John

3 minutes ago, Solar B said:

Check this out & yes they nor I 

can spell Lanthanum..a la Vixen 🧐

The one I linked to says 1 ED and 2 Lanthanum. Obviously keeping the real design a secret to confuse the competition

1 minute ago, RobertI said:

 

Great information, thanks both. I am new to the world of barlows and teleextenders so this is all very helpful (despite the fact I have already bought the Baader!)

I've owned Powermates, TeleXtenders etc in the past and they are very good.

Now though I'm happy with the simple Baader 2.25x barlow. It works really well

2 minutes ago, Alan White said:

So clearly it’s not an instant answer then.

@FLO is the place of manufacture known?

Manufacture = China. I'm pretty sure of that Alan. Design, specs, QA - don't know.

29 minutes ago, johninderby said:

I used to have a 10” flex tube but didn’t like it.....

 

Care to expand on that for the OP's sake John ?

If we are done here I can close the topic. It's been quite good up to now though

1 ED and 2 Lanthanum elements according to the Baader specs:

https://www.baader-planetarium.com/en/downloads/dl/file/id/431/product/2855/morpheus_information_and_applications.pdf

23 minutes ago, DeathWarpedUp said:

Have you tried filter stacking before John (or anyone)?

Probably but I don't recall the results being any good !

I later realised that stacking a UHC and an O-III is pointless when I thought it through. What you end up with is an O-III filter with a lower peak pass %.

I don't think there is an Orion branded version of the Flextube in the 10 inch aperture. There is a solid tube version though, which is the same as the Skywatcher in terms of optics.

Yes, I would buy one again and either the Flex or solid tube versions. I would want a light shroud for the Flextube version though. I would also consider the Bresser 10 inch dobsonian as well which is solid tube but has some nice features. More £'s though.

I'm sure someone who has used both will come along soon with specific answers. I've only owned the solid tube version.

Optically, they are the same, I know that much. The Flextube version weighs slightly more.

Not sure re: collimation frequency although it's something that should be checked and tweaked as needed each time a dob is used anyway. Like tuning a guitar before playing.

Flextube is not a great name for a dob is it ?. I guess they were referring to the ability to reduce the tube length for storage / transport but still .....

If the skies are really dark you can hold a UHC or O-III in front of your eye and see the NA and a few other large Nebulae apparently. I've tried it but not with much success so far.

4 minutes ago, markse68 said:

Were does one find a Highly-Orthoscopic eyepiece (number 9)- is it just theoretical or were (are) they made by anyone?

Out of production now but Takahashi used to do a 2.8mm and 4mm Hi-Or which might be that design ?:

1 hour ago, bomberbaz said:

It was only recently I re-read the difference between a telecentric barlow and a standard barlow. Cannot remember the webpage but it was a good janet and john type explanation. Gave me a much better understanding of the mechanics of the telecentric version and I understand now why the price difference.

I have heard but not verified that there is no discernible difference on the clarity of the views from a telecentric barlow and a standard barlow but standard barlows as @Don Pensack states can play games with the eye relief and also introduce vignetting. Especially in shorty versions. 

I also did a little research on 2 and 3 lens standard barlows and found this statement on the oreilly.com webpage:

Ignore the marketing hype. It doesn’t matter if a Barlow has two or three elements or is described as “apochromatic” (which is marketing-speak for a 3-element Barlow). What matters is the figure and polish level of the lenses and their coatings and the mechanical quality of the Barlow. There are superb 2-element Barlows, including both Tele Vue models, and very poor 3-element Barlows.

The fact televue do a two element barlow says a lot so it is something to bear in mind when researching your next model. 

Steve

 

Interesting thread on here a couple of years back illustrated the differences between how a barlow and a teleextender / focal extender / Powermate works:

I'm pretty sure they are manufactured in China.

Along with many other excellent eyepieces

Amazing movie - thanks for posting it

I have both Ethos and the Delos eyepieces.

The Delos was developed from the Ethos to offer longer eye relief, a lower price, the same optical performance and still a generous 72 degree field of view.

I use the Ethos with my 12 inch dobsonian and the Delos more with my refractors.

They are both superb eyepiece ranges. Pentax XW's are a lower cost but still excellent alternative to the Delos. I have some of those as well

Some people do not like the 100 / 110 degree fields of view so the Delos are for them - they are very comfortable eyepieces.

Naglers are an older design but still very good. There are a number of different Nagler types which cover 1.25 inch and 2 inch formats with focal lengths from 2.5mm to the huge 31mm Type 5 Nagler.

There are other ranges from ES, Baader and APM that perform almost as well and their cost is lower so it is worth doing some research before buying. If you have an SCT the F/10 focal ratio may mean that other brands perform pretty much as well as the Tele Vues.

The Andromeda Galaxy is a very large object so a low power, wide angle eyepiece is what is needed. Something like a 30mm 82 degree or a 40mm 70 degree would be what to use for that object.

For a used ES 100 eyepiece I think £200-£230 is a reasonable price.

Looking at photos of the bottom end of the zoom, the 1.25 inch barrel and the chrome flange seem to be a single piece ?

I would guess that the whole thing would unscrew from the black body of the eyepiece but presumably it won't budge ?

Meade used to have a TeleXtender which I think is the same thing.

Nice work Gary !

The Celestron version of the AZ-3 is called the "Heavy Duty Alt-Azimuth Mount", a title which caused me to smirk a bit I have to say

Good to see that it's tripod can be put to good use.

16 minutes ago, Dr Strange said:

I have the 31 Nagler and have used it in my EdgeHD 8 and 11. Truth in advertising I no longer have those scopes. I replaced them with a Mewlon 250. I have no other hobbies, take a sack lunch to work to save for spending in the hobby, scrimp and save other places, and justify my addiction ^H^H^H^H er ah I mean hobby spending by telling SWMBO that by allowing me my folly and the corresponding spending it keeps me out of the pubs.

Yes it gives a wider field than other EP's. Not the point. The SCT with that EP gives you a 1.25 degree FOV. Pretty nice for an SCT. With the 0.7 reducer for the EdgeHD it gives a 1.79 degree FOV. Better than the 1.25 degree but not by much when you compare it to a "fast" refractor. Which leads me to my next point. The place where the 31 really shines and is where it should be used is in a "fast" (low f stop) refractor. For example my Tele Vue NP101is with that EP gives me 4.71 degrees.  That is a huge difference. And justifies the $900 a 31 Nagler costs in my mind. I can and have gotten the entire Veil complex in the TV with the 31 Nagler and a OIII filter. That cannot be done with the SCT.

To put it in perspective the 80mm ES APO and that Nagler gives a whopping 5.3 degree FOV. And the 18mm ES 82 degree in the 80mm APO gives a 3.08 degree FOV. That is far better the 1.25/1.79 degree FOV the Nagler gives in the SCT. So if he wants the super wide field sweeping views he would be better served with the 80mm APO and the 18mm EP than spending $900 on a 31 Nagler for his SCT.

All quite true.

I use my 31mm Nagler with my Vixen ED102SS F/6.5 refractor and the Lumicon O-III filter to get the whole of the Veil complex in as well - one of my favourite Summer sights

I was just pointing out that some people do use and enjoy the mighty "terminagler" in their SCT's and really enjoy that experience even if it is not the best value for money when bought solely for use with such a scope.

The 31mm Nagler costs the equivalent of $800 here. I got mine for much, much less by buying pre-owned. The ES 30mm 82 would produce pretty much the same effect in the SCT and costs considerably less of course.

Sorry if we have delivered too much info. It is a complex subject

On other forums threads on this topic have run for months !

On 06/07/2020 at 23:51, DeathWarpedUp said:

Hi John, what abut Nebula? Thats primarily what Im after. Ive got a swan 40/70. I was hoping the lower power would brighten up the veil ect, and not just the sky around it.

Thinking back (it was a long time ago that I owned an SCT) I don't think I used it much on nebulae apart from the small bright ones and not with filters.

I can see that the longer focal length eyepiece would produce more effective exit pupil when using O-III or UHC filters.

40mm plossls (the NPL is a plossl) don't show any more sky than a 32mm because of the restriction of the 1.25 inch barrel.

For wide field I would go for a 30/32mm plossl or the 25mm BST Starguider which shows nearly as much sky. It's not the best of the Starguiders but should work well enough in your F/8.3 and F/7.5 refractors.

4 hours ago, RobertI said:

A lovely array of fracs Stu, not a dud amongst them. I’ve just placed an order for a Skywatcher ED100 and am fully expecting this to be the slippery slope! My first task when it arrives (not expecting it until August TBH) is to do a detailed comparison with the Tal to start to really understand the differences between the different flavours of fracs. Hoping to be able to get a squint through a Tak at some point. 

I'm sure you will like the ED100. I bought a blue one when they first came out and loved it. It replaced my TAL 100 RT, also a fine refractor telescope

Lovely images Victor - thanks for posting them

I was really surprised and impressed with Comet Neowise when I saw it back on the 6th July with my 11x70 binoculars. I guess I've got used to looking for faint patches of light with a difficult to discern shape but Neowise just looked so "comet-like" that I stared in disbelief for a while.

We have had clouds here since then but I'm hoping for more observations here over the coming days as the weather improves.

I've not used a Meade zoom. They seem to have gone through different designs over the years. At one point they were very similar / the same to the Tele Vue / Vixen 8-24 zoom and pretty good. Other incarnations have been more mediocre.

Worth some more research to find out just what you are buying with this one to be sure that you are not paying a premium for an otherwise quite ordinary zoom.

Sorry I can't be more help on that one. Never been a real Meade fan to be honest with you