Adreneline

Well I guess you won't know until you give it a go. My experience with OIII has not been good unless it is very dark and clear - i.e. no Moon and very good seeing. I've found that although I can get something to start to produce a HOO or H(HO)O image the noise from the OIII can really spoil excellent Ha data. SII is better but not a lot of use to combine with Ha unless you have OIII as well. Good luck - I look forward to seeing how you get on.

I tried OIII once I'd taken 20 frames of Ha. Just one frame convinced me I was wasting my time with no astro darkness; OIII will have to wait a few weeks I think. When I went to longer than 180s in my previous location all that happened was the background levels came up and there was no perceptible improvement in detail from the target. With my CCD (Atik428ex - now sold) I was able to push it up to 300s and even 600s and there was an improvement in depth but at the expense of more wasted frames from low flying aircraft which would literally obliterate pretty much everything in the fov. Some nights the planes were landing 2 minutes apart so a 10 minute sub would be a total write-off. Adrian

Hi. Thank you. Habit is probably the honest answer. I used to live in a Bortle 5/6 area and going beyond 180s offered no benefit. Haing moved to a Bortle 2/3 area I'm still using 180s (and sometimes 120s and 60s) simply because I have Master Dark frames to match. I also used to live under the flight path for a fairly busy airport (EMA) and when I used 300s or even 600s with my previous CCD far too many frames were wrecked by passing aircraft coming into land - the discard rate with 180s was far less. I suppose I should try experimenting in this location with (a) longer exposures and (b) changing the gain when the astro dark skies return. Have to say I am pretty happy with the depth I get using 180s, gain 139, offest 50 and -20 degrees but I really should experiment more I guess. Adrian

Not really. The slightest movement across the DEC axis in either of the orthogonal directions and it's winging its way off. The CEM25 is extremely free-moving and it is quite difficult to incrementally slide the rigs in the Vixen clamps. I've used the tape approach too - but it doesn't help that I keep tinkering and modifying

Looks really good to me. I find it interesting to see how people evolve their rigs. How easy do you find it to balance on the mount? I presume your Samyang weighs quite a bit more than the mini guide scope. I have thoughts about using my Samyang RGB rig alongside my RedCat NB rig. So far I've found it very hard to get it perfectly balanced on the iOptron. The RedCat and Samyang as configured weigh nearly the same but I find it really tricky to balance in DEC. Adrian

Hi Jonny. Flats aside I think this is excellent. I hope you don't mind but I did a bit more tinkering in PI. On my screen the image has a noticable magenta cast (sampling the background showed the R and B were consistently above G) so I inverted the image and removed that and then I re-inverted the image and removed the resulting green cast, both with SCNR. I then reduced the noise a little bit with MLT and finally aligned the histograms in HT - Red needed a very slight adjustment. I've attached a cropped TIF. I know many people like magenta in an image but magenta is a colour that does not occur in the spectrum so I tend to feel it should be removed. This is purely a personal thing and not based on any science or accuracy or anything quantifiable - it's just me! Great image - magenta or not! I wish my first attempt at M51 had been this good. Adrian M51A_aa.tif

Thank you Tristan - it worked better than I expected. I tried the OII filter at about 01.00 - a moment of particularly wishful thinking - how foolish of me! Adrian

Thank you Lee. I've been reconfiguring my Samyang - again! My brother-in-law has printed some stuff off for me. It's still a w.i.p. - I'm trying to learn how to use Fusion 360 so I can create an HTD form gear to attach to the lens focus ring - I'm getting a bit old to learn new software Also got the WO handle/guide-scope mount on order to improve that aspect. I know the 294 (which I bought with the RC in mind) is not a good match but for adding RGB to NB I still think it has potential. It might be a rubbish time for serious imaging but it's still useful for trying new things and refining existing gear - like fitting the EAF to the RC in preparation for 10th June. Does refining ever finish? Adrian

No astro darkness and pretty rubbish seeing but hey-ho the gear was suffering from a severe lack of use so decided to brush off the dust and have a go anyway. This is 45 x 180s of Ha using the RedCat + ASI1600MM; calibrated, registered and integrated in APP, processed in PI and tweaked in Affinity. I thought it was worth including the starless image as well as there is so much structure to see in the nebulosity. Thanks for looking. As always C&C welcomed. Adrian

Welcome to SGL. Enjoy! Adrian

Hi John I have Topaz DeNoise AI and have used it selectively on some DSO images; I use it in Low Light mode and set the denoise to 2/3 and sharpen to 0/1. I have seen some on SGL express the opinion that the programme can introduce 'false" detail and that it's use should be declared. I am not qualified to comment. Regarding planetary sharpening I'm not sure why DeNoise AI is any different to wavelet sharpening in something like Registax, or indeed sharpening in any other image processing software. Providing the sharpening is done in moderation and with care then it can enhance the final image and still give a very natural look. Personally I prefer your second image - to me it is much more pleasing on the eye and I think the end result looks very good indeed. Adrian

I do but for no good reason other than I'm a bit OCD'ish.

Wishing you a well deserved retirement. Thanks for all the advice you have given me over the past four years. Good luck and good health to you both. Adrian

I think you are probably correct on that one; it's certainly looking a lot better now. Are you using any sort of focussing aid, e.g. a Bahtinov Mask? - or software such as SharpCap? I would get everything else sorted before you start experimenting with gain and offset. On my ASI1600MM-Pro I only ever use unity gain (139) and the default offset of 50. I also only use 120s or 180s exposures and all at -20 degrees. Sticking with 139 / 50 / -20 keeps the number of calibration frame options down to a manageable number. Good luck!

That looks like a really promising start. To help people help you did you take any other calibration frames? e.g. darks, dark-flats, bias? If so how many? Adrian

I am pretty satisfied with the way my Samyang 135mm and ASI294MC performed imaging IFN from Bortle 3/4 site. A Samyang 135mm costs a lot less than a RASA 8" and an ASI294MC is a lot less than an ASI2600 so it goes without saying the images won't be anything like as good.

.... or there again, perhaps not! I'll be good and ready for the return of astro-darkness in late July that's for sure Adrian

I like it a lot because it has a natural look to the colour. Nice to see you’ve avoided the temptation to force every last shred of colour out of M27. Adrian

My latest Samyang configuration. The 294 has an Astronomik L2 filter fitted in the 11mm spacer and the 135 focuses in the middle of the ‘L’. Adrian

Very nice Lee - another excellent Ha image from the Samyang. Mine is now permanently attached to the ASI294MC complete with EAF belt drive and my ASIair-original ; it’s very light weight. I’m itching to try it alongside the RedCat+ASI1600MM narrowband rig. Just need a clear albeit short night!

I purchased a RedCat at the end of last year and I am delighted with it in all respects. The build quality is excellent and the I have been very pleased with the resulting images. One advantage of the RedCat over the GT81 is that you won't need a dedicated reducer/flattener which will save a few pennies! The lack of r/f also make the RedCat a little more forgiving regarding spacing between the end of the OTA and the sensor. I guess it comes down to what you want to image to some extent. I like to image NB targets and I like to image them in context so I prefer the wider fov. I use the RedCat alongside a Samyang 135mm with either an ASI1600 or an ASI294MC all controlled via an ASIair. Which ever you chose I am sure you will be delighted with the performance. HTH Adrian

I think this is really good - lots of structure in the nebula - great stuff. PixInsight can be a bit of a challenge but it is definitely worth it in the end. One thing you might be interested to try is the EZ Suite of scripts one of which allows you to reduce star size a little in the image. HTH Adrian

Wow! Very impressive.

I think GCs are the hardest things of all to image and you've done a great job. Adrian

Excellent! I know the CEM120 is in a different league but I have been delighted with my CEM25. The iOptron Commander software is loads easier to use than EQMOD etc. and it works flawlessly with the ASIair and SkySafari. The only issue I have had, and it is probably entirely down to me being a numpty - or incompetent - is no matter what I do I cannot get Astroberry to work reliably with the mount but that probably won't bother you. Hopefully you won't have to wait too long - I'm sure it will arrive in plenty of time for the next nebula season! Adrian