ONIKKINEN

I am well aware of this, i had to use this knowledge once i realized the EQM35 was not going to work the way i wanted. After realizing this i looked at targets in very high declinations, like 65 and above and only shot those. And to be fair i was able to get reasonable performance at these latitudes, but this is to be expected. I am fairly confident in saying that if someone absolutely must use an undermounted system, or some obscure DIY solution, shooting high in DEC is the way to go. The Astromaster pic was on M31, so fairly south. Took me 45 minutes to fiddle with polar aligning and the RA motor speed though (stepless speed adjustment).

Isnt LRGB like (at least) 50% faster than OSC? And the pixel sizes between that camera and your current one are also wildly different so i dont know if these 2 could be compared. Youll probably need 2 nights to reach this if the shooting conditions are the same as they were then, and more than 2 if they have gotten worse.

Is this picture really true? Looks like the mount only goes to 50 degrees of latitude? I was going to comment that those knobs are not really usable with thick gloves in wintertime but looks like they solved the issue by having the mount be restricted to areas around the world that do not get winter 😎.

My very first astrophoto was taken with a Canon 550D and a kit lens at 100mm fl piggybacking on an Astromaster 130MD with the motor running. Took 12s exposures and stars were very much round, so i think if the astromaster can handle an 8 arcsec/pixel resolution any mount in the universe can. Wasn't a good picture of course, but point is at this kind of resolution i doubt you can find a mount that just flat out fails to work.

I reckon some harmonic drive manufacturer just came up with a conveniently sized and priced package that all these different manufacturers can implement on their own mounts. I find it difficult to believe that all of these would be unique in-house designs just launched at the same time.

Orbital speeds wont be happening from atmospheric launches, whether it be from sea level or from the summit of Mt Everest. Or maybe they could, but it wouldn't be efficient and the satellite would still need to do a several km/s insertion burn at apogee. In an airless world you could point the launcher sideways and just a small correction would be required at apoapsis, but from an atmosphere you do want to launch at a fairly high angle, or the projectile will either burn up or slow down before escaping the atmosphere. The atmosphere acts like a soup made of brick walls at hypersonic speeds in the thick parts (below i dont know, maybe 30km?). Launching at an angle of lets say 45 degrees could work, but then you would be going 45 degrees to the wrong way once in space, and you're actually probably only half way to orbital speed at apogee. If you just launched the projectile faster you would still be going the wrong way, but now faster and the apogee would be pushed higher, so still a problem. If this is the projectile in question it would fit a decent sized mini-satellite that could have enough propellant of its own to reach orbit, but not sure if all this trouble is worth it to make sure the satellite can survive the G forces and all the design decisions that come with it.

Anything coming out of the launcher tube will be a mist of atoms as soon as it hits the atmosphere at those speeds. This would be neat on the Moon though, if a base ever gets built. It could be orientated so that it gets put into Earth atmosphere intercepting orbit straight from the Moon with no propellant used. Not really usable for human transportation unless the centrifuge is absolutely massive in size to reduce G forces to crew, but if you wanted to move payload from the Moon surface to the Earth it would be pretty cool. What would you want to shoot back to Earth though? Minerals? Rocks? Whatever someone figures out can be mined from the Moon for profit i guess.

I think one of the best parts of astrophotography is the part where i can look at an image i took and say "i did this". Every step of the way was something i learned to do through research online, trial and error by myself, nights spent out with the telescope. Pack all my stuff into my car, drive to a location, setup the gear as best as i have learned, start the session, troubleshoot at least 1 unforeseen issue per night, its always a lot of work. Sometimes the trip is a complete waste and i feel like a clown for doing this, but when the result gets put to an image in the end its all worth it, i still cant believe its possible for me to take pictures of galaxies with amateur gear in very much amateur conditions. Buying results taken with some other persons equipment in a desert somewhere out of my reach wouldn't feel the same to me at all and i doubt i would really care about the data quality then since it wasn't mine to begin with.

Having imaged with an EQM35 (similar to EQ3, a bit better) for a bit more than a year i can wholeheartedly say that i recommend absolutely nobody ever buy the mount. There is nothing but regret in my voice when i say that i bought the mount and tried to make it work while also believing all the time that its a waste of money and time. I ended up buying an AZEQ6 for 1900e to get a mount that works better, but thing is the AZEQ6 actually cost me 2650e considering the price of the EQM35 so did not in fact save money. Doubt i will be able to sell the EQM35 for more than half the price i bought it, if even able to sell it at all. In your case, the difference would probably be small or nonexistent with the little 50mm scope but once you put a telescope larger than a finder scope on the mount you will see the difference. I dont think im too far off when saying that most folks will want to move on to bigger scopes sooner rather than later regardless if thats a good idea or not. You can use the EQ3 with the redcat51, you can also use the HEQ5 with the redcat 51. Difference is one is upgradeable with a bigger scope and one is really not. I think putting emphasis on the mount is very good advice for beginners, and advice that i ignored and now understand why it is so.

I too found that 50ms flats calibrated my lights well with my Rising cam OSC. They were so fast because i was experimenting with different gain settings, i dont usually use so fast exposures for flats. But usually mine are somewhere around 130ms and also work well.

Could be an internal reflection of some sort, but a more pressing issue would be focus. Zoom in and you see stars have hollow and dark cores which means you were out of focus when imaging, so best to fix that first.

My GTX1080 proved to be a great value purchase in 2016. I think it will stay in its socket until it bursts into flames 👍.

This looks great for a first try.

I remember this as i had just built a gaming PC for myself before this happened. If i recall correctly the prices at least doubled and stayed higher than the before normal pricing for years afterwards.

Depends on the type of astrophotography targets in mind and how much you are willing to compromise in quality and ease of capture on the final images, but yes if the goal is to get any picture of the sky, then a DSLR and a wide lens will do the trick for a lot cheaper than a mount + telescope. Cooled camera + lens + cheap mount would probably be cheaper, though not that much and you get i believe far less for your money. But how much cheaper really? Not that much cheaper IMO. Good lenses are more expensive than cheap telescopes, like the 200P. The 200P is actually very aggressively priced, and you cant really find a decent lens around the same price so the difference is waning already (i think a better choice would be the smaller 130 or 150). Then lets say the cheap mount you get is either a star adventurer or an EQ3. Maybe you can get rid of them with a little loss on value after using them for a while, but many people probably still hang on to theirs and cant really get rid of them. This means the price of the HEQ5 will be the price of the HEQ5 AND the cheap mount. I also think that lens astrophotography is more of an experts choice for someone who already knows what they are doing and knows what they want. Beginners almost always want to do a bit of everything since they really dont know what they are going to be doing yet, so a lens will prove disappointing since you really cant do planetary, Lunar or smaller DSOs. You can churn out mediocre pictures with a cheap newtonian or an 80mm ED refractor much faster than with the lens and learn as you go so i think the HEQ5 + some scope is pretty good advice. I as a beginner would have never agreed with using just a lens as i wanted to image galaxies mostly. After M31 and maybe M33 the list of shootable targets just ends with the typical camera+lens combination. Most beginners always state the same things: i want to do Lunar, planetary, DSO both big and small and i would prefer to also be able to do visual, and it needs to be cheap. Impossible of course but when you balance the scales and forget about a few or more requirements, you end up with a telescope on a mount 9 times out of 10.

Newtonians are usually upside down though, this one without counterweights too... The Expanse is a fairly high budget series as well so it is quite surprising nobody bothered to do the little research it takes to point the telescope the right way up.

I do wonder what purpose the mount would serve as i dont think there is enough room between an EQ3 and an EQ5 to fit a mount. Maybe a sort of alt-az/EQ hybrid that also works manually and doesnt cost an arm and a leg like the AZEQ5/6? I reckon that kind of mount would find buyers quickly.

Could have been any of these actually. Went away with a change of camera into one that has none of the above.

Hmm, that went away as soon as i changed to a shutterless camera, so what was it then?

My brain is in Monday mode...

The image looks noisy because it is noisy? I dont think im conpletely off the rails here by saying that the image has quite low SNR due to the resolution.

4x4 bin is 16x faster than 1x1 bin? 180/16 is 11,25. So if the image was taken with a 1.2 arcsec/pixel resolution with the same aperture the same SNR would be reached in 16th the time?

Exposure time alone is just part of the equation and goes hand in hand with resolution. If you did not use the reducer i believe your resolution is somewhere around 0.3 arcsec/pixel so about a quarter of what would probably be recommended. The reason why reducers make telescopes "faster" is they spread out the light to cover fewer pixels so signal to noise ratio improves. That would mean a 4x4 binned ideal(?) exposure would reach this result in 11,25 seconds = 180/ (4x4) so this exposure is actually very short (ignoring read noise and OSC here, its not quite that straightforward..). This is i believe also why it looks so pixelated because your pixels are just starved for light. Not sure how i would batch bin subs though. I split my images after calibration to 1R, 1B, 2G subs without debayering so the resulting mono images are half the resolution. That might makr them stackable but still far from ideal.

I had shutter shadow visible in 30s exposures on my lights, so with my 550D i dont think there is a point trying to increase flats exposure time since it will be an issue anyway. In theory though if i somehow managed to take 30s flats it would probably go away, but way too much effort. Mine were apparently 1/25s or 0.025s and looked like below. Histogram stretched monochrome and a false colour rendering to show the whole flat dynamic range better. The dark patch on the bottom would be the shutter shadow. Was the camera removed? If the camera is removed or something else is changed in the optical system, its almost certain you dont get perfect flats afterwards. If you image with a mirrored system its also possible something moves that shouldnt when the scope is just left doing nothing and flats would also not work. The remedy would be to take flats immediately after imaging, or even before imaging if you intend to leave the scope running overnight while you sleep. If the flats still dont work there are some mechanical issues that need tending because your optics change during the session.

If im not mistaken your Omegon 130/650 has a 1.25 inch focuser? If thats the case its not that well suited for astrophotography since coma correctors require a 2 inch focuser, and vignetting would be an unnecessarily big issue if you use your DSLR. HEQ5 is most commonly recommended for a good entry level astrophotography mount and fits your budget nicely and leaves some money left for necessary accessories. Dont skimp on the mount, so try to resist the temptation to buy a cheaper mount to leave money for other things, the mount is the heart of the operation! So an HEQ5 + Skywatcher 130PDS + TSGPU coma corrector (https://www.teleskop-express.de/shop/product_info.php/info/p6706_TS-Optics-NEWTON-Coma-Corrector-1-0x-TSGPU-Superflat---4-element---2--connection.html) would be around 1800e. There is a very long thread here on SGL where people image with this kind of setup and many pictures turn out fantastic: Without guiding you will be limited in the exposure time you can use, and there will be other nuisances you will have to tend to manually like dithering, framing, finding the target etc. All doable but much easier with guiding in the mix. But this would definitely get you started nicely and get good results already. For guiding there are options depending on whether you have some of the stuff already. If you have a laptop you could use with the scope you will save a fair bit of money, if not you will go over budget for now. If you do have a laptop you only need a guide cam and a guide scope. Something like the very simple but effective ZWO 120MM. This is conveniently sold as a package with a simple 50mm guidescope: https://www.teleskop-express.de/shop/product_info.php/info/p10396_TS-Optics-Guiding-Set-50-mm-Mini-Guide-Scope-and-ASI120MM-Mini-guiding-camera.html Guide scopes can vary in price but the differences are in the focusing mechanism. The above model focuses by rotating the lens cell, which could be annoying to do. More expensive models have a non rotating focuser. But focusing a guidescope is not really that important, it just needs to be good enough and you may find it doesn't bother you. If you dont have a laptop you can spare, you would need to have some kind of computer on the scopeside. Either a used laptop which can be very cheap, a ZWO ASIAIR which is expensive and only allows you to use ZWO products and some DSLRs, a Raspberry PI running stellarmate software, a stellarmate (same as previous), or the best combination of all of these: a windows 10 mini-pc. Prices with these vary but expect to spend around 300 euros or more. Without the computer you would be right around your budget with the HEQ5+130PDS+TSGPU+120MMguider package, but there will be additional costs, there always is. You'll need an adapter or two for the coma corrector, you would probably want to invest in some collimation equipment like a TS concenter eyepiece, you might need to buy a power adapter or if imaging in a remote location a battery of sorts to power everything. So maybe drop the guiding for now and stay within budget would be a good route to go.