vineyard

Hello, I noticed a strange thing last night. Had the AP rig running. Two hours on Fireworks Galaxy went fine until it went behind some buildings. And so switched across to IC 410, and the guiding just seemed to go to pieces. It would start fine, but then the RMS would suddenly become horrific and the whole image would shift w trails. I gave up after 49 lights - frustrating b/c the night looked pretty clear - but while looking at Blink this morning, noticed that the trailed images were lights number 4,13,23,30,31,32,38,39,49. Not quite a regular cycle but a few cycles of 9/10 dithers in there? Yet the same mount had just done almost 2h on another target the same night w/o any such problems. The only difference I can think of is that the Fireworks Galaxy was the scope pointing west of meridian, IC410 was the scope pointing east of meridian. Has anyone ever had this before? Is it a dithering problem, or does the mount need servicing or could it have been a balance issue - or something entirely different? (Its an HEQ5Pro belted, & I was using EKOS internal guider with an ASI120MM mini on a ZWO mini guide scope. The main scope was a 4" frac f8.6 but reduced/flattened 0.79x to f6.8). Cheers, Vin

The central ridge line (running vertically) & the dark objects (Bok Globules?) on the left hand edge are v interesting. V curious to see the full 24h image! 👍🏾

In wine, there are blind tastings all the time (even double-blind). In medical trials, double-blind is standard. Have people ever tried that in astronomy (either visual or AP)? The judgment of Paris was (rightly) famous in wine circles b/c it showed that when tasted blind, Californian wines knocked the hallowed French brands off their perch. Even French drinkers picked (unknowingly!) the Californian wines as better. Would be v interesting to see that tried in astronomy!

Thanks @Alan White - that's a great idea re the time lapse. Has anyone ever done an H-alpha analemma over a year? That would be so cool - maybe something for SGLers in sunnier/desert climes?

Hello, Here are a couple of whole disks, the first on 16 Nov, the second on 23 Nov. 16 Nov: 23 Nov: And here are more or less the same part of the disk about 24h apart (22 Nov & 23 Nov) 22 Nov: 23 Nov: It's interesting seeing how much changes, & how much stays roughly the same. Cheers, Vin

Thanks @Highburymark - yes v happy w the SF50. I actually dread to think what a DS version would show. You're right about the last image being soft - if I remember correctly, I was wary of doing too much in ImPPG. I think I still have the original footage so I may see if something more can be done with it, or if that's just the original footage limiting it.

Hello, The sun has been lovely the last few days & I have managed to get some data that I will process & post. On one of the mornings, I had enough time to try w and w/o a 2.5x PM. Which ones are better? The kit is TV76 w SF50 (ie effectively f9.6) w ASI290MM (2.9um pixel size). So w/o PM that's a ratio of about 3.3. With the PM that rises to 8.3. I think the ideal ratio is mean to be about 4-5x right? So would it be better to not use a PM and just use ROI? I think the w/o PM images are better (& file sizes a lot smaller for some strange reason)? Cheers, Vin No PM: PM: No PM: PM:

I've used my Evoguide50 (w a flattener inside it) and then a TV40+PVS14 - all on a straight-through basis (takes it to f3). It does work - is a bit like the old nautical scopes from a form-factor basis. I want to try one of the 3x lenses at some stage (might be easier form-factor?) Here's a smartphoneM42 with TV76+TV40+PVS14. Handheld (hence some trails) & I also shifted the black point rightwards b/c the low-light std camera takes 3s images so the background looks a lot brighter in the image than the EP. (PS - I definitely want to try a sped-up 7" on M42 later in the season!)

Wow only 3h50 from Bortle 8 - that's a compelling demonstration of the case for mono NB!

Just checked your astrobin for the fuller images - beautiful. I notice you used the L-extreme for a few of them - are you happy with that? May I ask what Bortle your skies would be? Thank you!

I use an HEQ5Pro belt-modded w an old TV102iis (880mm f/l) refractor. With flattener, spacers, OSC, guidescope&camera, Pegasus UPB etc mounted on it, the whole thing comes in at around 10kg & for me it is fine for AP (probably pushing it at times but still RMS around 1 - which is more linked to the length/wind I suspect, with dew shield extended its almost 1m long) so for visual that should be more than ok. (It's now on a pier, but I used to use it on an old Berlebach Uni18 - much less substantial than a Planet - it was fine on that too). I even put an old Russian 180mm Mak on it recently - it needed an extra counterweight (the Mak weighs more or less the same as the AP setup but its centre of gravity is a bit higher so I needed another CW). It seems to have coped - have yet to test that configuration out for full guided DSO AP though. Enjoy the new scope!

Thanks @ollypenrice - yes you're spot on the 0.79x is also a flattener & that's the main reason I was using it. And you're right about the colour too - when I compare to other images, there's more blue for example. I wasn't sure whether that's because 6h is still too short (but it's still quite a bit) or whether it's because of the double-stacking of the filters that some parts of the colour spectrum are being attenuated? I don't have PS - but will see if I can come up w similar workflows either within PI or GIMP. And thanks re the mono - yes I keep humming & hawing about mono but am quite happy w the OSC & frankly given how few these clear nights are, I'm not sure I can justify the mono expense. Its mostly the moon-ful nights that become a slight pain b/c I can't image properly then - maybe an L-enhance is called for, or just bite the bullet for narrowband. @kirkster501yes I did wonder whether it might be internal reflections - the Tadpole nebula I took on the second night didn't seem to have them, so maybe it was the tweak in spacing on the 2nd night that somehow put the reflections out. Who knows! Will see if they come back in future images whenever the next imaging night arrives! Cheers both

Hello, I managed to start getting some data on IC410 a fortnight ago (!). Not having had any chance to add to it, I became impatient thought I'd just play around with it (nice way of practising processing variations is my rationalisation). Obv nowhere near enough data, but in this star reduced version, it doesn't half look like a skull? Too late for Halloween - but funnily enough the data was captured on the night of 2 Nov (isn't that Dia de Muertos😱?). Cheers, Vin

Thanks @Richard_ will try that w a w-i-p image I'm playing around with. Btw your Veil mosaic is v nice - thanks for putting in such a detailed workflow there too!

240GB!! My laptop would keel over. It's like that quote from Jaws "we're going to need a bigger boa[rd]" There's a nice difference b/w the two - the first is more atmospheric (a bit like those slightly misty landscapes), the second is more action-y (like a space movie).

Ah that makes sense, thank you @wimvb - much appreciated!

So I went back & used DBE instead of ABE, as well as put some negative bias (-0.001) on the R layer in the MMT & MLTs. Here are a couple of 2x downsampled images (as per the ones above). I think I prefer this version. Cheers

Thanks @woldsman - ha hadn't thought about Nov 5th - yes v coincidental - craxzy how good some of these firecrackers are becoming. I did take flats (re-took them even). I reckon it might be a PI thing - I did ABE but while playing around just now with another w-i-p image I've done both ABE & DBE on that and the ABE has a similar dark halo which DBE doesn't. May re-try this galaxy w DBE in the next few days to see. Cheers

On my laptop screen that looks 3D, wow.

Hello, This is 6h27 of OSC data on this over 2 nights. TV102iis f/8.6 reduced by 0.79x. UHC & CLS-CCD filters double-stacked. ASI294MCPro -10C, gain 125. HEQ5Pro. Guided. APP then PI. I used the Photometric Colour Calibration in PI but also ran pretty much identical processes to an image where PCC had not been applied. I prefer the PCC. Unfortunately the first night my spacing was a bit off (as the uncropped image shows in the corners) so I tweaked that the second night (meant two sets of flats) - its still not quite right. It's not going to set the world on fire, but it'll do as a start. I'm not quite sure why there's like a halo in the centre of the image and a darker ring around the galaxy (see uncropped image). All critiques v welcome! It was just nice to get data on a clear night. Also managed to start the Tadpole Nebula on the 2nd night (5h+ of data in one night ) I'm v curious - had I been using a mono setup, would a lot more data have been captured in the same 6h27 and therefore would it make for a better quality image? Cheers, Vin (PS - this is probably a v silly Q. The 294MCP is an 11.7Mp camera, the bad pixel map that APP builds is 11.7Mb, but each light is 23.4Mb big - why is that?)

It's gorgeous - the second image sings more. Dare I ask how long it took to process 69hrs of data? 😮

Hello, Last night was unexpectedly clear in the first half. (I say unexpectedly b/c I had foolishly just gone by CO & not set anything up & then looked outside when I saw Jupiter shining and thought "oh %$^&" - too late to set AP rig up). Anyway, thought I'd do some quick NV, so popped a 6nm Ha filter on the end of the PVS14 (ie, only 1x) and just did a scan of the sky to see what I could see. Tootling along, I saw a cloud and thought huh, where did that come from. Took the PVS14 off and looked up naked eye - nope not a cloud anywhere near. Looked up again w the PVS14 and realised hang on, is that the California Nebula? Scanned right to see if the Pleiades were where they would be, and yep there they were. The California Nebula at 1x 🤯 The thing that surprised me even more was how big it is compared to M45. I know a star atlas shows their relative sizes, but actually seeing it in real life, and appreciating how big that thing is was something else. (I really want to see the NAN at 1x b/c I think that is ginormous). After that I quickly set up my old WO EZTouch, put my 0.5x reducer+TV40+PVS14 rig into my old TV76 and just went for a visual scan to see what else I could find by just wandering around. Thought I'd stay around Cassiopeia, and just panned around. Pacman, Heart & Soul! Took photos w my smartphone (really not v good images at all - handheld so there is glare & blurriness - for a better representation of NV at the EP experience, check @GavStar's posts, but this is just to show). The 0.5x reducer setup that speeds the system up to f2 definitely improves things for my equipment. Next time I have a chance I want to try that on a 7" f10 as that should speed it up to f/3.25. I cannot wait to get this under dark skies with more uninterrupted lines of sight. Cheers, Vin

Exquisite. Parts of Pickering's Triangle look like a Marvel female super hero descending with arms raised. And the delicate thin strands (from middle stretching down to 6oclock, 5 o'clock) 👏🏾👏🏾👏🏾!

That difference is palpable. I cannot wait to get to dark skies!

Thanks Geoff, that's v kind. It's all learned from the tips the serious experts have kindly shared here on SGL or CN or Solarchat, & then just experimenting & tinkering. Scope is an old TV76 with a Solarscope SF50 etalon mounted in front. That etalon is brilliant (it was actually a factory demo model that Helmut kindly let me buy). Camera is an old (now discontinued) ASI178MM-cool. I put a UV-IR filter in front of it b/c I think that camera originally did not ship with that on the sensor. Software is FireCapture --> AS!3 --> ImPPG --> GIMP. Cheers, Vin