John

I'm going to stick with my Nagler 31mm and Aero ED 40mm in these focal lengths I think. I don't use 40mm eyepieces that much but the Aero ED seems good when it's been used, even in my F/5.3 dob. The best one in the Aero ED series I think.

I don't actually use the 31mm Nagler that much but I know I'd miss it if I parted with it. Most of my low power observing is done with the 21mm Ethos.

The scope looks very similar to my 1960's Tasco 60mm F/13.3 refractor. Possibly from the same manufacturer. My Tasco has a good objective lens but the stock eyepieces and rather wobbly mount don't really do it justice. I've tried it on a good mount and with better quality eyepieces and the objective performs as a good 60mm achromat should.

The step from 114mm to 150mm newtonian might show some small gains, assuming a similar optical quality, especially on deep sky objects. Modest though, all things considered. Moving from 114mm to 130mm does not seem worthwhile to me.

I think you would need to think about moving to 200mm to see noticeable all round improvements.

If we were talking about refractors the step from 114mm to 150mm makes more of an impact.

25 minutes ago, parallaxerr said:

It just goes to show how personal preferences vary so much. John, myself, Mike and Stu all using different solutions that wouldn't suit the other. I can't merge bino views for love nor money!

I've tried bino viewers a number of times but I don't get on that well with them either while other experienced observers are very happy with them.

Eyepieces do seem to be very personal choices don't they ?

I agree with Olly. I have the Ethos in 21mm, 13mm, 8mm and 6mm focal lengths and they are superb eyepieces and not just in terms of their field of view.

The 21mm is eye-wateringly expensive if bought new though. The APM 20mm HDC-XWA is an excellent alternative at substantially less cost.

The image is only as good as the weakest link in the optical chain. In this case I think it's clearly the cheap barlow lens. There are pretty good ones available at reasonable cost as mentioned in the posts above.

I go down both routes with my refractors. I have a 21.5mm - 7.2mm zoom eyepiece which I use with a Baader 2.25x barlow to give a 9..55mm - 3.2mm high power zoom which I have found both good optically and very useful for finding the right magnification for particular target / seeing conditions. Coupled with a 30mm wide angle eyepiece the zoom + barlow makes a very good 3 piece set for travel or outreach.

I also have a number of fixed focal length eyepiece down to 3.5mm and the excellent but sadly out of production Nagler 2mm - 4mm zoom.

I've been pleasantly surprised how often I can use 250x - 300x or more magnification with my refractors but having the capacity to fine tune the power to suit the conditions / target is important so small steps in focal lengths makes sense when high power observing.

Here is a web page describing some other modifications to the Skywatcher 130m which has some photos and diagrams of the primary mirror cell including the attachment to the tube. These suggest non-captive nuts on the screws that hold the cell to the tube:

http://astrobeano.blogspot.com/2013/04/moving-mirror-on-skywatcher-130m.html

Also here is a thread from a while ago on someone wanting to remove the primary mirror for the same reason that you do. Skywatcher have not made it an easy task !:

13 minutes ago, Louis D said:

The Vixen SLVs are being closed out by FLO for a good price.  They view very similarly to the Pentax XL/XW, just much narrower.

Good advice from Louis. For a £100 per eyepiece max budget the Vixen SLV's are very good. Spending 3x more will get a wider field of view but not better optical performance.

If you get an eyepiece set of excellent quality now, it will last you for years and years and serve well in future scopes you might own

Its worth remembering that filters such as the UHC and O-III only really have an impact on nebulae. For clusters and galaxies, dark skies are the best "enhancer"

Still clear here but somehow the seeing is not quite what it was and the transparency no better.

While it's good to actually be observing, I feel that I'm "going through the motions" a bit just now. I can pick out stuff like M51, M97, M81+82, NGC 2903 etc, etc but I know that I've seen them looking better.

Perhaps its time to pack up and come back into the warm 

It's hardly blazing tonight but no dimmer either. The fight back begins !

10 minutes ago, joe aguiar said:

Antares also made the elite models at f8.8, f13 and bf15.  They were all 105mm refractors.

I see a Canadian dealer selling the 105 f13 one but I got too many right now at 13 scopes, maybe 14 I gotta count them

Joejaguar 

The Antares 105mm refractors looked great but were internally stopped down to around 95mm effective aperture. Challenging to mount such long tubes steadily as well. Perhaps choose elsewhere for your 15th / 16th scope ?

The Antares 105mm refractors looked great but were internally stopped down to around 95mm effective aperture. Challenging to mount such long tubes steadily as well.

Clearer again now for a bit - out we go again !

Having been there (twice) with young children I can fully empathize !

In your shoes I think I might prioritize replacing the 10mm and 25mm stock eyepieces with better quality ones. Hopefully you will see why when you get and try the 18mm BST Starguider.

You could think about a 12mm Starguider and perhaps a 30mm Vixen NPL plossl. With your barlow the 18mm and 12mm will also give you 9mm and 6mm eyepieces and the 30mm NPL gives you a low power option for open clusters brighter galaxies etc etc.

Filters would be slightly lower on the list than the above, I think.

See what others think as well - lots of good experience on this forum to dip into

Nice session on double stars with my 130mm refractor but a cloud layer has just crept across the sky masking all but the brighter stars

Just before the veil was drawn across the sky I managed to spot "The Pup" star Sirus B glimmering very faintly beside Sirus A. I was using 240x a this point and was getting quite a nice tight image of the A star with minimal shimmer. The encroaching cloud layer put a stop to that of course so the scope sits in the greenhouse now waiting to see if things clear up again.

Seeing is steady but transparency seemed a little down so the Orion and Eskimo Nebulae were not as extensive as they can be with this aperture. E & F Trapezium were nicely seen though so that was a fair exchange I guess.

Perhaps the cloud will thin out again ?. Hope so

1 hour ago, mikeDnight said:

That did it for me too John. I'd stare longingly at the pic of Patrick's 5"refractor in the "Observers Book Of Astronomy". His reflectors left me cold, but that may have in part at least, been because Patrick promoted the 3" refractor equals a 6" reflector myth. I still have that book 40 years later and i still look longingly at his 5" frac'. Its an illness!

I didn't find that my experience bore out that myth - maybe that was harking back to mirrors made from speculum ?

When I've done comparisons I reckon a good refractor can match a reflector around an inch or so larger in aperture perhaps ? It does depend on the seeing conditions as well though.

Anyway - nice to see Dougs new-to-him 5 incher and I'm looking forward to hearing about it's performance

If you go for filters I would strongly consider a good quality UHC filter over the CLS type. Unfortunately £40 does not really buy a good quality UHC unless its a used one. Astronomik are really good but their new price is higher than your budget:

https://www.firstlightoptics.com/astronomik-filters/astronomik-uhc-filter.html

The lower cost UHC ones are not as effective and the CLS have less impact again. Sorry if that sounds a little blunt but that's what I've found over the years I've been using filters.

For the Veil Nebula, an O-III filter is the tool of choice and, again, good ones such as the Astronomik are the ones to go for. A UHC does help on this target as well but an O-III gives noticably more "punch" to the contrast of the nebulosty against the background sky.

Can you be mobile with your scope ? - some £'s spent on fuel to get to a darker site would make a big improvement on your observation of deep sky objects.

I always wanted a 5 inch frac after seeing pictures of Sir Patrick Moore's 5 inch Cooke at Selsey

Nice scope Doug

I used to have one a few years ago. I liked it a lot - proper "big" refractor feel to it

It will be visible from the UK but low down in the SW sky in the constellation Capricorn.

Stellarium simulates it nicely so you can see if and when it is visible from your location.

There was a thread anticipating the 2020 martian opposition last year that might be of interest Barry:

Its going to be a little higher than the last one but Mars disk a little smaller. I'll take higher and smaller happily I think - it was so low last time that I had to observe between houses !

13 minutes ago, RobH2020 said:

Hi Joejaguar,

yes my scope has a 2" focusser so can definitely be in the market for a 2" wide-field (e.g. 60deg) 32mm-ish eyepiece.

Do let me know if you know of any worth having in a similar price range to the BST StarGuiders, i.e. around £40-50.

Cheers!

Rob

Keep an eye on the used equipment market (ie: classifieds here and the UK Astro Buy & Sell website). I picked up a Skywatcher Aero ED 30mm for £50 delivered last year and thats a decent low power eyepiece with a 70 degree field of view.

Quite a lot of folks get most of their astro satisfaction from observing the Sun. I know a few who do practically nothing else.