Tommohawk

Nice Jupiter, especially given its only 20 degrees and not yet at opposition. RGB tweak would make it even better! Seems to me that 8" scopes seem to punch above their weight for planetary imaging.

Don't want to hijack the thread, but fwiw I've given up using flats and do the correction routine for light pollution in Astropixel Processor. This fixes gradients / vignetting and works really well in most cases esp as I don't have any discernible dust in system. Apologies to OP!

Thanks for the comments and likes!

I've been astro imaging for a while now, but somehow never got round to doing clusters. Had a shortish window the other night (6th May) and I've got my 200P on the go at the moment so gave it a whirl. RGB only, wasnt sure about exposure so went for my default 60seconds. Lost quite a few subs due to cloud and a period of wind. Also I notice that I have the same issue as Ive had with my refractor ie that subs after the meridian dont quite match properly which I've discovered seems to be due to sensor tilt. It barely shows if all the subs are AM or PM but its really obvious if I do a flip half way through. In this case I did the blues PM, and because the centroid is offset this causes green fringes on one side of bright stars. It's a right pain - I really dont want to have but a tilt adjustor. Yet another thing to fiddle with/go wrong/etc ! Anyhow, I discovered that if I do star colour calibration in Astro Pixel Processor, this gives much too yellow / gold an image, but it does seem to lose the green. I then rebalanced the colour in PS and I think I've got rid of the worst of it. 200P, ASI1600 cool at -20C, 40xR 45xG 41xB at 60 secs, Gain 139 Offset 64, NINA, APP, PS. Thanks for looking hope you like it - happy for comments/criticism!

Terrific result.... I'd be very pleased with that!

Great image! I've imaged around Ursa Major quite a bit but somehow never picked up on this. Yet another one to put on the list!

Thanks for the likes!

Wasn't sure whether to put this in widefield, or Lunar - but its definitely the moon so I posted here. Actually Mars is there too lower right of the moon. I noticed these trees some time back and felt it was begging for a picture, just needed to get the timing right - and when I knew we had a clear night and Mars was in the frame too it was too good an opportunity to miss. Did this with my Lumix FZ1000, single shot F2.8 ISO 1600 exp 8 seconds, 25mm FL. I used the Android Lumix capture app which works really well for focus and remote exposure ... although seems a bit flaky occasionally. Quite pleased with the outcome, though it would have worked better if I could have captured slightly earlier because the tree separation is more striking then - but the moon was too high at that time. Exposure was good generally, as I wanted to get stars in and some sky, but washed out Mars' colour and also over-exposed the moon badly. It's only 26% illuminated but looks full! I should have done some shorter subs too and blended.... next time maybe! Hope you like it, thanks for looking!

Yes, and that's what I used to do - but a bit laborious having to do multiple boxes in the LP for each channel. Way easier to combine first then do LP routine all together. However, what I am looking at now is doing as you say and doing LP on each channel first and then combining just in order to get a formula which works. Then in future use that formula in the RGB combine, and then do LP all channels together - if that makes sense! Agreed - a bit of experimentation required I guess

Great thanks for that. I experimented with these APP setting yesterday doing Markarian's Chain, but TBH the data was pretty ropey and not really a fair test. I'll revisit M106 and see what I can achieve. Ideally I would find a formula that works for my filter set that I can apply to all images. Due to a capture glitch I had way more green subs, but this didnt make for an overly green image. So not sure that using the number of subs as a guide to RGB ratios would be effective with my setup. What doesn't help is that I'm experimenting with using LP correction to resolve all vignetting issues, and not using any flats. This works remarkably well, but the RGC combine is done prior to LP correction so when doing RGB combine there are huge gradients such that judging colour balance is tricky. Maybe I'll have to get this done best possible, and then do the final tweak in star colour correction as you say.

Thanks for that, very constructive! I realised I could change the multiplier value when combining but was reluctant to fiddle with it. In theory given I had a triple ration of green I was expecting to have to dial that down. But as you say that's probably the best stage to tweak it - I'll have another go. Right now I'm playing with some limited data from Markarians Chain - it certainly suffers the same pink hue, so looks like its just the way this filter set works. Once I've got a formula that works hopefully it will be good all - I'll have another twiddle!

Right I had another look and certainly if I crank up the saturation I can see the halo of M106 is very pink, as are some of the other pale galaxy areas. But if I do star colour calibration it really does something horrible - all the blue goes, and the whole thing has an obvious yellow/green haze. I tried randomly fiddling with the slopes but couldn't really get the colour back to anything like normal. One thing about APP which drives me bonkers is that the sliders, slider labels, and slider controls aren't segregated, so its hard to see which slider to actually move! I might post something in the APP suggestions area. But maybe its just me! Going forward I'll have to figure a way of tweaking the colours even if its just a subjective local adjustment in PS. I don't like doing local adjustments though because that always seems wrong ie rigging the data.

ok great thanks for that - got my hands full ATM but will play around with it later.

Aaah thats interesting. One of the issues I have when processing is that my red/green colour vision is a bit pants. I typically run the PS eyedropper thingy over the background to check it, and I found that APP did the background neutralization stage nicely, according to this check method. So I'm surprised you say there is a pink tinge - you mean the background, or the stars? I did try the star colour correction but it seemed to do some odd things to the star colours - I tihnk it seemed to desaturate the yellows from memory. But maybe thats how it should be - I'll look again.

Hi folks and thanks for all the likes! Just FYI, I had another look at this the following day and found a way to reduce the noise by tweaking the stretch settings in APP manually, rather than just using the drop down options. The difference isnt massive so I wont repost, but the take home for me is that doing as much processing in APP as possible makes sense not least because I think at this point its still 32 bit data.

Just bear in mind that a small amount of play is probably better than binding on some sectors. If you aren't noticing any issues with performance, it might be safer to leave well enough alone. If you leave slight imbalance when setting up this should prevent any sudden DEC swings in use. That said Astro Baby's guide is great and you might fancy getting to know and fettle you mount!

Evening all. I had a bash at M106 last year and was quite pleased with the results, but not realising that NGC 4217 was a bit of a looker, I inadvertently chopped it in half. So I had another go the other night, and quite pleased with the outcome although not sure M106 has quite as much detail as before - maybe the sky not quite so good. I think this framing works as a pair just about. Packed the refractor away, and back to the 200P for this. First time using the Newt with the new Astronomik deepsky/ L3 filter set - seems to perform similar to the ZWO filters perhaps not surprisingly. Worth noting that these filters don't seem parfocal even with the Newt, though this could be down to the coma corrector optics. Used NINA which has become my default and generally works well, except that my filter sequence went a bit weird and I ended up with a double ration of green. Guiding was good generally - it always seem to be better with the Newt which is bonkers given its 5 times the weight of the frac. Maybe something to do with the area of sky I'm looking at. The strangest thing was - not a drop of dew anywhere to be seen. By 1am it was all bone dry so I let it run overnight and it was still dry at 5am. Guiding log shows something ghastly happened at about 4am - probably the wind. I think I need to rethink my gain settings. I've always used 139 for LRGB but the LUM seems noisy even with 200+ subs. Also I processed in APP and used auto quality for integration - this is great but I can never be sure what its actually done, ie how many subs its used/ignored. Not sure if there's a way of knowing? The other thing I did different was to not use any flats. I combined RGB in APP rather than PS, and then used the excellent LP tool to correct the vignetting. This does a great job of keeping the backgound neutralised and avoids any gradient/cast.... I think!! My optics are pretty clean and I cant see any bunnies etc. Maybe not looking hard enough! So 200P with SW 0.9CC, ASI1600 cool, NINA, APP, PS. 217 x 60s LUM, 79 x 60s RED, 217(!) x 60s GREEN, 72 x 60s BLUE (RGB binned 2 x 2) All at -20 deg C. Happy to hear any feedback/comments, thanks for looking.

I need my beauty sleep more than you I reckon Craig!

That's lovely and not a target I knew of - so much stuff out there! Pretty low in the sky this time of year though isnt it?

Hi All. Having some issues with my refractor RGB alignment - hadn't noticed anything amiss before now, but by chance I've recently done a few images of the Beehive cluster with runs partly before and partly after a meridian flip. The colour alignment looked pretty good generally in the past - by which I mean that combining RGP images stacked in APP looks good. There is a slight eccentricity of the star centres but not really noticeable. But if I mix ante and post meridian flip subs, the displacement becomes quite obvious. Hope that makes sense! I started a thread on this here, but because this bit involves more detailed analysis with CCD inspector I thought I'd start another thread. So I considered three possibilities - flop in the focuser, tilt due to the optics, tilt due to the camera. I then did a more organised set of subs - a run of RGB before the flip, and then a run after the flip, to check for focuser flop. Then I put the results through CCD inspector - see chart below. The results are puzzling! The before flip (AM) RED1 GREEN1 and BLUE1 images from show differing amounts and directions of tilt - not huge differences I suppose. And the R and G tilt looks very different after the flip - BUT the Blue shows minimal change. This is baffling - isn't it? I'd have expected the tilt to be the same for all filters in the AM run, and then if any focuser flop for them all to differ on the second run by the same amount. I was expecting this to either prove or disprove focuser flop, and then I could go on to check whether the tilt was in the optics or the camera - but I seem to have fallen at the first. BTW, I did multiple images and the tilts varied only fractionally, so none of the figures in the chart are flukey. Also each filter was focused separately, and always using a star dead centre in the image. (I also checked the subs from the previous image run a couple of weeks back and the results seem similar although there were fewer subs - so pretty sure this wasnt just something weird on the day) Hopefully I've explained this clearly enough - anyone have any ideas??? AM/PM CURVATURE % TILT % AXIS COLLIMATION RED1 AM 12 7 -117 2.9 GREEN1 AM 20.6 28 -129 12.1 BLUE1 AM 28.6 44 -138 22.3 RED2 PM 19.3 50 41 14.3 GREEN2 PM 13.5 25 27 8.1 BLUE2 PM 31.7 47 -137 26.3

Ok well I'm going to be completely pragmatic. The "tensioner" screw does a pretty good job of locking it when done up tight, so I'll try just using that and leaving the "lock screw" undone. I have done some star testing in the past with an artificial star which seemed to work ok although that was with a Newtonian and maybe not so precise. I'll report back when done. Thank again for pointing me in the right direction

Trying to think through the implications of all this. Because the star centration seems reversed for R compared to BG, and I fIipped before doing R, I think this must mean that as you say its a gravity induced thing rather than a scope collimation issue. I've always considered the focuser to be very solid - but today I have checked it and there is some play for sure. Not much but discernible. Funny thing is this focuser has 2 screws, a small silver one (blue arrow) aand a larger brass coloured one (red arrow) I'd always assumed the smaller one is tension adjustment and larger one is focus lock. But heres a funny thing. If I tighten the small screw only, the tension becomes stiffer as expected, and there is minimal if any play in the draw tube. If I tighten the brass one this seems to have no effect at all ie it doesnt lock it at all. BUT once tightened there is then play in the drawtube, which reduces when the brass screw is loosened. Not sure how that can be! Edit: Just one tihng to add. I'd forgotten about the brass screw underneath (I dont get much chance to get out one way or another, and also memory not so good!) and it was done up pretty tight when I checked it today. But I've been merrily focussing away with this screw "locked" for some time - many sessions. So maybe if this has a friction material on screw tip it's gotten worn smooth) Edit #2. But I guess if its going to cause play somehow I dont want to use it anyhow!? So I'm hopeful that I'm homing in on a solution, just need to figure how to sort the focuser. Any thoughts??

I'll have a better look at this tomorrow. You're right I did green first then blue then red. Pretty sure the FR is screw connection both sides... I'll check. Thanks for your insight.

Thanks for wading in - that's a really useful observation. One thing about this hobby is it's so difficult trying to test anything because there just aren't enough clear nights, so goodness knows when i'll be able to do further tests - it's infuriating. I looked back over all my imaging for the last 14 months ie since buying the blue filter, and some was done binned, some in narrowband and some with a newtonian, but I only have two unbinned images done with RGB and the refractor. I dont think either of them shows this issue to any degree, even though they were both done with the same blue filter, together with the ZWO red and green. Ive posted below the previous RGB images, M31 and M45. Also posted single subs of RGB for this this image of The Beehive - these arent aligned though. If you could have a look I'd be grateful. Maybe the optics were pinched or something last night - it probably didn't cool down for long, and I did the red last, so maybe that has a bearing on it? Only other relevant point is I did red after meridian flip - maybe something funny with image plane?

Hi all. Well I've worked through (and resolved with the help of SGL members) a good few queries here over the years but so far this one has me beaten. Some time back I bought an Astronomik Deepsky blue filter, to try and resolve the blue bloat with my Sharpstar 61Mk1 scope (+ 0.79 reducer/flattener) and ASI1600 cool. This seemed to fix the blue issue nicely, but being a different thickness to the previous ZWO filters it was miles off parfocal. In an effort to resolve this I bought the matching R and G filters together with the L3 to sort the equivalent bloat in the luminance. Last night was the first clear night to check this set up, and I decided to keep it simple and just do the Beehive, just for star tests really. The result is rather odd. With the red image, following stacking (with either APP or DSS) some of the red stars - but not all - are slightly misaligned. When I compare the red image to the G and B, the brighter stars are not correctly aligned, although all the dimmer ones are fine. I thought I knew optics pretty well but I cant figure this at all. Ive attached an RGB image, which I've crudely processed to show the problem. If you blink between the RGB channels you can hopefully see what I mean. I've checked the raw subs and the same applies - its not a processing artefact. I've also checked carefully and don't have this on any or my previous images, so it does definitely looks to be to do with the red filter. Does anyone have a clue what's going on? The only thing I can think is that the red filter faces aren't quite parallel, such that there is displacement which somehow affects the brighter stars more.