DaveS

I'll have another go at this tomorrow (Maybe, I have other things to do as well), taking more care over the colour balance. Not much I can do about the streaks, maybe a masked inverted stretch.

Thanks Dave. That light streak is on all my subs but worse on the Luminance. I will recheck my focus, but the last time I tried the difference between filters ewas less than the difference between focus runs. Perhaps I will check with a Bahtinov mask on the next clear night (This year? Next year?? Sometime??? Never???!!!). I calibrate my monitor using a ColorMunki, and it's a wide gamut job. I had a similar streak on my images of NGC 3718, but only a single streak rather than the 2 or 3 on this image. Thought it was due to a star outside the field then, but not sure now. May need to buy a dew shield for the ODK to give a bit more screening. Not cheap though.

Hmm...57 views an only one other reply. Ah well. In the absence of any other suggestions I've been kicking the data around a bit more. Slowly getting there I think. The latest iteration. The core of NGC 7331 is less burned out, but I'm still not convinced about the colours.

Let's see Stephan and Deer

I've been going slowly barking with this. Captured 15 subs RGB using G2v calibration plus 36 x 10 min subs Luminance with the ODK rig in my sig. Stacked best 90% in DSS with Dark, Flat, Dark Flat and Bias frames, Kappa Sigma. Resulting stacks pulled into AstroArt 8, aligned and Trichomy before stretching. Applied Histogram Stretch, DDP, and Unsharp Mask to the Luminance. Applied DDP and Histogram Stretch in that order to the RGB before LRGB synthesis (Lab colour protocol). Cropped off the edges before Gradient Reduction, Adaptive Subtract. Pushed the Histogram and colour around a bit more. Finally saved as JPEG. The PNG is 70 MB. Need to get rid of an overall blue-green tinge to the background and a greenish tinge around the bottom of NGC 7331, which also has a burned out core, even more obvious in JPEG. There are also two or three light streaks coming i to the upper right, possibly from stars just outside the field. Any ideas? I could post up the unprocessed stacks but they are a bit big.

I also found this from Dr Becky

Thanks. I may have to pause this for this year as I'm rapidly running out of imaging time before it hits the walls of the obsy and trees. Besides I'm trying to get data on Deer Lick and Stephan's Quintet. Question is: When I resume do I go for more of the same (Realising that I will need the same again to make any difference), or else try to get enough [SII] to build a HST image?

I think I may be getting there. Grabbed another 2 hours worth of data last night which means DSS can dump some of the poorer subs. 40 x 900 sec subs (10 hours) each H-alpha and [OIII]. Stacked 75% in DSS with full calibration giving 7 hours 30 mins each. Post in AstroArt 8, Histogram Stretch, Gradient Reduction and a light Unsharp Mask. Colour Balance and Masked colour Reduction to try and reduce some red stars. Saved out as PNG. C&C welcome as always. Edit: May have pulled the Red down a little too much. Will give it a think.

That's pretty damn good for a first effort.

This is still WIP as I need more, better, data. the subs I have up till now have been plagued with passing high cloud and early shutdowns triggered by the weather monitor. Nevertheless, here it is, 7 hours H-alpha and 6 hours [OIII] in 900 sec subs with the ODK rig. Stacked in DSS and brutalised in AstroArt 8. The H-alpha data had full calibration, but the [OIII] only Darks since 1) I stuffed up getting sky flats for [OII] and [SII] and, 2) adding Bias stuffed up the stack. Note the file says "Third HOO" which might give an idea of the thrashing around I was doing. Still some uncorrected gradients to get rid of. Program of further work, collect more, better [OIII] to replace some of the dodgy data, collect new, correct calibration frames.

This is my obsy build thread, complete with wrong turnings and "how not to", but I set it up for remote / automated imaging. I'm sure it could be simplified and the cost reduced *considerably*

You're only stuck with ZWO equipment if you go down the ASIAir route, one reason why I didn't. My autofocus uses the Primaluce Labs Sesto Senso units. I would also add something like the Pegasus Power Box Advanced that has a powered hub, power distribution, and dew control. All my kit is connected vis ASCOM and Win 10 Pro running on industrial mini PCs

I would say that for truly remot (Even in your own garden) imaging you need an obsy with automated roof, that is if you want to be able to start and stop an imaging run without having to traipse out to it every time. Add a weather monitor (I use an AAG Cloudwatcher) to close down a session if the weather turns. Below that consider a fixed pier with all your kit under a robust cover, the Telegizmos 365 are pretty good.

Ouch!

Oh yes, banged my head on the counterweight shaft too many times. Not really an injury (Though it could have been) was when getting the RA cradle on my DDM 85 onto the pier during the obsy construction. I had managed to carry it out to the obsy and rested it on the platform before climbing in to pick it up. I've done enough manual handling to know how to lift heavy objects (This was 25 kg). Unfortunately in keeping it close to my chest I lost my balance and went tumbling with the cradle going flying across the obsy and me impacting the north wall getting a few bruises in the process. Fortunately I had contractors in doing some work in the garden so they were able to help me get the cradle onto the pier after I had recovered myself.

That's really rather lovely, masses of fine detail coming through. May be worth getting more data, but remember that SNR goes as the square root of number of subs. Doubling the number will only get you 1.4 x the SNR.

Oh, and Deep Sky Stacker is also free. On occasion I've found DSS to give a clean stack where AA8 just plays silly whatsits.

And don't overlook AstroArt, now at V8. It'll handle everything from your capture, guiding, through stacking to post-processing. Has a trial version too.

If you have Bortle 4 skies then you may not need a LP filter. My skies now are the dark end of 4 nearly Bortle 3 and I don't need one. I did though when I still lived in West London under the horrid orange glow.

If you are using a colour camera then i would use either a UV/IR cut if your LP is low, or else a LP filter, but see little point in combining the two. If you were running LRGB with a mono camera and your LP is poor then it might be worth putting a LP filter ahead in the train.

I started out with V5 but moved to Maxim DL for my capture when I bought my first ASA mount (The software needs Maxim), but kept on using it for processing. I updated to V7 when it came out, and now have V8. V7 is an easy step up from V5 just with some new tools, but V8 is more different to V7 in the stacking, and especially in the DDP routine which now has more controls. The Trichromy is also very different, but with more options. For me it is definitely worth the update.

Sorry Ed, but a dob is the last thing I'd want. Or any other alt-az unless it was One Of These

Hi Steven, welcome to the madhouse!

Thanks for alerting me to AA8. I had been keeping an eye on the MSB software page but missed the release.

I never had that problem as I was already running PHD2 with APT when I moved to CCD from DSLR and started running AstroArt 5 for capture. I did try guiding with AA5 as I recall (SX Trius 694 / QHY5 II) but found it less easy than letting PHD2 do the guiding. PHD2 will also do your drift alignment too. Since getting my first ASA mount and Maxim I have never had to guide.