Posts Made By: john raymond

Hello all,
In the past week I got to visit about 10 homes that I have not been in before. Each time Im in one, the first thing I notice is 'no telescope'.
It seems very odd to be in a house where theres no scope set up in the living room, no astro books in the bookscase, no Sky & Tel or Astronomy on the coffee table.

Also in the July Sky and Tel, theres no 7" Mak listed in the Meade LX 200 ad. Has it been discontinued?

John

Does anyone have trouble reading Greek letters on star atlases? The following often look similar under a red flashlight.

Zeta / Xi
omicron / rho / sigma
mu /nu / upsilon

Why are there two variations of Theta? Some atlases use the letter "O" with a line thru it, and others use a "v" with a curl on top, that looks a lot like upsilon. I personally prefer the "O" theta.

"O" theta:
Orion deep map
Stars and planets, princeton field guide
Sky and Telescope
Astronomy, Dec 1996
Uranometria 2000
Burnham's celestial handbook
every Greek language website I looked at

"v" theta:
Sky atlas 2000 delux and field
Night sky observer's guide
Astronomy, Sept 1993

Why? ? ?

Night vision Red, sleeps me and all equipment.
No more tent!

Hello,

I observed open cluster Dolidze/Dzimselejsvili 9 last month. This cluster is in Hercules. I used a 12.5" f5 dob.

My problem: How do you pronounce "Dzimselejsvili" ?

The cluster is easy to observe, but very difficult to tell a friend about!

John R.

I have both of these in my collection. Which one is older? Better? Any comments appreciated. :S

The 10.4: Wider top, taller "slope" Inscribed in green "TELE VUE 10.4MM Plossl Japan" with symbol in green. Symbol is a U or N in a circle.

The 10.5. Smaller top, less flaring, about 2mm shorter. Inscribed in green "TELE VUE (R) 10.5MM Plossl"
"Japan" is engraved on the side.

Thanks
John

What kind of ad is it?
393408

What category of ad is this?

396974

Hello

I had my first unpleasant dealing on Astromart. I replied to a for sale ad. In the reply:
1. add 3% paypal (not mentioned in ad)
2. send money to a yahoo email, not the astromart email.
3. Was insulted for asking about alternate shipping option

From now on I will only deal with perfect 5 star people.

John R

The 20mm Erfle, a real gem. This post reflects my opinions and experiences, not the "facts".

I recently purchased a Celestron 20mm Erfle and a University 20mmm. I wanted to share some comments on each. Old news to some of you, so please bear with me. The purchase was to satisfy my curiosity about 80's eyepieces and Erfles. In "The Light-Hearted Astronomer" by Ken Fulton*, a 20mm Erfle is mentioned 3 times, in the context of "reccomended", "sharp", and "best".

Descriptions:

'Celestron 20mm ERFLE 1 1/4 Fully Coated Japan'(Circle V)** This is a very nice ep. Volcano top, with ribbed grip ring. Has light purple coating. I believe the 20mm Erfle was sold under a variety of brand names in the 1980's, at an affordable price.

'University Super Er. 20mm M.C. Japan' (Circle T)***
Similar to the Celestron, but of recent manufacture. Smooth sided, no grip ring, and deep green and violet coating, a very pretty coating. Very close to parfocal with the Celestron. The only 1.25" Erfle I know of sold today as an "Erfle." Very nice lettering on the barrel.

My opinion: Both are very fine performers in f/15 and f/5 scopes. Wide field (60 deg?), sharp bright image, no ghost image. Some minor edge distortion in f/5, but not offensively so. Does not detract at all from viewing experience like some other ep's with edge distortion. The eye lens is positioned perfectly, not too far or close.
Both parfocal/very close parfocal with 35mm Panoptic. Except for the minute change in focus, I was unable to differentiate between the two by scope testing. I love the Celestron's grip ring, but the UO get points for attractive styling.

Shame on Celestron and the other brands for dropping this great eyepiece from production. Shame on University for not advertising it better. When I bought my first non-plossl, wide-field ep in 2001, it was the Meade 18mm SWA. A good ep, but twice the price of the current University Erfle.

I found another Celestron Erfle for a binoview pair. The University has been gifted to a friend on the occasion of his first homeade telescope and second child on the way.

Neither ep is mentioned in the article by Alan Dyer "Choosing Eyepieces: a Buyer's Guide" from Astronomy, June 1993.****

Neither ep will replace the 17 Nagler. I rue the day when the 35 Panoptic becomes obsolete.

I welcome your thoughts, opinions, and information.

Regards,
John R

*Where is Ken Fulton today?

**
***I forgot what the Circle V,T, etc. means

**** Ironically in 1993 I had no interest in eyepieces

Just opinions, no facts here. Jump to the bottom for performance review.

I recently acquired some antique kellners from the 80's. From reading S&T's from that era, it appears that eyepiece choices for the average amateur were the Huygenian, Ramsden, Kellner, Ortho, and Erfle. Of these 5 only the ortho appears to remain a popular choice. They sell fast here, that for sure. Guidebooks generally advise against Huygenian and Ramsden ep's, rate Kellners as the minimum acceptable,and praise the orthos and Erfles.

Today, where does one find these ep's? Huygenians and Ramsdens can be found at the auction site, usually as dinky ep's to go with dinky scopes there. I have never seen these ep's advertised in my time astronomical (1997 to present)

Kellners are still around. Meade MA's, Celestron SMA's, Edmund RKE's, and the 3-element, 2-inchers like the Celestron Elux are all Kellners according to various internet sources. Also the crosshair ep's in finderscopes.

Orthos and Erfles are still made by University Optics and Antares, but are rarely seen. Who's buying these?

The Kellners and Orthos of the pre-80's have been replaced by the plossl. The plossl explosion of the 80's may have been started by Televue in 1980. Compare a 1980 magazine with a 1984.

In the attached photo are several ep's. The top row are the Meade MA's, old Japan style and later Chinese type. The Japan is quice the nice ep and superior to later models. It has better coatings, larger eye lens, more eye relief, and better construction overall. Note the reflections.

Bottom row left is a generic silvertop 25pl and a 25 Celestron Kellner. The reason for the plossl's ascendance is quite clear: larger eye lens, wider fov, sharper in fast scopes, and (cheaper to manufacture?)

The bottom right are two identical Japan 40 Kellners, one is an Optica b/c and the other a Celestron. In the 1980 mag there were at least 5 different advertisers selling the same ep's.

How well do they work? Very well. In a 178mm f/15 the Celestron Kellners gave sharp, bright images with a narrow fov. The Japan Meade MA was right up there with the plossl, but with less fov. I also have an Edmund 28mm RKE. Its sharp in the middle, but the outer 1/3 is not.
In 80mm f/6 and 50mm f/4 the Kellers gave pleasing, sharp views with minor edge distortion. My 6mm ortho wont reach focus in these scopes, cant get close enough. The RKE is only sharp in the center, the outer 4/5 horribly distorted. Next week I plan to try these ep's in a 317mm f/5.

Its fun to experiment with these fossil ep's, they work very well. I have a curiosity about eyepieces that are no longer available. Makes me appreciate the Panoptics and Naglers all the more.

Regards
John R