teoria_del_big_bang

Personaly I would not buy a power supply off Amazon for my Astro Gear. That's not to say there is anything wrong with Amazon, or that they do not have some good power supplies but I think you just really do not know what your getting unless its a known make. The supply you are looking at may be great bit it also may be crap. Okay if it is faulty then Amazon I have no doubt will replace the supply or refund your £25 but if it damages any of your equipment then it will be you who has to pay.
I would stick to something off FLO or RVO or other Astro site (what I would do anyway).

The fact it is not fully enclosed (it has vents in the casing) means at the very least it needs housing inside a waterproof housing that is considerably bigger than the supply to allow good air circulation around it and cables glanding out to keep moisture out. Personally I would stay clear.

Just be careful with any mains equipment outdoors, generally 240V power supplies are not really intended for outdoor use.
Most of us do use mains when in backyard but need to be careful and confident of what we are using.

Steve

Just now, Stuart1971 said:

Both using windows…👍🏼

You should be able to do it over the network then.

Remote File Transfer During Windows RDP Sessions

Personally I find it easier using Teamviewer but also do it over the network using RDP from a RPi on my mount, I find it quicker than downloading to a USB stick and then uploading again on my laptop.

Steve

Hi Stuart, Is the mini PC running Linux and the desktop Windows ?

Steve

Thanks Dave, I like that, colours closer to what I would like and I think shows the detail in the Ha 🙂 

It is not actually too different from what I did at the end of mine to change the redness of the Flame using GAME to create a mask so I should be abe to follow that okay.

Steve

Well here is version 1 🙂 

I was really pleased during most of the processing but not really happy with the end result, don't get me wrong I still think it is the best image I have produced so far (maybe biased because this is one of my favorite targets and taken sometime to be able to do it properly) but I think maybe I lost my way along the processing and maybe messed the colour up slightly (possibly starting with PCC as @Laurin Dave suggests) and maybe missed a few tricks of bringing the detail out with a luminance or the Ha addition.

Still I am very happy with the data just feel I can still do better , which is fine that's how it is in this hobby.

I think all the detail in the Ha has not really transferred to the final image, so work to do there as well 🙂 

2 hours ago, Laurin Dave said:

Very nice Steve and going well, to me the initial image has better colour than the pcc'd one..  I'd highly recommend that you get as much luminance data as you can as it will transform your image and really bring out all the features.  As for Alnitak, masked stretching works well as does using the Ha as luminance over it. To do this in Pixinsight you'll need a round feathered mask which you can create using the GAME script in Utilities..   extract the Luminance from the RGB .. create a mask for Alnitak  ...  blend the extracted RGB  Luminance and the Ha together using Pixel math to create a new Luminance and then apply to the RGB  (eg Pixel math formula (RGBLum x (1-mask) + Ha x mask) ..  you'll need to fiddle around with the size of the mask and the blend ..  I find it a bit easier in Photoshop 

Dave

Many thanks Dave taking time to comment and give me some tips.

I have actually finished the processing now, well as a version 1 anyway, I will have a sit back now and have a think then another go (as you do 🙂 )  and like you am now thinking the red colour is wrong and too deep.
I have used a masked stretch for Alnitak but not sure what you mean by using Ha as luminance over it, but think I get it and certainly will have a try on the next version - thanks for the tip that's just what I need 🙂 

Steve

1 hour ago, vlaiv said:

Quite true. It's like dithering but better

I agree just not sure if I can stop EKOS doing it 😞 
I don't want to do it, but I still need EKOS to platesolve after the flip to ensure the FOV is as near as damn it the same but if EKOS knows there is a rotator then it just does it as part of the plkatesolve.
I will have a look at EKOS and see if any way to stop this (you would think there is wouldn't you as there is just no reason to move rotator after a flip).

Steve

1 hour ago, dannybgoode said:

Looking lovely.  When I started out on this AP lark a couple of years ago I thought it would be the data acquisition that was the time sink but no, the processing is what just eats time and you can just keep going and going with it!  You've got a nice balance here  

That must catch us all out then 🙂 

I think I am learning that often a little is best and Don't go mad, it may look like I have done a lot of noise reduction but each stage was pretty subtle, and the stretches done a bit at a time.
Also I think until all this comes naturally (which is practice and more practice) then takes time looking on my notes and on line, books etc.

I did begin to think at one time it was almost impossible to understand all the parameters, but I am getting there and often its only a couple out of many more that need setting.

 I think I said at the start if I wanted to do something that was easy it certainly wouldn't be this 🙂 

Steve

It's taking a while to process but coming together.

Taking longer than it should because for one I never added Ha to RGB, but after saying that not got to that bot yet, but also tried a few different techniques and also documented some notes for myself so I can remember what I have done.
So far done:

• calibration
• Alignment
• MureDenoise before RGB combination
• LinearFit all frames to Green frame
• RGB Combination
• PhotometricColourCalibration
• A bit more noise reduction with MultiscaleLinearTransform
• Removed any remaining  green cast off with SCNR
• HistogramTransformation to give a gentle stretch
• MaskedStretch to try and stop Altinak taking over.
• Some final noise removal with TGV Denoise

And that it so far, still have the Ha data almost untouched just a bit on noise removal to add into this.

Steve

7 minutes ago, michael8554 said:

Steve, your diagram is more conclusive than mine is (though 20 + 27.5 + 6.5 only makes 54mm)

Andywilliams, this 55mm Back Spacing is not difficult to measure.

Use Steve's diagram and post the result.

 

There should be 2 mm in the adapter I think on the scope side of the FV so this is still aiming for the 56 mm shown on ZWO website but either way 55 or 56 mm should give proeet good images that can be focussed.

Steve

I admit we do not know that the missing spacer is 11 mm as that would only depend on whether the spacer being used is 16.5 mm, which we do not know.
But the spacing is not correct which you can see form the shape of the stars in the corners, even though the image was out of focus.

So to get 55 mm if using only one spacer between the cc and fw it would need to be 27.5 mm and as the fw is only 20 mm I would say that spacer does not look to be 7.5 mm wider than the FW although measuring anything from a photo is very deceptive.


We can only offer advice to what we can see and cannot say for definite what is wrong only the OP can do that.

@Andywilliams can you confirm what size he spacer between the FW and CC is ?

Steve

11 minutes ago, wibblefish said:

Ah I feel for you folk doing astrophotography must be even more frustrating than visual!

Ah I don't know at least I can do it from a warm room, or even bed 🙂 
I think imaging or visual we have to be keen to even think of taking up the hobby in this country 😂

22 hours ago, discardedastro said:

Practically, for ease of calibration, I'd want to have flats for each rotation position (and maybe stick to a few common rotation positions if possible if you're able to and don't want to be taking flats all the time). I know that my flats generally correct more than just what's in the optical train and that tilt of the train isn't going to be exactly nil (e.g. vignetting etc won't be perfectly symmetrical). Better to be safe than throw out a bunch of exposure time, I think.

I also don't think you'd want to do synthetic flats e.g. rotate your existing flats to calibrate the flipped ones. This has the risk of correcting correctly all the optical train artefacts but incorrectly correcting for the scope.

After flips you don't strictly need to rotate the camera - there's no downside to rotating the image in software later, and then all your calibration data will match with only one set of flats. Obviously having the rotator is really helpful between subjects, though.

And while lots of people do suggest flats after every session I practically do just fine with everything left in place for months at a time with occasional imaging. I redo flats on occasion just to update for any new dust or debris!

I have only had the rotator a few months and its taken till now to get it working automatically and maybe that's the issue.
In Ekos as far as I see I have no real control over it after a flip. Ekos knows it has a rotator and just does it as part of the plate solving, which I need to do otherwise the whole image could be completely out. Personally if there is a way I am perfectly happy to let the processing software flip the images as happened before I had the rotator.

I agree about not rotating taking one set of flats and rotating them for the images before the flip, that won't work.

I need to look into the two sets of flats I took properly, on first viewing they looked the same for both angles so to get on with processing my images I just made one master flat with all the frames, technically not correct I know but it does seemed to have worked to an extent, but when I have processed this image I will revisit it and look again at the flats and maybe re-do it, I am sure the North of UK will provide me with plenty of cloudy nights to do all this 🙂 

Steve

5 minutes ago, wibblefish said:

I lugged all my gear out the other night in a clear sky, started observing and struggled to focus then looked up into a huge cloud bank 😕 Fortunately waiting about 10 mins or so and it cleared for the rest of the night but Ive had plenty this season where its been clouded by the time I am ready and then had to pack up! Seems to be a UK astronomy feature!

Definitely something we have to take on board, must be nice to live somewhere you can just do this hobby almost anytime you wish and do other stuff whenever, in UK it is a matter of Oh no clouds lets get out there 🙂 
Also when imaging I have it all automated and can leave it outside doing its stuff but sleep does not come easy as I keep waking and checking out of window for rain.
I so long for some sort of Obsy, even if not automatic roof and all that its just a matter of rolling the roof back and doing a bit and then if rain or clouds come shut it and off to bed.

Steve

13 minutes ago, wibblefish said:

Ultimately sticking the head out the backdoor at around 9 usually does it 😛

I did look out about 1am last night when I got up and it was clear but I don’t really have the enthusiasm to go out at random times of the night! 

Yes your right easiest way is to get off my backside and take a look  🙂 , I did look last night as well, again late around midnight as I took the dog out and although not totally clear there were plenty of stars but oddly enough it was raining on me so no way I would get my gear out.

Steve  

Even got 2 clear nights up here but I was so sure January was a write off I missed the first night on Tuesday and it wasn't till I took the dog out just before retiring to bed at close to midnight I saw it was clear but I needed my bed by then as had a hard day so just caught the Wednesday night.

So added to my resolution list to be more aware what the weather is doing as I need a much better year than 2021. here's hoping 🙂 

Steve

16 hours ago, FinleyChambers said:

I’ve had 4 clear nights this week, I got a 200PDS for Christmas and no mount haha, saving up for a mount now.

Now that is taking the proverbial, normally it is a known fact that when you receive new equipment it is cloudy for several weeks after they arrive, obviously the weather Gods saw you had not got the mount yet.
I hope you get the mount soon and the Gods are kind to you then 🙂 

Steve

Great image and a great tale.

That looks a lovely scope and it's great to hear its still doing a cracking job after more than 50 years, it's a pity the laptop in the third picture will be long gone by the time it is 1/5 of that 🙂 

Steve

3 hours ago, Quetzalcoatl72 said:

I think i know what dithering is but i've only been doing that with lights during the sequencing in nina, do i need to do that for all my other calibration frames?

As @tooth_dr says just dither for lights.

The idea is that whilst the camera is taking an image the scope follows the target perfectly (or as well as it can within the limits of your guiding) but then for the next image it just moves the scope a little so that the next image is a few pixels over one way, then the image after that it will move it a few pixels  in another direction. 
So over a session it will keep dithering around a position never moving more than a few pixels from where you took the first image but not taking all images in exact same position.
So when it comes to stacking the pictures together it will line up all the stars but any hot or cold pixels will not all be in same position on all the frames and so the software in the stacking program can remove them.

When taking darks or flats you are imaging either darkness or a light source at the end of the scope so dithering would not do anything. 
I guess the only time taking flats may have an issue is if you were to take them using a white T-shirt method and the dawn sky and kept tracking on the scope if it caught a few of the brighter stars or a planet but most people use a flat panel of some description, and dithering would probably not really help that in any case.

Steve

Yes looking at it again its not travelling in a straight line, I thought the erratic movements were just due to the fact the frames were not taken at consistent time intervals due to other issues I had but now I look again it does not go straight.

Winsorized Sigma clipping seems to have got rid of the bright part but there is still a bit of a glow in that area.

Never noticed anything like this before on this target so a bit odd.

Steve

8 minutes ago, Astroscot2 said:

Looks like a reflection,  certainly not a comet.

But it was moving at a constant speed over the 7 hours of imaging, so too slow surely to be a man made satellite

49 minutes ago, vlaiv said:

This is excellent piece of advice to determine if flats are impacted by rotator.

@teoria_del_big_bang

It really depends on scope. We could say that there are two main components to flats - one is dust shadows and other is vignetting.

Depending where rotator sits in optical train - dust that is responsible for shadows might rotate with camera and it won't change position.

In scopes that are symmetric if sensor is placed dead center on optical axis - vignetting will be symmetric as well and rotation won't matter. Refractors are prime candidates for this, but do be careful - camera can be offset, or rather sensor.

For example - look at latest ASI485 - sensor offset is very clear with that camera:

They did their best to make it centered (even if silicone is offset) - but I don't think it's centered properly. Usually this does not matter for imaging, but it can be problem with flats.

Another thing that can create asymmetric flats is type of scope. Newtonian scopes and especially fast newtonians have asymmetric flats (there is some secondary offset that I don't really understand - never bothered to properly grasp it since I never owned fast newtonian)

Interesting and good info, I need to look into this further.
I will check the flats as suggested
I do have some offset in the vignetting so also need to check further but when I initially looked at the two masters 180 degrees apart they looed the same by eye but need to do the calibration suggested.
My only other option without having to do individual flats, which would be a faff each session, would be to not use rotator after a flip but not sure I have the option to do that in EKOS. That way I might need different flats for different targets but not if on the same target.

Steve
 

54 minutes ago, The Lazy Astronomer said:

Have you tried calibrating one of the master flats using the other? If all the dust shadows and vignetting are completely removed then you'll know there's no appreciable difference between them. 

Out of curiosity, what rotator are you using? Sensor orientation is the last thing I have to do manually, using my hands like some kind of common visual astronomer (I kid! 😜) - I'd love to be able to computerise it, but the rotators I've seen are just too expensive for my liking. 

Good idea I can try that.
 

I am using the Deep Sky Dad rotator, reasonable price, even after import duty and seems very rigid, some videos somewhere showing them adding big weights to it and rotating it with no deflection.
Works well in EKOS and assume it will also do so if using ASCOM.

I did originally want the Pegasus Falcon rotator and did originally get one but the adaptors were a mm or two wider than stated on their website and I just couldn't get it in the back focus distance required, despite having a thin filter wheel (18mm) so thankfully RVO allowed me to return it and I then got the DSD one. I think the thickness is about the same as the Pegasus but did not need any adaptors and so just managed to get it in the 55.7 mm backfocus after the flattener.

Steve
 

1 hour ago, newbie alert said:

I'd assume that the rotator rotates the whole imaging train not just the camera.. so the camera relevant to a filter is the same.. only differences are the optics, as a rotator is rotating the imaging train around the optics 

That's how imagine it ...

Yes thats correct

Steve

28 minutes ago, The Lazy Astronomer said:

These look very nice already, looking forward to seeing the finished result!

Have you tried using the new GHS script for stretching? Takes a bit of learning and fiddling to find the right settings, but should help to control Alnitak and other bright stars without the need for star reduction later down the line. 

Thanks 🙂 

I have looked at the script and had a quick go with it on some of my old data and as you say there is a bit of a learning curve to it so I do want to give it a go, maybe do it my usual way first, keeping the project saved so I can back-track and then try again using the script.

Steve