teoria_del_big_bang

2 hours ago, VectorQuantity said:

Having used both EAF and Sesto senso (and Moonlite) on multiple scopes.

ZWO EAF works well, as long as one of the ZWO choice of mounting plates fits your scope, or you adapt a ZWO supplied one. Backlash seems good, accuracy seems good, undecided about load handling.

Sesto senso 'can' be fine but suffers from it's mounting method. The attachment point being the outside of the focuser train which is not necessarily concentric with the focuser shaft. If the focuser shaft and focuser 'outer' are not concentric the Sesto senso will 'wobble'. Backlash seems to appear if 'wobble' is present, otherwise accuracy seems good, load handling seems good.

I have two Sesto Senso focusers for my two rigs and very happy with them (hence why I bought the 2nd one.

The first one was the version 1 and that came with a solid coupling (well several couplings to fit various focusers) and yes that does have to be aligned pretty accurately but I really did not find that difficult.
The second one I got is the V2 (so I guess the version you would get if buying new) and that has flexible couplings to allow for some mis-alignment. So they are flexible to allow for this mis-alignment but in a rotary direction have no flex and so are very accurate.

Personally I like the way they fit to the collar of the focusser where you removed the focusser knob and find it a real neat solution with no flex at all between the stepper motor and the focusser fine tune spindle so super accurate.

I think focusers that are on a right angle bracket can suffer from some flex and those using a timing belt can suffer backlash and flex. BUT, after saying that my thoughts are that so long as you attach the motor to the fine tuning knob or spindle then a few lost pulses of the stepper due to flex or backlash should really have no noticeable affect of the final focus as seen in the resulting images. If the motor is driving the rough focuser knob then it might be more prevalent.
So it you are doing the first scenario I guess any of these auto focusers would be just as good as the other.

Steve

On 14/05/2022 at 09:26, fireballxl5 said:

yes, this seems to be the same part. It is listed on the TS website here.

I expect that you will need one to use the whole field of view with your QHY268M.

 

Hi, I have bought this flattener but struggling to get focus with it installed.
It looks like my focusser needs to go further in than its minimum position, it seems to be almost in focus but needs to go further,
I thought no problem and I could just remove one of the big diameter spacers attached between the focusser and the scope but if I do then the inner moving tube of the focusser hits the internals of the scope so at a minimum I have to have one of the 25 mm spacers + the tilt plate as I have below.

Can you post a picture of your setup that may help me understand my problem?

Steve

Oh dear, these things happen 🙂 

I guess it might depend on what software you are using to align and stack the images.
I think in Pixinsight you can stack fits and jpg images together.

However, personally although this has never happened to me I don't think would use them even if you can.
The reason is that there is probably very little signal stored in a jpeg compared to raw data and also when stacked you might loose any information stored in the fits headers which can often be useful to processing software.

I could be wrong but below are the same images one saved as a fits (left) and the other a JPG saved at 100% quality (right)

Both look the same.
But when I apply the same stretch to both images

Now all the data in the fits image is released but in the jpeg there is nothing worth using.
Whether a jpeg from a DSLR or other camera only has the same data in there I am not sure but I suspect it would be the case.

Steve

Still not taken any images yet but getting there and a few more bits arrived today to get me to the finishing line.
I just thought I would ask a couple of questions to see what opinions are (if anyone has a similar setup and knows the answers)

Currently this is how I have the setup.
 

The flattener requires 109 mm back focus + I have 3mm thick filters so adding 1 mm for these.

So the first question is basically does anyone see any obvious flaws in this setup ?

And the second question is do I need that tilt plate in there as I understand the Baader Steeltrack has the ability to align the focusser in a similar way. I am thinking that the tilt plate is just somewhere to have a light leak unless I put some sort of tape around it where the gap appears.

TIA

Steve

21 minutes ago, BrendanC said:

True, except that it didn't - it started at 23:00.

I was just going by the time stamp of the fits header when I said 10 (well 22:08 to be precise) but maybe your date/time is an hour out.
But also was not suggesting that was the problem with the gradients just that it might not be helping with the final image quality.

Steve

Found one HERE that would work but out of stock

What are you connecting the croc clips to, would some other type of connector fit ?

Steve

3 minutes ago, Chris Owen 66 said:

Thank you for the link Steve. How does that cable connect to my battery though?

Thats what I meant when I said you would still have to use your existing short bit of cable with the cigarette socket and if it was that socket that was going dodgy not the plug side then you would still have an issue so still looking for an alternative solution.

Steve

Yes I thought it woud be, I would be pretty sure if its for a SW Dob that it is a 5.5mm x 2.1mm connector.
Loads of cables available with this end, the problem will be if you want to get rif of the cigarette lighter plug.
THIS would be a direct replacement for your cable (dont get the ring end ones unless you want to attache a fuse yourself), so available in 2M or 5M and they are great cables.
 

But if the issue, or part of the issue is corrosion of the socket on the short bit of cable you have and not all to do with the long cable then you could still have connection issues,

Steve

Just now, Chris Owen 66 said:

Thanks Steve. Where might I get a new cable...I've looked and looked online but can't seem to find one. Thank you.

Ah, now not sure, I can have a look but can't promise 🙂 

Do you have a better picture of the end that plugs into your Dob ?

Steve

You can remove the cigarette type connector, they are pretty poor anyway I hate the things for poor connection issues
BUT please put an in line fuse in its place. If there are any short circuits car batteries, or many other types of battery for that, are capable of delivering many amps for short periods.
Also make sure the polarity is correct.
Personally for the sake of £20 or so considering the cost of your equipment I would just buy a new cable altogether.

Steve

2 hours ago, ollypenrice said:

OK, looking at the 5 greyscale images in this post, all but image 2 show very obvious inverse vignetting as caused, routinely, by over correcting flats. In image 2 something else is going on as well. 

I really can see no room for doubt about this but, to confirm it, you just need to make stacks without flats and see that the bright corners and dark centre will be transformed into dark corners and bright centre. So far this is all perfectly mainstream but, where it gets difficult, is in working out why the flats are over correcting

As I had all this data already open in PI I did what you suggested for the Lum anyway. A stack using uncalibrated data left and Right is after calibration with darks and flats.
Note: the uncalibrated was just the raw files so these do not have darks calibration applied either but  that should not affect the vignetting unless the darks had an issue which I do not think they do.

Steve

This is a long shot but is there anything in the processes you use for calibration that reads the fits headers.
Reason I ask is because I am trying to use WBPB script in PI to load files and it thinks the Dark Flats (which are actually darks for the flats)  are Flats and loading them up as flats.
I am sort of assuming that the software you are using is just manually loading files so not a problem for you the headers has the wrong image type, but just so you know if you do go to trying PI then this may be an issue.

Steve

I do feel that this set of data may not be the best to give you help with as the target is so feint and to be fair no real astro darkness when they were taken, although I think you said no moon so maybe that's not a big issue, but the feint target means the image with a quite low integration time was never going to be great. Looking at other peoples images of this target (not one I have even tried) many are poor and many not as good as yours.
When I look at the actual background levels they do not seem to vary that much around the image even the stretched image looks bad I think it is just stretched so much that any small change in levels looks huge.

Now some of the other images you put in one reply with much brighter galaxies are a different matter and these may be better data sets to look at.
I am not so much experience as others like Vlaiv but having got that camera (different scopes mind) and so many others that have it unless it is faulty I cannot see how it could be the camera.
But like other I do feel for you and understand your frustration (I know that's not helping and that's what you need).

Steve

Following on from @vlaiv observation about the external light I was also running the subs though a similar animation and for sure on the luminance subs you start imaging at 10 PM on 1st June and maybe at this time of year with no astro darkness in UK that is really too early. Once it gets to 11 PM the subs seem to vastly improve. So if you stack all the subs with equal weighting maybe these earlier subs are doing you no favours, especially on such a dim target anyway.

Below are just the Luminance subs but all with same stretch so you see the actual difference between subs, it starts with the first exposure at 10 PM and runs though all subs twice ending up back at the first one.

Steve

What a great  image, I just marvel at these images of galaxies, so many of them and what lies within them, who lies within?

Steve

17 minutes ago, AstroNebulee said:

Wow thank you Steve, that's so kind to say. I'm pleased you feel that way about it 😌. Yep it gets imaged a lot but I wanted to try it with my 294 mc pro as last year I tried it with dslr, so revisiting all last years dslr targets and re capturing with my osc. 

Cheers 

Lee 

Its a target definitely worth revisiting, especially when it fits your FOV so nicely like that 🙂 
Steve

I have seen so many versions of this target it should get boring.
But it doesn't, and honestly that is one of the better versions I have seen, absolutely superb.

Steve

Welcome to SGL 🙂 

Steve

Like all previous replies I too empathise with you, but unfortunately that does nothing to help you.

When I started I too had many problems, some same as yourself and some totally different and I too began to think was it all worth it as I seemed to be always taking one step forward and often two back.
Now I know you are not just starting out but you have several issues and for myself the way that worked for me was to eliminate issues one by one.
And, because clear nights were few and far between it took some weeks to do but if you have many issues trying to solve them all at once will just frustrate you more, so do it one by one.

Personally for now I would remove anything you can remove and still get some sort of images,.
When other issues are solved then start to reintroduce them.

In daylight get everything working the best you can, if you can improve the sag on the focusser then do so, in daylight, you need to eliminate as much issues with the focusser as you can. Sometimes stock focusers are poor when adding heavy cameras and filter wheels and really need upgrading but if for now that is not an option then there are usually tweaks and things you can do with shims to stiffen it all up a bit if you search on line.

Then get any computerised side working flawlessly, again a lot of this you can do in daylight, if you can work from your laptop for now and eliminate the RPi then do so.
However the RPi is well capable of running KStars / Ekos, so, again can introduce later when you have made progress.

Remove the CC for now, okay you will have some misshapen stars but get it all working for now, this may well stop the reflections, put filters the recommended orientation.

Don't bother guiding, again for now, with a HEQ5 well polar aligned you should be able to get good 3 minute subs without significant star trails, even 5 mins might be not so bad if using NB filters and after all the ide is to get what you have working. So even if some slightly elongated stars the aim is to get what you have working reliably and good useable data not the real aim for now.

Then after a couple of nights with that all working, shouldn't be too hard, camera should work ok, FW should be fine, mount should track if well polar aligned, hopefully focusser is holding its own, then try one of the things you removed.
If the focusser continues to make things difficult then maybe you have to accept it is not up to the job and needs upgrading. Not ideal and I am hoping you can get it to work but sometimes you just have to face facts and either lighten the load or upgrade the focusser, or even scope itself.

So CC is probably the next bit. If the reflections are back then that the problem with that and unfortunately all you can do is find out what CC works with your setup and try to save for one.

Then try guiding, often that can take a night or two to get working and set all up correctly.

Then try your RPi again, just make sure to use good quality, shortish (below 3M) USB cables and a good power supply. Again all the initial trials can be done in daylight to make sure it all works reliably. Connect to laptop via an ethernet cable for now to eliminate WiFi issues.

Just do it bit by bit and you will get there and once all setup you will have a reliable piece of kit that just works.
Each night you get another bit working you will feel a real sense of satisfaction I am sure, even if all that work and messing about meant no real useable data that night.

Steve

7 minutes ago, Stuart1971 said:

Well, I have to be honest, I would never use a solid coupler on the fine focus shaft, my advice was just for using the motor on the coarse focus side of the focuser, as my Pegasus is fitted….too much flex in the fine focus shaft and that could be easily damaged….😮

Ah well I guess we have two completely different setups.
Apart from a DSD focusser on my WO73, which was a timing belt, I only have had 2  sesto senso focusers which as far as I am aware can only attache to the fine focusser spindle, well that's what they are designed to do anyway.
So I guess because they are on the fine focuser then it takes a lot of pulses to move a short way and so a few pulses here and there really do not affect focus to any noticeable extent.
I guess if the two spindles cannot be lined up accurately then maybe a solid one s not a great idea.

Now then, this shows how forgetful I am but just went to check my setups.
My first  sesto senso was the version 1 and just looked that actually has a solid coupling, which I thought was odd because in my mind I was sure it was a flexible one. But what confused me is the 2nd purchase for another scope, which was a  sesto senso 2 that does have a flexible coupling, so they seemed to have changed the other way from a solid one to a flexible one.

But after saying that I cannot remember having much of an issue lining up the version 1 with the two spindles.

Steve
 

56 minutes ago, Stuart1971 said:

I had a flexible on my Tak FSQ85 and moved to a solid coupling, as long as it is fitted correctly, no issues at all. 👍🏼
 

fit the coupler to the focuser shaft, and tighten down, then fit motor bracket loosely, fit motor to bracket loosely, then slide the motor shaft into the coupler and tighten bracket down, then the important bit, with motor loose on bracket, run the motor slowly to centre the shaft in the coupler, this will move the motor on the bracket as needed, then tighten motor on bracket, run it again and make sure motor shaft turns in coupler with no radial movement, then tighten grub screw on motor shaft…then finally run it 360 degrees in both directions to check for and forced movement  in the motor and bracket assembly, which would indicate radial movement……..simples…😀

Yes I would agree, pretty much along the lines I was thinking in an earlier post..
I think maybe its another case of horses for courses. If you have a bracket with the stepper on and can easily adjust it as you suggest then a solid one probably is slightly better but I am not sure it would be as easy on a sesto senso where the coupler is inside and only can be adjusted through a slot and the collar of the focusser then attaches directly to where the rough focusing knob was attached.

And then there is the question are we over thinking this anyway.
If the motor is attached directly to the fine focussing spindle (not a belt) does it really matter to 2 or 3 pulses ????
To my eyes even really zooming in when I get everything in focus I can move 10 or more steps either side and I cannot tell any real difference in focus. 
Maybe that depends on the focal length of the scope and maybe some are more critical than my Esprit 100 ???

Steve

1 hour ago, Rodd said:

   The starless tool is no longer part of PI I don’t think. The script is no longer accessible.  I am using not the newest version, but almost 

Both StarXTerminator and Starnet (and Starnet2) are available still for PI.
Neither are scripts, as such, as they do not reside in the scripts menus, but modules. available under the Processes menu.

StarXTerminator sometimes does disappear when a new full release of PI is installed but you can easily get it back (assuming you have a licence as it is not free but a one off payment0.

• Occasionally PixInsight's update system gets confused. If anything goes wrong with the above procedure, or if StarXTerminator seems to install and work fine but then stops or disappears from the Process menu, please do the following:
  • Delete the "updates.xri" file from PixInsight's main application directory
  • Re-start PixInsight
  • This will force a fresh download/installation of all updates to your PixInsight installation, including StarXTerminator

StarXTerminator Support for PI

Starnet2 has now superseded Starnet.

Guide to install Starnet2

Steve

Having thought about it a bit more I will add that my statement does maybe also depend on the focusser being rigidly attached to the scope with no movement between the two whatsoever.
So a focusser say on a L shaped bracket could have some flex, in a back to front direction, not much but maybe enough to lose one or two pulses of the stepper motor. 
I have two sesto senso focusers and I like how they attach rigidly to both my Esprit 100 stock focusser and RC6 upgraded Baader Steeltrack and I think in this instance the flexible one is the way to go..

But, maybe on one with a L shaped bracket if it is not absolutely solid and it could flex back and forth ever so slightly there is a situation I can see a solid coupling being better, but I would get the alignment as near perfect as you can, so maybe even locking the coupling to both spindles before fully tightening to the L shaped bracket.
The problem being is if there is any movement back to front then the coupling sort of unwinds, or winds up depending on direction of movement, like a spring , all very slight but it would maybe again loose a pulse or two of movement, developing some slight backlash as the coupling winds up and winds back on change of direction.

Steve

Although these couplers are cheaper than what we used on our high precision grinding machines (we achieve micron and sometimes sub micron on some machines) for encoder couplings the principle is the same and there should be no difference in rotational position but the slight flex should allow for some small amount of error in alignment of the two spindles.

The coupling should not flex at all in a radial manner but can flex slightly side to side or up and down to allow for this misalignment.

So my opinion is that a flexible one would be better than a fixed one unless you can guarantee absolute perfect alignment of the two spindles which in most situations you cannot as they are just not manufactured to a high enough tolerance on most amateur equipment.

Steve

I think it is a great image. I got some good Ha and even some decent SII data earlier this year but my OIII was disappointing but you seem to have a lot of that feint outer shell.
I certainly would be more than happy with it 🙂 

Steve