ONIKKINEN

Try to colour balance an image taken entirely without blue for example. You'll find that no matter what you do you cannot get a true colour result in the end, i think that's the point. With the IR part of the spectrum the light is unevenly spread to the R-G-B pixels so colour balance is skewed or mixed in capture, mostly towards reds since thats where the IR response is strongest. I dont think you can balance this out if its too much out in the first place. Take the image CCD-Freak posted as an example, the colours are just not right and wont be although i think that might be an extreme example.

Thanks for the details, honestly didn't know it was even technically possible! The travel router method is the same, except steps 1 and 6 are not necessary so maybe a bit easier. There is some initial setup that does require a monitor and peripherals to do in the minirouter settings, but other than that it always creates the network on bootup. The range is not that great though, take that into account. Its meant to be something you use very locally in a public wi-fi, so right next to the device in use. I find that sometimes i lose connection for a few seconds if im sitting in my car and the telescope is running maybe 5m away. Doesn't really matter though, as the mini-pc will keep on doing its thing regardless of connection to tablet or not.

One such star in the earlier example from CCD-FREAK in the lower part of the dust cloud. Very bright pink star in the unfiltered version and almost undetectable in the filtered one, very easy to tell the difference. Embedded in dust so IR passes this better, i assume.

I trust this, and i plan on doing that. Still going to test what the difference is, if for no other reason than curiosity.

How would i create the hotspot if i cant access the PC? I dont have a monitor/keyboard/mouse or anything to connect to the PC in the field. Could i configure the hotspot to be created automatically? Honestly didn't know this was an option.

Yes, the Maxfield is a bit of a useless corrector. Only 2/3rds of the price of the GPU and does a significantly worse job than it. The only 2 reasons i bought it were: it was available and i could afford it 😃. Also didn't do research and just assumed that a coma corrector corrects coma and that's it. I assume your graph is from the GPU? I am getting one whenever i get fed up with fat stars.

Not sure what this means? But this is why my mini-pc has never and will never be connected to the internet. Windows updates cant ruin things if i dont update windows 😉. But i use one of these: https://www.amazon.co.uk/GL-iNet-GL-MT300N-V2-Converter-Pre-installed-Performance/dp/B073TSK26W/ref=sr_1_3?crid=3LKR2H5JTUQY6&keywords=travel+router&qid=1639849166&sprefix=travel+route%2Caps%2C103&sr=8-3 It is connected via ethernet cable to the mini-PCs LAN port and creates its own wifi network. I then connect to this wifi with my tablet via RDP, but you could also connect any other device to it. This works anywhere and doesn't require actual internet connectivity, just a device that can connect to a WIFI network. I dont think the mini-PC knows or cares where the network comes from as it just "receives it" from the travel router, so might not apply for whatever is no longer allowed on WIN10?

I got the filter out, with some out of the box thinking and trickery. I screwed another adapter on to the threads of the stuck filter holder to act as a better gripping surface and then put my 60mm guidescopes holder rings around that adapter. Tightened as tight as i could with pliers and it cracked open after a few tries. The nylon tipped screwheads also did not mark or noticeably deform either of the adapters or threads, turns out this is a pretty effective method of removing stuck things and much better than strap wrenches that i have tried! I am never screwing a single piece of kit together without some sort of lubricant in the treads again... Now just to wait for a gap in the clouds to test a filter/no filter difference with my corrector. Think ill shoot the double cluster, which doesn't take a long integration, has M type red/IR stars well as very bright B type blue/UV stars. Should bring out any internal reflections or possible CA out nicely. Usually, yes, but maybe sometimes? Attached is the spot diagram of my corrector on an F5 system, so my F4.5 primary should be slightly worse still. What do you make of this? It looks like not all colours are treated the same out of axis, so a bit like CA? Although CA would be on axis as well of course. I am not educated enough to guess how much refraction must take place before CA becomes noticeable, but you might be... The first lens element on the coma corrector is actually very curved, not unlike maybe a finderscope lens? It is about 130mm from the focal point and doesn't advertise ED elements of any kind, so i would assume CA is there, even if very small.

Probably more geared towards smaller pixel sizes, which do suffer from small fullwell? Maybe smartphone cameras could become closer to the performance of bigger sensors? I couldn't care less about the fullwell in my camera though as i use about 1% of the available fullwell for signal excluding starcores.

Bortle is a quick and "thereabouts" kind of way to describe skies, but SQM is better. But try explaining SQM to someone not in the hobby and youll find a convenient 1 to 9 scale is much easier to explain. The word itself does sound pretty "3AM conversation in a taxi".

It would definitely not cost billions to send a repair crew since little new tech would be required. Maybe a modified SpaceX dragon with a radiation shielded habitation module in tow would be enough. Although that's not the NASA way, the true NASA way is to spend as much money as possible and develop everything from scratch, even if alternatives exist so it could very well be billions in that case.

It is a bit far away, but i wouldn't call it impossible to send a crew there. From an engineering point of view the spacecraft going there and back in a timely manner needs a fair bit of delta V but not a crazy amount. Somewhere around the range of going to Lunar orbit and back perhaps, and a lot less if the most efficient route is taken (one that JWST takes, which takes weeks). Definitely not an amount that current rockets wouldn't be capable of. Being so far from Earth will mean that the magnetosphere is no longer there to prevent the crew from possible coronal mass ejections which would probably kill the crew, but this issue must be solved one day if a Mars mission were to be even considered. I could definitely see a JWST maintenance mission being a convenient excuse to practice further than LEO operations for crews. But of course NASA is not going to be interested in the idea if the mission fails so for now its "no chance".

How can you tell between the 2? Looks a lot like CA but just red instead of the usual blue. Also, if it is just reflections this would mean that some correctors might not have this issue if they are better coated with infrared in mind. I doubt the latter is true for me, since the Maxfield isn't that great of a corrector anyway.

I suppose the camera doesn't care whether the IR is in the coma corrector or not, as long as its not getting all the way to the sensor so not important how far the filter is. Assuming no vignetting of course, but it is a 2 inch filter so not an issue.

I am planning to shoot the Coma cluster of galaxies whenever Coma Berenices rises a bit higher and was hoping i could squeeze in the extra signal from without the filter. Its not a particularly colourful target so might not be an issue. Ill test it first and see if i could get away with not using the filter as i could really use the extra QE. But if true color suffers too much, i wont risk it.

If im not mistaken this particular camera has been designed around IR imaging? Mine is not nearly as efficient in near IR. Would make a superb Lunar camera though. I wonder if guiding would also be better with IR pass?

The pink starbloat is due to chromatic aberration, at least thats what it looks like. You can see the diffracted spider being out of focus and dark in the middle, not unlike a very out of focus shot. In that example a reducer of i believe around 0.7x is used with the Hypernewtonians and so the effect is easily noticeable. With my 0.95x? Remains to be seen (if the filter ever comes out 🙄). That particular star is also an M-type star (cold surface temperature, deep red) so it radiates strongly in infrared also, so this is probably the worst case scenario.

Sounds like a focus issue if you can see an image without the eyepoece but only the floaters in your eyes (normal btw). Try to lift the eyepiece out of its holder and hover it outwards. Does the image get better or worse? If you do reach focus at some point you might be missing a piece somewhere. Just to make sure, but you do have the diagonal in the back of the telescope and the eyepiece in it?

The Moon is very bright so youll be surprised how short the exposure time has to be. Set the camera to manual mode and ISO to the minimum. Try out different exposure times until you dont overexpose the bright parts of the Moon. Alternatively the "aperture priority mode" will also probably work. In that mode you choose ISO and the camera chooses the exposure time to be what it thinks is ideal. It works for the Moon a good chunk of the times. Preferably underexpose rather than overexpose, since you cant recover detail from a fully white pixel but can stretch the darker pixels to appear brighter.

Mini PCs come and go from vendors all the time so its hard to recommend something that you buy a while from now. But the basics would be at least 8gb ram and an SSD, and running WIN10. Any CPU basically works so dont sweat it that much. The key part here is the ability to run the thing off of USB C fast charge to work with battery packs. This is not always mentioned in the sales ad so takes a bit of research. Mine has an old i5 and 16GB of ram and it works for everything related to capture, but it probably doesnt have to be as good as mine.

If you dont like the color calibration result, try ticking off Auto and set the catalogue limit mag to a higher value? This way more stars will be used, assuming suitable stars are found in the image. I try to look at my image and see at which magnitude (referring to stellarium) the stars are still well resolved and not that noisy and choose that. Usually with mine i end up using down to mag 16 or fainter. Sometimes there is a difference, sometimes not, but worth a shot.

I would assume this refers to the Photometric color calibration tool in Siril. The actual photometric data comes from either NOMAD or APASS surveys i think.

Absolutely yes, in fact autoguiding is more common than not autoguiding. Not guiding will limit your usable exposure time to quite short ones, which will depend on how good your particular unit of EQ3 is but generally probably best to avoid exposures over 30s if you want to have most of the frames be usable. Since you are already gearing towards having proper PC control of the whole rig, you have done most of the job already. The only things you do need to buy are a guide cam, guide scope and some cable to connect the mount to the PC. And get used to some software of course, but its not super difficult. This is probably the most common camera for guiding: https://www.firstlightoptics.com/zwo-cameras/zwo-asi-120mm-mini-usb-20-mono-camera.html . I have one and honestly there isn't much to say. It does its job just fine. For the guide scope you have lots to choose from and its up to you how much you want to spend on it. Spending extra is mostly a convenience thing, not something that gets you better performance (for the most part). A generic 50mm finderscope converted to a guidescope with an adapter will do the job just fine. I personally found the finderscope style rotating lens cell focuser annoying to use so i bought an actual guide scope, but this is not something that has to be done. 50mm finders are cheap and i would assume you can find a used one for sale every now and then. For the cable, it depends. I think the newest model of EQ3 PRO might have a USB port on the handcontroller and/or main control box, but im not sure. My EQM35 has one and the mounts are quite similar in design. If thats the case, any USB2 printer style cable will bridge the PC to the mount just fine. Plugging the USB cable to the hand controller will let you use both the handcontroller and your PC to control the mount. This could be beneficial, but if youre going to only use a PC to control, then not that big of a bonus. The other solution is to get a USB to serial cable that plugs in to the hand controller port of the control box, note that this means you cannot use the hand controller anymore at the same time. https://www.firstlightoptics.com/sky-watcher-mount-accessories/lynx-astro-ftdi-eqdir-usb-adapter-for-sky-watcher-eq5-pro-heq5-syntrek-pro-az-eq5-gt-az-eq6-gt-and-eq8-mounts.html The second suggestion is probably the more common one, and many people find the USB to serial cable to be more reliable than the on-mount USB, but personally i prefer the first choice.

Remember that even if the spacecraft itself works perfectly, the launch vehicle can still malfunction. There is no such thing as a perfectly reliable rocket so it could turn into a 10 billion dollar fireworks show.

There could be frost developing on surfaces other than the objective lens, even inside the tube if you have moisture in there for some reason. I find a thin layer of frost develops quickly and is difficult to see by eye but the camera will pick this up as a dimming/bloating effect. How do you handle the gear after shooting? Do you open all the caps for several hours to let moisture out before putting the gear back to storage? If you dont, you could have moisture lingering inside the tube which sets as frost to a corrector/filter/inside of the lens or whatever and wkuld be difficult to spot with the objective lens being dry to the outside.