ONIKKINEN

2 hours ago, Astroscot2 said:

Its a very nice image, would be interested to know which focuser you have on your VX8, the focuser on my CT8 is unusable for imaging due to flexure. 

Yes, found the same to be mostly true with mine (i believe they are the same in VX and CT models). Rotating the focuser 90 degrees and adjusting tension with the locking screw helped somewhat but i replaced it in the end.

I have the baader diamond steeltrack fitted. Buttersmooth action and cant make it flex without considerable misuse and violence involved. Very satisfied with it.

The main hole for the focuser drawtube is barely large enough to fit the BDS, but i enlarged mine a few mm to make sure its not sticking to the tube. Also had to drill 4 holes to fit the thing, but not really that difficult to do.

13 minutes ago, Peter Reader said:

How can you tell collimation is off? Thanks

Stars look wonky when zoomed in really far. Maybe a bit square-ish or triangular? This shape issue is not as obvious as it could be in this shot but i am staring at pictures i have taken far too much and i pick up these issues easily.

Guiding was significantly less than half of my shot resolution in RMS so i find it hard to believe the shapes are purely from bad tracking. Could very well also be differential flexure in my guide scope but i will pretend its not as its harder to fix than collimation 😉.

The clips are not supposed to hold the mirror tightly, they are just supposed to prevent it from falling out and rattling in there.

You should be able to slide a credit card between the clips and the mirror without much resistance. If you cant, its way too tight.

18 minutes ago, Same old newbie alert said:

Looks superb to me 😊

Thanks you!

Probably my sharpest image yet, and one that i could not attempt with my previous mount at these declinations. Quite happy about the result.

120x60s from bortle 4/SQM 20.8 skies with the Rising cam OSC and my VX8. First astrophotography attempt with my new AZ-EQ6.

Mount worked much better than i hoped it would at 0.7'' RMS guiding. Some hiccups to iron out but i assume its on the guidescope attachment method and newt mechanics side rather than the mount, since stars are not as round as the guiding suggests.

Unfortunately looks like collimation is off looking at the star shapes, but still i think i captured some nice detail on the galaxies so ill include crops of each one for more comfortable viewing:

Should probably stop using the dodgy cheap 1.25 inch collimation laser that gives hit or miss results and get a better one, or just use a concenter in the dark too somehow.

1 hour ago, Sunshine said:

Literally astrophotography on ice! 

Had to handle the mount head on my knees so that i dont fumble on the ice and drop it. Who knew ice would be slippery 😲.

Its a very unwieldy shape with no clear place to hold it in your hands. Not too bad with the tripod at minimum height though as its quite low.

1 minute ago, scotty38 said:

You shouldn't have to lose much at all, just a fraction off the edges and not a great deal more than you'd probably take off anyway really.

I have considerable cone error somewhere in my scope which i have not bothered to fix yet. The tube itself is a bit crooked and the rings/plate are a bit agricultural for imaging purposes in the VX8 so both will probably have to be tended to at one point. I could probably try and shim it and make it a bit better since its so obviously off, but i try not to fix things that aren't too badly broken as to not create more problems. More in the ever growing list of things to fix and tinker with in astrophotography 😬.

13 minutes ago, scotty38 said:

@ONIKKINEN no need to worry about the rotation as star alignment will take care of that and no need for different flats, just flip and carry on……

Ah, i meant if i dont have sensor real estate to spare. I am imaging a target where i dont really want to have to crop anything off, and having rotation means some parts have to be cropped. If the target is small enough then yes i dont care about it at all.

14 hours ago, Realtimedoctor said:

More experienced members may give a better opinion. 

But if you are using a very short telescope, and nothing is going to hit your tripod legs, and no cables pulled then, the answer is as you said, you can carry on way past meridian. 

Having said that, depending on the mount you are using, some have an internal meridian limit, and will stop tracking once it hits that limit irrespective of any other factors. 

I usually image 30 mins past meridian with my 200p, but anything more than that I get into the territory of too close for comfort. Meridian flips, are quick and completely automated for me. I only align, after a meridian flip and guiding is resumed with the previous calibration ( some would disagree with this, that I should go another calibration). I only recalibrate guiding, if I switch targets. My focus is checked throughout the session, and usually I just focus after a certain degree of drop in temp, so don't bother re-focusing after flips. 

Hope that helps. 

Cheers, 

Nish 

I use NINA so the flip itself is not really an issue. Platesolving will take the scope to where it needs to be after the flip. The image rotation that will happen with the flip is something i may have to deal with manually, and that would require new flats which i would rather not take. Also would require refocusing. Takes maybe 5-10 minutes total but i was planning on staying no longer than an hour so its a chunk of time lost. I havent heard of this internal limit before on Skywatcher mounts, but i think this is a thing in Ioptron CEM mounts with their internal cable routings. I should test this with mine.

14 hours ago, Same old newbie alert said:

Most Gem have a limit on how far past the meridian they can track , then they have to flip.. the Avalon is one that can... 

I was window shopping Avalon mounts and the M-uno looked really nice with full night rotation and no flips necessary. Would have to sell a kidney for that though...

1 hour ago, Chefgage said:

If the mount allows it then no you do not need to do a meridian flip as long as nothing is getting snagged or trapped/hit.  An example is last night. I was imaging the rosette nebula with a heq5 pro and 72 ed refractor. As this target is low in the sky I was able to image 2 hours past the meridian.

I am imaging with a VX8 and an AZ-EQ6 and ended up going 1 hour past the meridian and then went home. At this point there was no extra room left and i would have had to flip soon. The AZ-EQ6 and i believe the EQ6r have the tripod legs "backwards" where 2 of the 3 legs are towards the north side unlike most models where 2 legs are on the south side. This means the legs are pretty far away and even fat long tubes like my newt dont really hit the tripod legs anytime soon.

Night was a success, clouds stayed away after showing themselves for a bit early on. Only reappeared once i started to tear down my kit. Thanks for all the well wishes, no doubt the clouds heard them and didn't dare to interfere this time 😉.

My VX8 has new legs! The AZ-EQ6 works much better than i expected from a first try, i had 0.7'' RMS total towards low declinations on the first try without much fiddling with settings or anything else. If anything the guidescope attachment to the tube is the weak link now where as it did not matter before.

Never set up a mount on thick ice before, but seems like it worked well. Just had to carve dents for the tripod legs to stop it from moving around on the ice 😅.

Very frosty and humid, but the dew shield did its job again. Some frost had creeped all the way down to the tube, but none had made it onto the secondary. Also had to prop up my power supply up as much as possible with some other equipment as it gave some low temperature warnings when directly on the ice.

May be a silly question but here goes:

Do i have to do a meridian flip if the scope isnt hitting the tripod anytime soon or anything is on risk of being snagged?

My gut says no, because why would the mount care? Could be wrong of course but just wondering.

Imaging maybe an hour past the meridian doesnt look like trouble and gives me more time with the target at its highest so its a preferable choice for me.

Some high cloud, looks like it passes soon. Even if not, had success already as the kit works well.

Mount works butter smooth. Doesnt notice me walking around it, guides well and had no hiccups in calibration or guiding assistant even though there is a bit of wind here. The EQM35 i previously struggled with would have been a no-go in this slight wind so im glad this works well.

26 minutes ago, banjaxed said:

I hope the skies stay clear for you, good luck.

Hope so too, far too often the forecast does a 180 and the session is cut short. But it is how it is in this hobby.

7 minutes ago, david_taurus83 said:

Get there early and setup before it's fully dark. AZEQ6 is a big lump to be setting up in the dark.

Not just a heavy lump, but an awkwardly shaped heavy lump. I have it in a sports bag on my shoulder and the weight seems manageable enough so its not that bad but since its very slippery outside ill need to be quite careful with that.

Last time i was out with my scope properly was in 2021 before i got the cursed virus and had to take a break. Honestly still not feeling as i was before, but its a moonless Saturday clear sky, an extreme rarity, so i will definitely not be missing this one!

Hauling my gear to a bortle 4 location today for those sweet photons, i am frantically checking every bit of gear so that i dont forget some key piece of kit. Im packing 2 of every cable, a pack of every fuse i need, 2 power supplies, tools etc...

First time trying astrophotography with a new mount (the AZ-EQ6) so i am half expecting to spend the time troubleshooting and not getting anything of value done, but that's how it goes with new gear so just gotta get it over with.

Noticed that you had included the stacked file in the post so i dont have to guess if SiriL or ASTAP gradient tools work on the file but can test them. Both of the files processed the same, in 4 simple steps. First BIN2x2 in ASTAP, then gradient removal in either ASTAP or SiriL, photometric colour calibration in SiriL, then SiriL autostretch with 1% blacks clipped. Both tools removed the gradient well, but i think the SiriL version worked better and without leaving the emptier half of the image green.

ASTAP:

SiriL:

If you're looking to improve, i would recommend trying to learn a dedicated astronomy processing software for the early part of processing which for me consists of: Background extraction (gradients), colour calibration and a stretch. These are easy to do with SiriL, a free app that is somewhat easy to use for an astronomy software. Especially the photometric colour calibration and stretching in SiriL is really painless. For stretching these images i just clicked the autostretch button and pushed the blackpoint a little bit further afterwards, so 2 clicks whereas with Photoshop manual stretching its a bit more involved. The photometric colour calibration tool checks which stars are in your image using platesolving and then tries to match your captured colours to the measured colours of the stars in some photometric star catalogue to produce the best (realest) possible colour balance in the image. After these steps you have the groundwork of the image laid out, and can then adjust every little thing how you like in photoshop. I find that i do this early processing in a few minutes with SiriL and then spend who knows how long tweaking things with masks in Photoshop.

Gradients like this will be in every shot not taken in perfect darkness. I dont know if some pristine bortle 1 location is different since have not imaged from one, but at least from bortle 4 upwards its not something you can really avoid.

There are a number of tools available for the job, some free some not. In SiriL: https://siril.org/ There is a background extraction tool that is meant to fix gradients, although for images like yours that have signal from corner to corner it is sometimes tricky to get working.

Another option would be the linear gradient removal tool in ASTAP: https://www.hnsky.org/astap.htm that i find is sometimes easier to use than the SiriL background extractor.

GradientXterminator i have found to be almost foolproof. It can remove pretty much any gradient (with some practice), but costs 60 USD so a bit pricey for a plugin with a single use. Astro pixel processor and Pixinsight have gradient removal tools too, but both are quite expensive.

I have found this to be almost unusable in cold weather = almost all the time for me.

The action freezes/gets sticky easily and it gets difficult to operate. If i try to use it with one hand it just loosens itself from its threaded connection to my coma corrector. I have to grab the body with my left hand and then unlock the clicklock lever with my right to use it. I just went back to a simple 1 screw compression ring adapter from TS.

Not recommended for folks who live in winter countries (-5 or colder maybe). Works well when warm though.

46 minutes ago, Captain Scarlet said:

It cost €300 but I think that included a “patience discount”, and no holes! I’ll be doing the perforating myself once I get the VX8 to Ireland 

Thats a very good price for what looks like a quality piece of kit. My summer break from astro is 4 months anyway so might as well order one at the end of the season.

38 minutes ago, Captain Scarlet said:

A few months ago I bought an Orion Optics VX8 from Grumpy Martian (whose account no longer seems to exist, I hope he’s OK).

Although the mirror is their ultra grade, their tube is somewhat flexible.

So this arrived today from Germany, it should be MUCH stiffer! ( @ONIKKINEN might be interested too as a further upgrade to his imaging setup)

Starting off of course with the obligatory picture-of-cardboard-box.

Cheers Magnus

Is it the helmerichs carbon tube? Looks very nice. 

How long was the wait for it? i read somewhere that the pandemic has impacted the production times for these somewhat.

1 hour ago, FiveByEagle said:

100% I do believe that was my issue on an old rig, but on this new one flats are taken after PA but before the sequence, so focus should be identical.

I started doing this because of exactly what you said.

Hows the focuser then, any wiggleroom or unwanted movement if you try to grab the camera while its attached?

Focus position is less important, as long as its close it shouldn't matter this much.

You get a ring like this when you move the camera between taking your lights and flats whether intentional or not.

Solutions to that problem: dont touch the camera before taking flats or fix the mechanical issue causing the movement. The mechanical issue i would assume to be in the focuser. I am not familiar with your scope but just looking at it online i see that the focuser looks pretty good so maybe not. Could also be some other adapter/thread or mechanical issue somewhere else in the scope. Basically your flats will only work if the entire optical train is exactly the same in your lights and flats, and if not you get these artifacts.

1 hour ago, Eruliaf said:

To the wider community - It has also been mentioned that light may be getting in at the bottom of my scope - Can anyone advise how this has been effectively prevented?

Thanks

Showercap, DIY a cap from cardboard, dustcap that fits your tube etc. 

My VX8 came with caps to both the front and back end of the tube. Doesnt have to be fancy, nobody will notice it in the dark.

Insane. I thought this was one of the least offensive hobbies out there and cant really think of any reason why someone would act like this...

Some anti-science folks perhaps? Or just good old traditional crazy.

3 hours ago, shropshire lad said:

Can I use Siril with only light frames, as this may be my problem ... I keep getting an error see below.

14:00:17: Setting CWD (Current Working Directory) to 'C:\Users\Paul Lewis\Pictures\biases'
14:00:17: Running command: convert
14:00:17: No files were found for convert
14:00:17: Error in line 25: 'convert'.
14:00:17: Exiting batch processing.
14:00:17: Setting CWD (Current Working Directory) to 'C:\Users\Paul Lewis\Pictures'
14:00:17: Script execution failed.

Paul

 

Well, the easiest solution would be to take calibration frames. Especially flats are very important, and its really not something that's optional in the long run if you want to get all the data out of your images. For some targets omitting flats is not a big deal, like when the target is small enough to only be in the center of the image but for most targets not taking flats means you will have serious trouble getting a presentable image in the end.

If you dont want to take calibration frames for some reason you can just stack without the script. Its a bit more involved but nothing you cant learn in an afternoon of playing around with it, check this tutorial out: https://siril.org/tutorials/tuto-manual/

If you follow this tutorial but dont have calibration frames, you need to skip all the parts that have anything to do with them. Without flats you will also need to skip the background extraction process, as it requires your image to be reasonably flat to have a chance of working.

Basically just:

1) convert the CR2 files to fits using the conversion tab. Click the + icon and select the images you want to include for stacking. Click "Debayer" on and give the sequence some name and press convert.

2) Register the frames (align them) in the Registration tab. Registration method can be left to Global Star Alignment (deep-sky) and Registration layer is best put to Green, as that has the highest signal to noise ratio in a colour camera. Just click Go register and Siril does its thing.

3) OPTIONAL: Use the Plot tab to inspect the frames and remove the worst ones. I would recommend doing this but its not strictly necessary. I dont have a strict rule on what quality must a frame be to include in stacking but i would just remove the clear outliers.

4) Stacking: You can leave most settings as they are and use Average stacking with rejection, Normalisation as Additive with scaling and Rejection as Winsorized Sigma Clipping with values 3 and 3.

Doing the above will stack your frames without calibration of any kind if you must do that for some reason, but i would recommend you take calibration frames as part of the normal workflow as soon as possible.