Shibby

Thanks very much for your comments @SamAndrew Hmm, you might well be right in terms of the risk to "fun"... I really like how, at the moment, I can be up and running in 10 minutes and everything works nicely.

As for combining data, did you try Registar when you were doing it? I know it can account for distortion etc so should solve that problem.

Anyway, perhaps I should think about another use for my 428ex or try again to shift it.

Having been unable to sell my old Atik 428ex, I've been casually thinking about the possibility of using it in a dual imaging rig.

I may or may not pursue this, but thought I'd ask the more knowledgeable folk here for their thoughts and to sanity check this (possibly foolish) idea.

I currently have a 190MN mounted on a Mach1GTO with a 50mm finder/guider. I image with a 460ex. My idea is to side-by-side this with a smaller scope that has roughly half the focal length of the main scope, then use this to capture the RGB for my targets at the same time as luminance / narrowband with the 190MN. The pixel size of the 460ex and 428ex is the same. Something like a Sharpstar 76EDPH might fit the bill, although it's FL is 418mm. The smaller sensor shouldn't give an FOV issue given the shorter focal length.

I understand that the resolution would be halved, but figure this is okay for RGB. I also understand that the smaller aperture means longer exposure times than if I binned the RGB with the 190MN, but at least I would be doing it in parallel with luminance. Does this make sense - would it be worthwhile?

I've read that flexure is a real problem with guiding on a dual setup. Given that the guider is mounted on the larger scope, would I be okay if I manage to keep the smaller scope as lightweight as possible? Is side-by-side the only way to go? Will the extra weight on my mount cause guiding issues despite how it's mounted?

If the above just doesn't work, perhaps I'd be better off going for widefield images with much smaller optics. However, it's a shame the sensor on the 428ex will limit just how wide that field would be.

I like your project - the scope really does look cute and could end up being a very nice little imaging scope once you are finished. You will of course need a coma corrector if you want to call it an "astrograph" and these are unfortunately expensive. You can hunt for a second-hand one but it will still likely cost more than you paid for the OTA.

@dannybgoode I'm interested. How about that result?

Here's my image of the Hidden Galaxy, a surprisingly large but very well shrouded galaxy. Certainly a different one to process and I'm not too sure about the result; the colour balance isn't perfect, but this is just how it came out for me. Also, I need to work on my star handling processes as I struggled a bit with them as you can probably tell.

Anyway, I gathered LRGB and some Ha data for this one, totalling around 11 hours.

MN190 + Atik 460ex

• L: 33x600s
• RGB: 3x18x300s
• Ha: 10x600s

Thank you for looking

@teoria_del_big_bang The 3nm, but I should also add that it replaced the 8.5nm Baader, not the ultra narrow one.

For what it's worth, I replaced my Baader Oiii with an Astrodon, while keeping my Baader filters for everything else. I find this gives me star sizes that match quite nicely in narrowband, since they don't bloat as much in Oiii as they did with the Baader filter. Yes, I have to refocus but that's not a major problem for me since the NB runs are typically long.

Huge improvement - hard to believe it's the same data!

I absolutely love using my "shedservatory". Like you, I got sick of setting up and packing away every night - as well as having nowhere to properly store the kit. Now, I can start an imaging run within a few minutes - and most of that time is just waiting for the laptop to boot up!

I've also developed a new-found fondness of DIY and carpentry since building it.

Do it!

I deliberately tried to make it look shed-like as possible, so designed the roof to roll back over the warm room, rather than having extra supports sticking out in to the garden.

Here's my build thread:

Excellent - fine detail and you've handled the core very nicely.

As others have said: fantastic, strong colour. I started capturing this the other night and doubt I'll get such a vibrant result!

@rickwayne Perhaps you're right, but when you look at the star profile above it is very noisy, because the SNR is very low. It has lead to constant corrections in both directions. As you say, multi-star will help and it all depends on what works and also how bright the stars used are.

My Oiii is the Astrodon and I don't have the halos, however I have a reflector so that's probably not relevant.

I would have thought that, with 51 sub-exposures, the halo would stack/reject out if it was only on a few of the subs.

I would also recommend increasing your guide camera exposure time, otherwise the guiding chases the seeing and noise. The SNR of 14 is not high enough, so that will help.

Nice - looks like you've got some great data.

However, to me it looks like a bit too much noise reduction may have been applied to the nebula? I feel it could be far more detailed with a gentler touch.

Fantastic work, a very nice result!

Am I reading that right - 28hours?! Great dedication.

I can't really help with the processing of blue halos... what Oiii filter are you using?

Love it. As you say, the numbers are mind boggling. As are the incredible number of galaxies you've captured in this image!

Seems like a popular subject to wade in on!

My two cents - I spent many years imaging happily on a second-hand Vixen GP, second-hand DSLR & 150PDS, no guiding, with a total outlay of ~£550 IIRC. I wouldn't hesitate to recommend the same to anyone else. Before that, I had a borrowed Nikon D70 on an Alt-Az mount. I've always been a proponent of starting small, getting the most out of your kit, then gradually upgrading / increasing budget depending on how things go. After all, if you find you don't enjoy it then there's also no need to upgrade.

However, it is our course important to set expectations correctly as a beginner as to what is required for what level of result.

2 hours ago, The Lazy Astronomer said:

quite surprised at how little apparent Oiii there is

Thanks - yeah, originally I had ~10 subs taken under a bright moon and only managed to resolve a little bit of the brighter stuff. Adding another 11x600s on a dark night made the world of difference!

After a few nights, I got together enough data for some nice looking Ha and Oiii layers (despite much of the captures being under a bright moon) so processed them together into HOO bi-colour. I do still struggle a bit with my processing, I feel I can never quite get the balance (and brightness) right.

The nebula is quite a bit larger than I expected and I can't fit much of it in with my FOV, so I decided to go for the "business end" and framed it how I felt looked relatively pleasing.

It consists of ~7hrs exposure

• 20x600s Ha
• 21x600s Oiii

MN190 + Atik 460ex

This is at 50%. Thanks for looking

Superb! Framed everything in nicely - is it a mosaic? Also, have you tried it in HOO?

A lot to like about your image. Great colours and nice to see all that dusty stuff that, as you say, you don't normally see in the narrowband images.

Can you post a full frame of these two images? To me (certainly the second image) it looks like the halo could actually be an internal reflection of the bright star, not the star that happens to coincide with the halo.

Having read through this, I would have to conclude the same as you - the arcs are some sort of reflection of the dust bunnies. Although it's hard to fathom exactly, it makes sense that the moon could be responsible, giving you light from a different angle than your light panel does.

Very nice job! I once had a go at this in Ha only and just got the faint whisp. Nice to see it with RGB.