John

3 minutes ago, Ships and Stars said:

John, that has to be about the ultimate set of eyepieces! Very nice. If you ever come across the Leica asph ww zoom see what you reckon. I have a couple of Ethos (Ethoi?) but have been wanting to try the Pentax XW's. 

I was given two flight cases which I didn't use for years, but as soon as the astronomy bug bit me, they've seen frequent action. 

Thanks

I have owned the Leica ASPH zoom for a while and it was very nice but I decided in the end that it was not for me. I know other folk who feel that its a "must have" eyepiece so it must be my odd tastes

I keep mine capped and in foam lined flight cases. My cases are the plucked foam ones from Maplins but they have gone out of business now. I'm sure something similar is availabale elsewhere.

I think the Giro Ercole uses a sensible approach to the counterweight bar fitting. The steel alt axis is drilled and threaded to accept a 10mm screw which is what the C/W bar screws into. The end of the steel axis is recessed within the machined alloy arm and the C/W bar slides into a 20mm diameter sleeve in the alloy arm end and then screws into the alt axis. So the C/W bar gets support from around 50mm of precisely machined alloy sleeve as well as being screwed firmly into the alt axis.

The Altair Sabre mount uses a similar approach to C/W bar fitting.

11 minutes ago, PlanetGazer said:

I have a similar thing on the 10inch SW, i thought that if you remove the 1.25 inch adaptor, you are left with the 2 inch default opening.

Maybe on the latest Skywatcher focuser designs but not one the older ones. It's a rather odd and annoying design that Skywatcher went for back then - other  brands gave you a 2 inch drawtube with a 2 inch eyepiece fitting on the end of it then you use a 1.25" adapter when the smaller eyepieces are in use. Skywatcher decided that you would need to use an adapter for both eyepiece sizes (used separately) so their drawtube has an adapter that is a touch over 2 inches in internal diameter and that needs a flanged adapter fitted into it to house the eyepiece.

Maybe they have seen sense more recently and adopted the approach that other brands have always used ?

10 minutes ago, jetstream said:

...This is a personal preference, thats all and the ES eyepieces are VG performers overall.

Actually I think low light scatter around bright targets at medium to high magnifications is quite an important practical characteristic. Light scatter is one of the issues that can actually make seeing certain target types eg: faint planetary moons and very uneven brightness binary stars, somewhat more difficult or even impossible if it is extensive.

4 hours ago, johninderby said:

Something like this TS one.

Actually think this idea would be quite usefull as you could move the counterweight forward or back to help adjust the alt balance of the scope. 🤔

I used to have one of those - I used it with my old Ambermille (anyone remember them ?) alt-az mount. It worked well but I didn't put more than 5kg on it.

12 minutes ago, heliumstar said:

Check out Baader 18mm Classic Ortho as well. To my eye one of the best eyepieces I looked through. I had 18mm BST Starguider and BCO is brighter and I could see more detail on the Moon when comparing both side by side.

I agree - the 10mm and 18mm Baader Classic Orthos are superb - possibly the best optical quality eyepieces that you can buy for under £50. They don't have the wider field of view of the BST Explorers, the exterior gloss or as much eye relief but their sharpness and light throughput are really top class.

On 22/09/2019 at 19:54, oldfruit said:

I am happy to report that I managed a short observing session the other night and wow, what a difference a Paracorr makes. Using a 28mm Skywatcher Nirvana I used the middle setting on the Paracorr and with a slight tweak it was great, flat field almost to the edge with minimal coma on the very edges of the FOV.

I can see that my observing experience will be much improved in the coming months.

Thank you all for the help and advice.

Mark

Was that with the F/4 20 inch Mark ?

Are you going to use the Paracorr with your 12" Revelation F/5 ?

It would be interesting to see how much the slightly slower focal ratio benefits from coma correction.

9 minutes ago, johninderby said:

Right EQ6 top for my Berlebach tripod needed then. 🤔

Same here. Is there an adapter or will I need a new hub section ?

Edit: Don't want to derail this thread into a Berlebach tripod discussion - I'll pursue this elsewhere.

It is a really good looking mount Grant

I've been interested in the AZ8 for some time and very nearly bought one but from the feedback that I could gather on it, I had some lingering doubts whether the AZ8 would carry my F/9.2 130mm triplet refractor more steadily than my Skytee II currently does, which would be the prime reason for me to acquire such a mount.

Of course the AZ8 is much better machined and finished than the Skytee II, that is obvious

Thanks Grant

With a couple of DT clamps the AZ100 will be pretty much the same price as the AZ8 I think.

It's the capacity to handle tube length that I'm interested in

2 hours ago, Alan White said:

... the posted price is lower than the AZ8 by a decent margin.
 

Does the AZ8 cost of around £1K include DT clamps and a tripod ?

Lovely looking mount

Can I ask if a dovetail saddle for the AZ100 will available in the Vixen fitting as well as the Losmandy D fitting ?

Can other makes of DT clamp be fitted to the mount ?

Also, as per Omo's question above, what is the tripod fitting ?

Many thanks

I think jock1958 is simply using the mirror on the floor so that he can see where the laser is exiting the objective and the paper target from the focuser end of the scope ?

I'm not sure that he is using the mirror on the floor as part of the collimation system apart from the above ?

I've owned a few Meade 3000's and thought them great as well. Better than the 4000's IMHO, I've had a couple of mediocre 4000s over the years.

Piero mentions using a 2.25x barlow with the 11mm TV plossl. That will have the effect of increasing the eye relief a bit of course.

Solid clouds for the past few days here too. Looking forward to viewing Africano again if we get a clear patch. Good that its brightening. When I first observed it I thought that it was below the billed magnitude and was going to be a damp squib but hopefully it will be a decent one.

Glad you have had some good sightings Neil and Mark, hope you get to 1st light the 6mm Ethos soon

I've owned a few barlows and some Tele Vue Powermates. The Powermates are superb in my opinion. They just seem to be invisible in the optical train apart from amplifying the image.

Your SN-10 is an F/4 I believe ?. F/4 is very challenging for eyepieces that have wider fields in respect of maintaining sharpness across the view. Tele Vue have made this a strength over the years.

Be prepared to spend as much or more on eyepieces as you have on the scope though !

13 minutes ago, jetstream said:

The Leica Asph is very sharp for sure, its too bad that the zooms (my 3 anyway) fall short in the transmission dept IMHO.

The TV plossls have really good transmission IMHO. I saw some data a while back resulting from throughput tests and the TV plossls were a bit better even than orthos (both classic and top tier HDs).

2 minutes ago, kirkster501 said:

Scopes’ a-imaging whilst I’m observing 

So you are both enjoying yourselves ?

37 minutes ago, jetstream said:

Is the TV plossl really a plossl? or is it a symmetric?

I ask because there might be a difference in spot size and technical performance.

Piero, have you considered the Zeiss ZAOII 10mm? for the level of performance you like this might be a needed step IMHO.

I'm pretty sure that the TV plossl is a symmetric. I've seen the optical diagram on the TV patent and it sure looks like a symmetric. I've taken a few plossls apart over the years (not TV ones) and those have had what looked like 2 indentical doublet elements in them as well. Some of the older Vixen orthos also use the same design I was surprised to find, rather than the 1+3 abbe type ortho design that I had expected.

I believe the feature that enabled Al Nagler to get a patent on his plossl was the curvature applied to the outer two lens surfaces which improved edge correction as I understand it. There is a rumour that Vixen NPL's use a similar design.

On the 11mm TV plossl, I've owned a few over the years and found them sharp and contrasty. The eye relief is limited to around 75% of the focal length as it is with all plossls. The stiff rubber eyecup that TV use on the 11mm plossl can make accessing the full field of view a little tricky.

34 minutes ago, Captain Magenta said:

... this is the sort of bevel my existing 1.25" has - although this pic is a 2" adapter - perhaps this is precisely what I need...

That is exactly what you need. You might need to try a "wanted" advert in our classifieds or on the UK Astro Buy & Sell website to see if anyone has one to spare.

I'd tend to go for a mirror at F/6.8. Thats what I use with my Vixen ED102SS F/6.5, Skywatcher ED120 F/7.5 and TV Ranger F/6.8. The Tak FC-100DL F/9 gets the Baader T2 Zeiss prism.

2 hours ago, sonnymoon said:

One more thought. If I line up the focuser and then shine the laser through the scope and there are still two points of light that hit the wall (or the floor), overlapping or otherwise, does that mean the lens cells needs collimating?

What matters is where the laser exits the objective. Don't worry about what it looks like when it hits the wall / floor / whatever.

The tilt of the objective (stage 2 of the checks) is done with a cheshire collimating eyepiece, not a laser collimator. The last 2 photos posted by jock1958 show the the view through the cheshire collimating eyepiece when the objective tilt needs adjusting. You should see a single illiuminated disk rather than the 2 partially overlapped ones.

Just to re-iterate, there are 2 stages which need to be carried out in sequence and 2 tools involved:

1. Check and adjust (if needed) the focuser alignment with the objective optical axis. This is done with a collimated laser collimator.

2. Check and adjust (if needed) the tilt of the objective lens. This is done with the cheshire collimating eyepiece.

Where there are no collimation adjusting screws (very common), you can apply some tilt to the focuser by loosening the screws that hold it onto the scope tube and adding a shim or two to one side to tilt it slightly. Then tighten up the holding screws. If the objective tilt is out then things are more tricky but there are some tricks which can help.