TMB Paragon/Skywatcher Aero

[DMC]

Can anyone confirm if these are the same ep. I have read reports stating that they look identical and are available in identical focal lengths. If they are one and the same the Aero has to be a bargain.

[John]

I've owned a couple of the Aero's (30mm and 40mm) and, from everything I have read, I reckon they are, optically, the same as Paragons. Good eyepieces and a step up from the Panaview's. Edge correction is not in the Nagler / Panoptic league though in faster scopes.

[johninderby]

You can include the other ones that seem to be identical such as the Astro-Tech Titan Type II ED Premium 2" Wide Field Eyepiece and the TS Paragon ED 2" Super Wide.

http://www.scsastro.co.uk/catalogue/astrotech-titan-type-ii-ed-premium-2-wide-field-eyepieces.htm

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p2333_TS-PARAGON-ED-40mm-2--Superweitwinkel---68-Grad---6linsig.html

John

[cs1cjc]

Tom Back was very excited by his design of this eyepiece, writing as as below, but the full set he writes of was not completed before his untimely death:

A New Standard in Wide Field Eyepieces

Thu Dec 29, 2005 9:35 am

"tmboptical" <TMBoptical@...>

Hello All!

I'm on vacation right now, but after I got a package at 10:20am,

from FedEx today, from Burgess Optical, I had to come out, and

go back to work.

My next promised step in our new eyepiece line was in that package.

Inside was an eyepiece that I have been working on for months. To

say I was nervous, and excited, is an understatement.

I opened the well boxed eyepiece, and held it in my hand. I could

not believe that it was so light! I weight it, and it came to 3/4

of a pound. Now, you might ask, what is so light about an eyepiece

that weights 3/4 of a pound? Well, if it is a 68 degree, 2", 40mm

focal length eyepiece, then I would say it is very light.

Running down to my shop, I had my autocollimator ready, using a

TMB 130mm f/6 apo lens as the test lens for the new TMB Paragon

68 degree wide angle 40mm focal length eyepiece. I can set up a

multitude of tests with my 10" flat and autocollimator, but for

this test, I used an Edmund laser pin hole, with a 50 watt Halogen

light source, and also a simulated planetary surface, with a metal

surface that has very fine details scribed into it. This way,

I can test all telescopes, lenses in cell, eyepieces, Barlows,

diagonals and so on, that all are under temperature controlled

conditions, that will simulate an Airy disk under "10" seeing,

and the detail test, that is simulating a Lunar and planetary

test. Also, I used a lamp well off axis to simulate how a bright

object might show off axis scatter light, in another bench test,

at 60 feet from the very bright, light source. The skies here in

Cleveland have been cloudy for weeks, so an under the sky test

will have to wait, but if anything, these tests under laboratory

conditions, will allow me to see aberrations better than under

the night sky.

The new TMB 40mm Paragon eyepiece gives about 20x with the TMB

130mm f/6 apo refractor. The spot sizes, wavefront errors,

distortion, curvature of field, lateral color, astigmatism, coma,

false color, and the on and off axis performance is the best I

have ever seen on my computer in a wide field design. Before I

tested the eyepiece, I looked carefully at the coatings, and they

are among the very best coatings ever put on an eyepiece, in the

same class as the Zeiss/TMB 25mm Aspheric eyepiece, which has the

best coatings I have ever seen on an eyepiece. I specified matched

coatings. What that means is that every surface index was matched

with coatings that were optimized for it. This gives the maximum

light transmission, right at the .1% reflection level per surface.

There are 6 elements, but only 8 air to glass surfaces. All the

glass types (and yes, glass types do make a significant difference

in eyepiece performance) were the most expensive, exotic, high

index glass -- I used the best glass for the job for every element,

price being of no concern.

So, on to testing. All the aberrations I spoke about above were as

good as the computer said they would be -- truly superb performance.

This is an orthoscopic eyepiece, in that it has no noticeable

distortion, something I can't say about any other 68 degree

eyepiece that I have ever tested, or heard about. Lateral color is

gone, even at the field stop, and curvature of field is under

control, as is color, astigmatism, coma, and edge sharpness. There

are no exit pupil aberrations either, the eyepiece not having

any of the "kidney bean effect" and the comfort and eye relief

is outstanding. The entire field is very easy to see, and the

images are bright, contrasty, very sharp with very low scatter.

This 40mm eyepiece will have the largest true field of view in

a 2" eyepiece, without having distortion, like so many other

wide angle eyepiece do.

In concluding the tests, I felt that this wide angle eyepiece

is unmatched in its field size, and focal length. It will be

a TMB eyepiece, called "Paragon series," our top of the line

models. Each eyepiece will come in a TMB black engraved box,

with a nice foam cut out for the eyepiece (no bubble wrap

here), and each eyepiece with be serialized.

I am so excited about this eyepiece, I will design a full

set and we will put them all in production.

They are: 40mm, 35mm, 30mm, 25mm, 20mm and maybe a 15mm.

The 40mm should be ready for sale in a month, and soon

after, the other focal lengths will be available.

I will post a drawing of the final production eyepiece in

the files section under "TMB Paragon Eyepieces," and also

with the spot sizes of an optimized 50 degree Plossl, and

the TMB 68 degree Paragon 40mm wide angle eyepiece, and

with pricing. It is getting very late, so I will post all

this tomorrow.

We will soon have this eyepiece in the hands of an unbiased

reviewer, and then I am sure that CloudyNights will also

have a review. I just wish you all could have been there

with me, testing this new eyepiece. Thank you.

Thomas Back

[DMC]

Thanks guys. They sound really good for the price. I'm considering the 35mm for the extra fov over my 32mm plossl.

[John]

Thanks guys. They sound really good for the price. I'm considering the 35mm for the extra fov over my 32mm plossl.

That 35mm Aero ED would be a great low power, wide field eyepiece in your F/6 dobsonian

An added bonus is that they are not as heavy as some other 2" eyepieces which helps with maintaning scope balance.

[russ]

I'm evaluating the 30mm Aero ED at the moment. Pitting it against the 31mm Hyperion Aspheric and Meade 4000 32mm SWA. Due to the weather only had one chance to use and compare. But that one chance was enough to tell the Aero ED had the edge on the Hyperion and there was clear air between it and the Meade 4000 SWA. The Meade performs on a par with the 32mm Panaview i had previously, just to give an indication of where the cheaper Panaview lies.

There are some other factors though that may not make it a clear win for the Aero over the Hyperion. I found the Hyperion the easier to use and see the whole field. Especially with my glasses on, essential for me as i have an astigmatism in the eye. Need more testing really.

I'm also realising that the 30mm Aero ED doesn't give the field i was needing but was put off the 35mm due to the exit pupil. Not sure why i considered this as a factor though.

[DMC]

I look forward to your final report Russ. The 35mm would give a 6mm exit pupil with my scope so i think i'd be ok. Also as John stated its not an overly heavy ep and shouldn't upset the balance of the Dob too much.

[John]

... the 30mm Aero ED doesn't give the field i was needing but was put off the 35mm due to the exit pupil. Not sure why i considered this as a factor though.

For me it's an unwillingness to loose the precious light that the primary has collected through vignetting by the iris. When I was younger I did not bother too much about large exit pupils. Recently however I'm trying to keep to something that my 50+ year old eye can accommodate. Olly Penrice wrote an interesting piece a while back on his experiences comparing oversize and "right" size exit pupils which I found quite pursuasive