DaveS

With OSC there's no point in getting the LRGB / NB set, and I would argue, no need for a filter wheel, a simple filter drawer like the ones that ZWO do will do as well, cheaper, and avoid the need to balance a big off-centre wheel. Although I don't use OSC I have considered it and would go with just a duo band filter for H-alpha and [OIII], and either a LP or IR / UV cut filter depending on your light pollution levels.

Plus, you'll be hard put to achieve any real resolution below 1"/px unless you have a night of exceptional seeing and a premium mount that can guide below 0.5".

@ollypenrice Probably "problem";was a poor choice of word, "question" would be better, as between guide scope and OAG.

As expected Jordan goes off the deep end... For myself I think this whole hoo-ha is down to accumulated measurement errors.

I side-stepped the whole guiding problem by going to encoder guiding.

i went to boarding school in Dorset , late '60s-early '70s and remember nights so dark you couldn't see your hand in front of your face, and so many stars that even familiar constellations were lost in the sea of stars. Must have been Bortle 1-2

I did the big move for dark skies nearly 5 years ago, moving from a 1930s two bedroom bungalow in Ruislip with horrid orange sky to my (Hopefully) forever home, an 1849 stone 3 bedroom semi (Though I have about 2/3 of the property) in a dark area of Dorset and built an obsy. On a good night in late summer I can see the milky way glittering down to the horizon.

Pudding, proof of. That's a gorgeous image.

I have set myself a little project to image as many of the Hickson Compact Groups of galaxies as I can. I won't be able to image all of them from here as many are too far south, and some of the groups are *very* compact. there are 100 of them and I've manages about 4 so far, so a way to go. I can see myself "cheating" and buying time on remote telescopes at some point.

It doesn't get much better for an imager with an obsy. The number of useable clear nights this year has been dispiriting. In fact I've stopped buying any significant astro gear and don't expect this to change anytime soon.

H-Beta filter Not usually used since the H-Beta signal can be inferred from the H-Alpha.

When I first moved from DSLR to CCD I went with AstroArt, version 5 at the time, and am now using version 8 SP2. I still find the stacking exceptionally good and blindingly fast. I was a long time PI refusenik until the RC AI tools came out which caused me to bite the bullet and stump up for a license. I still use AA* for some of my processing as I find the DDP stretch often gives better results that either ArcSinH or Masked Stretch though the latter is useful. The "Attenuate Single Colour" in AA8 I find very useful for its control and visualisation of the areas being attenuated, I've had a better reduction of magenta stars in SHO palette images than in anything else. Occasionally AA8 will throw a wobbly when trying to stack NB images (I'm still not sure why) in which case DSS will do the job. I have also had WBPP turn its nose up at my subs, but AA8 will do the job.

I try not to make plans as they are invariably stuffed by the weather but I have my HCG project on the go with the ODK 12 and Trius 694.

OK. After some experimentation I found that I had to do an initial RGB combination, then split into individual RGB components then recombine into RGB before AA8 would allow me to make the fine sub-pixel shifts needed. Ignore the dark star centres, I was more interested in the overall alignment. I think it's better. This is a Synthetic LRGB ETA: I've been blinking between the original and realigned LRGB and the improvement isn't marginal, not only the stars have tightened up, the galaxy structure is much better defined, even though the restacked version didn't have Unsharp Mask applied. Thanks @ollypenrice

Thanks Olly. Actually I do think there's slight misalignment. The alignment in the AstroArt 8 Trichromy routine is very much better than it used to be as it now attends to rotation and differences in scale. but a touch of manual adjustment might be in order now you've pointed it out. I will go back and have another look.

I dunno. I made a Synthetic Luminance from the entire data set just calibrated with a Master Dark then used it for a Synthetic LRGB. I was able to apply a touch of Unsharp Mask at the end of the processing but not sure if it's made a great deal of difference. I'm going to be without my main PC for at least a week as it has to go back for investigation, probably a PSU issue, so without PI or the RC AI tools that wouldn't run on this now low spec machine.

Work, very much, In Progress. This is just 6 hours RGB captured on the 7th in 10 mins subs at Bin 2 and Drizzled during stacking. My main computer blew its power supply last night as I was shutting down so I'm on my 2011 eara 17 with AstroArt 8 but no PI. All my calibration frames are on the new computer so I had to put new ones together from the data on my NAS. Cropp, Gradient Reduction for the sky gradients, DDP, Richardson-Lucy Deconvolution, Selective Colour for the background, Then a light Unsharp Mask and slight Saturation Boost Saved as a PNG. North is up. It needs a shed-load of Luminance as it's noisy as hell, the sky was rubbish with thin hazy cloud and a bright Moon. @wimvb Also captured this in his wide-field of galaxies in Pegasus.

Thanks, going to need it with our weather.

And you've also got HCG 93 down in the bottom left, my next target with the ODK 12 / SX 694 combination

I do note that Lukomatico has a review on YT that is very positive, though he admits that he can only afford an APS-C camera. He also says FPL 53.

I can't see any future for astronomy of any kind from this dank swamp of a country.

I had clear sky forecast for this Friday and Saturday. Friday has already disappeared, now waiting for Saturday to do the same. It appears to be the norm that forecast clear nights gradually disappear but how often do you see a clear night appear out of nowhere.

The FRA 300 is a quintuplet with a triplet front group and widely spaced rear pair, while this 'scope is a quadruplet.

If you look on the graphic at the top of the thread you'll see a tiny white enclave on the south west coast between Weymouth and Bridport. It's where I moved to, look up the Bride Valley.

The emporium that begins with "A", named after that long river in South America.