Adreneline

It is an interesting question but even if it is recorded by the sensor your eyes won't see it anyway unless we map the UV/IR to a colour range our eyes can see. I know my eyes can't see in the infrared range nor the ultra violet - maybe some folks are more fortunate - or unfortunate - depending on how you look at it! I don't believe eyes are like ears - my son can clearly hear bats - I just hear tinnitus

This is the third and final version of my experimenting with L+osc data on M13. The first version was 3hrs of Lum from the ASI1600; the second version was Lum + 30 mins of osc from a Canon M6 MkII; this is the Lum + 30 mins osc from a Canon 6D. The 6D has offered more colour content but with less definition; combined with the Lum data however I think overall the 6D has delivered a more pleasing end result. Processed in PI using the GHS script to try to preserve star size and maximise colour; I've not used any star reduction processes/scripts. Thanks for looking. As always C&C are welcome. Adrian

I have no experience of doing this in ImageJ but I have done a lot of mosaics in AstroPixelProcessor. I've tried both approaches in APP and have found the best results are obtained by stacking, registering and integrating the individual panes and performing any light pollution correction and then combining the individual panes into the finished mosaic. APP does an amazing job of not only registering the individual panes (even from different camera/optics combinations) but also blending the background of the individual panes seemlessly. P.S. This is the approach recommended in the Sara Wager tutorials using APP.

No. Fortunately I don’t need to guide with the CEM25-EC. Mounting the EAF below the Samyang would allow a small guide-scope to piggyback above I suppose.

Rarely imaged Sh2-150 and Sh2-145 in Cepheus. Really happy with the corner star shapes.

The EAF (or similar) is essential for the Samyang 135. I bought my belts and HTD gears from Motionco.co.uk . The red ring was 3D printed from an existing design intended for a RedCat 51. Prior to the red gear ring I used a section from a second belt which I attached to the lens using a double sided tape purchased off Amazon - that arrangement worked really well considering it was so simple. You don’t need to cover the whole circumference - just enough for the drive belt to engage to ensure good registration. I tried using the drive belt alone on the focuser ring but unless you employ excessive tension the drive belt will slip or ‘process’ and you won’t get repeatability in absolute focus position from the EAF. HTH Adrian

I use an EAF on all three of my OTAs (RedCat, 6"RC and Samyang 135mm) - they are perfect for my needs allowing fine focus control and repeatability. I used to own an ED80 and used it with a SW dc motor focus unit, initially with the stock focuser. The problem was the drawer tube kept slipping so I could not go back to a focus position with any degree of repeatability. In the end I swapped the stock focus unit for a Baader Diamond SteelTrack (BDS) and never looked back. There are times I wish I'd never sold the ED80 - with hindsight it was a great scope. Good luck. P.S. The EAF comes with an 'L' shaped bracket and a variety of couplers and will definitely fit on a BDS but it does leave the EAF sticking way out at the side of the OTA which made it really difficult to balance when used on my CEM25 mount. I have the BDS+EAF on my 6" RC but chose not to use the direct shaft coupler - I prefer a piggy-back belt drive arrangement. The BDS focus unit has a HTD compatible belt pulley built in! Very handy HTH

Thank you Rodd. I've always steered away from GCs in the past because in my opinion they are the hardest things to image and image well. My previous attempts have been dismal for a whole variety of reasons. I'm hooked now! I think my L data is all good, it's the osc/RGB data that needs more time. I might have a go with the 6D in the coming nights just to see how it performs alongside the M6 - the big pixels should help and as the detail is in the L the lower resolution should not be limiting. Thank you again for your feedback and comments. Adrian

Hi Rodd. I've taken on board your comments about background and had another go at the image. As ever I've introduced another variable, namely the addition of my 7 x 120s iso1600 subs. I hope you think the background has improved albeit at the expense of the stars - I probably should have left the 120s subs out. I need to keep in mind this was never really intended to be an M13 imaging session - M13 was just convenient as part of the process of collimating my RC - a bonus so to speak. It has certainly encouraged me to have a proper go at M13 once we get astro-darkness back in late July/early August. Once again thank you for taking the time to give me your advice and feedback. Adrian

Thank you Francki for the kind comments. I've only been at this AP game for six years and I have always thought that imaging GCs is the hardest thing of all - which in part is why it's taken me six years to post one - my previous efforts have been dismal in all respects Hopefully I can get some more colour when the dark nights return and improve the signal to noise issue. I might also try my 6D instead of the M6 as the larger pixels would gather more signal and be better suited to the RC. Adrian P.S. Your M13 is definitely better than my effort - your background is much cleaner (no mottling) and there is every bit as much definition and colour in the core - if not more! Excellent job.

Hello Steve, I've been playing with my M13 osc data, this time incorporating the 7 x 120s subs at iso800 - dithered - with the 15 x 60s at iso800. Lack of astro dark, a Moon and clouds conspired to limit what I got but all I was wanting to do was try out the Canon M6 with the RC and see if the colour it collected was any good - if not next time I'll try my 6D instead. Anyway! I did a comparison of NoiseX, MLT-NR and EZ-NR and this is what I found on the same stack of data (prior to NR I used BackgroundNeutralization and SCNR). You need to accept that the total amount of integration time here is only 29 minutes so you can't expect too much from the integration - it is noisy! This was all about trying hardware and checking collimation and not about imaging M13 - M13 was just bright and conveniently placed. I only tried the one setting of NoiseX (0.7). Personally I would not be too quick to dismiss it. As with all of these NR processes and plugins (irrespective of the parent application) the results will differ from stack to stack, target to target, and as with all of these things there is no magic bullet or setting that works on every image. I get very frustrated by this smash and grab approach to imaging and processing these days; too many images show a marked lack of care and attention to detail - just get it out there. Everyone seems driven by a desire to get an image of a target with minimal integration time using the new low noise CMOS camera, throw the lot into their preferred application and with the press of as few buttons as possible get an amazing image. With AP it is the total challenge that matters and makes the hobby so enjoyable. Too many are too quick to dismiss new things - and I am old and entitled to the view Draw your own conclusions from the above. Adrian

Thank you Steve. You see too many images where colour seems to be everything - the more the better - but I think it often hides detail and structure and less is often more in the finished image. The RC6 can be a challenge and it can be tempting to invest in all manner of expensive collimation devices - I have been tempted! In the end I just used a cheap laser eyepiece type thing to get it in the right ball park and then cast caution to stars and set about the secondary outside pointing at not too densely populated star field. I have to say I have taken it as a given that the primary was 'true' and upgraded the focuser to minimise droop. I've also used spacers to try to ensure there is minimal focuser extension. I think it has paid off. Non-astro dark is a perfect time to get these things sorted. Good luck! Adrian

Thank you. This is a rather poor screenshot of the defocused stars - the rings are as close to concentric as I can get - I fear if I try any harder to get it perfect I will mess it up! Adrian

Hi Peter. I'm not sure I am qualified to comment but maybe this will help: As it happens I have just been imaging M13 with my 6" RC + ASI1600/M6-MkII and this is my equivalent (roughly) plot: I am happy my eccentricity is <0.5 across the plot - my FWHM could be better but the contour looks reasonably distributed about the centre. I know my collimation is not perfect but it is close enough for me. I'll let you draw your own conclusions from the plots for your image. HTH Adrian

Thank you Rodd - I am pleased that you like it. Thanks for the tip - I'll give it a go later and see how I get on - your observations on the image and advice on fixes are much appreciated. Adrian

Thank you. I was surprised just how well the M6 performed considering it was only 15mins and there was a 97% Moon lighting up the heavens! I also captured 7x120s dithered but chose not to use them; I don't think it needs anymore but that a personal taste thing.

With the last throws of astro darkness I decided to have a shot at M13. I have already posted the mono version here but on Friday night it looked like the last chance to add colour so I attached the Canon M6 MkII to the RC and managed to get just 15x60s worth of colour at iso800, guided but not dithered. The colour image was processed separately in PixInsight using the new NoiseXterminator process and the relatively new GeneralisedHyperbolicStretch plugin - just two moderate applications of the latter. I then applied CurvesTransformation too pull out a little more colour taking care not to over-saturate - I just wanted a trace of colour and not a Cecil B DeMille representation as is so often seen. The mono and colour were then combined using LRGBCombination. Thanks for looking. As always C&C are welcome. Adrian P.S. The M6 attached to the RC

I use a Baader UV/IR filter on my ASI120MM-mini with SW EvoGuide and in my experience it has improved the performance compared with no filter fitted. I also use an Astronomik L2 UV/IR filter with my ASI290MM-mini with WO 50mm guide scope on the RedCat 51 - again I think it helps. With either of the above on my SW AZEQ-6 I get ~0.5"-0.8" guiding - with good 'seeing' it's been as low as 0.3".

P.S. I just fitted my Canon M6 MkII to the RC and I am hoping it really does stay clear enough for me to grab 60 mins on M13 again and grab some colour. Fingers crossed!

Hi Steve, I've had a StellaLyra RC6" for a couple of years and almost immediately upgraded the focus unit to a BDST and purchased an AstroEssentials reducer. I was reasonably happy with the results but the star shapes were never that good. Just this week I have 'played' at improving the collimation using a star test and, with reducer fitted, got the best concentric rings patern I could - it wasn't perfect but I couldn't get it any better. I then went on a imaged M13 and was pretty happy with the results. On Thursday night I removed the reducer and imaged M13 again with better results- better focus and better star shapes across the image. I'm not saying I have a perfect collimation but for a £375 OTA I am more than happy with the result. My reducer is staying out and I am going to enjoy 1370mm for a while. Adrian P.S. I did share the results - I guess you've seen this:

Very nice Francki - great detail again and very natural colours. Your TSA120+2600MC are doing a great job. Adrian

Excellent image with great definition and excellent colours. Thank you for including the most interesting NASA link. Adrian

This is a second session on M13 with the reducer removed giving a pixel scale of 0.562 arcsec/pixel and implying an effective focal length of 1390mm. This is four sessions : (25 x 60s) + (25 x 120s) + (25 x 180s) + (25 x 60s) finishing just before transit. I am really happy with the collimation now and don't think any further tinkering will improve things - quite the opposite in fact. I used NINA to collect the data, APP to calibrate, register and integrate and PI to process using two careful and restrained applications of GHS - as little processing as I could get away with. There is no dynamic or automatic background extraction (PI) or light pollution removal (APP) - this is literally how it came out of integration. All I need now is some RGB to bring a bit of colour - later in the year I fear as astro-dark has all but gone. Adrian