AMcD

The optimism displayed by you both @Xsubmariner and @tomato regarding my negotiating powers is most kind, but entirely misplaced😂. I suspect the shiny chrome of the stack is going to be declared off limits DIY wise. I have in mind a tall matt black board that can be mounted on the outside of the observatory to screen the stack on those few moonlit nights when I image at the particular orientation that results in the artefact.

The smokestack gets unbelievably hot. I think the flock tape would bend whether it liked it or not - right before it caught fire 😂

That is going to require a considerable amount of negotiation with my better half 🤭

Life is full of compromises. The quid pro quo for my spending time and money automating my observatory during lockdown was agreement to the installation in the garden of a wood fired hot tub from Sweden. For the past number of clear nights, I have been gathering hours of data on the Pac Man Nebula. Imagine my dismay when I finally got round to examining the integrations (yes, I should have checked earlier) and found this... After scratching my head for a number of days as to what the rather prominent artefact at bottom left could be, I finally identified the culprit. As the full moon has been rising it has been reflected beautifully in the chrome chimney of the bloody hot tub... As can be seen from the warm orange glow on the scope, I already have to contend with an old sodium streetlight that shines directly onto the observatory and which the council stubbornly refuse to convert to something downlit and LED 😠 Interestingly, the artefact only appears when the scope is at a certain orientation to the smokestack of the hot tub. I have now moved to shooting the Iris Nebula in LRGB and the artefact has gone... The moral of the story is: don't put the hot tub next to the observatory... 😂. The next question is whether I can process out the artefact from my hours of data?

I have been experimenting with adding Ha to my LRGB imaging of IC396, using the method whereby the red signal is removed from the Ha image using Pixelmath prior to combining the Ha with the red channel ahead of building the LRGB image. This image comprises approximately 16 hours comprising 4 hours each of LRGB, and 6 hours of Ha taken with my QHY268M attached to my TS Optics130 Triplet APO mounted on a Losmandy G11. I am not sure what the Ha has added to the image really but include the original LRGB for comparison. I think I prefer the LRGB to the LR(Ha)GB as more natural looking. I am at present doing a project on small nebula (the Pacman Nebula and Lower's Nebula), so will try and refine this method on those images. LR(Ha)GB: LRGB:

This is my take on IC1396 taken with my QHY268M and TS Photo Line 130 Triplet Apo on Losmandy G11. The data was gathered on 12-13, 14, 18 and 20 November 2023. L, R, G and B approximately 4 hours each of 120s integrations for a total of approximately 16 hours. Processed in Pix Insight and Photoshop.

I have often wondered whether they could design what might be called a 'filter cube' for the RASAs, at least for narrowband. This would be a cube with openings for the light path at the front and back and enclosing a cylinder mounted across and rotating within the light path. The three narrowband filters would be mounted on the circumference of the cylinder with a hole opposite. As the cylinder rotated, the filter and its corresponding hole would enter the light path. The profile of such a gizmo would certainly be smaller than the filter wheel. Just musing over my lunch...

Thank you for your kind words. Yes, I have a TS Optics 2.5” Field Flattener on the TS130. No h-alpha used in this image. I am going to try integrating some h-alpha into the red channel on my next target - if the clouds ever clear!

Over the past six months I have been upgrading my equipment. I have replaced my QHY8 with a QHY268M and have replaced my TS Optics 152 Individual achromat with a second-hand TS Optics 130 Photo Line Triplet APO mounted on my Losmandy G11 reconditioned with high torque motors and one-piece worm blocks. This is the product of my first proper project with this set up. The image represents approximately 16 hours of integrations comprising 4 hours each of L, R, G and B under Bortle 5 skies. The integrations were acquired using SGPro, calibrated, stacked and processed in PixInsight and finished in Photoshop. I had some problems with my flats, particularly on the R, G and B channels but, overall, I am quite pleased. Constructive criticism always welcome 😀

It is faster than my old HP desktop but not as fast as I had expected with the new spec. Reading the other replies, it looks like the programme is just very resource intensive. As @tomato and @gorann say, I guess it gives more time for other activities 🤓

Each year my mother gets me a magazine subscription for Christmas. Lately it has been the London Review of Books, but I am thinking of making a change this year to astronomy related publication. I am aware of the obvious magazine choices, does anyone know of a good astronomy or astrophotography type periodical that has an easily accessible subscription?

I recently purchased a Lenovo Quad Turbo Laptop with an AMD 3020e 2.6GHz processor, 32GB RAM, 500GB SSD and AMD Radeon RX Vega Graphics. The machine was very good value on Amazon at the time and I wanted a large amount of RAM for a price that was not crazy. I have found that this machine is much faster than my old HP i3 desktop when working on the huge files produced by my QHY268M, both in PixInsight and in Photoshop. However, even on this specification, the laptop still takes a very long time to work its way through my files notwithstanding the increased spec. For example, Local Normalisation of 120 x 120sec light frames can take well over an hour and a half. The Radeon graphics chip (essentially a GPU) is engaged by Photoshop to a limited degree on some processes. However, my understanding is that PixInsight does not access the GPU (although, if you have an NVIDIA GPU, the NVIDIA CUDA code can be used to allow Starnet2 to access an NVIDIA GPU). It may be that I do not have the machine's memory set up correctly and if the above sounds too slow given the specifications, I would be grateful to receive any tips for optimising the set up.

I am lucky to have a permanent, remote-controlled set up, but even with being able to operate it from wherever I am I think I have managed only one dusk to dawn session in the past two months. A large number of initially promising early evenings have turned to thick cloud and very high humidity. I find that using a combination of Clear Outside, MeteoBlue and the Met Office gives a pretty reliable indicator of the position over in the coming two or three days, but it does not stop that position being thoroughly depressing most of the time at the moment 🙄

When registering mono frames in PixInsight, is it better (a) to use the best frame from the channel being registered as the reference frame for that channel or (b) to use the best single frame from amongst all the channels as the reference frame for each channel, to ensure that each stack is registered against the same reference. When I tried option (b), I got a result with black haloes around the stars and poor eradication of satellite trails etc. which has made me wonder whether I should be using option (a). Apologies if I have not articulated the question sufficiently clearly!

I have recently moved to mono imaging and went with 2” Antlia LRGB filters and a 2” Antlia 3nm Ha filter. I have been pleased with their performance so far. I have stuck to LRGB in the first instance, with some Ha to supplement the red channel, as I have found that there is so much to learn when moving to mono. I plan to get the 2” Antlia OIII and SII once I have some experience with LR(Ha)GB and my bank balance has recovered 😳

I have just switched from DSS to PI. It does indeed take much longer. It has taken me nearly a whole day to do one channel, although I suspect I will get faster as I become more familiar with the PI process. However, the results in PI are, at least to my eye, better than those produced by DSS. I was also a bit of a sceptic regarding the whole “if you use PI you get to know your data better” thing, but I am slowly being converted to that argument too 😂

Beautiful images. Quite stunning.

Many thanks Olly. The idea of “dosing” my data with various applications made me laugh. I almost have a complete set of LRGB data on the Elephant Trunk nebula so am keen to try a complete workflow on mono data. It is clear here at the moment so I might get my blue channel- although I am probably speaking too soon 🙄

I am currently finding my way with processing LRGB images. Is there a recommended point in the processing workflow at which to undertake star removal and replacement? My instinct says after channel combination but before further processing...

If the target was close to the zenith when you tried to slew back to it, I would check your mount safety limits (if you have them). I had a similar difficulty recently on my Losmandy G11. Both my East and West safety limits were set to less than 90 degrees following the installation of a new and much larger camera and filter wheel. This had the effect of preventing the mount from accessing an area around the Zenith. When I increased the safety limit on the West to 120 degrees (still safe for my set up) I could access the zenith again.

I too have everything except my processing software on the PC in the observatory (a HUNSN industrial PC) and I access that PC using MS Remote Desktop either from the house via a hard LAN line or from elsewhere in the world via a WAN using port forwarding on our home Internet router. I have found the MS Remote Desktop connection to be reliable and stable in both configurations.

I am banking this one! 😃

I went to the party. It was very good, and I saw lots of old friends I have not seen in years. But also, I could not resist testing and calibrating the new set up from my phone and running a sequence. Rather a risk strategy with a new configuration but managed to get 9 hours of data in the end (together with a few odd looks whenever I retreated to the corner with my phone to check on progress 😂).

My set up is remote control but, in addition to needing to test and calibrate the new configuration, I too like to be hands on, if only from the comfort of the house!

I have for some weeks been revamping my system with a mono camera, second hand Triplet APO, remote controlled scope cover etc. On the first night in weeks when it looks to be clear enough to test and calibrate the new system I have a family 50th Birthday party. I will have to go, but it led me to wonder how many would choose the clear skies instead...?