Hughsie

I use Pixinsight too and use MLT before stretching and then TGVDenoise afterwards if still needed. There are some great tutorials on https://www.lightvortexastronomy.com/tutorials.html which will provide some insight into Pixinsight. John

Hi Chris, Yes, I have the .63 reducer but wasn’t sure whether to use it or not. Seemed like a bunch of added complication what with back focus. Also, when using the calculator on RSpec-Astro to judge dispersion and coverage it didn’t seem to make much difference. Happy to hear alternate views. John

Thank you both for your reply’s. Most helpful. John.

Hi, I have spent a lot of time reviewing tutorials and reading guides on spectroscopy and I am close now to pressing ahead with a night under the stars. In terms of gear I plan to use the following; Celestron Nexstar 6SE; Star Analyser 100 and the ZWO ASI174mm camera Just two questions, I have a ASI120mm and ASI1600mm, does one of these three cameras have a benefit over the other? Also, in regard to capturing the spectra I was planning to take short AVI's, then take flat and dark AVI's and then stack into Autostakkert to get a single image. Would that be the way forward or is there another better route to take? Thank you in advance, John

It has been interesting reading the comments here. I have the spectroscopy bug and just waiting for a clear night. Looks like a great first effort Louise, hope I can achieve something similar. John

I love the Z61. It allows such great wide field images such as yours. John

I posted a 'work in progress’ of this image a few days ago prior to taking more sub-frames on a following night. The image below represents my interpretation of NGC 7635 in the Hubble Palette and has been framed to also capture M52 an open star cluster. Both targets are located in the constellation of Cassiopeia. The acquisition details are as follows; William Optics Z103ED scope with guiding provided by the William Optics 50mm guidescope and ASI290mm- mini guide camera. Imaged with the ZWO ASI1600mm Pro cooled camera using Baader 1.25” narrowband filters - Ha 7nm, Oiii 8.5nm and Sii 8nm. Acquisition software was Astrophotography Tool and guidance provided by PHD2. Sub frames all taken at a gain of 139 and offset of 50. All 5 minute exposures; Ha x 41 Oiii x 35 Sii x 40 Total integration time 9.6 hours. Backfocus remains an issue though I am gradually getting there with modest adjustments each time I image. Thanks for checking in. John

The whole region of the Veil Nebula is one of my favourite targets and I have yet to image this part. Your presentation is lovely image and a fantastic commitment at 11 hours. Thank you for sharing. John

The images are great especially the top one, crystal clear and sharp as a tack.

Wow, looks like we are on final approach!

Hi, I am not sure what your circumstances are such as working full time, retired or somewhere in between. For what it is worth I have just completed the Open University course S177 Galaxies, Stars and Planets. It is a module, cost c£500 and ran from April to September. It needed c8 hours per week study time. The reason I took the course was to get a grounding of the science behind what I was observing. There is a little bit of maths involved and some use of Aladin - imaging software. Overall I found it fun and gave me a better appreciation of what I am observing. There is an end of module assessment which I have just completed involving short essays, math calculations and observational work. The course is run on a distance learning basis with as much or less contact with the tutors as you need. There is a text book to work through which is also accessible online via iPad etc. John

Having fun with narrowband too. Great image Knobby.

Please see attached a close up of an image in the SHO palette. If you examine the larger stars you will see two points of lights positioned at the 2 o’ clock and 8 o’ clock orientations and this is consistent for each large star. Although the image is a combination of Sii, Ha and Oiii, these artefacts only appear in the images produced using the Ha filter (Baader 7nm 1.25” filter). At first I thought it was hot pixels but then this would be a random distribution across the image whereas these appear to be associated with larger stars in a specific orientation suggesting a ‘mechanical’ issue. The image is taken using a William Optics Z103ED refractor with a Flat 6AII reducer attached using a ZWO ASI1600mm Pro Cooled camera. I have done some research online and can’t seem to find any mention of this type of artefact and was wondering if anyone else has experienced this before? Thank you in advance, John

Image from last night. Ha 20 x 300s Oiii 20 x 300s Sii 20 x 300s just stacked in PixInsight and a splash of colour added. Further work needed. John

Lovely picture Francis especially as the Moon wasn’t too far to your East. John

As Laurin mentions, click on the brain icon and select the ‘Algorithms’ tab. Look at the bottom right hand button under Dec. You may have “Dec Guide Mode” switched to off in which case turn it on. Then take some dark frames, calibrate and run the guiding assistant from the tools menu for at least two minutes and apply any suggestions it makes. J

I have this joy to come when another clear night occurs. I recently purchased this https://www.astroshop.eu/extension-tubes/astoptics-extension-tube-variable-m48-extender-23-29mm/p,57790 to help make the adjustments to back focus. It's attached to the field flattener at one end and a couple of spacers at the other and wound and locked to give 55mm spacing. I hope, let me say that again, I hope that with this in the image train I can then calculate the exact spacing needed to put in permanently. I hope. John

Mac user here but bit the bullet and purchased a recon windows laptop. However, this may provide a starting point for your research as to what is and isn't in the realms of possibility. https://www.macobservatory.com/mac-astronomy-software Cheers John

Hi Francis, I am no expert here but I follow the processing of calibration images which is posted on the Light Vortex website. https://www.lightvortexastronomy.com/tutorial-pre-processing-calibrating-and-stacking-images-in-pixinsight.html#Section2 .Just scan read Warren's book on calibration frames and there are subtle differences between his workflow and that described on Light Vortex. During my brief spell astro imaging I have used the ASI294MC and always taken dark flats opposed to bias frames and followed the Light Vortex workflow with no major issues. Might be worth a look. John

Stars nice and tight, great contrast and subtle colours. Looks lovely. J

Microsoft. The only Windows you can’t look through because they are covered in Microsoft clag. J

Thank you Adam. I have ready many of your responses on here and welcome your feedback. You are correct, I have been struggling to get the back focus correct and this was as close as I have got so far. I have been playing with the Flat 6AII on the WO Z103 and got the spacing right at 4.6mm but there are still some stars which are elongated as you have identified. I now have an adjustable spacer and (hopefully) it will allow me to establish the correct B/F and then put the right permanent parts in place to correct this. But a question for you. With the filters in play do I need to account for the thickness of the filter glass too? I understand this to be 0.7mm on Baader NB filters. Thank you in advance, John

Just ordered a small part from the guys and girls at Astroshop.eu. Arrived promptly and came with a small packet of Haribo Flo, I have to ask, I get Haribo's from our Euro friends and polystyrene and clouds from you! Only kidding, Flo and Astroshop.eu are top merchants and come highly recommended by me. Jelly Beans Flo? John

That will be the cling film kicking in!

I would have to be careful of the wife first!