Dustspeakers

It's been a while since my last post, but its galaxy season so...

NGC 2903 is a barred spiral galaxy in the constellation of Leo about 30 million light years away. It is about 100,000 light years in diameter.
Imaged on 19 Apr 2023:
- CGX mount
- C925 SCT scope with x0.7 reducer
- ASI 533MC camera
- 66 x 180s (~3.3 hrs)
Processed in APP, StarTools and Affinity

Ditto - all kinds of weird intermittent problems using WiFi and rock solid since I went to a wired connection. My PC is running Linux and has a dhcp server configured to provide the Rasp Pi with an IP address, so the ethernet interface on the Rasp Pi should be set up for dhcp client in this configuration. Can't speak for how to configure this on Windoze 8 though - stopped using Microsoft products many years ago...

Has anyone been able to download the command line version for Mac - not for PixInsight. The source forge version doesn't seen to include any binaries like rgb_starnet++ that was in version 1?

I can't resist doing this popular target every year as it looks so pretty.

Imaged on 05 Jan 2022, from my Bortle 5 back garden.
The core is extremely bright in comparison with the outer diffuse layers so this is a composite of 3 layers of:
- 30 x 2 sec RGB
- 20 x 10 sec RGB
- 60 x 120 sec RGB
(about 2 hours exposure total)
with a Redcat 51 (250mm) and ASI 533C cooled astro camera on an iOptron Skyguider Pro, no guiding.
Processed in APP, StarTools and Gimp.

On 12/12/2020 at 19:22, rickwayne said:

Even easier, if you're already in Ekos, is to click the "Mount" tab, click the "Mount Control" button at upper right, and notice that that dialog also has a magnifying-glass button. Brings up the exact same search dialog, when you find the thing you want with that and close it the object will now be listed in the Mount Control dialog. Click "UNPARK" (if necessary) and "GOTO". Bingo!

It took me a LONG time to notice the second method. Don't feel like the Lone Ranger, Ekos scatters things about its user interface as if it were the cockpit of a 1960s Russian fighter plane.

Oh man! Great tip - I hadn't noticed this one. It will save a LOT of time 🙂

Great detail Geoff

I've had a Celestron CGX over 2 years now. The CGX was not keeping time/date at all so I decided to change the RTC battery in the CGX. When I opened up the panel, which has never been removed before - by me anyway, I was horrified.

• Flapping around on the pcb was a 1 inch shard of metal shaving
• The twisted wires from the inside of the CGX to the pcb connectors had had their insulation cut/scraped away and with high chance of possible shorting.
• The standard of soldering on the pcb was pretty average too.

How can these kinds of sloppiness possibly get through QC?

5 minutes ago, PeterCPC said:

Team Viewer now thinks I am using it commercially even though I am not. Can't find anyway to send them an e mail or raise a ticket. No Machine works fine. Really annoying though having used TV for years with no problems.

 

Ditto. TV claims I'm using commercially which I'm not. Deleted TV from all devices and using Anydesk - works fine.

Thanks Mark, you are right. Weirdly I can only just make this out on my original now you've pointed it out. Also there's a reddish background tint which is also not (as) apparent on the original. Uploaded again without the blue band, hopefully

14, 20, 21 Sept 2020 – The Wizard Nebula, NGC 7380

The Wizard Nebula (a.k.a. SH2-142) is located just 8000 light years away in the constellation of Cepheus. The nebulosity surrounds the open star cluster NGC 7380 and the active star forming region is about 100 light years across.

From my UK bortle 5 back garden – CGX, C925 0x7 reducer, EFW, ASI1600MM, ASI120MM guider.

 ·      Ha  – 22 x 300s at 139 gain bin 2x2

·      OIII – 25 x 300s at 139 gain bin 2x2

·      SII  – 30 x 300s at 139 gain bin 2x2

 Total integration time ~6.5 hrs

 Processed in DSS, StarTools and Gimp in SHO -> RGB

With 20/20 hindsight I store mine horizontally too now 🙂

On 05/09/2020 at 11:06, billhinge said:

Its easy to open up and remove the plate. There is a plastic retainer with some cardboard shims and the glass sits on  a  circular ledge. After removing the retainer just mark the edge of the glass and tube so you can put everything back in the right orientation. Make sure you use the correct size screwdriver to avoid tearing the screw heads

You may read on cloudynights that there are celestron marks and serial numbers already on the glass, well my circa 2010 model didn't  have any

From the outside you may think it is wafer thin glass but its actually quite hefty

There are loads of videos and methods on the internet, I tried using water alcohol and acetone to clean it in the past (you can see I flocked the tube some years ago). 

I use those microfibre cleaning cloths and paper tissue for dabbing off liquid (one of those pc blowers helps remove dust etc)

Don't spray liquid on the glass but apply it to the cloth and clean small areas a bit at a  time. Alcohol products seem to leave a slight purple residue or smear so I actually found distilled water and detergent the best. Applied water to the cleaning cloth and residue  gently wiped away, dry with a second cloth and blower.  In all plan for a weekend, its not a  rush  job, just needs patience. Acetone can work on small stubborn spots but I think you could get away with water if you take longer

Check and double check before you screw everything back together, it may look clean and shiny in your hands but any marks really stand out when you have a black tube and mirror as a backdrop

Putting the shims back under the plastic and then trying to find the screw holes is a nightmare as the shims will move respective to the plastic ring. Easier to add glue to to the ring & cardboard shims to keep  them lined up before trying to replace, glued together its a simple job.

After you put everything back  you  need to collimate everything - still need to do  mine, I have one of the Hotech laser jobbies, done it before just  haven't got around to it yet

So the out take is it requires patience and methodical working

I've only just seen this thread. I had almost exactly the same kind of staining on my C925 which I put down to condensation inside the tube and storing the OTA with corrector plate down, i.e. on the scope cap, so that the condensed water ended up resting on the inside of the corrector plate. Unfortunately, due the the looooong intervals between imaging sessions in UK, I didn't notice the this for a while and was horrified to see a stain on the inside of the glass.

So I was also faced with the dilemma of what to do, and after watching the Internet videos I decided to clean it myself. There were a couple of issues. Firstly, I couldn't remove the corrector plate without removing one of the scope cap retaining pins, and secondly the stain was so ingrained that in order to remove the stain, it also removed a small section of the coating on the inside of the glass. Other than that, the job went pretty much as described in the quoted section. It doesn't _seem_ to have affected the optical quality much on the basis of images taken since. Given the above, in what orientation do you store your OTAs. I've looked for recommendations on t'Interweb but can't see anything.

Superb!

Ahhh. Great explanation - I understand that now. At the moment I'm going through the my whole setup to try and eliminate anything really inane that I may be doing, and increase my understanding of the whole calibration process so I'm doing some more testing and I'll post based on the results.

Thanks for the assistance.

Steve

10 hours ago, vlaiv said:

One way of doing it is to set gain that you are going to use, and then set offset at particular value - for example offset 10 that you already used. Then shoot a bunch of bias subs and see if there are pixels that are too low in value - something like 4ADU or similar and if histogram is well away from left side. If you find that it's not the case - raise offset and repeat. Once you find value that you are happy with - then prepare your darks with those settings (temp, gain, offset and wanted duration) and use same settings when you go out and gather actual data - lights.

Hi Vlaiv,

I'm also having issues with calibration frames (flats in my case) but I was interested in your comment above in trying to understand the whole calibration process. I have an ASI1600MM-Pro and I do see that raising the offset does shift the histogram from the LHS towards the RHS. For example on Bias, for Gain 200/Offset 10, I get a 'bell curve' of ADUs values between 0.78 - 12; for Gain 200/Offset 20, values between 6 - 18; for Gain 200/Offset 40, values between 19 and 29. So if I've understood you, if I shoot Darks (and Lights) with the latter value this is the correct way to proceed. I've just done a 300s Dark and it looks as I would expect with even random noise. So far so good (I think). But what is the action of increasing the offset to move the histogram to the right actually doing to benefit the images. Can you illuminate, so to speak.

Thanks

Steve

I endorse all Frank says about the quality of these OTAs. I've had my Redcat for about 6 months and when I've been able to use it from UK I've been pleased with the results. Here's my version of the same area of Orion with Redcat/Canon 550d (unmodded) 90 x 60 sec on 6th Jan 2020

Beautiful detail 👍

19 Oct 2019 - Before the clouds came in

Canon 550d 156 x 15sec 1600ISO, f/3.5 18-55mm stock lens at 20mm

I’m fairly new to narrowband and trying different processing software for what is best for me. I’ve spent the last 2 weeks with Pixinsight (free trial) and various Youtube tutorials trying to process test data sets. The results from PI are still not as good as a 4 hour first attempt with StarTools. Still evaluating but it’s a 👍 for StarTools from me.

Beautifully clear images

i have a Redcat 51. Happy with the optics but the focus lock ring doesn't lock the focus tight enough.

Dust clouds turned out really well 

Nice moons as well

Great detail!

Thanks for the nice comments Wouter, Craig, Glob & Matt.

The Apollo 15 landing site was near Hadley Rill here. You can just about make out the rill on the large image in this post - even better in the full resolution image on Astrobin, linked in original post.