StuartT

2 hours ago, teoria_del_big_bang said:

Looking at the image it looks a nice setup but what is all that tape or something wrapped around the power cable to the UPB ?  Could that cable be giving you an issue ?

Steve

Actually that is the cable taking power from the PSU to the UPBv2. Gravity pulling on the cable started to break the joint with the plug. I tried to find a replacement cable but it seems Pegasus don't make them as spares and it's impossible to find one elsewhere (due to the XT60 connector). So I repaired it with epoxy and tape. I don't think that's the problem. 

2 hours ago, teoria_del_big_bang said:

Regarding draping the cables you look to have a fair bundle of cables looping back to below the scope whereas I only have 2, the 12V supply to the UPB and one good quality USB3 cable. I route everything then to the UPB except the mount which goes direct to my PC as the power and USB connections do not move with the scope I find this a better solution.

Although that should still not cause the issues you are having but I would keep any looping cables that move to a minimum.

Then however many cables you have to get back to earth they need fixing at some point  on the scope, but do not tie-wrap really tightly and maybe wrap something soft around the cables first, then use fairly wide tie-wrap (not thin ones that can curt into cables, or better a 3D printed clamp or similar. The leave a nice large loop of cables that will suffice for any position of the scope without any danger of getting trapped, and then secure the other end to the fixed part of the mount in a similar manner to how it was to the scope.  The idea is that the only portion of cables to move is this loop and between the fixed points and the connectors they never move.
Then to keep all cables in the loop neat and tidy use velcro wraps (not tie wraps) these are easy to remove if needed and they cannot gut into the cables or squash them.

Steve

The looping cables you see are mostly just from the UPBv2 to the cameras. The reason there is so much cable length is that I don't want it wrapping too tight when the mount slews and flips. As it is, whenever I make major movements or a meridian flip happens, I have to go outside and 'supervise' to move any cables that are in danger of snagging. It's a real pain and there must be a better way of doing this. If only we didn't have to connect stuff with cables!
 

I only have two going 'off scope' - the power from the PSU (which sits on the tripod instrument tray) and the USB back into the house to my laptop. The EQ8 has a hub built in, but apparently it doesn't support USB 3.0!! (a known issue), so I can't make use of it as cameras need a fast connection.

1 hour ago, scotty38 said:

How long is your USB 3 cable from PC to powerbox?

about 15m. It runs from my laptop in the house out to the scope.

15 minutes ago, Fegato said:

I also use Lindy cables. For DSO imaging, I also force everything to USB 2. This is generally more stable than USB 3 in my opinion (and others too), and you just don't need the USB 3 speed for long exposure imaging (and when I say long exposure, it's fine for me with 5 second imaging (full frame 24mp) plus 2-3 second guiding).

this is intersting. I understood you needed the speed of USB3.0 for deep sky cameras? When you say 5 second imaging, what do you mean? Not exposure, I assume.

I seem to have endless problems with cables. Cameras don't always connect, images down't always download, cameras disconnect when cables move etc.

I think part of this is a physical issue. USB plugs are terribly flimsy and loose fitting for a demanding moving system like a telescope rig. I never seem to be able to find the right way to drape my cables around the scope so they don't get pulled or snagged. See photos for how I am set up - advice please!

But another issue is the electrical quality of the cables. Some USB cables just seem very poor. Can anyone recommend really good ones?

Thanks both. The window looks a bit closer to the sensor than that in my 2600MC, but maybe not.

I was also forgetting that there is an OAG between my camera and filter, so that's definitely more than 1.53mm

I'd better try and clean the window then.

I've plotted the transit altitude of Jupiter from my location up to 2025 (during astronomical dark only). In case it's of interest. Some nice observing windows there.

13 minutes ago, Nik271 said:

Oh yes, sorry, the midnight timing is only around opposition, after that the highest point is reached about 3-4 minutes earler each day. 

In summary we will have good views of Jupiter earlier and earlier in the evenings, all the way to January, and it will be rising up to 35-40 degrees viewed  from the UK.

 

Thanks. Figured out how to get all the altitude data from Stellarium now. In fact, Jupiter looks like it will be better next year (as it will be up over 50 degrees for me)

12 hours ago, Nik271 said:

For each night the max altitude will be near midnight GMT. You can calculate it from the declination of Jupiter for the day by the formula: 90+ (Jupiter declination)-(lattitude of location). 

Currently Jupiter is moving retrodrade, so its altitude will dip a little for the next month or so, then from the end of November it will start to increase again.

thanks. But the RA matters too presumably? (since that will mean Jupiter soon isn't visible at night) 

On 06/10/2022 at 20:33, vlaiv said:

That is on filter (my guess).

Use calculator to determine distance of dust from sensor to give you idea what surface it sits on.

https://astronomy.tools/calculators/dust_reflection_calculator

oh cool! I didn't know there was a calculator for that! Awesome.

Yep. Looks like the filter. 

Does anyone know if it's possible to plot out a line showing the position of Jupiter at various times? I want to figure out when it's going to be at its maximum altitude (which is kind of around now, I think).

Thanks

14 hours ago, The Lazy Astronomer said:

I'm going to hazard a guess that StarX created the stars only image by subtraction in this case, so the stars (and other bright areas it misidentified as stars) that were extracted from within m33 are dimmer than they should be, and where you've rescreened the stars back in, they've been put back in at this dimmer brightness value from the stars only image.

I'm not sure I'm following you here. I don't know how StarX removes stars. I assumed it only had one mode of operation. I don't know what 'unscreening' means. I assumed it just took the stars out and then I add them back in, but I've not really looked into what goes on under the hood

5 hours ago, The Lazy Astronomer said:

That formula can work, it depends how the stars only image was created.

The post I linked to explains how to unscreen stars using starnet (I think the latest version of starX has an option to create an unscreened star image automatically). The pixelmath

~((~starless)*(~stars))

is used later to add the stars back in

Ok, I tried your pixelmath expression (on the left) and my simple additive one (one the right). They are indeed subtly different. I think yours has lightened the sky a little more. Not sure which I prefer to be honest

edited

On 04/10/2022 at 15:08, The Lazy Astronomer said:

The joys of image calibration!

The first thing I would think it would be is improperly subtracted darks. Did you take darks (for the lights) and flat darks (for the flats)?

By the way, I figured out the problem. I used ABE rather than DBE (note to self... don't be lazy)

Usually I don't bother to look at the master flats that come out of WBPP, but tonight I decided to debayer and stretch and take a look. Clearly some kind of dust on there, but I don't see it on my camera window or filter. It's presumably too in focus to be on the objective, so where is it likely to be? I'd like to clean this off if possible but I need to know where to start looking in the optical train.

Thoughts?

3 hours ago, The Lazy Astronomer said:

That formula can work, it depends how the stars only image was created.

The post I linked to explains how to unscreen stars using starnet (I think the latest version of starX has an option to create an unscreened star image automatically). The pixelmath

~((~starless)*(~stars))

is used later to add the stars back in

Starnet2 and StarX both have the same options. You can either simply remove the stars, or you can remove them and generate a star only image too. I always do the latter, then I fiddle about with the starless image (deconv really only works well on a starless image for example), then when I'm happy I add the stars back. Being a simple man 😉, I just use addition, but I'm going to try your rather fancier equation next time. Actually I have some data in the oven now, so I'll try this when it's cooked.

(I am using the latest version of StarX btw - AI 11 - and it's now clearly superior to Starnet2)

5 hours ago, DaveS said:

I'm with Adam on this. I had the trial version but it just , so for what passes for my sanity I went back to using AstroArt which just keeps getting more powerful, and is now at V8 sp2.

I do totally understand that. PI is rather 'its own thing' and I was put off it for a while thinking "I don't need that" "too complex" etc. But then I took the plunge and it's been a massive game changer for me. But ultimately, each to his/her own. The best results come not from the tools but from the user of the tools.

12 hours ago, The Lazy Astronomer said:

On another note, I recently happened upon some nifty pixelmath for removing and re-adding stars on the pixinsight forums: https://pixinsight.com/forum/index.php?threads/unscreening-and-re-screening-recombining-stars-with-starless-images.18602/

Probably already a well known technique to some, but it helped me, so thought I'd share. 

To remove the stars I just use StarXTerminator in Pixinsight. The latest version works incredibly well and is fast if you use your GPU. Then I just re-add the stars with the simple PixelMath expression

$T+0.8*stars

or similar

12 hours ago, tooth_dr said:

This is why I own a copy of PI but haven’t used it.  It looks amazing but my head can’t round it even to get started 

Oh boy, you must learn PI! It's absolutely fantastic. Game changing. I don't use any other software now from raw data all the way to final image. The Adam Block courses are well worth it.

9 minutes ago, The Lazy Astronomer said:

Light leak? (in either the darks or flat darks) - would only have to be very slight to make a difference

I wouldn't think so. My flat darks are always done at night and my darks were done with the camera in a bag

9 minutes ago, The Lazy Astronomer said:

How old is the master dark? 

Gain and/or offset inadvertently changed? 

Not very. It's only from May this year. Nope, same gain and offset.

9 minutes ago, The Lazy Astronomer said:

I vaguely recall something with APT's flat wizard where it did something weird which made flats overcorrect, but I think I've seen you use NINA right? So probably not that. 

I've not heard of the 2600 being particularly fussy (unlike my 294...😑), but I temperature match all my frames. Might help for future if you don't already (certainly won't hurt in any case).

Yes, I only ever use NINA and the flat wizard is great.

This time the temperature was higher for the flats and dark flats (because I accidentally disconnected the camera before remebering to do my flats (it was 3:30am 🥱) so when I re-connected it to do them, the camera had warmed back up (from -15C to about +9C). Maybe that was it?

2 hours ago, Ouroboros said:

Very nice @StuartT.  Lots of lovely detail there.  It’s maybe a bit colour saturated for my taste but then that’s personal choice. The stars are in nice proportion to the nebular. Did you have to do any star reduction of does the filter do that for you? Nice anyway. 

Tecnical question. As a fellow owner of an ASI2600MC do you attach the Optolong L Pro filter on the front of the camera and then the spacers to that?  Is it the 1.25” filter version? 

Thanks. I generally do most of the processing on the starless image and then add the stars back in at the end using Pixel Math (generally I multiply the stars by 0.7 or 0.8 to reduce their emphasis a bit)

My optical train is Esprit 150 (native) --> spacer --> 2" filter --> OAG --> camera

1 hour ago, The Lazy Astronomer said:

The joys of image calibration!

The first thing I would think it would be is improperly subtracted darks. Did you take darks (for the lights) and flat darks (for the flats)?

yep. I used a master dark, 20 flats and 20 darkflats

11 hours ago, The Lazy Astronomer said:

 

I think you may have some over correcting flats (inverse vignetting visible in the corners)

Interesting. I wonder how that could have happened? Surely the flats are the flats (as in they are only showing what the optical train is), so what would be causing over-correction?

6h 24min on M33 with my Esprit 150, ASI 2600MC and an Optolong L Pro filter (processed in Pixinsight from start to finish)

A bit late to the party, but I just fancied trying my hand at this one

On 14/09/2022 at 22:21, teoria_del_big_bang said:

 

So certainly you would gain knowledge from both  but Fundementals is the most value for money in my opinion and probably enough for most peoples needs.

Steve

Absolutely agree. I did the Quick Start first, now I am working my way through Fundamentals. It's incredibly thorough and systematic and I feel I am gaining a true understanding, rather than simply which buttons to press. Given the sheer volume of the content (there are lots of video-hours in there) I consider it excellent value. 

I know he has free videos on YouTube, but I find the structured approach in his courses much better as you build your knowledge in a logical way rather than just dipping into youtube to find the answer to one question.

33 minutes ago, Ouroboros said:

Thanks for that, @StuartT.  Somehow I overcame the problem, but I’m not sure how. I reloaded the two master darks which I’d renamed to include the duration. Don’t think I did anything else. Nevertheless it knew the durations afterwards. 

Apologies, I should have said that WBPP can read key info from both the FITS header and the filename.

Glad you got it sorted out. WBPP is really superb once you get used to it.

14 hours ago, Ouroboros said:

As a first time newbie to WBPP I’m not sure what the new features are.  

Just now I’m getting error messages saying the Light frame’s exposure differs from the Master Dark exposure.  This is because  neither my master dark file (nor master flat file)  contain the exposure duration. Is there a way to simply tell WBPP what the duration is?  

Normally WBPP will read the exposure time from the FITS header. But if it can't for some reason, you can just remove your darks, then re-add them using the "Custom" button. This will allow you to specify things like filter name, exposure time, binning etc

The other way to do it would be to go up to the "calibration settings" (top of the calibration tab) and select the darks from there (usually it's set to Auto, but the drop down should allow you to pick a different file)