ONIKKINEN

Whatsapp also is guilty of gutting images sent through it, which is why sending it as a link to somewhere its already posted or attaching it as a file is the way to go. I tried to compress images myself to see if there is a point where whatsapp agrees to send it as is but as far as i know there is none and the image always goes through some rough cuts.

27 minutes ago, Iem1 said:

Ah well, I was going to take my EQ6 R Pro out for first light last night now that my battery has arrived, but I would have to carry it from my flat, down the road and then up a winding 100m Elevation hill to escape the worst of bortle 5 LP. I got suited and booted, had around 30 KG - 35 KG of equipment in my rucksack on my back, the 7.5 KG tripod in one hand and my telescope case in the other, I made it down one flight of stairs and thought "This isn't going to work..."

I consider myself somewhat fit, 27 year old guy (but only 65KG myself) but I think I'd have been calling the coast guard for assistance if I had tried it

I find this pretty funny as i do some of this (not the hill, but 6th floor and elevator is kinda dangerous) when i escape TO a B6 or 5 zone from where i live 😀. You get used to it. Or do i just tell that to myself? Who knows.

3 hours ago, alacant said:

I think any assessment of tilt needs to assume the integrity of the mechanical and optical components. Only then can you begin to fine tune focuser, secondary and camera mechanics.

Agreed, too many variables in play to point towards a clear problem. Ill see what i can find from the hardware store to beef up my current kit somehow. Rather not spend a fortune on this right now.

6 hours ago, alacant said:

Does the cc have an undercut?

Does not. Smoothbore 2'' barrel, fits the focuser very snugly.

7 minutes ago, rickwayne said:

I am famously bad at visualizing geometry, but if I understand you correctly, you haven't ruled out tilt in any part of your system. I take it that it's not possible to rotate just the camera, even just a little? That would be my first try.  Next up would be an attempt to simplify the imaging train as much as possible -- eliminate the corrector and filters, and attach the camera as directly as possible to the telescope.

Are all your connections threaded?  What happens when you take the image train "as is" and point to different parts of the sky? Can you induce or change the tilt  with gentle pressure  on the camera?

Im gonna be honest and say that i was a few cans too deep into a case of beer at the time of posting and im not sure what my point was or if there even was one, other than tilts exists somewhere in the system 😅. Im sure there was a train of thought going through my mind when posting but i couldn't tell you what that was now.

Connections are threaded as far as they can be, with a 3-point compression ring connection between the CC body and the focuser, which is a Baader diamond steeltrack. I dont see a difference in apparent collimation with removing the collimator and placing it back in, trying to find out if the connection is sloppy.

If i understand my own post right, i made the conclusion that the CC would be somehow to blame, but since it moves with the camera when rotating the imaging train, the tilt should travel with it as well. And seeing as the bad corner has traveled 90 and not stayed in the top left corner of the sensor, the tilt is something before the imaging train (collimation). Of course its possible the CC is miscollimated too and i would have to collimate trough it to get the best result, but i think most of the tilt is in collimation. I did a little test by punching the OTA (lightly) with a laser attached to the CC and it did move a bit every time, erratically. The OTA itself is very thin and soft aluminium in the VX8, so i have reason to believe that might be part of the issue.

The effect is most apparent in stretched and rainbow rendered flats below:

In this view reds represent the brightest pixels and purples the coldest. The bright spot doesn't stay in the same spot over the sensor when the imaging train is rotated so id say its just my collimation is out of whack.

Picture 1 is at 90 degree orientation, picture 2 at 0.

Both images are from different sessions, and so have different collimations, although both are collimated via the same method to the best of my ability using a cheap 1.25 inch laser collimator (that i have collimated myself) NOT through the coma corrector, but i am 100% certain it was "right" on both cases. in the first issue the tilt is to the top left of the frame, on the second image that is rotated 90 degrees to the left it is to the bottom left, as i would expect if it was not sensor related. Rotating the camera involves me rotating the entire imaging train, which consists of a filter, the coma corrector, some adapters, and the camera. Am i right in saying that the tilt in my system is located in some place other than the sensor using the above information? I feel like this is a simple question and i should know the answer, but im no expert and am proven wrong left and right.

If the tilt is not in the imaging train, it must be in the scope am i right? That leaves just collimation with my newtonian as the culprit. But here is the issue, i have my imaging train intact when using my scope, so i collimate without the coma corrector. I have a 2'' to 1.25'' adapter where i put my trued cheap laser into and i confirm the colimation each time i use the scope (because all of my imaging is at darksites, so bumpy roads etc will guarantee the scopes needs checking). I think this is due to my coma corrector itself being miscollimated? Sounds reasonable? Just guessing. I cant be certain because it involves removing equipment but im pretty sure i have different collimations with the CC and without.

Easy solution: Collimate through the coma corrector. This step is not what i want to do as it has me unscrewing and screwing out equipment each time i want to use my scope. Rather have a solution without.

??-difficulty solution: Try to un-mess the CC alignment, if it is even possible. Or some other method. Feel free to suggest if you have one in mind.

12 minutes ago, Adreneline said:

Great star colour and definition. Cluster, open or globular, are the hardest objects to image in my opinion. You've done a great job with beautiful object.

 

Thanks for the feedback. I think applying just the right amount of saturation before things get "crunchy" is key to get different star colours nicely balanced. I think the diffraction spikes of my newtonian also work with me in this, nicely spreading out the colours where applicable.

60x30s exposures with my VX8 and Rising cam IMX571OSC, binned 2x2.

Took this while waiting for my main target Abell 1656 (coma cluster) to rise above a treeline, but that data ended up being quite cursed for a multitude of reasons so time will tell if that picture ever gets finished, but probably not this year.

I like the contrast of different star types in this cluster, the bright blue (stellar blue that is) B-type stars, and the few noticeably differently coloured A, F and G-type whiter stars along with the few M-type stars that have made it to the end of their lives and will soon blow up or wither away as white dwarfs.

31 minutes ago, blinky said:

Thanks for the comments, yeah I was thinking about a double process then maybe try and blend the galaxies back in

Have a go with starnet++V2, would be relatively simple to process the galaxies, stars and IFN separately with some layer trickery.

I would be happy with the capture itself though since IFN is such a pain to capture with a reasonable integration. So maybe some tweaks but the picture still looks good.

Quick look at the Moon with my 7x50 Nikon Aculon binoculars. Always surprising how much the little binos can show of the Moon with so little magnification. Plenty of craters and little nooks and crannies around the terminator.

Of course looked at the other bino targets too: Pleiades, double cluster, Orion, smudge of M31 close to setting. Cant find other galaxies with the Moon still up. Will wait and see if skies are still open once the Moon sets.

I hear you. This is what 100% clear skies look like according to clear outside, good to stargaze, windy.com and others:

Ah well gotta use what we can when we can. Would go even crazier if i only used the actual clear nights...

The Astronomy.tools CCD calculator is hardly helpful with what it considers good sampling rate for a given system. Its best to think of the higher estimate as the better choice than the lower one. For example the higher estimate of 2'' per pixel is perfectly fine for my 8''  scope, but the lower estimate of 0.67'' is without a shadow of a doubt oversampled. I would have to live on a mountaintop, or a desert, or better yet a desert mountaintop to be able to sample at this rate and not oversample. Guiding would also have to be epic for this to work. By binning 2x2 you get a very reasonable resolution with your scope and camera combo.

But for the mount question i think the EQ6 would do just fine with the 200PDS. I have an AZEQ6 and have no major complaints with my 8'' F4.5 newt. It can be a little bit windy and will work just fine, but if there are sudden strong gusts it can still be problematic, but that's just how it is with long scopes, especially newtonians. So far i have gotten 0.7'' and 0.65'' RMS guiding in mild wind and less than great seeing with mine guided by a 60mm F4 guidescope.

Whether the L-pro is worth it depends on a few things IMO.

Level of light pollution and type of target you have in mind. Also, whether you want to have a real colour result in the end, or make it easier for yourself to get one. Using a light pollution filter will make it very difficult (impossible for most) to get a real colour result in the end because you have blocked a part of the visible spectrum during capture.

If your sky conditions are very bad, like lets say bortle 8 inner city skies then yes you may want to use one, but in conditions better than this maybe not and even in these conditions also maybe not. Broadband targets, like galaxies benefit very little or not at all from a filter like the L-pro, because light pollution and galaxy light shares the same spectrum so by blocking light pollution you also block starlight coming from the galaxy. For emission nebulae it would work just fine, because emission nebulae have 2 major emission lines that produce most of the signal imagers are interested in: Oxygen 3 and Hydrogen alpha. Neither are effected by the L-pro and here there are only positives when using one. But for emission nebulae there exist much better filters than the L-pro, like the L-enhance and the L-extreme. So personally i would not be using the L-pro in pretty much any situation. When imaging galaxies, better without, when imaging emission nebulae, better with another filter.

Perhaps its best to start without the filter as its not really necessary or wanted for some cases.

For the 550D you will probably want to install the 3rd party firmware package called "Magic lantern" https://magiclantern.fm . It expands the Canon limitations for many parts and unlocks features such as an intervalometer, improved focus detection (works actually decently for astro too), more freedom on shutter and ISO settings, more video shooting modes (if you want to do planetary/Lunar). Do keep in mind though that its still 3rd party and something might go wrong. I personally had a few hard crashes where i needed to reset the software. These happened when playing around video capture FPS which the firmware warns you about so not unexpected.

12 minutes ago, 900SL said:

When I'm not in Saudi I live in Lauttasaari, Onikkinen. I'm hoping to find some dark sky sites when I get back later in the year, and Ive lived there long enough to get the Finn thing about not interacting

To be honest im still looking for decent spots myself... The Helsinki light dome extends much further out than one would expect from its population. There is one reasonably close spot with decent skies in Porkkalanniemi to the southwest of Helsinki. Its barely outside the light dome and every direction except north east is decent with bortle 4 skies. The place is often quite windy though and requires a sturdy mount to make imaging possible. For skies better than this im not sure which direction i would drive. Probably north a couple of hours, but no such places that i have found closer than this kind of drive away.

You can check Finnish stargazing spots looking at this map: https://www.taivaanvahti.fi/locations/browse/map

Porkkalanniemi is the lone spot to the south of Kirkkonummi on the map. Accessible by car (its a parking lot) and not too far away. There can be some traffic during normal waking hours, but usually after midnight its quiet. Some folks also know its a stargazing spot and turn of their car headlights once they get close and see there is a guy with a scope.

I have only had a handful of experiences with other people whilst out with my scope and most of them dont care or know what im doing. Most also dont approach and just sort of glimpse from a distance for a few seconds before moving on, but i think that's a Finnish personality issue rather than a hobby issue 😅.

This one lady stopped by with her car once and asked if there is a good place nearby to try and image the northern lights from (was forecasted that night) and asked what i was doing and i just answered oh im imaging this pair of galaxies in Ursa major (M81-M82) and pointed upwards to where it is. I would have loved to explain everything because talking astronomy with strangers is such a rarity, but she just sort of looked at me confused and didn't say anything? She then just said oh well thanks for the help and drove off to where i recommended a better place would be.

The one time a person has actually come to talk more about what im doing was pretty nice though. They were curious as to what im doing and asked what the giant tube is and how it works (newtonian). They were surprised to see that you dont look through it from the behind and generally didn't seem to understand how the scope works. Newtonians look really strange to people who are not in the hobby it seems, but anyway ended up looking at the Moon at 200x while it was setting. Wasn't the best view i have had, but im pretty sure it was the best view this guy had seen.

Friends and family also dont seem to care or understand that much. If i show some half-acquaintance from work what i have imaged 50% of the time they just straight up dont believe me and think its impossible to image these things without NASA equipment.

This hobby really is quite niche and underground it seems.

I like the legacy sky survey viewer: https://www.legacysurvey.org/viewer

It has many different catalogues to choose from like several optical surveys, some IR, some H-alpha, some dustmaps etc. Hunting IFN imaging targets with this is a piece of cake.

5 hours ago, CCD-Freak said:

Waiting for the stars to come out.....

AP900 / SS15028HNT on new "Texas Style" Todmorden pier at SRO.

The pier will be getting a nice white coat of paint during my next visit.

Is this setup balanceable in DEC? Your mount probably handles it fine either way though.

Last session from somewhat poor skies:

The mount and scope lit up by my flat panel, various bits of electronics and the background skyglow. On the ground is my tablet connected to the scopeside headless mini-pc that i use to control everything.

Thought it looked cool with the different light sources. Its not sunrise on the horizon by the way, just the way it is in this location...

1 hour ago, AmritNZ said:

yikes thats scary. glad it hasn't come back but sometimes those are more annoying because worried it'll come back randomly at a bad time.wonder if there is some buffer issue with shorter exposures that resolved after reboot. didnt realise the recommendation is less than 80% humidity? living in Auckland (NZ), that is simply not going to happen ever lol our average annualy is closer to 90% and some nights 100%

1 hour ago, Astro Geezer said:

That alone speaks volumes. At around my budget mark, the 533 is looking good (although the 414ex still has the best FOV I'm after)

You can just crop the image in the end so you lose nothing by having a bigger sensor area, so dont choose the camera just because you want a zoomed in view.

29 minutes ago, Astro Geezer said:

Thanks for that.

I'm not tied to ZWO so would be open to other brands using the same sensor...

For some reason I've been very wary of binning. Are there any implications regarding binning? I tried binning while taking exposures and although the sensitivity massively increased, I was horrified to see the images turned out mono 😃 so I'm presuming binning afterwards loses any extra sensitivity and just creates bigger pixels.

I've seen the 174 sensor seems well suited (correct me if I'm wrong) but the ZWO isn't cooled, however the QHY version is. The 294 is definitely too big as I'd like to image smaller galaxies such as M109. So would the 533 be a good match for an RC6? I guess I'd at least be able to use it with my Evostar 72ed as well as a bonus?

Thanks again

Binning during capture can have weird effects if the software doing the binning doesn't treat the camera as a colour sensor with a bayer matrix, and in these cases the colour information is lost. I do know that with my camera i have not found a software yet that loses the colour information and binning works as intended (tried RisingSky, NINA, Sharpcap). But with CMOS sensors you dont have to bin during capture and its actually better to not bin during capture. Leaving the binning process for post processing leaves you with the ability to choose the required binning level depending on the conditions and the quality of data you gathered. With the 3.76 micron pixelsize cameras (533/2600/variants) you would probably be choosing between 2x2 and 3x3 binning depending on the data. The easiest way to bin colour images is to bin the image after you have stacked it (before other processing). That is just a couple of clicks with apps like ASTAP. You can also bin the raw subs, or calibrated subs and then stack but that is a couple clicks more (still not that difficult). I would say dont worry about how to bin for now, there are many options and none of them impossible.

The 174 would still definitely need to be binned with its resolution of 0.88'' per pixel. Really at focal lengths over 1000mm hardly any camera will work unbinned in usual conditions.

You can also not bin and shoot oversampled, but you will get a worse signal to noise ratio result and not capture any extra detail in the end. Oversampling in simple terms makes your scope "slower" like it would have a smaller aperture than it really has.

29 minutes ago, Same old newbie alert said:

Old tech is just as capable as it always was, did the skies change, if read noise is so significant why does a ccd produce cleaner subs,without the need for calibration..

True, its just a small detail in the growing list of tech jargon advertised with cameras, but less read noise is just straight up better than more read noise, no contest around it (given equal specs otherwise). If the mount does not play along nicely the long subs required with high read noise cameras could be a deal breaker, but probably not in many cases.

I think the age of saying that CCD subs are cleaner are well in the past. The backlit sony sensor cameras, like the IMX571 variants produce clean 16bit images with no jumping through hoops required in calibration for 10-30% of the read noise in CCD cameras.

Do you have a budget in mind? I have a few models in mind but greatly dependent on budget.

The 294mc is a capable camera, but one that requires careful calibration as it suffers from amp glow and some other quirks but there are many users of the thing and these issues are solvable with proper methods so dont let it affect your decision making. The 533MC has newer tech and is pretty much completely trouble free in terms of calibration and issues, and would have a small sensor, if you want to have one for some reason but you also could just crop the final image to the size you want?

A bit more expensive but an excellent camera would be the 2600MC, or one of its variants. If you dont have an ASIAIR pro and dont need to use ZWO products because of it, you could get the RisingCam version of the 2600MC (well not the version of the same camera, but a camera with the same sensor) from aliexpress: https://www.aliexpress.com/item/4001359313736.html?spm=a2g0o.productlist.0.0.6f047164JGhOx6&algo_pvid=88c7fc7f-59b2-4b58-9bdc-a75b08237944&algo_exp_id=88c7fc7f-59b2-4b58-9bdc-a75b08237944-0

Many users of this camera in this forum and elsewhere as well (including me) and from what i can gather its liked and trusted by its users.

All of these cameras would need to be binned at least 2x2 or have their sampling rate reduced otherwise (like superpixel debayering) to reach a more reasonable imaging resolution. Dont sweat this part too much, you can do it in post processing with several different methods, some more easy than others.

19 minutes ago, Astro Geezer said:

The Asi 294mc pro looked like a good fit on the Astronomy tools calculator but the chip size isn't small enough. The Atik 414ex looks a good fit on there too but is CCD technology old hat now?

The Astronomy tools calculator is quite vague in how it describes suitable sampling rates and its suggestions on sampling rates are all over the place. Imaging at less than 1'' per pixel seems like a complete dream to me from personal experience. From thousands of subs i have taken with a 200mm aperture scope not a single one of them could have benefited from such a resolution even though the tool suggests a resolution of 0.67''-2'' for average seeing conditions. Its better to think of the higher end of the suggested range as the resolution to go for rather than the lower.

Unless you find some old CCD camera like the 414EX for dirt cheap, its probably best to skip them as they are indeed quite old tech by now. The 294 and 533/2600 (same sensor tech) have higher QE and lower read noise, so you quite literally get more done in the same amount of time. Read noise especially can be 5 times higher in older CCD cameras compared to these new CMOS ones.

120 x 60s from less than ideal conditions with my VX8. The location is usually better, but transparency was not great this time. Seeing was also not great, hence some processing decisions made.

Calibration and stacking in SiriL, BIN 3x3 in ASTAP, linear processing in SiriL, fiddling with Photoshop and Starnet++V2. Think it turned out half decent considering only 2 hours from a target i previously felt like required much longer.

I have done one mosaic project, on M31. I used Astro pixel processor to do the mosaicing work and it worked quite well outside some minor issues with some panel edges being perhaps more visible than i would have liked, but then again the data i fed it was not great and taken under significant light pollution. In the end it wasn't a big deal and some spot healing brush and other fiddling got rid of the few issues afterwards. APP takes forever and a half to do the processing though, i had to leave it running overnight on a pretty capable desktop PC because it took so long.

APP has a trial period that is free and has no limitations on how to use it.

Had my first issue with the camera that resulted in some real head scratching and worrying on my last session: I was focusing with 2s exposures with gain 251 as i normally do and some alarming artifacts appeared. There were horizontal rows of completely dead pixels that randomly changed locations in each frame, but each frame had these. I estimate around 20% of all the pixel rows were dead in each of the frames effected. It appeared as i was still cooling the camera and didn't go away by itself once at -10c (8% cooler power lol). I disconnected and reconnected the camera in NINA, but the artifacts remained. Then i did the good old "have you tried turning it off and on again" by pulling the power plug and it went away and didn't come back again.

I had NINA in loop exposures mode but no frame saving so unfortunately cant show what it looked like now, and cant reproduce it. Since i cant reproduce it and it went away, im not super worried. But since i have not read of something like this happening it does concern me a bit. I should note that software hiccups and electronics temper tantrums are sort of expected for me since i use the camera almost exclusively in high humidity (85%+) and low temperature environments where the camera is not meant to be operated. But if i use the camera in its adviced less than 80% humidity type weather i would still be waiting for that first light 👍.

Drop the barlow, it only makes things worse for you. The target is emitting the same amount of light all the time, but with a barlow you are spreading this light thinner, over too many pixels and so thee frame looks darker. What looks darker (and is) would also be the target itself. Without the barlow you are shooting at 1.5'' per pixel resolution, which is pretty well matched. With the 2x barlow you are shooting at 0.75'' per pixel which is definitely without a shadow of doubt oversampled and not helpful. When you are oversampling you reduce the speed of the system by spreading light over too many pixels but dont actually capture extra detail from the object even if the resolution seems greater. The second stack looking noisier and worse is to be expected, unless you spend 4x the amount of time capturing it comparing to the no barlow one.

This sort of differential brightness during the night is not that strange, although ideally you would get rid of the outlier subs when stacking. You can have high cloud that is not visible to the naked eye and it will look like the image got a bit brighter, but lost some of the faintest stars. Since you have local light pollution it could also be that at some points during the night your scope is pointing closer to a local light source than others. Subs can also get darker during the night as the target rises higher, and so you shoot trough less atmosphere. There is a dramatic difference in light polluted skies between shooting lets say 35 and 70 degrees above the horizon. Some street lights and yard lights can also be automated to shut down at some point of the night, so the amount of light pollution is reduced. The darkest subs in your session are the ones least affected by your conditions, so would be the best. Subs getting darker as the night goes on is a good thing.

ISO speed and noise have some misconceptions around it, increasing your ISO will lower your read noise, not increase it. That said, there is a point of diminishing returns for most cameras where it makes little sense to keep increasing ISO. Dont have a 500D myself, but from what i have read the astrophotography recommended ISO would be 1600. You definitely also dont need to be taking 8 minute subs. 1 or 2 minute subs will do just fine (without the barlow that is. With barlow, dont expose and take the barlow out), even shorter if you have lots of light pollution. If your histogram is not touching the left edge the subexposure is long enough, no special trick to it. If your histogram is getting close to the right edge you would be clipping data, so best to avoid subs this long.