Adreneline

When using my Canon 70D or M6 MkII I use BYEoS - it's stable, well laid out and a joy to use - I love it! When using my ASI1600 I use an ASIair; it has transformed an imaging session. Yes it has a few shortcomings (like I'd like to be able to input filters manually when I use a manual filter changer) but I can live with the interventions I need to make. It also works with my 70D but sadly not with my M6. I now use SGPro only for taking calibration frames! Like @ollypenrice I find it's constant interference and "deciding what is best" in what I'm trying to achieve infuriating. It used to be my main imaging software when I first started four years ago but I have lost so much time with crashes or just trying and failing to use features like autofocus that I gave up. Adrian

Nicely framed image. M31 is indeed a tough subject but also a rewarding one to image. I agree the background is clipped. I downloaded your image and the PS colour sampler tool tells me your background is R:G:B = 0,0,0 - it needs to be more like 20,20,20. There is also quite a lot of jpg artefact noise in the image (quite apparent if you zoom in) which in my experience seems to arise if you convert and image the jpg rather than the tiff or raw master file (I assume your 250 lights are shot in RAW mode). I've attached a zoomed in look at your image showing the background level and jpg noise compared with a similar image I took back in 2017 using a Canon 70D which might help to illustrate the points. Why not upload/attach your stacked, unprocessed master image (as a tiff) and someone might have a go and see what they can find lurking in the data. AP is a real challenge but definitely worth the effort. Good luck. Adrian

A lot for me to absorb here but on the point above and in particular "no proper colour" - hope this is not a red herring! - there seems to be an obsession with stretching r,g,b or ha,oiii,sii in none equal proportions when processing astro images, especially oiii which is often stretched out of all proportion with ha. If it is preferable/necessary to carry colour balancing surely equal exposure times and equal stretching should be applied to each component otherwise we are intentional unbalancing the colours in the image. I always try to expose each channel equally and then stretch each channel as equally as I can in PI which means I tend to end up with a pastel image. Doing the likes of removing stars so I can stretch oiii more seems intrinsically wrong - or am I missing something? Adrian

Interesting! Could you combine the colour balancing transformation, your own derived transformation and gamma correction into one all embracing transformation matrix? - effectively a one-stop-shop colour correction matrix for any image taken with your 178. Adrian P.S. I've been trying to visualise your transformation matrix on a 3D rgb axis transfroming r,g,b to r',g',b' - struggling with my visualisation tools. Have you tried any sort of visualisation - maybe in MatLab?

@discardedastro this is how mine ended up - camera on top of the lid. The challenge is to heat the dome and cool the camera!

I have exactly the same problem. Dark subtraction helps but I have found that the temperature can vary so much you would almost need to have a separate dark for every 5 degree increment! I don't really want to go to the expense of a cooled camera just for this application. Having said all of this I need to keep things in perspective. I've now got about 50 nights worth of videos and only a handful have allowed me to produce a half decent star trails image. Clouds have spoilt most of the videos from the point of view of catching meteor strikes or imaging star trails. Sensor temp has increased again - now at 32!

JUst read your account @discardedastro with interest as it is almost exactly the same construction method I adopted. I have made a couple of changes to mine which might be of interest. I have now mounted my ASI120MM on top of the box lid under the dome so that the distance between the dome and the lens is about 5mm - it gives a clearer image and is much less prone to spurious light sources causing annoying reflections on the dome. I bought a circular dew heater (2.5W) which was mounted around the camera body on the box lid, however, the camera sensor temperature would readily go above 30 degrees C and even above 40 in the day giving rise to an unacceptable amount of noise. I have now put the heater in the box (on one side) and drilled holes around the camera below the dome to allow warm air to get into the dome and stop the dew. So far it has worked well although the sensor temperature at the moment is still pretty high and there is some noise as you can see on the image below. That said we experiencing some exceptionally warm weather at the moment. The focus could be a little better as well. Good luck. Adrian

I've spent the last few weeks putting together a nice compact weather proof all sky camera to record this years Perseids meteor shower all based around a Raspberry Pi. Looks like the weather gods have blown a big fat raspberry at me Adrian

Last night I managed to use my new GSO 6" RC for the first time. When I started out on the AP path 4 years ago my first image was M31 so I thought it only right that I image M31 with the new OTA using the Canon 70D unguided but on my CEM25-EC (not the NEQ6 which I sold). This is manually focussed and manually dithered (!) and captured using BYEoS which reported an FWHM of 4.2 on my target star. The image comprises 20 x 120s lights stacked in DSS and post-processed in PI and PS. There are no flats ( I took them but they are all mis-orientated as I forgot to turn off the auto-rotate feature on the camera!) but I did take darks and bias. As I am completely new to reflector type scopes I would really like some advice on the state of collimation as the scope came "straight out of the box". The lack of guiding is evident although I feel the CEM25 coped really well with the payload; I did spend an age carefully balancing the OTA+camera. The intention next is to use the ASI1600 with ASIair but it was easier in the first instance to take advantage of the LiveView on the Canon. Thanks for looking and any advice would be much appreciated. Adrian

I use a Samyang 135mm with an ASI1600 on an iOptron CEM25-EC and it is perfect for me especially now it is all controlled by an ASIair. I too had an NEQ6-Pro and ED80DS and in the end got tired of lugging it out, setting up and then lugging it all back in at the end of a session. At a push I can pick up the current setup in one go and be out and imaging in 15 minutes having polar aligned with a PoleMaster. @Skipper Billy's setup looks great and I may well take that route once we've moved house in a few months time. I've just purchased a GSO RC 6" - I needed a challenge - which will push the CEM25 close to it's limits but should give me the opportunity to image some of the smaller nebula targets. I just need some clear nights so I can get to try it out! Good luck! Adrian

I use one and I am very pleased with it. I don't use a dslr but that said there are no power out sockets on the ASIair other than via the usb sockets. My dslr requires 7.2 volts - not what you'd normally expect in the 12V/5V astro world. It does and as far as I can tell on the occasions I have used it, it works pretty well. Having said that I use a PoleMaster and that definitely works well. There is an auto stretch and I can't see why it wouldn't work with a dslr. The ASIair has transformed my imaging experience when used with a ZWO ASI1600, EAF and EAW on an iOptron mount all controlled from an iPad running SkySafari and the ASIair app. I love it!

Thank you. It happened by accident rather than by design - it just evolved. Well there is a degree of star distortion at the extreme corners but you can minimise it by getting the spacing spot on and by ensuring there is no droop in the image train. To be honest I usually end up cropping the extremities anyway. I really like imaging with the 135mm - it is great from these large nebula regions. Adrian

You also have just about picked up Sh2-129 - The Bat nebula - which contains the elusive Squid Nebula (OIII) - top right of image. Well done! I did this random mosaic in Ha earlier this year for the whole (?) region which might be of interest - lots going on up there! https://www.astrobin.com/uxip1w/0/ Adrian

Thank you for a really interesting read and well done on your perseverance to capture Pluto. I fear (£££££) I may be starting to develop an interest in EEVA. Adrian

This one?

Hi Mike, I use a CMOS camera and take flats and dark-flats (same exposure time as flats but with the cover on the camera), and I also take darks; I take them all at the sensor temperature I used for taking lights (-20 in my case). Adrian

I used a 428ex-mono with my Samyang 135 and found the undersampling to be an issue in the end as the star shapes were not good at all. Having said that I quite like starless images when imaging nebula because I feel it can make the structure of the nebula more apparent so I was quite happy to remove the stars and just process an image of the nebula as at the end of the day I am imaging the nebula and not the stars. I tend not to post starless images because I sense most don't like the lack of stars as it is apparently not a true representation of the nebula - not sure I follow the logic of that one really as most of the stars are no where near the nebula in question! Prior to using the 135mm I used my 428 with an ED80. As you point out the fov is quite restricted for the larger nebula targets so unless you are into mosaics in a big way it can be frustrating. There's no easy answer - or maybe there is and I just don't know it.

Great image and I too really like the colour and the way you process your images - very subtle but full of detail - the more you look the more you see - just how it should be IMHO. Thanks for sharing. Adrian

I've found it to be so satisfying to use compared with my previous scopes (both now sold). I know you don't get a high level of detail but you get a great fov that is so well suited to the larger nebula targets. I've spent two nights on the Veil - on the left one hour on each filter, on the right two hours on each filter. Should I go for three hours on the next clear moonless night - whenever that might be! Adrian

Brilliant - I love this analogy. Thank you! P.S. Following this thread with interest. P.P.S. I guess when you've got 'a hole in your bucket' it equates to a bad pixel

Thank you. I might try adding more data but it gets to be a bit of a diminishing returns thing in the end. I had previously imaged the Veil with my Canon 200mm but it only just fits into the fov and even then the 'tails' hanging out the bottom are all lost - there again you get a bit more detail. Just goes to prove you can't have everything. Good luck with your processing; I look forward to seeing the end result. Adrian

This is now the original 20 x 180s Ha combined with 50 x 180s OIII and 30 x 180s of SII. I've tried to process exactly as before. I think the extra time on SII and OIII has helped reveal some more of the nebulosity. This is a side by side comparison; there is a slight difference in the background: Thanks for looking. Adrian

Hi John. I hate it when people answer a question by asking a question but blow me I'm going to do it - is there a reason why you don't plug a usb hub into one of your good, working usb ports? Running two laptops with two pieces of software trying to work in harmony sounds like a recipe for lost imaging time! Apologies again for asking a question in response to your question. Adrian

Thank you These are the three component images to make up the PixelMath (unprocessed) SHO image - definitely some useable SII, bottom left. Adrian

Thank you @MarkAR. The 135/1600 combination is good for capturing the whole target but detail tends to be lacking. Agree, more data is definitely required! Adrian