolences! Rest assured you aren't the only one who did something stupid today... I will be making an "oops" post myself tomorrow. It's possible you could buy a replacement optic from TS themselves, as they have a selection of telescope-building supplies including lenses: https://www.teleskop-express.de/en/telescope-accessories-5/telescope-diy-improvement-299/telescope-making-optical-parts-91 Maybe there's even a triplet that fits your telescope OTA? Who knows.

For a small sensor I'd agree with the samyang. No direct experience but people's results with it that I've seen have been terrific. I own a 135mm f3.5 canon FD lens for my AE1-Program. Even wide open it has incredible full frame coverage but just a bit of blue fringing that could probably be taken out with a UV-IR cut filter:

Might explain why my hammerite application went so badly... It was 5c at the time!

I've used hammerite at work, sadly they bought it in paint pots and we were painting onto paint (valve handles needed to show what the valve carried by colour) Brushing it on wasn't most effective... They looked a bit like a red tar monster when we were done haha. Bare mild steel will corrode very rapidly in wet environments. Rust is also supposedly self-perpetuating and a small amount of rust formation will crack or bubble paint allowing more oxygen access to the metal. I suggest completing rust removal, preferably by wire wheel (you can buy them for home electric drill chucks, flapper wheel may also work). If you want to ensure it's moisture free in the cracks or pits you could always stick the metal in an oven at a skin safe temperature for a few minutes. I need to think about all this myself, as my HEQ5 is starting to look a bit shabby with some parts of it rusting up and the counterweights losing their paintwork... Eventually it just catches rust and there's nothing you can do about it I guess. I suspect modern cars can avoid rusting on bodywork much more easily since they can control the conditions and state of the bare metal much more easily in the factory before applying multiple layers of rust protection below the paint.

Same here. I look in mine and see rust and during operation it sometimes stops and needs to be off-on cycled so I fear repair could be in its future... Or the crashes are purely software based...

The film cost was that high!?!? Was Kodak tech pan that dear or are we talking about some sort of scientific glass plate that's hypered, high speed but fine grain, and comes in sizes of 4x5 inches at the smallest and requires cooling and gases to store? A normal colour roll of 35mm or 120 was quite affordable until only very recently when the costs rocketed up.

The sky at my home has an Exposure Value (EV) of about -5.5 or so, and it's already dark enough that the ground is very hard to see even once I'm adjusted. However a place near me is much darker, dark enough to see the MW core and even sometimes the outer spirals, which means it's probably closer to EV-7 or even EV-8, I can see the ground at this level but not clearly. I would guess if it were just the MW core in the sky and no sky glow at all, I'd struggle to see any ground at all as you say. The milky way just isn't that bright!

It may be different up north where you are, but in devon I can manage about 1.5-2 hours of imaging during the astro dark holiday if weather permits, and with narrowband imaging I can get away with a bit more. The brightest sky I see from that period here is when the moon is out, which means a moonless night in that time window is still better than normal full moon conditions, under which I'd either image a target at opposite sides of the sky to the moon, or use narrowband, and my results are usually somewhat decent as the last few years the summer period has had a good number of clear nights so I can make one target a multi-night project (relative to UK average...)

Wait noise adds with the square root?? How does this work?

I want to improve the speed of my setup. I worked out that if shooting only RGB then the ASI 2400MC would afford me effectively the same resolution image as my RisingCam 571 (6000x4000) but with a wider FOV due to the larger pixels, since I am speeding up my imaging with a normal camera lens I expect that would be best for star shapes anyway, while affording me a 1 stop boost to my speed (so 6.2x faster than my RisingCam+ f5 scope) However it means narrowband (My main interest turned out to be Halpha only really, not worried about the loss of SII and OIII) becomes much less efficient as only one subpixel gathers data for it. If I got the ASI 6200MM I can keep my narrowband capacity but with the 3.76 micron pixel size, the same as my RisingCam, I won't gain the speed increase as I would with the 2400MC. Unless, I binned. A 3200x4800 image might be a little small for me but could be servicable. However this increases the effective read noise by a factor of four even though in theory is gives me a 2 stop light sampling boost right? So am I worse off with the 6200MM and should stick to RGB imaging with the 2400MC if I want speed, and simply forgoe narrowband for now? Interested to hear thoughts. Thanks

I only have a cursory knowledge of electrics in motors in general, but I think as a motor spins faster the magnetic back force increases which means you need yet higher voltage to move the motor. I'd guess if voltage correlates to max speed it's because of that. Holding torque I'd guess would be current based as the strength of the magnetic field is proportional to current and not voltage.

The number of bars on the rotor shows you the step angle. A 1.8 degree motor will have 100 bars on the stator and 98(IIRC) on the rotor. A 0.9 deg motor will have twice as many. Yours certainly looks like an 1.8 to me

I bought one of these and it seems to be quite good Of course it will be most effective once the sun goes down. You can position it some distance away while your camera is on a tripod, focus on it and the picture will show you the sharpness you can expect from stars. Just adjust the camera's orientation to position the fake star at different parts of the frame: https://www.firstlightoptics.com/other-collimation-tools/hubble-optics-5-star-artificial-star.html For smaller camera lenses (nifty fifties?) I'd guess the larger holes will be suitable and nice and bright once more than 10m away. For bigger lenses ideally you want as much distance as possible. Most lenses will decrease in quality as you focus closer.