ONIKKINEN

Mini-PCs do exist and are very popular in place of an Asiair if someone wants to have non ZWO cameras. I guess the reason why other manufacturers have not jumped on the Asiair competitor opportunity is that the Asiair is actually well priced for what you get with it. ZWO can sell the Asiair at a good price because they make the money back tenfold by imprisoning the user to the ZWO product catalogue for good. Another reason might be that its difficult to make one product to fit all imagers (which the Asiair does not do by the way). DSO imagers might be happy with slow storage, slow RAM, slow CPU speeds and USB2 ports while planetary and lunar imagers will absolutely need faster everything and USB3 ports.

The last 2 nights i was imaging from a very humid location by a lake and so i am assuming close to 100% humidity, the temperature also dropped by about 8 degrees in 4 hours coming to a stop at -2 just before sunrise. The scope was wet (and later frosty) within an hour of setting up but this is not the first time this has happened, just this time i noticed that stars on one side of the image were horrible, while the opposite side was much better, but still not great. One of the problem images (calibrated and split green channel image) below. The top right corner is awful while the left side is not so awful. An animation of a top right corner star from all the frames that night: And then an animation of a left side star: Ignoring the few frames that are out of focus these 2 look very different. The flaring out does not seem to happen on the left side of the image. I had the fan on at first as i always do to cool down the scope, but turned it off once i noticed the hairy flare on the right side. Doing this alleviated the issue a bit and the flaring retreated a bit, but came back after a few frames. Then turned the fan on and it again retreated, rinse and repeat for the entire night. I looked down the scope with a bright light and noticed that the primary mirror was a little bit misty which is not unusual for a night this wet. Usually this just very slightly reduces the reflectance of the mirror and i may notice a slight drop in levels from the images i have taken. Not given it much thought before. I looked at the reflection of the secondary and i saw no obvious dew or frost there, and neither did i see any on the coma corrector/camera. What dew related problem would this be then? Only affects one side of the image, leading me to think its something related to tube currents. But how the fan being turned on and more oddly, off, helps here i have no idea. Maybe the mirror fan heats up in use and so heats the back of the mirror very slightly? Then once the fan has ran for a while that heat gets overrun by the cooling humid air running over the mirror. Or maybe this is frost on the sensor itself? Could be, because it does not affect the entire image and the way i have understood it any smear on either the primary or the secondary would affect the entire image. Thoughts?

You are probably right, firearms and hunting is much more popular in the US so makes sense that the market is focused there. Have only been following astronomy for 3 years now so have an incomplete picture of what the prices were long ago.

Im sure you can figure this one out quite easily? Lets just say there is more demand for night vision kit at the moment for some places in Europe.

Harmonic drive and other non "normal" GEM type mounts will probably become more popular, and hopefully more affordable in the not too distant future. Light pollution combating equipment can only get more advanced as more and more areas around the world get consumed by city lights. AI tools for image processing and maybe even image capturing will become more popular if and when more tools are released, especially if someone starts to compete with Russel Croman tools and release their own suite of products. Cameras will keep getting better and better until one day discussions about optimal exposure times are met with rolling eyes and comments about not bothering. For many scope/camera combinations we are already there with very low noise cameras and fast scopes becoming the norm rather than a lavish expense. For visual only folks i think the world of astronomy will not change all that dramatically. Scopes keep getting better and cheaper and more ways to fight light pollution will become available. Camera aided EEVA being one of them, and maybe an electronic eyepiece type night vision another.

43x 120s with a UV/IR filter + the usual stuff: 8'' newton, paracorr, Rising Cam IMX571 OSC. Surprised how much red appears from the background with just a UV/IR filter and an OSC camera. Expected nothing but got an image that i quite like for such a short integration. Last minute decision to switch from imaging Arp94 to this, because the former was low in the sky and producing really bad data with up to 5'' stars - basically just wanted to image anything else so that the trip was not a complete waste of time. This one was also low in the sky but to the opposite direction which was much better. I was imaging at a lake which was only partially thawed and i think the open water sections produce some kind of thermal current rising from them that ruins the image every time the scope points over one. That and dew on the secondary, which was a first. Unplugged the cooling fan on the primary and it went away in a while thankfully, but the Arp94 data probably wont see the light of day at least yet.

Surprisingly detailed given this much cropping of this pair what Stellarium says is only about 6 arcminutes across. Only 4 hours too! Sounds too good to pass, im going to try and blatantly copy this framing with my 1018mm fl newt 👍.

Actually not a bad price compared to the vanilla 2600MC (but expensive compared to non ZWO imx571...). SC2210 is the chip used in the 220MM, so should be workable for fast scopes in narrowband too.

Of course, hoping that the camera does have the 220MM or some of the other new lower noise cameras. If its the 120MM then probably not so great (also why i changed the guide cam)

For those doubting guiding capabilities with filters i will mention that i am guiding with the new 220MM in an OAG in an 8'' f/5 newtonian through an Antlia Triband RGB ultra filter, which while not very narrow is still a narrowband-ish filter. No trouble finding stars to guide on and typically i am running on multiple stars if not the full 12. Guide star SNR is in the range of 40-1000 from what i can gather from my guide logs so room to go narrower or shorter in exposures (4s with mine). 7nm and the like filters are probably a pain but i reckon something like the L-enhance would still be tolerable in a fast-ish scope.

Interesting, never thought to doubt it when i first saw the video a while back when all this was announced. Just kind of thought these guys must know what they are doing but it doesn't look great here wit the examples.

I should mention that i found this off google image search and its not something i have made myself. Should you google 533MC sensor analysis you find a number of results, some of which have slightly different values so for the purposes of creating a spread sheet you should probably take an average of the found measurements instead of one of them at face value (although the differences are very small). I have done the sharpcap analysis on all of my cameras a few times and the measurements vary a little bit. Both vary between different runs of the tool and between the measured and camera manufacturer stated amount i mean.

Here is a sharpcap sensor analysis result sheet from the 533MC: Should contain all the details one needs to figure out what number to put where in the read noise swamping formula. So at Gain 200 we have 1.42 read noise and 0.32 e/ADU rate (ADU=camera measured value, in this case 14-bit). Offset was already defined as 50 which is 500 ADU or 2000 in 16-bit. So for a read noise swamp factor of 5 we get this: 1.42*5 = 7.1 which when squared comes out to 50.41e. 50.41e divided by the e/ADU conversion rate of 0.32 comes out to 157.5 in 14-bit values. Multiply by 4 to get 630 in 16-bit values which is what your software using the camera will report. This is the number you are looking for to have on top of your offset. Your offset being 2000 in 16-bit means @BrendanC you are looking for a number of 2630 given by APT/NINA/whatever else when out in the field in order to swamp read noise x5 at gain 200. I think in your shoes i would rather shoot at gain 100 as the drop in read noise is really not that much. Unless you are scraping the barrel so to speak in terms of mount performance. With gain 100 we get: 1.63*5=8.15 squared to 66.42e, so only 16 electrons more compared to gain 200 but you get triple the full well. In the case of gain 100 you are looking for a number of 2260 reported by the capture software to swamp read noise x5.

@BrendanCand others, i think this part was skipped in the above calculations. The 533MC is a 14-bit camera but as far as i know every software will report measured values in 16-bit. The output value must be converted back to the original to have meaningful e/ADU conversion rates and other measurements regarding noise amd whatnot (divide by 4). Offset of 50 equals 500 in 14-bit values (the only thing the camera cares about) and becomes 2000 when converted to a 16-bit number. The above calculations come out as 237e if converted to 14-bit which sounds a lot more reasonable than 950e.

You want to have the longest integration possible, but only have the best subs in it so you have to compromise. Look at the average quality of subs and deselect the ones that are clearly worse than the rest, but definitely dont reject 90% of the stuff. If you have a fair bit of variation in the data you should use some kind of weighting for the subs that are stacked, so that the worse ones have a lesser effect on the stack as the good ones. That way you can stack almost all of the data except for the clearly wind/high cloud/mount issue stricken ones. I have seen the number 6 floated around for the minimum number of images that rejection algorithms can work with so less than this might result in satellite trails not being removed.

Doesn't look like stacking the 2 would have any effect because the L3 has a much wider pass than the L-enhance. You could stack the L-enhance + red or green filter to let trough only OIII or Ha instead of both. This would tighten the stars a fair bit, but of course youre only letting one of the bands through so it will be more time consuming to get an HaOIII image out.

Last night was clear with some high cloud, was imaging there. Even though it was technically a full Moon night the Moon was only above the horizon for about an hour and even then so low in the sky that the conditions were still pretty good (B5 probably). Saturday was clear too! I know the forecast said something else but that's just how it is. Imaged something else than this though because i am a fool and have started another long project. Hopefully dont have to spend 35 hours on this one .

f/12 with the tiny 2 micron pixels of the 678MC is going to be a really bad time with DSO imaging. Not saying its impossible, but we are getting there especially since you are not guiding. If you wanted to try and make this work you would need to guide and expose for probably at least 5 minutes (as long as possible really) for the images to be something other than mostly noise and for stars to start to be visible beyond the noise. Really the sanest approach to starting DSO imaging with your mount/camera is with another scope. Probably some short focal length refractor which will be more forgiving with your short exposures and lack of guiding. The camera is still not optimal and maybe you would have better luck with something else, i think you may have pretty much one of the worst combinations of kit for DSO imaging with all this, sorry!

Looks very clean, these should work well.

The main sensor looks pretty large, maybe a full frame. If so its going to be very expensive and most scopes wont be able to take it. But if this is a range of new products then maybe there could be more wallet friendly options with 21-28mm diagonal sensors? Seems like a useful idea, one less imaging train trinket to worry about.

I have a steeltrack on my newtonian too and it does leak a tiny little bit around the drawtube and around the base. The base is easy to seal with some black duct tape or whatever you have on hand. Other than that have found it to be not an issue when shooting lights so have done nothing too drastic about it. My scope is well flocked though so any light that creeps through the focuser to the inside of the tube mostly gets absorbed and not reflected back to the imaging train.

Just went trough the files, and yes you have significant light leaks that make calibration probably impossible, even with the new files. First your old dark which is completely ruined by the rear leak, see a rainbow rendered stretch (blues are dark and reds are bright, the light leak is clearly skirting around the primary mirror from the rear of the scope): But your new one is not great either: Clear gradient, which shouldn't be there. Median values in the new dark are around 460 when they should be very close to the offset value of 10 which with your camera results in 400 in 16-bit values so you still have almost 60 electrons of light leak per pixel here when just one will make calibration difficult! In short, light leaks still reign supreme and to fight that i recommend you take the camera off the scope and shoot a library of darks and darkflats in complete darkness. The light leak issue still needs to be solved because they will imprint the weird gradient onto the light frames themselves, which may result in funny looking flats calibration even if the darks were taken in darkness. On the exposure length and histogram, i think yours are just fine. Unnecessarily long exposures though, there is no need to expose for 4 seconds with your camera but of course also no downside other than it will take a while to capture the flats. Your flats histogram looks like this: Mine looks like this with a triband narrowband filter: Mine calibrate the image just fine even though 1 of the peaks is nowhere near the center. Basically dont worry about the histogram, as long as nothing is clipped to black or white you will have good flats calibration. If you want to nitpick the flat you could push the histogram a little bit further so that all the peaks are centered around the midpoint but i dont think there is a point for doing this other than peace of mind. In short, round 2: i wouldn't worry about the histogram at all, seems good to me. I think a lot of the flats related talk found online relates specifically to older cameras that can have nonlinear sensor responses to light and/or exposure length and so need to take some specific histogram and a long enough exposure to make the flats work (294 might be one of them). For the new Sony sensors (533,571, the fullframe version + others) you just dont need to do any tricks since the sensors are 99% linear and have no weird instability issues with any exposure lengths. I take my flats at 0.05, 0.2, or 1s depending on what gain and filter i used and never had any weird calibration issues.

I am assuming you have taken the flats after the imaging session, without touching anything on the scope such as removing the camera etc? If so, need to do some educated guesswork. Post a flat, a light frame that matches that flat, a dark frame and a bias/darkflat frame in .fits format as an attachment so the raw data can be seen for possible clues. I am guessing it will have something to do with light leaks if all the calibration frames are otherwise sound. The rear of the tube will let in light unless you have blocked it somehow for example.

@vlaiv is wise and has given good advice. I f i were you i would stick with the 8'' newtonian and maybe look into a better quality coma corrector if you happen to have one of the cheaper ones (Baader, Maxfield 0.95, Skywatcher 0.9 etc) as they reduce the maximum sharpness you will get out of the scope. Vlaiv's advice was difficult to swallow the first half a dozen times i read it, but time and time again it has been proven to be right at least in my conditions. 1.5'' resolution is already a very demanding target and more than half of the time the skies will just not allow it no matter how much quality glass is in the scope. In my typical seeing a resolution of 2''/pixel would be ideal, with 1.5'' being a nice good seeing night target. 1'' however i am not sure if i have ever had the conditions to reach. Definitely, makes all the difference. This wont give you sharpness any more than your DSLRs, but it will improve signal to noise ratio drastically allowing you to get a much better image in the same amount of time.

Nice and tight diffraction spikes, works really well with open clusters.