Adreneline

I've been a numpty - Sh2-155 is in Cepheus and I was looking in Cassiopeia. Thanks again.

What the heck - here is the png version. Calibrated and integrated in APP, processed in PI and noise reduced in PS. Thanks again.

Thank you. I wondered if it was the Cave Nebula but I wasn't sure. You're right - the jpg compression spoils things but the png is a bit on the large side! I think I'll be trying to get some more Ha and even some OIII over the coming nights if CO is to be believed. Thanks again. Adrian

I can't help but feel that if this is your infinity focus position then the spacing is incorrect - probably by a fraction of a millmetre. When my stars are in focus the centre mark is right in the middle of the base of the 'L' mark which in my understanding is where it should be. Modern lenses will focus "beyond infinity" so you should not be looking to align the centre mark beyond the 'L' toward the infinity mark either. It took lots of trial and error for me to find the correct spacing and even then inserting/removing a 0.15mm spacer would throw the whole thing out. Even once I achieved the correct spacing the star shapes in the extreme corners were not perfect compared with the centre of the image; I guess it all comes down to just how good the optics are in your particular lens. Astrophotography makes demands on focussing that are never/rarely required in regular everyday photography. Good luck.

This is a wide field Ha image of the an area centred on IC1470 taken with my Samyang 135mm + ASI1600MM-Pro combination comprising 65 x 180s subs. I've used PixInsight and Astrometry.net to plate solve the image but not all features are identified in particular the feature at approx 62deg 30' : 22h 55m. I can identify Sh2-152, Sh2-157 (Lobster Claw) and Sh2-161 but not the feature in the top left just above the 63 degree marker. There are Sh2 emissions in the catalogue at 22:58 and 22:59 but they are not at approx 62.5 degrees. Thanks in advance and for looking. Adrian

Very impressive David. I will be well chuffed if mine works that well. Thanks for sharing. Adrian

Well I guess you are correct that there is no explicit requirement, however, iOptron provide a lead which connects to the controller and is terminated at the other end with an RS232 type connector. The instructions for iOptron Commander state that you need a suitable RS232 to USB interface cable with FTDI chipset and that is the lead that either plugs into a PC or into the ASIair. I agree it is not that clear but be assured it works! Yes, I have a Samyang 135mm mounted on the ASI1600MM-Pro. I also use the ZWO-EAF for focussing the lens - connected to the ASIair, and a ZWO-ASI120MM-mini for guiding which I rarely use as the CEM25-EC tracks very well without guiding, certainly for exposures up to 300s. Hope you get it sorted. Adrian

The hand controller needs to be attached to the mount and then connect the ASIair to the hand controller. It's pretty dificult to take a decent photograph but this is my setup. Hopefully you can see the hand controller is connected via the 232 type connector to the ASIair. Adrian

I use an ASIair with a CEM25-EC and the only time it has not worked as expected was after an update to the firmware and the correct mount was not selected but I guess you have checked and double checked that already. The only other problem I have had was when the Home position was not set correctly but I fear that was operator error! I presume you have checked that the ASIair is reading the GPS information correctly from the mount (via hand controller). Hopefully someone else will have some ideas on what might be causing the problem. Good luck. Adrian

Thanks to your help @Skipper Billy with the AllSky settings I had my first successful session last night - not that there was much to see! The software successfully uploaded a startrails image (with not a star in sight), a keogram (um? - the jury is out on that one) and a video showing a great deal of cloud with a brief break when the Plough and other features were clearly visible. It was enough to convince me the focus is good. The session last night was not headless - I ran a 3m usb3 cable out to the camera. I'm going to have another go tonight with the headless system but hard-wired to the network and see how it goes. If that is successful I'll try going wireless. 20200416-trim.mp4 Thanks again. Adrian

I have just started using Astroberry headless controlled from a remote laptop and so far it works consistently and reliably - for which I am mightily relieved! Fired up the pi3 allsky this morning and normal service is resumed - a perfect image uploaded to my local NAS box (acting as an ftp server) - something weird is going on somewhere. Thanks again for your help. Adrian

Unexpectedly I managed to add some OIII (30 x 180s used - 70 x 180s rejected 😭) to my Ha (60 x 180s) image - I need to try and get another 30 x 180s of OIII to balance things up. It would be nice to add some SII but I don't have a 2" SII filter! This is pure HOO: Thanks for looking. Adrian

Hi Gina, I am just starting to venture into this world too. I really like the convenience of the ASIair with my 135mm + ASI1600 but rather than buy two I decided to have a go with a pi4 and Astroberry. Not done any imaging as yet as I am still at the setting up and learning the software stage. The plan is to have it permanently set up on with my ED80 and EFW; I'd really like to buy a second 1600 one day but that might have to wait a while. First challenge is to get the allsky setup working! Adrian

Thanks @Skipper Billy and @stash_old for all the help and advice. The god's are against me today. I had the camera working this afternoon looking at a clear'ish blue sky with the odd cloud but as it got darker the image got brighter and now I've got this! I'm well confused. I've brought it back inside and reconnected it in the study and it has made no difference - I just get a featureless white image. Time for a glass of wine me thinks! Tomorrow is another day and fortunately I don't have any plans to go anywhere - again! Thanks for all your help. Adrian

That's brilliant - thank you so much David. It's looking like it might be clear'ish tonight so I'll have another go. I've been struggling today because I have now discovered that even when operating the pi3 headless I still need to shut it down in an orderly manner; I've managed to set up SSH so I can shut it down from the MacBook but not before having to reinstall the OS and the AllSky software. When it comes to Pi matters I am a complete novice! Thank you again for your help. Adrian P.S. The Rad Bike is on hold - as is just about everything else, including moving to Lancashire!

Hi David, I've just started doing the same thing using the thomasjacquin software and a pi3b+ along with my ASI120MM-S. I'm struggling to get a decent result and wondered if you could tell me what settings you use in the settings.json file in particular for "exposure", "maxexposure" and "gain" and whether you use autoexposure and/or autogain? Some sources I've found on the web indicate the exposure time is microseconds and not milliseconds as indicated in the table below. I've been saving the created startrails and video to my Synology NAS box working as an ftp server - works a treat. Any help or advice would be much appreciated. Thank you. Adrian

I own an iOptron CEM25-EC mount and recently bought the Polemaster system as opposed to the iOptron system. My reasoning was I may one day change my mount and by buying the Polemaster all I would need to do was buy a new adapter. Experience with the QHY system is so far very positive. Once you've got the hang of the software achieving an accurate PA takes only a couple of minutes. I say 'accurate' on the basis that my guiding (when I do it) is now much better with a far smaller RMS error that previosuly achieved prior to using the QHY system. I have struggled with the SharpCap system. The software is great but the resulting alignment always seems well off from the polarscope alignment. This may well be due to me using my ring mounted guidescope with SharpCap and maybe I have a degree of misalignment between the RA axis and the guidescope axis - I'm not sure. I am confident the QHY camera is very well aligned with the mount RA axis. Adrian

I have wasted so much time trying to get autofocus to work (in SGPro) that in the end I spent one night just establishing the best focus position with a BM. With my Baader filters and a ZWO-EAF I got these focus positions: OIII 28302 -50 G 28312 -40 B 28312 -40 SII 28322 -30 L 28352 0 R 28372 +20 Ha 28382 +30 The mean position is 28342 so close to L but far enough away from G and B (and OIII) to give bloated stars. Adrian

Very nice. I really like the level of detail you have revealed in the core region and the fact the outer arm structure is so clear. Thanks for sharing. Adrian

Hi Simon, My experience is it is all down to trial and error. If your focus mark is the other side of the 10 then I would suggest the spaceing is not correct and the star shapes may suffer. There is no doubt that 44mm is a good starting point but my experience is it is never 44mm. If I replace my Samyang 135mm with my Samyang 85mm the spacing is wrong again! If I use my Canon 200mm that is different again and I have found the correct spacing by trial and error - mainly error! A 0.15mm shim can make all the difference. I am pretty sure that these minor differences between lenses do not have a huge effect on day-to-day photography although you do see reviews by 'professional photographers' saying some lenses are not as "crisp" or "sharp" as others. I have spent hours outside on clear nights assembling and disassembling in order to find the correct spacing for my Baader filters. When I recently changed to Astronomik I had to start all over again. Good luck - it's worth it in the end. Adrian

My experience with the Canon fit Samyang plus Baader filters is that the spacing between the end plate of the lens and the sensor is 46.75mm and that is assuming that the sensor is at 6.5mm back focus as specified by ZWO (although I read somewhere that they quote a manufacturing tolerance on the sensor position of (I believe) +/- 0.25mm). The focus position is then dead centre in the 'L' mark - anywhere in the 'L' mark is good. There are numerous sources on the web advising how to use/interpret the 'L' mark. Adrian

Thank you! I'm glad you like it. I've seen Sh2-129 imaged on its own and it is very tempting to force the exposure. By adding Sh2-129 to this mosaic of IC1396 I hope I've managed to keep the relative 'brightness' in proportion. Adrian

IC1396 is one of my favourite targets and it seems only appropriate to include its near neighbour Sh2-129 in the image. Mu Cephei is Herschel's famous "Garnet Star," one of the most deeply-colored stars in the sky situated within the field of view of IC1396. It is a red supergiant star in the constellation Cepheus, and one of the largest and most luminous stars known in the Milky Way. μ Cep is big enough to show a measurable angular diameter, around 0.02" - equivalent to approximately 1,420 times the size of our Sun. If put in place of the Sun, μ Cep would extend midway between the orbits of Jupiter and Saturn; it could fit over 1 billion suns into its body. Mu Cephei is in the last phase of its life. Although it has certainly stopped internal hydrogen fusion, its exact evolutionary status is uncertain. Most likely, it has begun to fuse helium in its core into carbon. This great star is almost certainly destined to go supernova within the next million years. It will leave behind a vast hydrogen cloud which, for a star as massive as Mu Cephei, may be centered on a black hole. Now that will be worth an imaging session if mankind is still around in a million years! This is three nights of imaging amounting to 6.5 hours of 180s Ha exposures using a Samyang 135mm (f2.4) and ASI1600 (gain 139, offset 50, -20 degrees), unguided. Because I don't have a camera rotator there is some cropping to produce a rectangular image but left and right represent the extremes of the mosaic; North is "up". Calibrated and mosaic assembled in APP. PI used for background extraction and stretch. PS used for minimal noise reduction and contrast enhancement. Thanks for looking. Adrian

I know I've done IC1396 before but this is the best 3 hours of 6 hours of 180s exposures of Ha using the 135mm + ASI1600 (gain 139, offset 50 at -20 degrees) with guiding and dithering. Calibrated and integrated in APP followed by ABE and HistogramStretch in PixInsight and a minimal noise reduction contrast enhancement in Photoshop. I tried using MultiscaleLinearTransform with a mask in PixInsight to reduce noise and all it seemed to do was introduce lots of little black artefacts into the image. I'm not convinced that this image is that much better than the image I got with no guiding and no dithering! I'm beginning to think guiding and dithering is not worth the effort with this light weight, wide field setup on my CEM25-EC. Adrian

A single lucky (?) shot with dslr - better then nothing. Adrian