ONIKKINEN

Done and dusted, this time with rightly measured, rightly drilled to the measured places rather than someplace else. Perfect collimation and visually even looking vanes. Looks like my particular spider has a little bit unsymmetric attachment points of the vanes to the central part so may have been on a wild goose chase before with them. Have not noticed this to be an issue in the previous tube so doubt i will care in this one. I will also cover the old holes with velcro tape which i will use to attach a dew shield so nobody will ever know that i had some spider hole drilling practice 😉. Didn't lose any clear skies in the process, as have not had them for more than 5 weeks, and looks like the situation is not changing for this week either judging from the forecast of snow and warm winter weather. Only once winter really sets in with a cold front we will get clear skies here, this almost winter with barely below 0 is guaranteed full gray sky 24/7.

I dont have experience on either of the ones you had in mind, but i have an Askar OAG which i think is great value for money (and good quality otherwise). It is natively M54 and comes with threaded adapters to M48 and M42 for both the scope and camera side so you can fit it to almost any scope without extra kit. This one has a 10x10 prism, so a little bit smaller than the 12x12 on the 2 bigger ones. But on the topic of that, for your 290MM you definitely will not need to have a bigger prism and the 10x10 is plenty enough. Not so sure about the 174MM though as the sensor is a lot larger, but you might be surprised how many stars even the small sensor will pick up. While i dont image at 2m focal length so its not an exact comparison, i think its somewhat close. I am imaging with 1025mm focal length and 200mm aperture with a 120MM using just 3s exposures. So far i have never come across a situation where there aren't at least 5 suitable guide stars in the tiny little sensor with this short exposure. The 290MM is more sensitive, but has smaller pixels so i think it evens out in terms of usable sensitivity. I would be very surprised if you have trouble finding a guide star with the 290MM with sensible exposure times. The bigger ones are probably a safer bet if you do intend to buy the 174MM but thats a fair chunk of cash so you may want to think about that and try with the 290 first.

Yes i remember that, i was dreading the (w)hole process fearing i would somehow fumble with the big hole. I was almost neurotically obsessed with getting that right so must have spent all my available focus on that and somehow let go of the brain after i was done with it. I also see what you mean when you mentioned back that the tube is rigid, i am sure i could drill 10 focuser holes in it and would not notice a change in rigidity, this thing is ridiculously sturdy.

Pipe installment practice run in the end. I will definitely redrill the holes, looks like i also did not do them symmetrically enough and the spider has trouble having straight vanes because of that. 9mm instead of 8mm holes this time to give some adjustment room, and also this time to the correct place 😉.

Or drill once, as i did just now drilling holes in a helmerichs carbon tube where i will place all of my current VX8 to complete the un-VX-ing operation of the scope. I measured the holes in the correct places, twice, as the saying goes. Then just drilled them, piece of cake. Drilled the holes nicely too, not much scruff and bite on the easily biteable carbon tube so everything is clean looking. Just one problem though, even though i had measured the correct locations of all the holes i drilled 2cm away from them for the secondary spider so now the secondary mirror cant get fully under the focuser to be illuminated correctly 🤪. Collimation is still possible but one side of my APS-C sized camera sensor receives 15% less light and under the stars there will most likely be awful tilt issues with star sizes. So measure twice and cut once, but remember to cut where you measured instead of next to it 🤣. Thankfully not a huge disaster, just have to find or make my own collimation screws that are long enough to hold the secondary mirror further away. Thing is i already had quite long 45mm M4 screws as the VX8 had a similarly (almost as) far away drilled spider holes. This was one of the things i wanted to fix with the new tube, but for some reason i forgot that and actually made the thing worse. May have to drill new holes and call the earlier ones practice holes.

Hmm, maybe, but not qualified to say as have not owned a RASA type scope before. But the aberration itself looks familiar as failed newtonian flats also looked like that but its been a number of years since mine failed so bad as to cause that as i have fixed most of the issues. But when i was taking flats the next day or used previous flats they looked like that with a bright ring and some weird things going on on some of the corners. Is it possible something mechanical has failed like mirror locks, focusers etc? Probably not as the RASA11 is not exactly entry level kit and one would hope its mechanically stable.

Did not find the galaxy, but IFN pops up in a cropped field of view with a very heavy stretch so safe to say the exposure is already quite deep and the galaxy is seriously elusive: By the way, there is loads and loads of IFN and background galaxy stuff in the image for just 3.5 hours. In case you decide to sacrifice a couple more nights to it you'll get a killer IFN image out of it for sure, even if the galaxy stays hidden somewhere. Cropped feature from middle of the flat calibration ring artifact thingy (was easier to process the flaws out when cropped): Never had a chance to play with a full frame RASA 11 shot so this was an experience, thank you for sharing!

Taking a quick look on the file just out of curiosity and to my eye it looks like you do have IFN, but it appears to be at the edge of your flat calibration artifacts (the ring). Right in the middle of the the bright flat ring are wispy somethings that i believe would be IFN. Its in pretty much the worst location from a gradient removal perspective but i think its workable with some careful gradient work.

Dont need a 14" scope for that, my 8 inch shows clearly separated RGB rings with Saturn at 10-14 degrees. My 90mm, almost does it too, there i can see that there is clear extra fuzz on both sides but its not an obvious separation like in the 200mm.

That tool is hardly usable, best not to give it much thought. If you must use the tool, aim for the lowest resolution it suggests as the higher estimates are pure fantasy and not really possible to achieve for most imagers. But the critical sampling thing i mentioned is only applicable in lucky imaging applications, so planetary, lunar, solar where we use exposures fast enough to freeze the seeing and hope that some of the frames are sharp. And maybe dont stop down the scope, while its true you could manipulate your f/ratio like that, its going the wrong way with it. Use of a barlow is what will get you to the ideal ratio. With your mak you will not need a barlow with that camera by the way, when doing lucky imaging that is (or with DSO definitely).

First of all, warm welcome to the lounge! Then, i would say you need to take a step back and figure out your total budget for everything required to do what you want to do, that is mount, scope, scope corrector (most scopes need some kind of corrector at around 200-500USD) scope related accessories, camera, camera control accessories, dew control accessories, mount control accessories, etc. Write "astrophotography" on the side of a bucket and start throwing money in it. Dont stop for 3 years. Maybe now you have all you want, maybe not, thing is you will spend 3x what you thought was the "max" you might have spent at first. Its very easy to overlook the extra spending needed to do AP. What kind of imaging is it that you want to do? 127mm Triplet is hardly entry level and you will find that there are many scopes that do the entry level stuff for half the price, just depending on what exactly you want to do. And i would not do imaging with an AVX, at least not with a serious scope like this. The more realistic imaging limit for a mount is 50% of the stated manufacturer limit, so you would be severely undermounted with a fully equipped 127mm triplet with the AVX. With that scope i would recommend no less than an EQ6, and even that will not be "trouble free".

If we follow the ideal sampling formula for broadband captures of: f_ratio= pixelsize in microns x 4 (for 500nm light). Most or all of the modern sensors will do the trick excellently or just plain well. Some will do the trick without a barlow. What f/ratio of scope do you have? All of the new ones are top tier if matched with a suitable scope, and almost all of them can be matched. Only outlier is the 678MC with its tiny 2micron pixels, which means an ideal scope is f/8-f/10 (preferably closer to f/8).

Problem is, almost all telescope systems will have a mirror or 2, or 3 in them. So the average guy looking through a telescope is just as likely to have a different experience as the next one with another system; hence the RA and DEC coordinates used in real measurements and not left and rightedness that are rather subjective and useless. But i get what you mean, some are more right than others if we were to compare to naked eye orientation.

Its all relative and subjective in space where there is no real up or down and really even left and right carry little meaning IMO. Whatever composure makes the best image is the "right" way to take the image. Up to the imager to choose that orientation of course.

Since i work evenings and wake up no earlier than 13:00 each day, the sun has set permanently for this year many months ago. Doubt i will see the sun at observable altitudes before March! It would be funny if it wasnt somewhat sad, but we have a day for the grayest day of the year: https://www.originallongdrink.com/en/history/2010/the-greyest-day-of-the-year/ By an alcohol company of course, because what else is there to do in November . The celebrations have sadly lasted all of november, and according to the forecast, will be lasting throughout most of December. Astronomy is a terrible choice of a hobby for someone in the nordics.

If you take just one filter then Winjupos derotation will be optional with sensible recording lengths. Its just that if you take 4x 3min recordings it will be necessary as Jupiter will have moved on (3 minutes is a good length for Jupiter). since you have a USB2 camera the framerates will likely be under 100, so you will have smaller files, but still gigabytes per 3 min. Stacking for planetary/lunar/solar is best done with Autostakkert!3 and then processing in Registax6 with wavelet sharpening. Registax6 stacking cant keep up with AS!3, so not recommended for stacking. PIPP preprocessing is not always necessary, like when the recording wasnt jumpy and the target was centered all the time, up to you whether you want to do that or not, i usually dont bother. Orion and Pleiades wll both likely benefit from thr L-Pro under your skies (Orion definitely will) so keep it in. If you try a galaxy like M31/M33 its not so clear whether there is a benefit as they are broad spectrum targets kind of like the white LEDs.

L-Pro for planetary will not be useful, in fact it will hurt quite a bit since it blocks much of the light you need, so definitely dont use it for planetary. Since you have a mono camera to do planetary with you will need 4 filters to get a colour image out in the end, a luminance filter which is basically just blocking UV and IR wavelengths, a red filter, a green filter, and a blue filter. Not sure what the best way to work with this is since i do planetary with an OSC camera that takes all the colours at the same time, but if i have understood it correctly you would be shooting these filters back to back and then derotating them in Winjupos to match eachother as Jupiter (assuming you want to image Jupiter) rotates quite fast and you will definitely have some discrepancy between the last filter to the first one. You could also just shoot luminance and get a mono image out in the end, much simpler but up to you if you like mono images or not. As for data size, that seems very small, like a single short clip. Tens or hundreds of gigabytes per night are easy to come by with planetary and single video clips are often 10+ GB. You should be shooting in RAW 8 with the file format set to .SER so that there is no data compression, also use ROI to limit the frame size to be just barely larger than the planet to limit the file sizes in the end. Still they will be several gigabytes per recording. Here it largely depends on if yours is USB3 or USB2 as framerates will dictate how large a single video file is across a period of time. The 120MM-S is USB3 i believe, and the mini version just named 120MM is USB2 and will have much lower framerates, so also smaller files. As for if the L-Pro is useful for DSO, i would say depends on the target and how much light pollution you have. For galaxies, little effect, maybe a tiny little bit better. For emission targets it will isolate the emission lines a little bit better and block some unwanted light. The L-Pro blocks high pressure sodium type lamps (old yellow ones), but does almost nothing to newer LED type lamps that radiate across the spectrum (so there is no emission line to block). So if you have a lot of the old yellow ones around, it will block some light pollution but not as much of the target = SNR increases, if you have LED lights around, it will block the LED lights as much as the target = SNR does not increase but you will have less signal as some was blocked. If i were in a bortle 6 zone or better i probably would not bother with the L-Pro with galaxies, but would maybe use it for emission nebulae or primarily blue reflection nebulae (pleiades for example, maybe the Iris too).

Here: https://nighttime-imaging.eu/docs/master/site/quickstart/uioverview/

True, but you can use 3-star alignment as a polar alignment method since it will tell you your error after the third star is aligned. I think OP was trying to do that in this case. You have to do that several times to get it anywhere near aligned, but its doable for situations where Polaris is not visible.

Dont worry about tripod leveling, it has 0 impact on any of this, unless you are setting up on a clear incline of 10 degrees or more. And in that case you could still polar align perfectly too, its just a tiny bit more tedious as adjusting altitude will also affect azimuth and vice versa so you have to fiddle. Forget the spirit levels and just eyeball the leveling to be ok. If Polaris was outside the circle it means you were not polar aligned. When aligned Polaris should be on the circle (never in the center) no matter what orientation of RA you are in. I should note that the polar scope must be collimated for it to work since Skywatcher mounts are assembled with little care and they come out of the factory out of collimation. Why the software method didnt work, couldnt tell you. You would need to keep doing the 3 star alignments to find out how much further adjustments are needed. Keep in mind that large amounts of cone error will complicate this step and its possible you are on a wild goose chase. I would advice to do the manual polar alignment through the polar scope instead of the 3-star alignment. Then do 3-star and ignore what the mount thinks your errors are.

Between that and an L-enhance, looks like: High pressure sodium lamp suppression is of little use these days since more and more of them get replaced by broad spectrum LEDs (might even be 50/50 now here). Maybe better to think of the Antlia one as a wider pass narrowband + blue filter instead of a light pollution one.

Could be designed to be folded into a similar sized package as JWST since the individual mirror segments are still very small. More complex no doubt but the current space origami team might feel confident about it since Webb worked out so well.

New(?) filter from Antlia caught my eye when doing some window shopping for kit that i definitely dont need, but maybe could find a use for. Does this have a use or is it dead on arrival? This one: https://www.firstlightoptics.com/antlia-filters/antlia-triband-rgb-ultra-filter.html Bandpass: Here is why i think it could be useful: Wide bandpass so presumably exposure times are still more or less normal and not narrowband length, something that i need to keep in mind with a newtonian under typically at least somewhat windy skies with a hiccup every now and then guaranteed in guiding. With an OSC camera like the one i shoot with i could easily just extract the greens for OIII and the reds for Ha-SII. I dont expect SII to contribute much here, but still its there. Blue would be extracted more or less as normal blue would and this i would just throw in with the rest of my blue data so its not "lost" like maybe with typical dual pass filters its not contributing nearly as much, and since blue in the IMX571 is quite weak its a welcome addition to get more blue data. I would not use this filter entirely, but perhaps try to get 10h of UV/IR and ? hours of this filter (remains to be seen how much would be needed to get some meaningful emission data). The existence of the blue pass here also means its a lot easier to work into a normal real colour image, unlike just OIII and Ha which is guaranteed to not be presentable as real colour, at least thats what the gimmick of this filter seems to be. I would initially use it to shoot OIII and Ha on M33 and M31, maybe M101 later in the season (this list is already 2 full imaging years long..). Dont really plan on shooting emission nebulae so im not all that stressed about the very wide bandpasses that would for sure be less than ideal for some dim supernova remnant hunting. The filter seems like a bit of a gimmick, but an attractive gimmick at that. Maybe a good old L-enhance/Extreme/Ultimate would be better still. Any thoughts?

That sounds like its running on USB2 speeds. Double check that no USB speed limiters are active in the capture software? Even an older HDD will keep up with such a small ROI so dont think that is the issue.

I would not worry about the big pixels for DSO work, in fact they are helpful for almost all setups as big pixels gather more light than small ones so the whole process of imaging goes by faster (in terms of how long a subexposure needs to be and partially how long an exposure is long enough in total). 14MP is still a very high resolution image for astronomy work, and unless you have excellent seeing night after night and a mount that guides your large aperture scope flawlessly, you are going to be oversampled even with that. For comparison i bin x2 to 7.52 micron pixel size or x3 to 11.28 micron pixel size with a 200mm scope guided reasonably well on an AZ-EQ6, so you definitely dont need to worry about 5 micron pixels being too big.