John

BGO = Baader Genuine Ortho = out of production for some years now. Really superb quality if you can get hold of one.

BCO = Baader Classic Ortho = in production at just under £50 each. Focal lengths available are 6mm, 10mm and 18mm. The 10 and 18mm are really good eyepieces and, IMHO still probably the best in terms of pure optical quality that you can get for £50. The 6mm is not quite as good as the 10mm and 18mm but still a comptant 6mm eyepiece.

The Baader Classic Orthos work very well with the Baader Q-Turret 2.25x barlow lens which can also give 1.3x amplification if the optical element alone is used in the 1.25 inch barrels of the Orthos.

All the above come with the standard ortho characteristics of eye relief that is around 80% of the focal length of the eyepiece. The Baader Classic Orthos have a slightly wider apparent field than the Baader Genuine Orthos (50 degrees vs 42 degrees) but the outer 5% or so of the Classic's field is what I call "framing field" and not quite as well corrected as the rest of the view. I believe this was a deliberated design decision by Baader. The eye lenses of the Baader Classic Orthos are slightly larger and easier to find in the dark than the Baader Genuine Orthos.

The above includes the Baader Classic 32mm which is a plossl rather than an ortho design.

Good to hear that the Japanese have produced a competent 3.1 inch F/15 achromat

Disagreements are fine of course but lets keep the discussion friendly and respectful folks.

Many thanks

Normal price is £15.00 I seem to recall.

Very interesting report Louis, thanks for compiling it and posting it here. I know how much thought and effort goes into these things

One line in your report jumped out at me:

"....It is not a good choice for studying objects as they drift across the FOV in undriven scopes....."

I would have thought that the above would be exactly the sort of use that a 26mm "100" degree eyepiece should be aimed at. Whatever it's other strengths it seems a great shame if they cannot deliver in that sector.

For all of that, your report was very comprehensive and an interesting read. Thanks again

One of the much renowned Circle-T abbe orthos. Proper 3+1 optical layout. Still very strong performers. I wish the more modern ortho designs had been of the "volcano top" style. Lifts that eye lens toward the eye so helping with the usual tightish ortho eye relief.

You used to be able to get these for peanuts but I've noticed that the used prices (they are well out of production) have crept up to equal the likes of Tele Vue plossls now and rightly so.

I used to have some of the University Optics branded versions - wish I still had them

1 hour ago, Chefgage said:

Combine this with the A5 spiral bound book, the Sky and telescope's pocket sky atlas. It is nice and small to take outside with you. The book is spiral bound so the pages stay open while you observe. Also the pages are slightly glossy so they don't really get damp/get soggy.

+1 for this atlas. I've owned it for 4 years now and it has proved an invaluable companion to my deep sky exploring

Back in 2016, when I was on the hunt for a top end refractor, I would have happily gone for a nice Vixen FL102. It would have made a grrat companion to my Vixen ED102SS. None came up during my "window of patience" though so I went for the Tak FC100-DL instead. With the objectives of the same spec (all bar 2mm of aperture) and from the same optical company I would imagine that the 100DL and the FL102 would produce very, very similar performance. Maybe I'll get a chance to find out someday

34 minutes ago, russ said:

Omg the time is just flying by so quickly. John, Did I bring the eyepiece down to you and we met just outside Bristol on the M5? 

I think we did meet up in a car park somewhere around there Russ

I have done quite a few car park astro equipment exchanges over the years

I think John might have hit on the problem ?

When you say that you can't get the Skywatcher bars to fit in the clamp, in what way ?

I assume that you have opened the clamp jaws and then tried to fit the DT bar into the deeper and narrower of the 2 recesses ?

I have the ADM equivalent clamp and it fits the Skywatcher DT bars OK.

2 hours ago, russ said:

.... Aero ED 30mm will do the job. Had one of those and enjoyed it. 

Russ,

Do you remember back in 2009, you had an Aero ED30 on loan from FLO then passed it on to me along with your thoughts and I added some of my own to produce this review

Was that really 11 years ago !!

I've read that those Lomo 102 triplets are superb

My TMB/LZOS 130mm F/9.2 was assembled by APM and uses the Kruppax 50 tube as well. One of the benefits is that it seems never to dew up. Even if the outside of the tube is running with it, the objective stays clear.

Do you find that with your Lomo 102 ?

24 minutes ago, Barry-W-Fenner said:

So to summarize, A larger aperture will give very small gains on detail on DSO from my light polluted location.

 

 

I don't want to complicate things Barry but it does depend on the type of DSO.

Some, such as globular clusters, are not adversely affected by light pollution as much and the additional aperture will make a real and noticeable difference there.

Extended objects such as the large nebulae and face on galaxies are hit harder by light pollution so the difference there might be that you can actually see something rather than nothing with the larger aperture.

I don't want to oversell benefits from aperture from a light polluted sight but I'm trying to get the balance right.

Unless the target object is quite bright (ie: magnitude 9 or brighter) I can't see it in any of my finders. I find fainter objects by "star hopping" using the finders and a good star map such as the Sky & Telescope Pocket Sky Atlas. The final finding of such targets is done at the eyepiece of the scope with a low power eyepiece.

I really only use an RDF / illuminated reticule finder for getting the scope to the right part of the sky, to within a 4-6 degrees of my target.

I've found this method works well for me

It is hard to beat the Baader Clicklock system.

If I was just going to use an illuminated reticule type finder on it's own it would be either a Telrad or a Rigel. I have also used the Baader Skysurfer III mentioned above and that worked well.

The Baader Super Skysurfer V gets enthusiastic reviews:

https://www.firstlightoptics.com/finders/baader-40mm-super-sky-surfer-v.html

And if you really want to push the boat out, Tele Vue can help relieve you of quite a lot cash:

https://www.widescreen-centre.co.uk/tele-vue-starbeam-finders.html

Currently I have a Vixen RDF which I use from time to time but most of my refractor finding is done using 6x30 or 9x50 RACI optical finders.

45 minutes ago, rl said:

In my experience the short focus refractors can suffer from excessive spherical aberration as well, which is often not noticed over the CA....

So do many of the longer ones from these sources

24 minutes ago, CraigT82 said:

This is true, but refractors are not immune to collimation issues, and as you do get coma with newts you get field curvature with fracs (well, and pretty much all scopes really, to a certain extent)

Quite right and with the 150 having no collimation provision, if it is out (and they frequently are) it is harder to do anything about it.

5 hours ago, Grumpy Martian said:

.... the ST would give some colour....

A great deal of false colour I think.

Personally I would much rather have one of the 152mm F/5.9's such as the one below for deep sky observing:

http://ensoptical.co.uk/ts-optics-152mm-f5.9

I think your Baader zoom is the best tool for most of that complimented by a fixed focal length 2 inch. Any of the ones suggested would be good.

I would also want decent quality UHC and O-III filters for the nebulae so another £200 needed there

I don't use the locking screws unless I am transporting the scope in the car. Once I got the primary collimated I found that the locking screws were actually putting it out again so I leave them loose in general use. 

Having seen a few of the 350's and 400's I agree entirely with Ian. Try and see one up close and assess how practical it will be for you to store and setup the scope. The 400 is definitely a two person job.

No doubt that you would notice the aperture difference at the eyepiece but if the scope is not practical initial enthusiasm can quickly wear off

Whether the views are worth the cost and hassle is I think only a decision that you can come to. You might find that the BST's need to be upgraded to get the best from the larger, faster, aperture as well.

Actually I find using more magnification helps to tease out more detail on DSO's. For some targets you need the max true field just to fit the thing in but for smaller ones I'm usually using 75x - 150x or more.

12 minutes ago, DeathWarpedUp said:

...As I said in my first post I was recomended a 68/34 for my scope, I just wonder how it compares with a 68/40  and similar ep's. Its so hard to know when you cant try this stuff out in a real setting....

It is hard I agree. At F/10 though, your scope does not pose much of a challenge optically to eyepieces so you don't need to spend big bucks to get good performance.

My expectation would be that a 40 / 68 would perform pretty much the same as the 34 / 68 in your scope but the 40mm would show about 18% larger true field of view at a slightly lower magnification.

Edit: There is a 35mm Aero ED 68 as well by the way.