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EP Range for StellarVue 102

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#1 cmac7203

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Posted 04 June 2020 - 07:16 AM

Hi All,

 

I've been star gazing for a few years now and I upgraded my scope last year to this StellarVue 102 Refractor and Vixen Porta II mount (I got tired of lugging my 9.25 SCT and GEM). I already had 13mm Hyperion, and I just bought a 24mm Hyperion for low power. My idea was to sell the 13mm and buy an EP in the 9mm range. I also have a 2x TeleVue Barlow. I am using a 1.25" star diagonal vs using 2" EPs in this scope.

 

I am getting hung up. I am not the best with keeping track of numbers, especially when there are a LOT of them to consider such as eye relief, magnification, exit pupil, TFOV, AFOV, etc.

 

So, I would appreciate it if you seasoned eyepiece aficionados would recommend a range of EPs for this scope. I think I only want to carry 3 plus the Barlow. I don't mind spending $ if it makes sense to do so. I am more than a casual observer, but not an every night observer either. I don't do AP. I do like the moon and planets, and pretty much anything else within the range of this scope's ability. I do wear glasses, but usually take them off to observe, putting them on only to consult star charts.

 

Thanks in advance.

 



#2 jeffreym

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Posted 04 June 2020 - 07:59 AM

I have the SV102 Access.  I think you already are close to what you need.  24, 13, 6.5 (13 w/ 2x), and you need to add a TeleVue 6-3 zoom for double stars.  I didn't invest in the zoom yet so I carry a 5mm Nagler and a 3.2mm ED.

 

I use a 24 Panoptic, ES 14mm, and ES 6.7mm along with the 5 and the 3.2.

 

I still pack a barlow because on the very odd night (once or twice a year here) that high magnification is possible, I might try to split something in the under 2 arc second range.

 

Have fun,

Jeff


Edited by jeffreym, 04 June 2020 - 08:04 AM.

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#3 cmac7203

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Posted 04 June 2020 - 08:17 AM

Hi Jeff,

 

Thabnkjs for

 

I have the SV102 Access.  I think you already are close to what you need.  24, 13, 6.5 (13 w/ 2x), and you need to add a TeleVue 6-3 zoom for double stars.  I didn't invest in the zoom yet so I carry a 5mm Nagler and a 3.2mm ED.

 

I use a 24 Panoptic, ES 14mm, and ES 6.7mm along with the 5 and the 3.2.

 

I still pack a barlow because on the very odd night (once or twice a year here) that high magnification is possible, I might try to split something in the under 2 arc second range.

 

Have fun,

Jeff

Thanks, Jeff. I was going to pitch the 13 because the 24 Hyperion barlowed would be 12 so I saw the 13 as redundant. I get it that a single EP will beat the Barlow in resolution and brightness though.



#4 russell23

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Posted 04 June 2020 - 09:18 AM

With my SV 102 Access and AT102ED, both 102mm f/7,  my absolute favorite focal lengths are 13mm and 8/8.5mm for deep sky.  For wider fields, depending upon the target I will also use an 18.2mm DeLite or the 22mm Olivon 70 (but that is 2").  For higher magnification deep sky I will use the 4.7mm APM XWA.   For the Moon and planets I typically use my 13mm and 8.5mm eyepieces with several barlows, finding my preferred highest magnifications are ~160x but the scope can go much higher on the Moon if I choose.


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#5 Starman1

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Posted 04 June 2020 - 02:18 PM

I also own a 102mm f/7, but I use 10 different eyepieces in that scope.

Were I to have only 3, and use a 2X Barlow, they'd be:

18mm (9mm), 13mm (6.5mm) and 5mm (2.5mm) for:

40x, 55x, 79x, 110x, 143x, 286x

With a fine refractor, that last magnification might actually be useful on the Moon or on double stars.

I find I use 238x in mine quite often.

 

And there are very few objects that require a 24mm (30x) that aren't better at 40x.

I have both a 24mm and an 18.2mm, and the 18.2mm gets 90% of the use between those 2.


Edited by Starman1, 04 June 2020 - 02:20 PM.

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#6 SeattleScott

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Posted 04 June 2020 - 04:26 PM

Hi Jeff,

Thabnkjs for

Thanks, Jeff. I was going to pitch the 13 because the 24 Hyperion barlowed would be 12 so I saw the 13 as redundant. I get it that a single EP will beat the Barlow in resolution and brightness though.

Nooo do not pitch the 13mm. The 24mm Hyperion will probably vignette significantly. The 24 Hyperion probably has at least a 27mm field stop versus maybe 23-24mm clear aperture on the barlow. So you are losing some of your field of view. Not to mention the 24mm isn’t one of the higher regarded Hyperions. You want to use a barlow to get double duty out of one of your best eyepieces, not a mediocre one that vignettes significantly.

So keep the 13mm. Then you need to add a 7 and a 3.5. So you can barlow the 13 and get a 3.5 or get a 7 and barlow to 3.5. The Celestron Xcel LX is a great budget option if you are okay with 60 AFOV. I would rather get a 7 and barlow to 3.5 because there are fewer targets that need 200x, so you don’t have to mess with the barlow as often.

Have you checked and verified your Televue barlow fits in your diagonal without striking the mirror? It is a fairly long barlow. Probably ok especially if you have a 2” diagonal but test it out in the daylight.

Scott

Edited by SeattleScott, 04 June 2020 - 04:33 PM.

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#7 SeattleScott

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Posted 04 June 2020 - 04:37 PM

I also own a 102mm f/7, but I use 10 different eyepieces in that scope.
Were I to have only 3, and use a 2X Barlow, they'd be:
18mm (9mm), 13mm (6.5mm) and 5mm (2.5mm) for:
40x, 55x, 79x, 110x, 143x, 286x
With a fine refractor, that last magnification might actually be useful on the Moon or on double stars.
I find I use 238x in mine quite often.

And there are very few objects that require a 24mm (30x) that aren't better at 40x.
I have both a 24mm and an 18.2mm, and the 18.2mm gets 90% of the use between those 2.

Indeed a 4” F7 apo is a real problem because it can take such a range of magnifications. I tend to use seven eyepieces and on really good nights a barlow with my 4” Apo. There are many scopes that I could get by fine with just 4-5 eyepieces but a 4” Apo is not one of them.

Scott
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#8 Jon Isaacs

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Posted 05 June 2020 - 01:35 AM

Indeed a 4” F7 apo is a real problem because it can take such a range of magnifications. I tend to use seven eyepieces and on really good nights a barlow with my 4” Apo. There are many scopes that I could get by fine with just 4-5 eyepieces but a 4” Apo is not one of them.

Scott

 

Yes.

 

In my mind, one wants eyepieces that cover the range possible.. ideally that would be a 3.7° field at 17x with a 6 mm exit pupil if a 41 mm Panoptic or something similar on up to 300x.

 

Jon


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#9 cmac7203

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Posted 05 June 2020 - 07:23 AM

Nooo do not pitch the 13mm. The 24mm Hyperion will probably vignette significantly. The 24 Hyperion probably has at least a 27mm field stop versus maybe 23-24mm clear aperture on the barlow. So you are losing some of your field of view. Not to mention the 24mm isn’t one of the higher regarded Hyperions. You want to use a barlow to get double duty out of one of your best eyepieces, not a mediocre one that vignettes significantly.

So keep the 13mm. Then you need to add a 7 and a 3.5. So you can barlow the 13 and get a 3.5 or get a 7 and barlow to 3.5. The Celestron Xcel LX is a great budget option if you are okay with 60 AFOV. I would rather get a 7 and barlow to 3.5 because there are fewer targets that need 200x, so you don’t have to mess with the barlow as often.

Have you checked and verified your Televue barlow fits in your diagonal without striking the mirror? It is a fairly long barlow. Probably ok especially if you have a 2” diagonal but test it out in the daylight.

Scott

Hi Scott, the Barlow fits, but I have to be careful how far I insert...which is just to the end of the lens cell where it attaches to the tube.



#10 russell23

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Posted 05 June 2020 - 08:46 AM

Yes.

 

In my mind, one wants eyepieces that cover the range possible.. ideally that would be a 3.7° field at 17x with a 6 mm exit pupil if a 41 mm Panoptic or something similar on up to 300x.

 

Jon

I know.   I wish my astigmatism could accommodate the exit pupil with a 40mm eyepiece.  My new glasses do not provide sufficient correction for a 30mm eyepiece.  


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#11 russell23

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Posted 05 June 2020 - 08:52 AM

I also own a 102mm f/7, but I use 10 different eyepieces in that scope.

Were I to have only 3, and use a 2X Barlow, they'd be:

18mm (9mm), 13mm (6.5mm) and 5mm (2.5mm) for:

40x, 55x, 79x, 110x, 143x, 286x

With a fine refractor, that last magnification might actually be useful on the Moon or on double stars.

I find I use 238x in mine quite often.

 

And there are very few objects that require a 24mm (30x) that aren't better at 40x.

I have both a 24mm and an 18.2mm, and the 18.2mm gets 90% of the use between those 2.

My full suite of eyepieces (including equivalents with barlows) I use with mine is similar:

 

30mm/22mm, 18.2mm, 13mm, 9/8.5/8mm, 6.5mm, 5.5mm, 4.7mm, 4.3mm, 4.0mm, 3.2mm

 

However, most of my deep sky time is covered with 30/22, 13, 8.5/8, 4.7.

 

And realistically I could narrow most of that down to 13mm and 8.5/8mm.  


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#12 Chuck2

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Posted 06 June 2020 - 12:31 AM

From a different perspective... I also own a Stellarvue 102, mine is a grab 'n go that travels light and frequently goes camping.

 

My scope is predominantly used for lunar and planetary viewing, so FOV is less important to me.  I carry a Baader MK IV 8-24mm Zoom with matching 2.25x Baader barlow for continuous 35x-235x magnification. The zoom is razor sharp and contrasty up to 200x (minor lateral color at edge field stop). On nights of excellent seeing I switch to a Vixen 3.4 HR high resolution eyepiece for amazing 240x views of Jupiter, Saturn and the Moon. 

 

There are many eyepiece options are available to match your viewing style!


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#13 Starman1

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Posted 06 June 2020 - 01:16 AM

I was too used to 82-110° to be comfortable with 40-50° eyepieces, but I did fairly quickly adapt to the TeleVue Delites at 62°.

Though the 3mm field is only 15' wide.  That's still a good 30-45 seconds between nudges.


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#14 Jon Isaacs

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Posted 06 June 2020 - 01:34 AM

I was too used to 82-110° to be comfortable with 40-50° eyepieces, but I did fairly quickly adapt to the TeleVue Delites at 62°.

Though the 3mm field is only 15' wide.  That's still a good 30-45 seconds between nudges.

 

I find a 60 degree AFoV to be comfortable and have a wide feel to it.  This is particularly true if there is enough eye relief that it's unnecessary to work to see the edge of the field.. 

 

Jon


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