Filroden

I don't think you'll get much more from this with just 8 minutes of data. What you've done is a great improvement in terms of pulling some of the detail out and getting a better colour balance. The addition of more data is about the only thing left to do Once you have more data it will become easier to stretch and the image will support stronger processing, including noise reduction and sharpening. Let's just hope for some clear skies in February!

You can always try converting the flats into mono. Forgot to add, you don't need to apply bias and darks if you don't subtract bias from the dark in the first place (the dark contains bias anyway). However, you still have to remove bias from flats so as not to double up your bias correction. I get myself so confused when I calibrate as I don't calibrate darks but I do calibrate flats. I need to write my own process down at some point so I don't forget it!

You've really captured some good detail in the surrounding dust but I think you just lack enough data to really stretch it out of the background without the noise going crazy. A background wipe seemed to correct the vignetting and odd colour casts in the periphery of the image, so I think you might want to look at your flats to see what's different for this image. Otherwise, my processing pretty much matches yours. I noticed some horizontal banding in the bottom part of the image. Again, is this calibration? You were right about the stacked image already being very bright! It is possible to push the core harder, but the image takes on a very HDR overprocessed look and I don't think that works. The good thing is that it's easy to go back and shoot some very short exposures (even 5-10 minutes worth would be enough) which you can then use to blend into the core. That and I think it's worth collecting more data so you can really pull out the dust.

This is great news. Field test tomorrow?

Apparently, and totally unconnected, NOAA and the MetOffice have announced that global climate change was just a hoax and we are heading for permanent cold, wet weather...

You can always copy the raw image, process one fully and leave the other only slightly stretched. You can then blend them so you can pull out more of the core.

Indeed! /bow It is an amazing image and well worth being showcased.

Fate/shmate! Do it anyway I'm just about to connect my mount to my Mac to see if I can control it with SkySafari. If so, I'm considering a VM box with Windows so I can still run SGPro for capture but control the scope remotely (I've found no way to control the mount in Windows that doesn't break my goto alignment).

Thank you both. I have to admit that the Ha data almost processes itself. It requires no background wipe, needs very little noise reduction and so long as I'm careful doing the stretching you get a really good image in quick order. I can only image how much easier it becomes with even more data! The trouble comes when trying to blend very clean, strong data with much weaker data. My initial attempt used the Ha also in the red channel, but this totally dominated the image - so while there was some pale natural star colours, the nebula looked like a tinted mono image. With a little more work on my very poor RGB data I was at least able to achieve something. I have halos that I would like to eliminate but there is not much more I can do with the RGB data. It has some nasty gradients, is very noisy and the three channels are very badly balanced. Once I get another clear night my intention is to collect 60s exposures for RGB and discard all previous data.

All I could suggest is taking a test image of a colour card using the filter and find out what setting you need to bring the colours back to how they should look. I'd try with white balance/colour temperature first, as it's a single setting. If this works, then it becomes an easy step in the process. As soon as you start to rebalance the RGB histograms or try to synthesis a green channel you are back where you started I think (though obviously missing the light pollution which can dominate in that green/yellow region). Not necessarily a bad thing, but there must be a way to do this easily.

I suspect the layering has added noise and given you the impression of it now being blurred. I think there is some fine detail in the nebula but you probably need to mask the fainter details and potentially deliberately blur it more while leaving the brighter areas in their full detail. Not only will this draw attention into the detail but it will hide some of that noise You have a strange colour cast that almost looks like it's a vignette. Have your flats introduced something?

Looking good. How's the weather?

Here's my latest rendition of the Rosette using Ha as Luminance and some very poor RGB data to add colour (there is now no Ha in the colour data). There is a definite graduation of red shades. Looking at bi-colour narrowband images using Ha and OIII, you can definitely see a lot more OIII in the same areas as the lighter areas in my image, suggesting that it is the OIII signal shifting the colour from 656nm towards the lighter reds. There just isn't enough OIII to completely move the colour from red into a more green shade (which does occur in small parts of M42). I've never captured blue stars - mine all range from white through to red/orange, but when I check the yellow and orange stars they do match the expected spectral class (and the white stars match the hotter OBA stars).

UHC filters remove most of the green/yellow wavelengths (see the image below for an example). This probably affects calibration, particularly of the yellow stars. You may first have to manually rebalance the image and then run a more automated calibration.

I'd be proud of that with 7m of data! You have a colour cast which I think could be corrected by slightly raising blue in levels or pulling back on red a little. However, with some careful stretching using lots of small curves adjustments rather than levels (so you can pin the highlights) and I think you'll be amazed. There is a lot of fine detail leading into the core. You've probably picked a very difficult target for your field of view. M31 has an incredibly bright core and the fainter detail extends quite far. You may be better finding a bright target that will fit more within your field of view. M42 is a good target, especially at 10s subs as it also has a bright core. The Flame Nebula might also be good, but the nearby bright star can cause a lot of flare. The Pacman Nebula would fit nicely I think but is better with a camera with a very good red response (I don't know if the 70d is similar to the 60d but you'd get something, but not everything).

You're really pushing me technically. I haven't used Linux and I last used Unix in the early 90s!

And you can't just rename using cp? $ cp ssh.txt ssh $ rm ssh.txt

It will be interesting to see how you get on with Indi. I think PixInsight has started to implement some Indi controls.

That's so frustrating. I almost set up as it was clear at dusk but my intuition suggested clouds afoot. I waited an hour and it now looks like rain. I need far more RGB data for my Rosette, plus at least another 80 mins of Ha to really work on some of the fainter peripheral nebulosity.

I've just realised I have a 10mm extension that I think came with the camera to give the correct spacing for a DSLR. So I may only need a new M48 to M42 adaptor and the 7.5mm spacer. Just checked but it is a female/female, so needs the male/male adaptor which adds another 2mm. Still, worth a try before I buy another spacer.

So I'm now wondering if I can get away with the following: 11.0mm Skywatcher spacer ring (included with FF) 9.0mm FLO M48 to M42 adaptor (https://www.firstlightoptics.com/adapters/flo-m48-to-t2-adapter.html) 10mm Modern Astronomy spacer (http://www.modernastronomy.com/shop/accessories/adapters/10mm-t-spacer/) 7.5mm Baader T2 extension tube (https://www.firstlightoptics.com/adapters/baader-t2-extension-tube.html) 20.0mm ZWO EFW 1.0mm Astrodon filter 6.5mm ZWO ASI1600MM sensor distance inside body ==== 65mm Maybe add a delrin spacer to make up the missing 1mm?

I've just arrived at that exact same distance with my current adaptors.

I have this and it's currently solidly welded to my M48 to M42 adaptor. There is little grip on either for me to use my usual grip to unlock them! Hmm, the M48 to M42 adaptor adds about 10mm, have you taken that into account? Edit: I measured the adaptor incorrectly and it should have been 10mm (as stated on FLO website)

This is odd. A ) With my current spacing I have 64mm from back of focuser to camera body, so 70.5mm physical distance to chip and probably closer to 71 or 71.5 if the filter is taken into account (i.e. about 5mm over). B ) I have tried a different combination that shortens this to 56mm from back of focuser to camera body, so 62.5mm physical distance to chip and probably closer to 63 or 63.5 if the filter is taken into account (i.e. about 3mm under). My images look much better with option A rather than option B, even through B should be closer to the right back focus. I have no other combination that can extend option B or reduce option A without buying different spacers, so I think a custom made adaptor from the flattener to the EFW is the way for me to go, to reduce the number of connections and reduce risk of tilt.

I use the flattener but I don't yet have the adaptors for the right spacing (and had also been calculating that spacing incorrectly thanks to Skywatcher's manual!). Going to go remeasure my optical train and see if I can get to 27.5mm now.