John

My current "fab four" followed by a few from my past. The big achromats were generally used with a Chromacor CA / SA corrector to produce close to ED doublet performance:

Nice report Vin

Great scope and mount - I used to have one !

The red and blue tinges top and bottom might be atmospheric dispersion rather than false colour from the scope.

On the focuser, in an F/9.8 scope I think the stock Vixen rack and pinion works well when properly adjusted. If you feel you really need to change you could put a Moonlite dual speed on the scope as I did for a while with my Vixen ED102SS. Your tube is the same diameter as mine:

2 hours ago, globular said:

I got mine from https://okularum.eu/DGM_NPB_filter-2
It took about 5 days to arrive, was well packaged and seems like a good'en.

That's where I would have suggested. I've never seen the DGM NBP offered by a UK based dealer

I wish I'd kept my 2 inch DGM NBP reading this 

Obviously it was behaving as it was designed to do.

I'll have to look out for another one ....

The diameter of the eyepiece barrel limits the diameter of the field stop which is what defines the edge of the eyepiece apparent field of view. Once the eyepiece focal length gets over a certain length the AFoV just gets smaller and smaller so no more sky is shown, ie: the true field of view remains the same.

If you step up to a larger barrel size, you can get the wider fields of view with these longer focal length eyepieces. The is a matter of size and weight to consider though. These are 3 inch accessories:

Pentax is owned by Ricoh now I think. The Ricoh name is included on the boxes of my more recent Pentax XW's and just Pentax on the earlier ones.

Having scopes by Vixen and Takahashi I agree that the Pentax XW eyepieces are an excellent match but then again so are all excellent eyepieces

My 31mm Nagler gets used a lot less than my 21mm Ethos and the 40mm Aero ED much less than either.

If I observed regularly under very dark skies perhaps the result would be different perhaps ?

15 minutes ago, Stardaze said:

Yes, and I really do like it. But you know how it goes..: how much better is the Ethos??

You have to try to know

And be a skilled observer chasing challenging targets of course !

Most of the time and for most folks the difference will be practically zero I reckon.

19 hours ago, Pixies said:

Hi John,

Do you think the south polar cap is getting smaller? I'm under the impression that it is.

Quite possibly. It is still distinctly resolvable even with the 90mm mak-cass but it's a small feature.

Jupiters GRS looks smaller to me this year as well.

1 hour ago, globular said:

I've noticed a very slight colour splitting of very bright starts a couple of times - but only when the nebulosity doesn't improve with the filter.
When it does I'm probably taking in the nebula too much to notice.  Everything is so new and exciting to me.
I'll make a point to look out for this more carefully next time out.

I expect it up to a point with O-III and UHC filters but, for me, the NBP just took it a little too far. The effect of the filter on nebulosity though was really nice so I'm in two mins whether I should have held onto it. Maybe I'll get a new one and see if the latest coating tech / glass polishing has reduced the effect ?

I had the DGM NBP filter for a while. It is a really effective UHC filter, the best of that filter class that I've used in fact. It does great things with the Orion Nebula extending the "wings" greatly as they curve around and almost seem to meet each other.

The Dumbbell Nebula looks really three dimensional with the NBP filter.

The only downside with it, or at least the version of it that I had, was the marked splitting of stars into multiple colours. Most narrowband and line filters that I've used do this to some extent but my NBP did it more than any that I've used, to the point where it became distracting.

Perhaps the latest versions of the DGM NBP have tamed this effect ?. I hope so because otherwise it seemed a very effective UHC type filter.

Very nice views of Mars with just a 90mm mak-cassegrain and no filter tonight. Dark features form a distinct "Y" shape which includes the Syrtis Major. Bright white "button" of the south polar cap still well defined. Rather hazy skies probably helping to filter the planet naturally.

Very heavy dew though - everything is running with it !

3 minutes ago, harpy said:

Thank you all for your suggestions.

 

@Philip R its my first scope so not sure what I prefer yet, I do like the idea of having all the individual focal lengths but also like the option of just needing to grab one eyepiece say if I was going camping the zoom eyepiece would come in handy.

Saw the Televue, would be a nice investment, I'll probably hold off until I upgrade the scope before going for one of those.

Yeah I was looking at the shrouds, I was trying to find a shoe of foam big enough but nothing in the shops by me when I checked I might just order it online and make it next weekends project.

 

 

@John Yeah that's what I was thinking , I like the idea of shiny new eyepieces arriving  but I think a good filter might be the most rewarding to me at the minute. Is there any particular filter you would recommend?

One of these:

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

1 hour ago, johninderby said:

Hey the Skytee II is a nice bit of agricultural equipment. 😁

Works very well though despite it’s lowly origins. 👍🏻

It does work well. My Skytee II is better than my Giro Ercole at carrying my 100mm - 120mm refractors. It even does a decent job with the 130mm F/9 triplet although the T-Rex has now become the primary mount for that scope.

Not sure about the wisdom of a Skytee II on an aluminum tripod though

I've always used my ST II on at least a 1.75 inch steel tubed tripod.

Of the items you list, my choice would be a good UHC filter to give you something more from your observing.

The Baader zoom, in my opinion, will not offer you better performance than the eyepieces you currently have.

Thomas Back's passing was a sad loss to astronomy.

Among many other things he designed the objective lens that sits in my 130mm F/9.2 triplet refractor. A really superb performer.

56 minutes ago, Don Pensack said:

Oof.  That is poor edge performance even at f/10.  His measurements are in arc-minutes.  The predominant aberration is astigmatism.

These are not well-designed eyepieces, IMO.

Are they not the same optics as the TMB Paragons ?

Maybe those rumours were incorrect ?

I find the 40mm pretty good for what it cost. The 30mm is OK at F/7.5 or slower. I use that mostly for outreach.

I would probably add a Rigel Quickfinder in the position I want it. It can be popped off leaving the base in place easily enough when the scope is not being used.

11 minutes ago, Stardaze said:

What's your go-to filter for Orion please? Be interested to know. 

For me, either no filter or a good UHC such as the DGM NBP. I've used the O-III and H-Beta filters on Messier 42 to see the effects but on balance either no filtration or a UHC are my preference.

I'll be interested in Don's opinion as well of course

I guess coating and polish quality have improved over recent years as well, hence lower scatter  / diffraction in the latest versions ?

6 minutes ago, Ricochet said:

I don't think you can scrimp with filters. I would look at the Astronomik and the Televue (made by Astronomik) OIII filters. I've also got a Baader OIII, with an even narrower bandpass that only covers one of the two OIII lines, and that shows the brighter (denser) parts of the veil well, but it doesn't show the looser, more subtle parts that blend into the background sky like the Astronomik does. The cheaper "OIII" filters tend to have too wide a bandpass and with them you are more likely to see nothing at all. 

Saves me typing what I was about to type !

My 2 inc O-III is a Lumicon from one of their "really good" periods but there can be some variations in that brand. I have the Astronomik O-III in 1.25 inch and that is very good as well.

I appreciate that it's quite a lot of £'s to spend on an item with a rather specific use though

You can put the filter on the end of the diagonal barrel or on the end of the 1.25 inch - 2 inch adapter, if it is threaded for filters. If you try the 2nd approach, make sure none of your 1.25" barrels will come into contact with the filter before attaching the filter.

27 minutes ago, LDW1 said:

Yes I do, sorry to confuse, lol !

No problem

6 minutes ago, Captain Magenta said:

I finally brought my 12” to bear a few nights ago, Sunday I think, and My Goodness! The Eastern bit was easily evident without any filter at all, and with the Astronomik Oiii there was lots of wispy detail: I’m clearly going to have to spend time on it, weather permitting. And I now also want need a UHC.

M

The O-III makes quite a bit more impact with the Veil than a UHC does.

22 minutes ago, LDW1 said:

Have a look at the 2” WO 40mm, 72°, its a great ep, I get some great views with my f6, f6.25, f6.6 and also my f11.4 refractors. The last I looked they were about $125 US at Agena Astro out of California, hopefully they are available your way maybe under a different brand ! And it barlows (2x) very well also.

Do you mean the WO SWAN ?:

https://www.firstlightoptics.com/william-optics-eyepieces/william-optics-swan-eyepiece.html

I bought the 33mm (pre-owned) for my astro society and it works very well in their 12 inch Meade ACF LX600 F/8.

When I compared it with the 30mm Aero ED in my scopes I thought they were corrected to a similar level.

I've not used the 40mm SWAN though.