Whistlin Bob

Thanks @Ken82- yes it looks that way! I think the IDAS has an especially high transmission for Ha. The colour balance is pretty awful (despite what the marketing says!), but Pixinsight sorts that out easily. @vlaiv that's really handy- thanks!

I bought my ASI1600mm back in December 2019 and have been very pleased with it ever since- it comfortably outperforms my cooled, modded Canon 550d, especially on narrowband. However, one area that I've had to work hard to match my previous camera is with Ha regions on galaxies. I used an IDAS D2 filter on the Canon, and it picks out a bit of Ha as per this M81/82 from 2 years ago with a 200p: I returned to this target last year (in a 130pds) for the image below. As you can see- the hints of red are much weaker: This is partly down to a smaller scope and I can compensate for this by taking some Ha subs, but I don't understand why that should be needed when the DSLR managed quite well without them. As an experiment I dug out the IDAS filter and attached onto the front of the Coma Corrector and ran an LRGB sequence against the same target (back on the 200p). This was the result: I'm really pleased with this, to the extent that whilst I took a 40 minute stack of Ha subs, I haven't bothered incorporating them, because I can see that they're not going to add a lot that isn't already there. I'm still not sure about my attempts to leave the dust in, as it looks a bit noisy and patchy, but I can have a play with that later. The reason for the post is that I've always understood the received wisdom to be that you don't add an LP filter over your LRGB filters and I've never understood why that is. The usual domain for these filters is on an OSC camera over a bayer matrix, and I know from my DSLR days how much they can help with picking out detail. Following this experience I'm definitely inclined to continue using the IDAS filter for LRGB work, even if that's not what the textbooks tell you to do, but I wondered if anyone could shed light on what the thinking is behind all this... is it just a misunderstanding on my part?

Just laughing at myself... Your star hop sounds identical to mine but is 180 degrees in the opposite direction. What an amazing coincidence, I thought, that similar asterisms of stars exist around the same target in opposite directions. Then I spotted your location. 🤦‍♂️🤣

Loving the references to dob wobbling. It's a very effective technique on galaxies, but also works really well on nebulae. I was able to pick out the tadpoles nebula the other night with it, and nearly the whole extent of the reflection area around the Pleiades.

Great report Joe. I liked your description of getting to the Sombrero- it's a good star hop and a great sight when you get there 👍

It's called Bluelight filter but doesn't seem to be on the play store now. Like like there are loads using the same name so hopefully one of those will be ok. It literally dims my screen and cuts out blue light in a controllable way, which is exactly what I need.

I'll second what @Stu said- I use Sky Safari too, using the custom equipment menu to get the exact fov for my finder and most used eyepieces. I'm pretty lost now without it. I'm using the Android version- and I use it with a blue light filter downloaded from the Play store to preserve night vision. I used it at a Bortle 2 site a couple of years ago and it was fine.

I clearly got greedy!!! Subs like you had a good time with M3. I was just heading there when it clouded over, but I need to save something for next time 🤣

Wow- this had been my best session in many months. Forecast suggested it wouldn't be great, so a really nice surprise. From my log: Leo triplet. All three. Very nice. M51- very good views in 30mm and 7mm. Really nice. Bridge and disks clear in 7mm M101- very faint. AV only The beehive- rich stars. Too much mag even in 30mm M105 and two satellites nicely seen M96 and M95 at same time. Fab view. M91 AV only. Barely seen. M88 much clearer. Easily seen Markarians chain. Just a phenomenal view. M87 / Virgo a. And satellites. Phenomenal. M89 nice and clear M90 bit trickier but I got it Porrima- nice split. Like two cats eyes. Nice and even M104 sombrero first time from home M53- nice view. Hint of resolution in core Ngc5053 Really faint. AV only and needed sky Safari to know where to look. M64 black eye. Clearly seen. No detail. NGC 4725 nice clear view NGC 4565 needle shape really clear NGC 4494 nice little splodge Cor Caroli- white and yellow, clean split. Fantastic view Arcturus- gold in the eyepiece Izar- very nice clean split ... And then it clouded over. Never mind- that session will keep me going for a while.

I guess clusters aren't quite as photogenic as nebulae and galaxies so I don't often go for them, but during winter I always enjoy doing a little tour with my dob through the clusters of Auriga and down to Gemini so I thought it was high time I did a little collection. These were taken with an ASI1600mm on an Explorer 200p with an HEQ5 mount, each image is 10x30 secs per RGB channel @gain 250. Stacked in DSS, processed in Pixinsight and then put into a collage with GIMP.

Nice. Loving the faint galaxies you've caught in the background.

Just a quick thanks for posting this report. Was looking for some nice doubles far away from the moon as it rose over the house and here were three new ones to me. Got the first two no problems at all, but couldn't hop to the third as the sky seemed to go misty. Turned out afterwards I'd breathed in my finder. Never mind- the first two were lovely.

Effort 2 from me. Mostly the same process, but I always find with this really strong data that the temptation is to make the Sii and Oiii more dominant than they are (and why not- half the time I barely even get an Oiii or Sii signal at home!), so I tried a stronger mix of the Ha into the Red channel to make it a bit more stronger.

Effort 1 from me- Masked Stretch on each channel. Starnet, then switch to GIMP for a bit of layered blurring around Navi to soften some of the star removal artefacts. Pixelmath to combined in HSO, with O boosted x2 in it's own channel and subtracted from the signal in the other 2 to make it stand out more. Bit of Local Histogram Equalisation to bring out some of the texture in the nebula. Then, for the stars, back to the original channels and another masked stretch, but with background set to 0.05 and combined HSO. Then combine the stars back in using a formula of iif(Stars>0.5,HSO*.4+Stars*.8,HSO). Finally, back into GIMP to soften Navi a bit.

Thought I'd post a little well done (with a bit of envy!) to everyone who has seen it. I tried for ages on Wednesday night in my 8 inch dob. Tried 150x, 175x and a slightly silly 300x but no dice. Rigel and e/f in the trapezium were all quite easy, so it was definitely the night for it, but couldn't get Sirius b. It was my only miss of the session though- lots of lovely views of other winter treats, so not so bad really!

I made the most of a short clear spell last Wednesday. This is the Crab Nebula- the first object in Messier’s catalogue. I captured it with my ASI 1600mm and 8 inch Newtonian – its first use since last September- with 30 minutes of RGB on the stars and then half an hour each on Ha and Oiii. Not really enough, but there was intermittent cloud throughout the evening and I rejected more of the narrowband subs than I kept. I’m really fond of this object for several reasons: I love its place in history, with clear records in China in 1054 observing the actual supernova, it’s a good observing challenge and really jumps out with an Oiii filter, and it’s one of only 2 natural phenomena (the other being a neutron star collision) that we know of that produces Gold. I always get a bit whimsical and hold my wedding ring when observing M1, as a direct physical link to a similar ancient astronomical event. Doesn’t look much like a crab to me though!

Nice one! That'll be an excellent choice for the mount 👍

Must agree with the previous posters- although you can just about get away with a 200 for imaging in an heq5. I have mine in a converted shed which protects it from the wind and I can usually guide at 0.7-0.9" RMS. It's not ideal, but I do think the extra aperture helps with fainter targets.

Another vote for Rigel and RACI. You're right about the bit of polystyrene and the collimation cap as well. It does frustrate me that Skywatcher miss these easy open goals that make this telescope so much better for relatively minimal cost. I've had mine for getting on for six years now. It was my first proper scope, but having owned quite a few others now I really appreciate just how good it is.

@Ibbo! and @CCD-Freak those have both come out quite funky!

Very nicely done.

A tipsy dither. We have an Astro-imaging sub-group at our local club, and at the last meeting @Stub Mandrel suggested sharing bloopers, and I was thinking afterwards that it was a good idea- so here’s my submission… Sods law dictated that the only clear night in weeks should coincide with a pre-arranged zoom drinks and quiz night with some local dads. I thought that at least I could get some imaging done whilst it was on. Trouble is, to avoid walking noise on my Star Adventurer, I have to manually dither the mount. Three rounds in, before my turn to be question master, I suggested we have a ten minute break and quickly hared into the garden. Unfortunately it’s quite a delicate procedure, involving a tiny couple of degrees on the slo-mo knob. I completely botched it and had to do a hasty re-alignment. Just about got it done and ran back in thinking ‘Phew- got away with that’. No, I didn’t. See below: imaging restarted with completely different framing and polar alignment knocked out, leaving the mount slewing drunkenly off track. Anyone else want to share their 'less than perfect' efforts?

Wonderful report- really enjoyed reading it- also gave me a strong longing for my 14" to come out for the first time since November. There's a few favourites in your list I haven't seen yet this season- especially m1. The HH is an odd one. An Hb filter is very helpful for it, and UHC helps too. I had a pretty clear sight in Cumbria once, and some very marginal views at home. It's a funny object because, as John says, it's more darkness in a nebula bank that you're looking for than anything else.

Nice- I've found that to be a tricky target.

It's pros and cons- a good prime eyepiece will beat a good zoom, but a zoom wins hands down for convenience. My most used eyepieces are the Baader zoom, OVL Aero 30mm and Celestron 7mm. I use the zoom most of the time, it's great for zooming out, finding your target and then finding the right magnification. I use the 30mm for large targets (eg the veil, m31, the Pleiades) and the 7mm for close in work (the moon, planets and planetary nebulae). The improvement from the zoom at 8mm to the prime at 7mm is marginal, but it is there. The zoom will magnify by 150x which gives you a lot of detail. The scope will go much deeper on a night of good conditions but most nights you don't want to go too much deeper than 200x. Things get better, but the quality doesn't improve.