smr

With my DSLR (CMOS) I've found that using Bias frames gives a much smoother background. Without them I get all sorts of streaks and artifacts. Unless you mean dedicated astro CMOS cameras?

https://astrobackyard.com/ngc-6992-eastern-veil-nebula/ If you have a look here, this image was taken in Bortle 8 skies, with the 294MC Pro and a duo narrowband filter, and full Moon. Just 18x5 minute subs.

I've just finished for the night. 4 hours more data on the Eastern Veil so 7 and a half hours now. Good night all. Two great nights. Looking forward to some sleep now!

Hi guys. Imaging more Eastern Veil tonight. The seeing seems very good. Focused on Vega and I've never seen the star spikes so still before.

Yes its a stack of 3 and a half hours. I was surprised by the amount of red that got picked up actually. But then I read a post by Olly earlier today that said it's a broadband red so easier to pick up. I think I'll just leave the dithering as is then thanks.

Hi, Is this colour noise, and can it be cured by dithering ? at the moment I am just using APT default dithering values. And it's been fine for hot pixels etc. on other targets, but on this target there seems to be a lot of what I presume is colour noise? If so do I need to dither more aggressively to get rid of it or is it a different type of noise ? (over stretching to see the neb etc.?)

Hi all, This is a quick levels and bit of curve adjust on some data from last night. Just wondering if I am dithering enough. I can see that its working by virtue of being zoomed in on APT between images and seeing the pixels move around slightly. I have APT dithering at default settings. Or is this just general light pollution noise ? Here it is at 50 percent crop... What is this mottling colour a result of ? ie. type of noise? Or is it more so because as you can see I've stretched the data excessively? Will more signal improve it? I hope to get a lot more signal but on this but I didn't want to attain said data sub optimally if there was something I could do via software, as hardware wise I am limited with no cooling on my DSLR.

First time imaging the Eastern Veil nebula tonight which was nice. Also first time doing a meridian flip. Not sure if I did it too soon though because when it slewed the veil was a bit off center so I had to use the handcontroller to adjust, test shot, adjust, test shot, restart guiding etc. lost about half an hour. Not easy to see the veil with a DSLR and an unmodded one at that. Would be much easier with a more sensitive astro camera. Good conditions though and the Moon washed out the sky around that time anyway. Packed up now and off to bed. Good night!

Imaging the Eastern Veil for the first time. Skies are good here. Will try and image for as long as possible!

Just a slightly OT question... Is it better to shoot longer subs (4 or 5 minutes as opposed to 3) ? Or should I leave the subs at 3 minutes with the histogram data where it is?

This thread is brilliant, thanks for all your replies. Really interesting reading. I'm definitely going to upgrade to a dedicated astro camera, whether that's Mono or OSC I'm not sure. I do like the results I see from imagers using cameras like the ASI294MC Pro and with duo narrowband filters, often from skies which are Bortle 8 as well. So that is encouraging as I have Bortle 5 skies, but obviously Mono equals best data but with the caveat of added complexity. Maybe the next logical step is to buy an OSC, learn more, get better images and more experience and then progress onto Mono. At the moment I'm still in the phase of being happy to just find and image new DSO's. Tonight I'm imaging the Eastern Veil Nebula for the first time and just to find objects like this which I have never attempted before very much has that wow factor for me ! I'm currently imaging 3 minute exposures, ISO 200 and will image as many as I can tonight. A stretch in Lightroom showing the veil (cropped in a bit).

I prefer the first one, I don't really know why, maybe looks like it has more depth in the cluster.

Me? Zenithstar 73 apo refractor, 430mm.

With regards to a modified DSLR vs my unmodified Canon 80D... If i were to buy a Canon 600D modified for instance, would I be giving anything up in terms of quality? My Canon 80D sensor is quite a bit newer than the 600D sensor. The 80D has on chip ADC and is purported to be ISO-less meaning that there is no benefit in shooting higher than ISO 200. With the 600D I think I would have to shoot at ISO 800 or 1600. Would this be a negative thing compared to the ISO-less sensor on the 80D in terms of noise? Obviously the advantage of the modified DSLR is that it is a lot more sensitive to Ha and I could have a go at using Ha filters to combine with broadband subs. I could get a Canon 600D modified for about £250. And that would mean I am not straining my 80D (with long exposures) which I also use for landscape photography. If I do go for a dedicated OSC I think it would be the well enamoured ASI 294MC Pro which is £1000. The biggest difference between the 294 and a modified 600D would be just the cooling and noise reduction / proper calibration or is there more to it than that?

Indeed a lot of Astro cameras have DSLR sensors in them dont they? Therefore the only advantage in them is that they have cooling and are also without the IR filter found in most DSLRs (with the exception being astro DSLRs like the Canon 60Da). I have seen some great images taken with the camera I have but they can be the result of using fast lenses/scopes or very dark skies, as well as the camera having been modified. Another point about the Canon 80D is that its 'ISO-less' meaning I shoot at ISO 200 and that helps with noise. The biggest noise problem however can be light pollution.

The 120MM Mini is superb.

There seems to be quite a bit of a trend with narrowband and OSC imaging now, with Trevor Jones and his 294 / STC Duo narrowband images etc. I see Altair have a Tri and Quadband filters for OSC as well now which seem to be priced very well compared to some of the other tri/quad filters, though I notice the bandwidths aren't as narrow compared the more expensive filters.

Having said that I could imagine being quite happy with the results of say, 7 hours on Bodes and Cigar I have got this year, 5 hours on Rosette and 4 hours on M42 with a cooled OSC and much increased sensitivity to Ha with the ASI294MC Pro or the 071MC Pro.

Very interesting replies. I am actually leaning towards mono a bit... but I'm still not sure. I'm happy gathering data on multiple nights. My last image of M31 was taken over two nights, about two weeks ago whilst on Holiday. In that week there were only two clear nights with extended spells of clear night at that. After the second night I was still looking at the forecast and bearing in mind the Moon's position with regard to wanting to image more and gather more data on top of the 5-6 hours I had achieved. If the whole week was clear skies I'd have imaged every night, Moon permitting, possibly coming away with 10-15-20 hours of data. I was actually making a mental note to myself to carry on imaging M31 when I got home from my garden and add as much data to it as I can but haven't been able to now because of the Moon. That combined with the fact that since my Holiday we have had one clear night, and that was on Tuesday I think of this week with the Moon almost full. So pointless gathering anymore data. So then I've got this data on my computer and I want to see what the stack looks like... so you begin processing and then carry on, and carry on, and think that looks nice. So you go about finishing it whilst cursing the cloudy and moonlit skies you've got at present, using them as an excuse for just calling that project wraps. I guess that comes down to partly patience though, and learning to keep the data but just add more to it when you can, if you want the best results possible. I guess it also comes down to a choice with such skies ... moon and cloud etc. as to whether to concentrate on one target as much as possible per season, going for 15+ hours of data and trying to get as much as possible data before diminishing returns apply, or whether you want to image more targets in the same amount of time at the caveat of having inferior results. My Rosette Nebula image taken last winter (first time on that target was taken over 3 to 4 nights), M42 was also taken over over 3-4 nights too, so I'm firmly not in the camp of having to or needing to image one target a night. I really like Hubble palette images too so I guess mono + narrowband would make more sense. I'm not ruling out OSC at all though.

I guess there are quite a few variables and facets between imagers though (sky quality, elevation, camera gear, location etc.) with Maurice I can see he has a dedicated astronomy camera with the D810a and a £5k scope in that ultra light gathering f/2.8 aperture. But as well as this he is also in France where clearer skies are more frequent than here in the UK with 21.2 mag skies too.

Mono or OSC. I'd like to hear what you suggest... have you gone from Mono back to OSC and why? Or have you gone from OSC to Mono and not gone back to OSC and why ? At the moment I have an unmodified DSLR and I'm at the point where I have gained enough experience setting up, autoguiding etc. but my camera is holding me back by not being Ha modified. I can't mod my DSLR as I use it for other photography so it's either an OSC astro camera or a Mono. Is narrowband and OSC worth considering nowadays too, with the advancement of filters and OSC cameras in general? I notice from astrobackyard and others that they're using duo or triad narrowband filters etc. with their OSC cameras. I really love nebulae more than anything. I have bortle 5 skies and image from a village in a semi-rural location.

Thanks for the feedback. Currently sitting on top of reddit r/astrophotography with 1.2k uovotes in 13 hours. Very happy with that!

was it a light pollution filter?

I'm thinking about buying the ASI294MC Pro. These are good results considering the lack of calibration files, full moon etc. Shows the colour it can achieve and how sensitive the camera is with such a short integration time on these targets, go for 5 or so hours on each at new moon, with properly calibrated files and they should look very good indeed. I'd be interested to see what the results look like.

Hi all, Just wondering what is the advantage in using EQMod instead of the handset controller... what will it enable me to do?