Daniel Karl

That's pretty awesome - did you take that with the 80ED? I've tried my luck on this pair, but from London I only have NB data in SHO and I haven't managed to process that in a way that looks quite right to me.

I did get SII and OIII as well, but haven't managed to get the colours balanced in a way that satisfies yet. I think I need to find a way to get some blue data despite the light pollution here ... still wondering if a H beta filter would help. Meantime the Ha in grey 130/800 Triplet Apo - reduced to f/4 with Starizona Apex L 0.65 | ASI 294MM | CEM70

Love it! I need to try to get some RGB stars some day ... tried this one from London last night despite the wind. Always find it fascinating how different the same objects come across in different colour and processing combinations.

Dragged the scope out into the wind yesterday and got about two shaky hours before the houses got into the way. 90mins Ha and 30mins SII through 130 Triplet Apo @f/4 (Starizona Apex 0.65 reducer) | ASI294MM | CEM 70 Really love how much is going on in this region - some day I'll have to get it from a nice dark site and get some RGB as well.

Love it!

@AdamJ Thank you With regards to how bad my light pollution is, I'm not quite sure to be honest - I would have guessed it's a 9, but ClearOutside seems to think my location is an 8. It's certainly not great for galaxy season - 😂

3.5 hours of Ha and SII and two hours of OIII with no nebulosity - haha - the last hour had some tree branches in shot that gave the nice diffraction pattern around my bright stars ... Thought I'd go for a bit of drama since it's such a dramatic name - haha - too much? 130/6 Triplet Apo reduced to f/4 with Starizona Apex-L | ASI294MM | CEM70

130/800 APO Triplet reduced to f/4 with the Starizona Apex-L 0.65 flattener CEM 70 | ASI294MM | 7nm ZWO SHO filters Got 4.5 hours before the powers noticed that I had new kit and rolled the clouds in ... there's a bit of tilt in the system, but for the first try on backfocus I'm quite happy with the reducer. Tried an all PS workflow with this one ... (except for stacking). Cheers, Daniel

Awesome

Got the reducer back on - still the old one, the Apex obviously arrived the morning after I can't seem to get the JPGs here to look quite right - the BG always becomes a bit darker and I lose a bit of the faint details, which is annoying because now it looks cut out ... some day I'll get my blacks to stay where I want them - maybe ... my dog still only stays if he knows I have a treat ... 130/6 Triplet Apo ("Super") | ASI294MM | CEM 70 | 4.5 hrs 7nm SHO

Tried again, this time with the old focal reducer (The Starizona Apex arrived the day after, obviously) ... bit of tilt in the imaging train as well, just to add a bit of dynamic 🤪 Managed to get 7.5 hours of data, and there is more nebulosity visible in the channels, but I like the contrast. Still haven't managed, to get the JPGs here to look quite the same as in Photoshop - the blacks are just a tad too dark and the transition between nebulosity and background becomes too hard. Maybe I'll get another chance with the Apex 0.65 tonight (that should almost fit the entire nebula) - but then again perhaps it's time to switch to a new victim?

My focuser doesn't even have threads, so the heavy camera with reducer and filter wheel just hangs off the 2" tube (which probably tilts as well under the load) ... and the tube is about 7cm out to get in focus. I also don't know if the focuser is square to the tube and I bought the refractor second hand, so who knows if the objective still sits square to the tube (I hope the elements are still aligned - 😄) I don't own a barlow or even a decent eyepiece and it's been 20 years since my last star test ... so at the moment my standards are: If I go full screen on my monitor and I can't see the distortion without squinting, I'm okay with it. It's a decent 32" 4K IPS monitor, so I'm still quite a bit away from that - hehe. But my eyesight is getting worse, so the problem might sort itself out over time ...

Nice detail - distortion is clearly not something that keeps you up at night (although I suppose the distortion free Tak still keeps you up at night - haha) I just ordered a new flattener, so I suppose I'll be entertained with shimming to find the right backfocus for the rest of the year and then trying to get the tilt sorted and the objective properly aligned ... maybe I should start saving for a Tak instead

@carastro Thank you, that's very kind! @CCD-Freak The Soul Nebula really surprised me actually - I'll give that another try when my new reducer arrives. @scotty38 Thank you ... It's kind of nice to have the London sky pollution as an excuse - haha. I think if I were to be in a dark location, I'd feel a bit of pressure - haha. @The Lazy Astronomer Funny, that you should mention that today - haha. I'm even lazier than you, because so far I have not taken any flat frames, but I just dragged the gear out to give IC 1848 another try with my old reducer and I was planning to get flats at the end of the night this time ... so I might be able to answer that tomorrow - or more likely have a load of questions - haha. I've also just seen some tilt on my first sub, but can't be bothered to try and fix that now ... I think I'll soon start a lengthy cry for help here to sort out my imaging train, because I haven't really figured out how badly my whole setup is out of alignment yet @TakMan Yeah - I was a bit surprised as well ... hopefully I can give that another try without distortion soon, but as things go. I'll probably end up not being able to get the colours like that again ... it seems they turn out differently on every attempt, even with the same data - haha. There's always another night ... (until there isn't but then I suppose I have more pressing problems) 🙂

Haha ... well, it took a lot of attempts in processing to get it even to this point - think that was attempt No. 7 ... next time I will get flat frames 😂 whoops - forgot to mention that ... it's a part of the Soul Nebula IC 1848 ... not easy to recognise from that mess - haha.

Decided to play around a bit without reducer/flattener on my 130 f/6 Triplet APO. Result was 4.5 hours of SHO under full moon with the ASI 294MM on CEM70. Conclsiuon: I ordered another reducer/flattener - 🤣 And then I thought ... Bortle 9 skies - full moon, only 650mm focal length - let's try a galaxy - hahaha.

@vlaiv I had not even thought about it that way (which shows that after 20years there is no trace of my physics degree left in my brain). I actually did what you suggested on my last picture and just added the stars from my Ha stack to the starless SHO - I guess aesthetically proper RGB stars wouldn't look great in this anyways. (please ignore the star shapes - this is without a field flattener - the one I am waiting for I was just wondering if it would help to have some blue data for some objects ... I tried to get M81 just to see how it looks, but only 800mm, London seeing and light pollution and a full moon was a bit too much I guess - 🤣 I should probably also take flats in future ...

Hey all ... it's cloudy and I'm waiting for a new flattener, so I got some time for stupid ideas I'm imaging from Bortle 9 London, so anything but NB doesn't really get me great results. I'm surprised with the SHO I can get from here, and so far just stayed away from objects that look better in RGB. But sometimes I wonder if I could get slightly less ugly star colours if I could get some blue data ... H alpha, O III and H beta as a kind of Narrowband RGB for stars. Then again, since stars have a more or less continuous spectrum, narrowing the blue down to H beta would only give an advantage if my light pollution somehow were less in H beta than in the rest of the blue spectrum, otherwise I could just go for a blue filter? Then again, again, a H beta might be a better fit and also give some nice details on the odd object? What do you think? Not worth or worth a shot? Am I missing something? Cheers, Daniel

@scotty38 - thanks! I'm pretty happy with the 294MM - but I don't have much to compare it to, because my last camera before it was a Canon 10D almost 20years ago - haha. I'm using the ZWO 1.25" 7nm filters - HSO - in the mini filter wheel. I only use dark frames for calibration, no flats (might give that a try some day). I've had a look at your thread regards the flats - to be honest, my backgrounds of the composites are far from even - I assume that the light pollution here in London accounts for most of that, but my illumination is certainly not perfect either. So far I've just tried to use Dynamic Background Extraction in PI to even it out a bit, but I haven't had the patience to do it properly. @Sterrenland Thank you - I admired your picture just before I shared this one ... I really like it. I actually feel like I'd like to have a shorter FL quite often. With the seeing here, I don't think I'll get a lot more detail very often. I sometimes wonder how a RASA 8 would compare in practical terms, but then I try to remind myself where that is going - haha. 20 years ago I had a 15" f/4.5 monster Newton on a German Equatorial Mount ... back breaking 192lbs for the RA/DEC assembly alone, then the counterweights, the OTA etc. My little Apo now is so much more convenient @carastro Thanks Carole!

Thanks Trevor! I tried some deconvolution and a different stretch, exaggerating the structure a bit ... it's so hard to decide, which way to take the processing.

3 hours through 130/6.6 Triplet Apo with ASI294MM on CEM70. The space bagel ...

Only just slowly getting back into this, so of course I couldn't resist M42. I only got about 2.5hrs of integration due to trees and houses and the seeing wasn't great ... but it was fun Started with a HSO Version for now - still getting used to this kind of data. Think I pushed it a bit too far - haha. I'll have to revisit this with fresh eyes Have a lovely evening!

I'm still experimenting wildly with completely new mount, scope, camera, guide system and processing. Still not sure where I am with the telescope. There's definitely tilt and backfocus issues with the reducer to address. IOptron CEM 70 guided with ASI120MMMini on Skywatcher 9x50 finder SET Optics CF - 130 Triplet APO f/6.6 with 0.79 TS Photoline reducer flattener ASI294MM-Pro with ZWO 7nm HSO filter set manually focused and controlled via ASIAir 40min Ha - 20min SII - 20min OIII (120s subs) combined to weighted SHO. All from Bortle 8 London - there's definitely room for improvement on all fronts First the reducer, then more exposure time, then a lot of stuff to figure out about the processing.

Thanks @AstroAndy and @JeremyS

Hey all ... So I had another late one last night playing around with my new setup. I had a look at the data today and am trying to interpret it in my sleep deprived state and decide what to do next - perhaps anyone has some suggestions The setup is: 130 f/6.6 Triplet Apo ASI294MM Pro EFW with ZWO 7nm HSO filters iOptron CEM70 ASI120MMmini on Skywatcher 8x50 finder/guidescope ASIAir Pro I chose the Crescent Nebula in Ha as my test subject. (I live in London, so Bortle 8 at least) The exact optical design of the APO objective is still a bit of a mystery to me. Some guy called Stevie T sold them about ten years ago under the label SET-optics. I found a few old discussions about them but nothing too illuminating in regards to the optical elements. The tube and cell seem very nicely made and visually the scope seemed fine to my out of practice eyes. This leaves me with the task of finding a reducer/flattener that works and the question of collimation after ten years or so. I currently have a Skywatcher 0.85 FF from the 120 ED Apo and a 2" TS Photoline 0.79 reducer. Yesterday I just tried both of them with a standard backfocus to get a starting point. The closest I could get to 55mm with the tubes that come with the ASI294 and EFW is 49.6mm+6.5mm=56.1mm with a 2mm ZWO filter I should theoretically aim to get 55.7mm right? So I am not quite on target. I focused with a Bahtinov mask (waiting for EAF) and interestingly the focus point of Skywatcher reducer setup was a whopping 3cm closer than the TS reducer which surprised me. Don't know how bad the seeing was, but the guiding was between 0.33 and 0.45, so good enough for now I think. Stacked, registered and stretched the results of 30m Ha were very similar in the image centre: But the corners were a different story - haha. Top left Top right Bottom left Bottom right Now I'm trying to interpret that - haha. It looks to me like the TS adapter wants to have a larger distance to the focal plane, whereas the Skywatcher is happier where it is, potentially a tad too close. Both do not show consistent distortion across all corners, so I suppose there is tilt in the system - either from the focuser or from the optical cell. I should probably try rotating the camera/reducer setup and see if the distortion rotates or stays in the same position? TS Corners SW Corners TS seems to be best bottom left, SW seems to be best bottom right? What would you do next? It seems I need to get the distortion evenly across the field first, before I shim the backfocus, right? Should I do a series of exposures rotating with each reducer to eliminate that it is a problem from mounting the camera etc in the focuser? Unfortunately the focuser does not seem to have any threads, so I have to use 2" connectors. Wow - this has gotten a long one - haha. Well - any thoughts are appreciated