Clarkey

I'm not sure you really need as powerful computer as PI suggests. I use a Rysen5 5600X and a reasonable graphics card and PI worked fine when I trialled it. Maybe try you existing pc first?

On 09/03/2022 at 12:24, johninderby said:

The extension tubes have no real effect on collimation

Technically no, but.... As well as making the visual collimation a bit easier it also prevents any tilt between the main mirror and the focuser less of a problem. They should be perfectly alight but experience says otherwise - especially for the 'cheap' RC's

Sorry. Maybe came out a bit wrong. It wasn't meant to be patronizing.

1 hour ago, Catanonia said:

I think I have it done.

I would still suggest a star test as this is the last step. However, carefully I have aligned everything visually when I do a star test it is always slightly off.  The good news is that once set I very rarely need to adjust it. Also, once you put the extension rings back onto the scope and star test you might find there is a small amount of tilt (between the mirror and the focuser). Tests up to now assume everything is aligned - which if you are lucky it will be. If you put the cheshire back on with all of the extension rings in place - after doing the star test and getting it 'perfect' - you might find the secondary slightly off centre for this reason.

I use the Mele Quieter2 also. I have two and both have been fine so far. I went for the 8Gb RAM and 128Gb storage and added and additional SSD for storage. The Wifi range seems OK - I remote from my PC indoors. 

Personally I think fanless is good for 2 reasons. 1 is the lack of vibrations, secondly they generate a bit of heat which keeps the dew off.

Performance is OK, but not blistering. However, running NINA with guidescope etc, it was only ticking over looking at the CPU usage. As long as you do not intend to do you image processing on it, they are fine. Just as an additional point, they use a 12V supply and say you must use the adaptor supplied. However, on the latest one I brought it said that it would run up to 26V so it should be OK on battery or 13.8V supply. (I did have to make my own cable though as I struggled to find a suitable power cable).

Fortunately I don't have an observatory and I'm not sure I could lug that around.

Great images, especially M51. Goes to show what the extra aperture can do.

I have had exactly the same issue with the same stars. Using my 6" F4 reflector I got these reflections from the filters. All my other scopes are fine so I might have to keep this one for OSC only so I can go without the filters. I did just about manage to remove the halo - but it took quite a bit of work. Not something I am going to go again. (I have no idea what I did to get rid of it though).

Ok, I'll get this one started....

Here is my rendition of the Leo Quartet or Hickson 44 which consists of NGC3190, 3193, 3185 and 3187 Approximately 13 hours of usable data over two nights on the 5th and 6th of March from Bortle 5/6 back garden. Seeing was at best average, so not as sharp as I would have hoped. Imaged using the StellaLyra RC8 on an AZ-EQ6 with an ASI1600mm pro in LRGB. Made up of about 2 hours each of RGB and the remaining 7hrs of luminance - all in 3 minute subs. Processed in Astro Pixel Processor, Startools and Affinity.

Hopefully I might get another session in before the competition ends, but that will depend on sunny Cumbria😁

Leo_Quartet-LRGB_ST AP2.tiff

Good advice above. Some of the old prime lenses are dirt cheap on flea bay.

I image from bortle 5/6 and as a rule I don't use any light pollution filter. I would rather sort out the gradients but get as much signal as possible. Given a lot of the LP is from LED's without going the extreme narrowband type filters, there use is limited in my opinion. (If you still have old sodium or mercury vapour lights then a LP filter makes more sense).

22 hours ago, teoria_del_big_bang said:

Oh of course it would, feel a bit silly now, of course that's a far better option

Fwiw you can rotate the focuser which reduces the risk of introducing tilt. I put this on my RC8. Very good upgrade.

Some Cracking images in there.👍

I think I might move to Suffolk. That's about a years' worth for me.

43 minutes ago, michael8554 said:

And the problem is flex in the relatively long, heavy, guidescope, often mounted in adjustable guide rings, with a guide camera held by lock-screws instead of threaded connections.

I definitely agree with the need for strong attachment. I use this set up for mine which seems to work well:

Guide Scope Bundle - Suitable for Piggy Backing | First Light Optics

Also gives me a nice grab-and-go scope for camping!

5 hours ago, alacant said:

I've never yet met an accountant who would say no to a weekend away, Especially on the promise of sun, sea and sangría;)

You haven't met my accountant. 🤣

Maybe I'll try the sangria first....

Not sure my 'accountant' would approve🙁

Nice image. One of my favourite targets.

I'm just jealous of how many clear nights you get!😁

4 minutes ago, Elp said:

general rule of thumb for guidescope FL is for it to be at least a third to a half of your main scope focal length

I think half is a bit excessive. I have guided without issue at 1000mm FL with a finder at 180mm and it was fine. I accept it was pushing the boundaries a bit, but it was at about 4 to 1 pixel scale which is not too unreasonable in my opinion.

It's a great start! Just add more data now you know it works. You'll get some excellent images.

As above. Darks and Canon DSLRs does not really work. Stick to flats and bias.

55 minutes ago, StuartT said:

What guide scope would you recommend? Is there a relationship btw the FL of the imaging scope and the guidescope? 

I use an ST80 with a ASI120mm along with the RC8 and an ASI1600mm. The pixel scale ratio is in the region of 3 to 1 as although the FL is 4 to 1 the 120mm has smaller pixels. I think the general advice is keep it less than a 4 to 1 pixel ratio. For an 800mm most 50 or 60mm guide scopes would be OK. 

I am using a guide scope at 1600mm which is not causing problems. However it will depend on rig a set up. I also image at 1000mm and less with a scope. I do have an OAG but it was often struggling to find a decent guide star so I went back to the trusty ST80 to guide.

At 800mm both would be OK, especially with a refractor. Personally I find the OAG a right faff!

They do vary a bit. I have a cheap one that I have to use with one of my scopes because the more expensive one would not get close enough to focus. I'm not sure by how much they different though - only a few mm's.

8 minutes ago, teoria_del_big_bang said:

And to be honest I am now a bit scared and thinking maybe this scope is beyond me

Don't be. I felt similar when I got my RC8. Collimation is tricky, but once sorted it is relatively simple. I now have my own method which works quite well. I collimate the secondary first (lining the centre spot reflection with the centre of the focused draw tube. I use a Reego, but you could probably do it with a Cheshire. I then align the focused directly with the centre of the secondary to get a near alignment. Once I have done this I use a star test (or lights on the M6 a few miles away also works) to get the primary collimated accurately.

WRT a reducer /flattened you will probably be ok without. I use my RC8 without a reducer or flattener and it is fine. I do have a CCD67 which is good, but not needed. As for the focuser, mine was iffy and I replaced it. However, it was better than many so you might be ok.

Work with it. I think they are great scopes.

That is a stunning image! Well done 👍

1 hour ago, Catanonia said:

M78 in Orion has always been my nemesis as it is such a difficult target from my Bortle 6 back yard.

Nice image and better than my one attempt so far. (A few subs then canned the idea)

It's always been one I had on my 'to do' list, but I have always left it due to my light pollution problem. I am in Bortle 6, but imaging to the south is the worst area of sky for me. One for a dark sky night.

I did find this on the SW website:

Evostar 72ED Reducer/Corrector Adapter — Sky-Watcher (skywatcherusa.com)

I think this is what you need, but not sure where you will find one in the UK.

No idea then. Seems a bit conflicting though.🤔