Adreneline

Good luck David! Hope you get some good results tonight; not easy on these short nights when Mr Moon is up and about but it's still a good opportunity to sort out a few niggling issues and problems. Next time I get my gear out I will be sure to screenshot the focussing results I get with SharpCap for comparison. Looking forward to seeing the results of tonights endeavours! Adrian

From purely personal experience I have found SGP hdr focussing not to yield good or consistent results. I have wasted so much time trying to get autofocus to work that I now focus manually, albeit with a stepper motor focus unit - I go and stand outside and use SharpCap on a laptop - five minutes (if that) and I'm done. As for SharpCap I've decided £10 year is money well spent; it is constantly being updated and improved. I use both the FWHM Measurement and Bahtinov Mask options and find I get very good results. Solving problems is all part of the fun! Not sure you ever reach the point where you've solved 'em all though! Good luck. Adrian

Hi David, I've used a BM with and without success. I've recently started using SharpCap (£10 per year) to help me focus with a preference for FWHM measurements but success depends on so many things, including the 'seeing'. I do pretty much the same but I have had more success using a uniform light source; I use my iPad running a lightbox type app and get very consistent results; the flats also work! Well done you! I'd be happy to have that average over an imaging session. tiff is just fine but I wonder whether it is DSS that decided to save as rgb rather than greyscale. I presume you have checked it is expecting to process mono images - it's in one of the Settings menus somewhere - can't exactly remember where though. As for the artefacts I'm really not sure what to say - it doesn't look like dew to me. It may be the flats just not doing their job properly. Another thing I would say is that the advice seems to be not to use Bias with a ASI1600 Pro. Rightly or wrongly (but it seems to work for me) I've started using flats + dark + dark-flats (instead of bias). If I'm doing something very wrong then hopefully someone will pop up and put me straight! Dark-flats are exposures taken with exactly the same exposure times as the corresponding flats but with the lens cap on - hence dark! You can use them in DSS. I would have another bash at taking your flats. I know dust bunnies may have moved but it might correct the vignetting problems you are experiencing. People use a variety of white light panels; I tried using one of the Huion panels but found it gave me severe 'banding' when used with both my dslr and ccd's so I gave up. HTH Adrian

Hi Brian, A really nice image; love the framing and I especially like the blues in the core region. NGC7023 is one of my favourite objects to image although my past efforts have hardly done it justice. I hate to be critical but there seem to be some strange 'linear' bands extending from the top of the image down toward the bottom; they are especially noticable on the left of the core. It's almost as if they are radial and the centre is way off to the top of the image. It might be my MacBook display or my eyes! I've looked at a few other images (e.g. APOD) to see if I can see the same thing but no joy. I am afraid I have no idea what might be causing them and unless someone else points them out maybe it is just me. Thanks for sharing. Adrian

Well I managed to get something for you although I'm sure those with more expertise could achieve far better. All the individual masters were rgb so I converted them to greyscale. I haven't used the Luminance master. I took them into PixInsight, cropped the vignetting (not sure the flats are doing the best job for you) and then applied AutomaticBackgroundExtraction (ABE) twice, once as subtraction and then as division. I then created a luminance mask and applied some noise reduction. I then duplicated the image and to one I applied incremental/multiple HistogramTransformation (HT) and the other I applied an ArcSinhStretch. I took the resulting images into Photoshop and layered the HT image over the ArcSinh image as a lighten layer with about 40% opacity. Finally I applied a little bit of extra noise reduction. You can definitely tell it is M81! Maybe the focus could be a bit tighter and there are a few artifacts on the masters I don't understand (especially the red for some reason) but hey! - you got a pretty good first image hiding in amongst all that data. HTH Adrian P.S. May I ask how you are taking your flats?

I think it is amazing what this 135mm @ f2 plus the ASI1600 @ unity gain, offset 50 can achieve on a 50% moon night; this is 25 x 120s of Ha and 20 x 120s of OIII taken between 23.50 and 01.30 last night. Sadr Processed in PI with a final colour tweak in PS. Adrian

Really frustrating with all the clouds of late which is stopping me experimenting with my new ASI1600 with the Samyang 135mm. There might be undersampling but I still love the level detail combined with the wide'ish field of view - a compromise I can live with. This is IC1396; 12x120s + 12x180s + 12x240s all at 200 gain/50 offset pre-processed separately in APP and then combined as HDR in PI, followed by a little bit of tweaking in PS. Stars removed using Annie's Astro Actions in PS. Next time I'll aim to get all of Sh2-129 in the shot as well! Thanks for looking. Adrian

Nice shot. What was the camera?

I also managed (just!) to capture 15x120s of OIII last night to add to the Ha in my earlier post. The target was only at 30 degrees elevation and well within the LP of Derby and LP from the moon. It's a testament to the 135mm and the 1600MM-Pro that I got anything at all! Just enough to add a little bit of colour and hopefully not too much noise. This is pre-processed in Astro Pixel Processor, followed by DBE and HT applied in PixInsight, and then Bi-Colour combined using Annie's Astro Actions in PS followed by a little bit of noise reduction using Nik dFine2. Adrian

Hi Rush. I bought the belt from MotionCo - along with the various pulley components, etc. I don't think I will be going for the electronic option thank you; I prefer the simple approach Good luck with sourcing an appropriate belt. Adrian

I've had my 135mm a year now and used it primarily with an Atik428ex and more recently a ASI1600MM-Pro. This is the Heart and Soul using the ASI1600; 15x120s + 15x180s at unity gain, offset 50. I really like the wide field of view offered by this combination. I use a fairly manual setup - manual filter change and semi-manual focussing using a homemade stepper motor system. Thanks for looking. Adrian

An excellent idea - and not just images but also images of how members have mounted the lens and overcome spacing and remote focussing challenges maybe? Thank you. Adrian

Welcome! Nice image - very evocative. The advice everyone gives (and gets) is read this book: https://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html Enjoy and looking forward to seeing more images from your equipment. Adrian

Very nice image Martin - I love the colours. May I ask the Ha/OIII/SII composition of the RGB channels? Is it simply SHO or is there more to it than that? I am being very tempted by the ASI1600 Pro to use with my Samyang 135mm. Adrian

I know this is a personal thing but I really like to see images of HH without the diffraction spikes. This is a great image Adam - thanks for sharing. Adrian

Hi vlaiv, Thanks for clearing that up. Adrian

Hi vlaiv, The PI forum article (the link I've sent) says in Warning (Note) 2 : "Do not combine denoised images. Signal-to-noise ratio (SNR) will be enhanced by combining noisy images and denoising the result. Combined images must be equally exposed, have the same pixel resolution, and be registered by projective transformation with no distortion correction." The LV tutorial ( https://www.lightvortexastronomy.com/tutorial-narrowband-bicolour-palette-combinations.html ) advises the opposite - perform denoising before combining. That's why I'm confused. Sorry if I am confusing you as well Adrian

This is the link vlaiv: https://pixinsight.com/forum/index.php?topic=9206.0 Thanks for looking. Adrian

Hi Wim, I agree entirely, but these two articles seem to be at odds - one says denoise before combining Ha, OIII, SII masters using PixelMath (or whatever) and the other says denoise after combining the individual masters. I have a feeling it's all pretty marginal if the original data is good and you would be hard pressed to tell the difference as to when the noise reduction was performed. As you say, best to have good data and not to have to denoise and not to have to use deconvolution either! Thanks for your response. Adrian

Hi vlaiv Many thanks for your reply. The PI forum article was specifically about combining Nb images, e.g. Ha, OIII and SII, and using MureDenoise, making the point that individual masters should not be denoised prior to combining. The LV article mentions MLT but previous tutorials make it clear MLT is only one option, others include MureDenoise. Hence my confusion. The only thing in common is that images should be stretched to non-linear before combining. Adrian P.S. This is the link to the PI forum article: https://pixinsight.com/forum/index.php?topic=9206.0

So far when processing Nb images prior to combining as Bi-Colour or HST etc. I have followed the advice given in the LightVortex tutorials, namely "They have been fully pre-processed, have been registered with each other, have had background gradients removed with DBE and have been noise reduced with MLT...... in order to get the most out of colour combining these images, it is best they are stretched to non-linear". I was nosing around on the PixInsight forum and came across a MureDenoise script for denoising linear monochrome images, where the advice given was "Do not combine denoised images. Signal-to-noise ratio (SNR) will be enhanced by combining noisy images and denoising the result". So now I'm confused - I think! What's the considered view on SGL? (a) pre-process, denoise, stretch and combine, or (b) pre-process, stretch, combine and denoise. Adrian

Well this is how I see it using the two basic formula f = m * a and f = (G x M x m)/ (r^2) where in this case M is the mass of the Earth, m is the mass of a feather, or a man or an elephant, and r is the mean equatorial radius of the Earth. So all objects fall at the same rate, i.e. acceleration due to gravity - neglecting air resistance. Does that help - or confuse?

Hi, I don't use heated clothing for AP but I do use heated clothing for motorcycling. Sports Bike Shop are excellent : https://www.sportsbikeshop.co.uk/motorcycle_parts/content_cat/1391 : they also have an excellent returns policy if it's not suitable/doesn't fit. It's also not too bulky as it has to fit under other protective clothing. Many of the units can be run from pocket power supplies - some run off the bike itself. Worth a look maybe if only to get some ideas. Adrian

I'll do some research. Have to say I hadn't thought about compatibility with BYEoS - I just assumed it would work! I'm thinking of getting an M50 anyway and was just wondering if I could get some extra gearing from the purchase. Thank you for your advice. Adrian

Hi Everyone, Just wondered if anyone had used a Canon M50 (or similar) for AP? If so any issues with spacing, using filters, etc. Thank you. Adrian