Category Archives: Astronomy

Imaging Session 21-Jan-2021

I continued to grab more data for M33, and have added the Hydrogen Alpha in a slightly different way to before, although I wasn’t able to get any more sub-exposures for Hydrogen Alpha due to software issues. Still think I need to continue to add more data.

Annotated Image

Focusing is actually working well now, although the focuser appeared to want to refocus far too often. Guiding was also being suspended during focusing. I think we will now manually move the focuser to 83000 steps at the beginning and probably limit travel to 1500 steps in either direction or so, and work with much smaller initial steps (initial step 200, max step 300). This should allow me to refocus often and quickly and not have to suspend guiding during focusing, which appeared to be an issue.
I am hoping some Kstars updates to Astroberry in the near future will sort some of the software issues I have experienced last night.

M33 Triangulum Update

Have managed to get some more data for the M33 image on the 24th December.

M33 Triangulum Pinwheel

We are now seeing some colour detail from NGC604.

Had some difficulty running from mains, seemed to trip out and reboot the Nevada PSU. Managed to overcome those issues by switching to the SkyWatcher Powertanks. I think I will have to look at a high-density LifePO4 battery. Also had some issues with the GPS detection, which might have also been rooted with the power issue.

UPDATE 29/12/2020

The issue with the PSU is that the PowerBox Advance does state it needs 10A power, I looked at my PSU and it can output 6A continuous (8A surge) – via the binding posts, and max 5A via the cigarette socket. I checked my cables and found that while the PowerBox only appeared to be drawing 2.7A for all the kit it must have been surging at times. I also found that in the length of cable from inside mains to the outside I had cigarette plugs with 5A fuses. I am now in the process of getting an upgraded PSU rated to 10A on the cigarette socket and have found a 10A fuse to use, the PSU also has a 25A-30A red/black binding posts at the back – which should suit me for any future requirements I may ever have. It also has adjustable voltage from 9-15 VDC, so I should be able to crank up the volts a little if necessary due to the cold. The PowerBox can accept 13.8V and will protect trip out at above 14.5V.
The issue with the GPS seems to have been that I located it at the back of the Argon One M.2 case, and there must be some electronic or radio interference in that location. I have now been testing semi-inside with attaching the GPS mouse with Velcro to one of the Tripod legs, and when not in use I can use that Velcro strap to wind in the cable and just store the GPS mouse in the location I had hoped to be able to use it from.

Here is a recording of the Live Stream of the capture, you might want to switch it to HD for viewing and then perhaps skip through playing at x2 rate. When switching to the second power block

Here is a picture of the rig, almost completely set up – I think we just needed to run the power cable at this point. We still have some cables on order which will shorten some of the lengths and improve the cable management, but this is a lot better than the mass of cables I had running before.

The set up for imaging

Pegasus Powerbox Advance and Raspberry Pi mounted onto a Perspex Sheet

In order to control the number of cables and perform some cable management we often mount equipment onto the telescope mount. This is commonly done by mounting an additional plate onto the tube rings of the telescope. These plates can be heavy Losmandy D-types. Here is a solution I found using some 3mm Perspex, which can be easily ordered online from plastic sheeting companies. I drilled a few holes into the sheets and mounted my equipment onto the sheet, which I attached to the Esprit’s tube rings.

M33 Triangulum Revisited

So, to start the Esprit Journey proper, we chose a simple, single frame target, which we visited before in 2019. The capture session was live, but here is the first draft of post-processing the data:

M33

This is clearly superior to the Startravel 120T!

Here is the capture session in progress, recorded live, exposure by exposure, I apologise for not being an active commentator, and lots of sounds in the background:

Last Outing with the StarTravel 120T

So we had a brief night of viewing, and as this is likely to be the last time using the StarTravel 120T I thought we would end where we started, with Andromeda.
The results are not great, it is a Luminence only capture, with a mono camera, a mosaic of three panes, and you can clearly see the egg-stars caused by the chromatic aberration that the StarTravel exhibits. The StarTravel gets really good results with Narrowband imaging, but not when trying to get true colour. I intend this to be the first target with the Esprit soon, and hopefully we will see quite a difference to compare the two against each other – you need to be reminded that the Esprit costs probably around 8x more than the StarTravel, and everything I’ve posted here so far was achieved using the StarTravel.
I have not bothered to perform much post-processing on this image, as I feel more compelled to focus efforts on new equipment, and hopefully better results.

We can compare that, with my first ever astrophotography photo, although I believe this was LRGB at the time, so avoided the worst of the chromatic aberration by re-focusing for each colour filter.

Created with GIMP

Esprit 120ED Pro Arrival

OK, Well the Esprit 120ED Pro has finally arrived. So a few unboxing photos, which I will follow up with a video comparing the upgrade from the Achromatic StarTravel 120T to this new Apochromatic scope, in particular testing out the Sesto Senso 2 on the Esprit, and comparing it with the DC Motor on the StarTravel.

Above, the box it came in.
Feeling like Russion Dolls
Now what might be inside this quality case.
Looks like they used a ED100 allocated focuser on this 120ED
It is definitely a Esprit 120ED though

I am told that there should not be any difference between the ED100 and the ED120 focusers, they are the same model, the only difference is the sticker, which I will either remove, or it might drop off with dew in time.

Eyepiece Collections and why not to go down that path

This is a quick video to look at viewing equipment on our side of the focuser – diagonals, eyepieces, and looking specifically at the Baader Planetarium Hyperion Zoom MkIV eyepiece.
Essentially how to avoid going down the route of eyepiece collection explosion, get a single eyepiece that adequately provides the views at all magnifications that your equipment can reasonably cope with.

SkyWatcher PowerTank 17ah

We are looking at the SkyWatcher (or Celestron) PowerTank 17ah, for use at dark sky sites away from home, to provide a constant 12V, upto 10A power over 17Ah of powerstaoge.

Obviously neither SkyWatcher nor Celestron manufacture this product. Here we show what its form factor capabilities are, and I will update you in time with how they perform:

Primaluce Labs Sesto Senso v2 has arrived!

OK, so I took a delivery and this is the first look at the Primaluce Labs Sesto Senso v2, although I don’t yet have a compatible scope to attach it to.
It feels sturdy, and without further ado, here is the review:

Just a note about the 12V power connector, my previous HitecAstroDC focuser accepted a 2.1 centre positive connector, and I hoped I would be able to use that. Unfortunately the Sesto Senso v2 power connector appears to be a 2.5mm centre positive connector, so you would need to buy another cable to get rid of the cigarette lighter cable that comes with the device.

Optimising Exposure and Gain Settings

So, an often discussed topic on online forums is what capture settings should I use, how much should I cool my CMOS camera, what exposure, and what gain.
The answers to all these questions depend on your equipment and the amount of light pollution at your site.
The following video was given at a recent Astronomy gathering by Dr Robin Glover, which gives a real insight into how far you should take the extreme possible settings of your equipment in order to optimise the gain in quality for the amount of pain and patience needed.

Towards the end of the video Dr Robin Glover ran out of time, but later posted the missing parts with relation to what gain settings are helpful in various set ups.

Retiring my StarTravel 120T

Well, it is approaching retirement, and I will soon be presenting it’s replacement to you, I thought my old SkyWatcher StarTravel 120T, deserved a look at on my site.

I hope within the next month of so, to showcase the new telescope, although it is now not due to arrive until early November 2020.

Thank you for watching!

The Session – 9th October

So, I did make a screen capture of the session on the 9th October, it is not particularly interesting as I was not really commentating throughout, had my webcam flap down for some reason, but you will see certain aspects – we are using the new SEP multi-star algorithm in Ekos, which is great for stability, it does show off the AS290MM mini, it shows how I have to manually focus every so often (APO and SestoSenso arriving soon will be greatly appreciated).

I would not expect anyone to watch this five hour marathon through from start to end, although if you happened to be watching it live it might be interesting if you were acquiring the same target, but certainly skipping through the footage, you might come across something I’m doing wrong, or right, and have some comments on my progress in this field.

Don’t expect so see the thumbnail in this video to appear in the video itself, this is the acquisition phase of individual sub-exposures, I will post a video on processing of the data, including this night’s, in a later video, when we’ve hopefully improve on the data substantially. The preview picture displayed is the accumulation of data so far, without any discarding of bad data so far.


I do have to wonder, how I will proceed when the APO arrives, it is a f/7 telescope, while these are taken on a f/5 telescope. Maybe I can proceed with a 3×3 mosaic, or something similar 3×2 or 2×3 and add to the data, or perhaps I need to choose to start all over again. APP will help when I start, as it will quantify the quality of the images I already have, and be able to merge frames from different optical equipment.

As always, if you are here as a genuine viewer with an interest in Astrophotography, then please leave a comment, I will moderate and reply if necessary.

Heart Nebula – More Data from 9th October, Oiii & Sii subs

So last night, we obtained some more Oiii sub-exposures in order to bring the number to the same level as our Hydrogen Alpha sub-exposures. I also started to obtain some Sii exposures, only managed 10 or so for each pane of the mosaic.
It looks like I should obtain more Hydrogen Alpha sub exposures as well now, as the quality does not appear to be as good as the other narrow-band wavelengths, and of course Hydrogen Alpha is a strong part of the composition.
You will notice we are now using a different palette for the RGB composition.
I probably need to flex up some of my GIMP processing skills as I still feel I am floundering around not really knowing what I am doing.
Anyway, without further ado, please find below the current rendition:

Here is a link to the online worldwide telescope