ONIKKINEN

Actually pretty funny that i had a similar experience. A work colleague of mine asked what could possibly be better in the new camera i bought compared to the old one when they are the same size. I then started trying to explain things like read noise in electrons and thermal dark current and they just left the room mid explanation 😂. Now i just say that its better and leave it at that.

8GB ram with (assuming) Windows 10 is probably to blame here, if you can source another stick of ram to put in your machine you might be able to do it. The process seemed very ram hungry and completely seized my PC for a few seconds with every sub, and that is with 16GB ram. Also, echoing what Vlaiv mentioned about conversion to TIFFs. Adobe Camera Raw, while not free can batch convert the .RAFs into TIFFs. The conversion took a while but not nearly as long as the stacking with the raws, probably just a few minutes. Then stacking with the TIFFs was as normal as can be, subs fly past the registering and stacking process. So if you find a tool that doesn't do whatever the original converter did to the files you should be able to stack. Interestingly i did find that the stack with the raws and stack with the TIFFs had different histograms, so something must be different even when to my eye they are equivalent quality. Probably a difference in the debayering method doing something different in DSS and Camera Raw. The Fuji does appear to work really well here, the purple parts are H-alpha which would not be visible nearly as much with an equivalent Canon or Nikon camera.

I scratched my primary mirror with an air can because the jet is far too powerful and can dislodge dustspots and make them projectiles so no i wouldn't recommend that.

I saw what could have been comet Leonard. Hard to tell in the conditions really. Took a late night walk with the Nikon aculons in hopes of seeing comet Leonard before it drops below the horizon, and this was probably the last chance. Nice and fresh -22 celsius with wind chill 😆. Skies were a bit milky, probably some high cloud and coupled with the city conditions of bortle 8 i wasn't really expecting much but hey its not going to be visible probably ever again. Scanned the skies up from Arcturus and i am certain it was in the field of view and one of the starlike specks of light in there. Just no way to be certain of the observation as there was no shape or tail of any kind. I am at least partly tempted to haul the VX8 outside but since its getting late (5am is late, not early for me), its probably best to let it go as it would be probably an hour until its set up and cooled. Did however see a shooting star of sorts, quite bright and lasted longer than a typical blink of an eye, possibly more than a second with a slightly brightening end before it faded. Probably burned in the upper atmosphere at that moment.

I noticed something like this with family and friends. The first few shots i showed them were well received, but as time went on its "just another picture of a galaxy" and i would rather not bother them anymore 🤣. I do think after spending who knows how much money on the hobby that the returns are very much diminished and keep on diminishing. Still i will keep on doing it as i find it unbelievable i can take pictures of other galaxies. I also think the internet is to blame for this feeling of the returns needing to be better than they are. Astrophotography is one hobby where a picture does not say more than a thousand words since you have no way of knowing what went on behind the scenes to get the image. Someone imaging from a place like always sunny and dry California will just flat out be better faster and produce amazing pictures compared to someone anywhere in northern europe where it is primarily cloudy. Also, some have more money than others, some have backyards while some live in tiny flats in a city (me 😆). Its not a fair hobby and never will be, but it is something i have accepted and hope to be able to keep thinking that way. Taking breaks for visual also helps to break the routine of AP.

Looks like a dust spot on one of the lens surfaces. Could be any of the lenses in the corrector or on the camera itself. Since it happens on all of your filters its not on any of them and they can be ruled out. Nothing to worry about though, you don't even need to clean it since that will calibrate out with flats just fine.

Tried cleaning with some strong cleaning solutions first? Not just a light spray and touch i mean, proper solvent and all. If youre planning on recoating the mirror it costs nothing to try and nuke the filth off it first. But i reckon that would still show a nice image actually because its not that filthy even. All newtonians have a massive and entirely opaque scratch bang on in the middle of the optical axis that blocks as much as 35% of the light on the way to the mirror. I am of course talking of the secondary mirror 😆. If you cant see the secondary mirror in use, why would you be able to see some small scuffs fractions of a percent the size of the secondary? Chances are you will not notice anything is wrong. That is a professional telescope with bullet holes through it and marks from banging on the mirror with a hammer. Telescope didn't care about them or really even notice, the resulted scuffs resulted in a 1% drop in light.

DSS 4.2.6 handled the RAWs for me, but it took very long even with just 40 best subs stacked and no calibration frames. The process was left hanging with the "not responding" message for about 20s per sub and then the registering or stacking went on. I suspect slower machines would make this pretty much impossible as i have a hefty PC. The stacked image looks like i would expect, the typical brown/red glare of city lights and not much else. Still very bright but this i don't think is a problem since the histogram is at half and not much seems overexposed. Still, probably shorter subs would be ideal in these conditions. Below is a PNG screen capture from a quickly touched upon image from Siril. You can see that the core is intact, starcores are not blown and there are no obvious separation lines between brighter and less bright pixels. The data is pretty nice by the way, more exposure and calibration frames and this will be a really nice shot. I suspect that for some machines the whatever thing DSS is doing for each sub that takes forever is not such a good option. Lets say you triple the subs to 120 and take 30+30+30 calibration frames, it would take hours upon hours to stack this. But it does at least work better than the converted subs.

The guy is a bit crazy but he knows his stuff when it comes to lasers, so just gonna drop this here: If you value your eyesight, you should never even consider using an Ebay laser of unknown origins however small and weak it seems.

Looking at one of the subs in photoshop, which apparently opens .RAF files just fine i can see that they look nothing like the Dropbox .TIFF files 🧐. But the plot thickens! At first Photoshop opens raw files in Camera Raw where the histogram is where one would expect it to be, somewhere close to the left side but once clicked done and opened in photoshop the sub looks almost white and the histogram is all the way to the right and now it does look exactly like the Dropbox TIFFs. Something funny is going on in the conversion process and this is the cause for the odd looking subs/stack.

Interesting weather related observation here: Now that everything is covered in snow here i noticed that skyglow is CONSIDERABLY worse than it was just a while ago. Snow acts as a reflector for light pollution and basically all lights are shining directly to space. I would estimate that bortle ratings went up at least by 1 class, possibly 2 classes in some places. Not that i have had proper time to confirm this, just a few glimpses through gaps in the eternal early winter cloud cover.

Used market does exist, but since the userbase is quite small there usually aren't that many interesting listings. But i do have a TS optics apochromatic 2.5x barlow (https://www.teleskop-express.de/shop/product_info.php/info/p55_TS-Optics-Optics-TSB251-2-5x-Barlow-Lens--1-25-inch---apochromatic-triplet-design.html) . Performs well, or at least has performed well with any eyepiece in it so far. Also had a shot at imaging the planets with it and cant fault the apparent quality. I am pretty sure its the same as the GSO 2.5x barlow as they look pretty much the same but with a different brand etched to the side.

Part1 of my purchases has just arrived: APM 24mm ultra flat field 1.25 inch barrel eyepiece. Might be able to test this tonight as the weather is 50/50 right now and every weather service seems to disagree what happens in a few hours. Part2 was not in the budget anymore since i had to use the money elsewhere, but since FLO is scheming against all the wallets of the northern hemisphere i ended up ordering a Pentax XW 10mm from the current sale 😃. Still not sure what focal length eyepieces i should have gone with, but if i would never buy anything if i just kept thinking about this, so these are the ones i ended up with. With these i get 35x and 84x, which i think i will be using quite often. TeleVue eyepieces maybe one day, but for now these will do.

Yes, a 32bit rational format. DSS actually does all of the background stuff in this format already, and the autosave file that is automatically created is in 32bit rational (which is floating point, the subject of the linked other thread). I am curious how big of a difference it is in your case as the subs themselves appear already stretched, but by stacking 40 subs with initial 14 bits you should be getting a 21bit depth final product if im not wrong on the math part. That means saving as 16bit will have the image be compressed from 21 effective bits to 16 bits = 5 bits of precision are lost.

My point on the typical-black-image was that such an image has all of the signal in a very tight area of the histogram when linear, unlike the example here which is actually quite bright. My shots with either a DSLR or now an astro cam always have all of the faint signal (nebulosity, the thing i want) within the first 500 ADUs or so. ADU = analog to digital unit which is a fancy way to say pixel value. On a 16 bit image which is 2^16 you have 65536 ADUs or posssible brightness levels of a single pixel (per colour channel). If all of the data excluding star cores and cores of galaxies is within 500 values, you essentially get less than 1% of the dynamic range of the 16bit depth to work with. When this is stretched to cover more of the histogram, say to cover all the way to 22k or about a third of the way to the right you now have stretched the initial 500 values to cover an area 44 times the range! This will definitely lead to the sharp brightness gradients and the image will be mostly unrecoverable. Using 32bit precision you get a ridiculous amount of precision, billions of ADUs i think? With that, you are no longer limited by the data precision, but the amount and quality of subs captured. @vlaiv is the master of explanations on the matter and i am mostly parroting what i have read from the man 😃. See this recent thread on bit depth: If the conversion process from Fuji to TIFF is weird somehow and alters the histogram, then im at a loss. What about shorter subs, like 30s. Are they as bright? 120s subs from light pollution could also just be too much and that's why everything is far too bright. The long subs required for astrophotography is actually mostly a myth these days, probably also applicable to the Fuji. Cameras are getting better and better and most times subs under a minute in light pollution is more than enough. Scouring around the internet some people claim that the XT-1 raws are supported by DSS with no conversion to TIFF first? Wouldn't know if that's true though, worth a try? Still, try stacking in 32bit. There should be a noticeable improvement. If i try to follow the tutorial on my very dark stacks converted to 16bit, i get a horrible mess with sharp gradients between bright and less bright parts as a result. What the stack looks like doesn't really matter, as stretching will bring out the detail in the image. That is if there is enough bit depth to do that. One of the biggest strengths of Siril is that there is a "preview mode" where you can preview the image as it would be if it was stretched (autostretch mode or histogram mode for full range) but keep the pixel values unchanged in the background. Edit: and i also got an almost entirely white image from the 17 stacked subs in DSS. Black point adjustments made the image normal-ish looking.

I have the Omni 2x and cant really fault it. The construction is a bit simple but i don't think it needs to be all that fancy, it does the job just fine. I have another, slightly better "apochromatic construction" barlow (2,5x) but honestly im not sure i can see the difference. Simple construction = low weight so might actually be preferable for the 150p heritage. The 2x is also good magnification wise, i don't think you would benefit from the greater power of the Baader 2.25x. The 10mm in the barlow will get you 150x, which is probably enough for the small dob. Remember that as magnification increases, you also increase vibrations and other wobbles in the mechanics of the telescope itself so you probably don't want to overdo magnification. And welcome to SGL!

Hope you don't mind some criticism of the process, but i have to comment. By the way i like the video as content and your videos in general, but as a tutorial this one sets bad examples (IMO). Noticed a few glaring issues right away that in my opinion should not be told to beginners, dont get me wrong its easy to understand and better than going around processing blind and with no instructions, but better alternatives are not more difficult to do! These things took me unnecessarily long to unlearn when i finally jumped to SIRIL (free!) to do the linear part processing. The final part that you mentioned in the video of processing always turning up different is born of these bad practices, and goes away with a few easy methods done early on. The problem with processing entirely in "normal" processing software is that you need to stretch the image first to see anything, when ideally a lot of the processing is done while the data is still linear. In Siril you can do the first steps: crop artifacts out, background extraction (gradient removal attempts), color balance (important in linear phase to have as much precision as possible) and then stretch the image. From that point onwards processing in Gimp or any other "normal" software is a piece of cake. Its hard to do the first steps wrong in Siril, but very easy in Gimp, which is why you have different results every time. Playing with levels and curves early on is also not a good idea and should be done on the almost finished image as a final touch up. First of all, this example shot sort of works because you have a supernaturally well visible picture straight out of the stacker! Personally i have never seen anything but the few brightest stars straight out of DSS and people who have similar almost black stacks will not be able to work with this tutorial. If you had a typical black/gray/brown image out of DSS the processing would not work at all because: The stack out of DSS in your case is in 16bit, which results in poor precision and separated values of pixels like shown in the first levels stretch section at 2 minutes onwards (the spikes in histogram values). This detail is unrecoverable and will result in a "choppy" final image as there is no precision to draw detail from. In your video you can clearly see the overblown parts do not smoothly transition to the less exposed parts but have clear separations of pixel values. The stack should always be in 32bit, there are no downsides! I am not Vlaiv but i think i have read enough of his comments to catch the 32bit good, 16bit bad vibe 😁. By the way it does not matter what bitrate the capture camera was, stacking multiple subs increases bitrate and 16bit is just not enough. Stacked the 17 frames in the dropbox (should it be 40?) myself and found that it produces a very overexposed image, Looks like the core is lost along with the starcores of most stars, not related to the video but taking shorter subs in the first place remedies this. Also i found that photometric color calibration does not find any suitable stars in the image, this usually means the data is already stretched or woefully overexposed, both are possible but i suspect a stretch looking at the histogram. Did you stretch the images or modify them in any way in the Fuji to TIFF conversion process? Modifying single subs in any way always leads to lost data, especially if there is any kind of stretch on them. In my opinion the sooner one learns to not do all of the processing in Gimp or Photoshop the better and Siril is a great tool for that. Very easy to learn as it only has a few features but extremely helpful!

Stellarium measurements can be missing completely or outdated as new data comes in. Gaia is working hard on rewriting many distance measurement so these things can change quite a bit. When i try looking up distances to galaxies in my shots i often have to resort to NED: NASA extragalactic database for any information of the target. For instance NGC 2614, a galaxy in Camelopardalis has no distance info on Stellarium or Simbad, but has one in NED: http://ned.ipac.caltech.edu/byname?objname=NGC+2614&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1

That i agree on fully, never blind trust that a setting works because "it should". In the case of your example either the tolerance was too sloppy, overlap was too little and/or rotation was ignored. The last part is definitely true, and also a mistake i have done myself. Preventable mistakes if one pays attention.

I really fail to see how platesolving can be anything but a massive time and headache saver. If guiding is already setup, clicking auto center in NINA is just a single button away. Actually 0 buttons if the sequence has auto centering on. Now of course you need to download the star database and point NINA to it but not really difficult and only done once. Think of the time saved not doing: star alignment, framing, centering, all manually and every time you set up the gear. Star alignment with an eyepiece: not that difficult, star alignment with just cameras: nightmare. I do understand the dislike for software but platesolving is one of these things that "just work" when setup.

Something not mentioned already would be platesolving, i dont think that was a thing 10 years ago (not mainstream anyway). With a guiding setup and a computer of some sort you can platesolve and auto center targets with many different software. Basically click a button and have perfect go-tos to anywhere in the sky. Never have to do star alignment again. Polar alignment can also be done with platesolving, polaris visible or not.

I doubt i would have noticed or mentioned the walking noise as a problem if you didnt point it out, it looks great! But yes more data should reduce noise nicely. Or binning, or both? The walking noise is really subtle and on its way out, i reckon 2 more hours will drown it out as long as there is enough dithering.

That thing really makes the mount look small 😅

20 seconds of backlash is pretty wild... If possible definitely have a chat with the supplier if there is something they can do as that should be fixable with a new worm, unless there are some other issues at play also.

I have one of these: https://www.amazon.co.uk/fenix-HM61R-Rechargeable-Magnetic-Headlamp/dp/B082DGTZVG/ref=sr_1_12?keywords=fenix+head+torch+hm61&qid=1638488003&sr=8-12 Impossible to break, rechargeable battery that never seems to run out and has a very low 1 lumen red light mode for astronomy that lasts 400 hours on one charge.