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Expanse 9mm question

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#1 RussL

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Posted 27 August 2018 - 09:16 AM

Last night while viewing Saturn with the 8" SCT a friend loaned me his 9mm Expanse. I had asked if he had a 10mm eyepiece of any kind so I could achieve 200x instead of 254x I was getting with my TMB 8mm. The 9mm was as close as he had, which gave me 225.8x

Well, the first thing I noticed was a glow around Saturn. My TMB didn't do that at all, nor did any other eyepieces. Is it something about the Expance series or the 9mm in particular? I didn't check to see if it was dirty.

Also, the glow didn't extend across the entire field of view, but seemed closer to Saturn. But, of course that could be due to not seeing the glow against the dark background. The glow seemed to end too abruptly to be covering the entire field, though.

I didn't try it on Jupiter. Should have.

Thoughts?

#2 petert913

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Posted 27 August 2018 - 09:33 AM

I have a 9mm Expanse but can't recall any glare around bright planets.  Let me try it again tonight and report. 

 

Hopefully your "glow" wasn't oil from a fingerprint lol.gif



#3 Jon Isaacs

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Posted 27 August 2018 - 09:58 AM

Thoughts?

 

The eye lens might have been dirty.

 

Jon


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#4 ccaissie

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Posted 27 August 2018 - 11:11 AM

Could be quality of manufacture or design.  Polish on the elements, better coatings, blackened lens edges, black interior coating, ghost images due to design, many factors.

 

Dirt or shmuz on the elements.



#5 MartinPond

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Posted 27 August 2018 - 12:18 PM

I'd go for the dirt theory...specifically a little layer of dust.

 

Mind you, if it's super-bright, you will see some bloom anyway..

In that case a 12--20% neutral filter would help.

 

I saw a lot of bloom on a 10" at 200x for Saturn a few weeks ago...

..it was high-altitude haze.


Edited by MartinPond, 27 August 2018 - 12:19 PM.


#6 jcj380

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Posted 27 August 2018 - 12:21 PM

I’m not a planetary observer but I’ve not noticed that on any bright object with my 9mm.

#7 MartinPond

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Posted 27 August 2018 - 03:22 PM

I’m not a planetary observer but I’ve not noticed that on any bright object with my 9mm.

I saw a lot of that at Stellafane, mostly at the big light buckets.

Mars, Saturn, and Jupiter were blasting.

The 9mm Expanse is ordinarily not bad for bloom or veiling.

Keep a Moon filter handy for planets if you have a big reflector!

Lower power lets you see the bands better with a thin stratospheric haze,

  but you still need to turn the lights down.  I suppose a circularly-polarized filter

  might help (still popular with photographers).


Edited by MartinPond, 27 August 2018 - 03:26 PM.


#8 RussL

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Posted 27 August 2018 - 04:48 PM

I’m not a planetary observer but I’ve not noticed that on any bright object with my 9mm.


Well, that's what I wondered, seems I had heard it mentioned by someone else before.

Granted, though, it could've been a fingerprint. I just gave it back to my friend after using it.

I don't think it was atmospheric because I didn't see any glow with any other eyepiece.

#9 Jon Isaacs

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Posted 27 August 2018 - 07:57 PM

Granted, though, it could've been a fingerprint. I just gave it back to my friend after using it.

 

 

As I posted before, a dirty eyepiece. When I start seeing unwanted glows around the planets, I know the eyepiece, most probably the eye lens, is somehow contaminated.  It could be fogged in which case I will warm it in my pocket or with a hair drier.  If it is not fogged, then the eyepiece needs cleaning.

 

Jon



#10 RussL

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Posted 27 August 2018 - 09:02 PM

Thanks Jon. I'll ask him to check it next time I see him.

#11 izar187

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Posted 27 August 2018 - 11:13 PM

There are reasons why budget wide field ep's cost less.



#12 Shneor

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Posted 28 August 2018 - 01:01 AM

There are reasons why budget wide field ep's cost less.

This eyepiece is a great performer. I tested one in an 18" f/4.5 in the late 90's against a Nagler 9mm Type 1. It showed appropriate color in E and F in M42, while the Nagler showed no color. Sure, the FOV was smaller, but the performance was better. I shared the comparison with a numbe rof fellow observers, and they, too, were quite surprised. This eyepiece is really a bargain.



#13 izar187

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Posted 28 August 2018 - 03:55 AM

Not my experience.

In mine the fov was well corrected... and that's it.



#14 RussL

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Posted 28 August 2018 - 06:32 AM

I don't have much experience with the Expanse series, but have looked through one or two previously through another friend's Starblast 4.5" Newtonian as well as through my ST80 at that time. I remember only that although the AFOV and eye relief were nice the images weten't quite as good as I had hoped(I forget all the specifics now). While also inexpensive, my TMB Planetary outperformed it except for shorter eye relief and a narrower AFOV. Sharper image for sure.

My only caveat with the TMB has been an occaisonal ghost image floating around Jupiter or Venus. Not bad for $40 when they were on sale several years ago on Astronomics (I think it was). I've never noticed it on bright stellar objects, I don't think. Mine is not Burgess/TMB, but a plain TMB, yet a real TMB, not a knock-off.

#15 Jon Isaacs

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Posted 28 August 2018 - 06:47 AM

This eyepiece is a great performer. I tested one in an 18" f/4.5 in the late 90's against a Nagler 9mm Type 1. It showed appropriate color in E and F in M42, while the Nagler showed no color. Sure, the FOV was smaller, but the performance was better. I shared the comparison with a numbe rof fellow observers, and they, too, were quite surprised. This eyepiece is really a bargain.

 

Shneor:

 

I am quite sure the Expanse eyepieces were not introduced until the maybe 2002.  Searching Astromart, the first Expanse's show up in February 2003 and then they are quite a few of them.  Late 90's, 2000's, I guess today, they're the same.  

 

In any event, I purchased the 6mm, the 9mm and the 15mm generic Expanse eyepieces from Adorama when they first came out and the 9mm was the last non-TeleVue eyepiece in my main case, I eventually replaced it with a 9mm Type 6 Nagler.  Since then, I have passed that one along and purchased others. 

 

I had a similar experience to yours, comparing the 9mm Expanse to the 9mm Nagler type 1 in my 12.5 inch F/4.06.  I was using an original Paracorr, the original one without the Tuneable Top.  But the Expanse was clearly sharper than the Nagler type 1.  The owner of the Nagler and I both agreed on that and it as also sharper in his scope but I don't recall what it was.  

 

Revisiting the 9mm Expanse, what I've noticed is the bright edge, EoFB, the edge is quite bright. I did some experiments with it and some similar eyepieces to try to isolate the cause of the EoFB, they're posted somewhere in CN.  

 

I also drift timed the field of view multiple times, the number I measured corresponded to a 70.5 degree TFoV. 

 

And then there is the story of the Antares 8.7mm W-70.. It was conjectured that these were identical optically to the 9mm Expanse clones. I had one the Antares W70 so one Saturday morning I got to messing around with it.  The Expanses consist of an front barrel with the negative lens, a body with no optics and a rear section that threads into the body with the positive magnifying lens.  

 

The W70 was very similar but featured an attractive, knurled aluminum body.  I thought maybe they had just discarded the original body and machined the aluminum body.  

 

But what I found was that all they had done was machined an aluminum cover for the existing body and glued it in place.  The 8.7mm W70 was nothing more than an Expanse Clone with a fancy cover.  The original lettering was even still there.  

 

5689544-Antares W70a.jpg
 
Jon

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#16 Shneor

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Posted 29 August 2018 - 01:39 AM

 

Shneor:

 

I am quite sure the Expanse eyepieces were not introduced until the maybe 2002.  Searching Astromart, the first Expanse's show up in February 2003 and then they are quite a few of them.  Late 90's, 2000's, I guess today, they're the same.  

 

In any event, I purchased the 6mm, the 9mm and the 15mm generic Expanse eyepieces from Adorama when they first came out and the 9mm was the last non-TeleVue eyepiece in my main case, I eventually replaced it with a 9mm Type 6 Nagler.  Since then, I have passed that one along and purchased others. 

 

I had a similar experience to yours, comparing the 9mm Expanse to the 9mm Nagler type 1 in my 12.5 inch F/4.06.  I was using an original Paracorr, the original one without the Tuneable Top.  But the Expanse was clearly sharper than the Nagler type 1.  The owner of the Nagler and I both agreed on that and it as also sharper in his scope but I don't recall what it was.  

 

Revisiting the 9mm Expanse, what I've noticed is the bright edge, EoFB, the edge is quite bright. I did some experiments with it and some similar eyepieces to try to isolate the cause of the EoFB, they're posted somewhere in CN.  

 

I also drift timed the field of view multiple times, the number I measured corresponded to a 70.5 degree TFoV. 

 

And then there is the story of the Antares 8.7mm W-70.. It was conjectured that these were identical optically to the 9mm Expanse clones. I had one the Antares W70 so one Saturday morning I got to messing around with it.  The Expanses consist of an front barrel with the negative lens, a body with no optics and a rear section that threads into the body with the positive magnifying lens.  

 

The W70 was very similar but featured an attractive, knurled aluminum body.  I thought maybe they had just discarded the original body and machined the aluminum body.  

 

But what I found was that all they had done was machined an aluminum cover for the existing body and glued it in place.  The 8.7mm W70 was nothing more than an Expanse Clone with a fancy cover.  The original lettering was even still there.  

 

 
 
Jon

 

The Orion Expanse is a copy of the eyepiece first introduced by Adorama around 1996 or 7. I do not remember what they called it, but it is the same eyepiece. I bought mine from Adorama shortly after seeing their first ad for this eyepiece either in S&T or Astronomy.


Edited by Shneor, 29 August 2018 - 01:43 AM.


#17 Jon Isaacs

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Posted 29 August 2018 - 04:31 AM

The Orion Expanse is a copy of the eyepiece first introduced by Adorama around 1996 or 7. I do not remember what they called it, but it is the same eyepiece. I bought mine from Adorama shortly after seeing their first ad for this eyepiece either in S&T or Astronomy.

Those were the exact eyepieces I purchased.  They showed up at the same time as the Expanse's.  

 

I looked through the Adorama ads in three 1997 issues of Astronomy as well as the January 1998 issue and October 1999 issue of Sky and Telescope,  I did not find the Expanse clones, I did not find them. I found the Proptic Plossls but not the Pro-Optic Expanse "clones."

 

:shrug:

 

Jon



#18 RussL

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Posted 29 August 2018 - 06:02 AM

Another question: am I wrong to say that I think that my TMB Planetary shows a sharper image than the Expanse? I need to compare them some more I guess, but is that possible?

#19 Jon Isaacs

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Posted 29 August 2018 - 07:31 AM

Another question: am I wrong to say that I think that my TMB Planetary shows a sharper image than the Expanse? I need to compare them some more I guess, but is that possible?

 

Russell:

 

You should compare them more.  They are very similar eyepieces, so much so that if you remove the twist up eye cup from the TMB, you will find that the barrell with the Telenegative, the body and the rear section with magnifying optics are interchangeable between the two.  

 

My recollection is that the main difference is the wider field of view and that with the 9mm Expanse, that added field of view meant a bright edge, i.e. EoFB.  

 

Jon



#20 RussL

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Posted 29 August 2018 - 08:22 AM

Thanks, Jon. I will do that. I would like to compare them both some more.
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#21 Shneor

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Posted 30 August 2018 - 01:32 AM

Those were the exact eyepieces I purchased.  They showed up at the same time as the Expanse's.  

 

I looked through the Adorama ads in three 1997 issues of Astronomy as well as the January 1998 issue and October 1999 issue of Sky and Telescope,  I did not find the Expanse clones, I did not find them. I found the Proptic Plossls but not the Pro-Optic Expanse "clones."

 

shrug.gif

 

Jon

I'm sure Adorama was first. It could have been as late as 2000-2001. I'll look for my original post.



#22 Shneor

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Posted 31 August 2018 - 01:31 AM

So far the only progress I have made is to find the name of the Adorama version, it's Ultraview, mentioned in a September 22, 2005 post by me. I need to go to the TAC archives to find my original post,



#23 Jon Isaacs

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Posted 31 August 2018 - 05:40 AM

So far the only progress I have made is to find the name of the Adorama version, it's Ultraview, mentioned in a September 22, 2005 post by me. I need to go to the TAC archives to find my original post,

I gave away almost all my old Sky and Telescope and Astronomy magazines, I looked through the few I do have.  If you have some or if anyone else wants to help resolve this question, Adorama had ads in both magazines.  

 

I am not sure that the name of the Adorama Expanse clones, they were sold under Adorama's Pro-Optic brand and were the generic 20mm, 15mm, 9mm and 6mm that are still sold today by AgenaAstro as the Starguiders. 

 

Jon



#24 Shneor

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Posted 01 September 2018 - 01:31 AM

My post of September 22, 2005 on CN in the eyepieces forum specifically lists my 6mm and 9mm Ultraview eyepieces, which are the name of the Pro-Optic eyepieces.



#25 Shneor

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Posted 01 September 2018 - 03:33 PM

Found one post in sci.astro.amateur from  December 2002, with a response from Jon. I can't paste anything on CN, so I'll try to attach a file.

 

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