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100º AFOV eyepieces on birding scopes? (1 Viewer)

Ethos 110º

Yesterday finally managed to look through an Ethos ep and it was a double experience since could test 2 Ethos.
One was a 17mm but this one cann't be used in a spotting since is a 2". However the result was great http://www.birdforum.net/showthread.php?p=2439117#post2439117
In my Optolyth100 I could test the 3.7mm after testing the 17mm. In this ep the AFOV is 110º and after the good surprise of the AFOV I could use with glasses on the 17mm (about 90º!), I was completely disappointed since only could see <50º AFOV on this ep with glasses...:-C
My interest is the 4.7mm (the 3.7mm result on too much power with the 630mm of the Optolyth 100), but don't know if has better useful eye-relief than the 3.7 version. My expectations decreased a lot!
 
Nikon HW12.5

Was hoping that this ep would reach focus at the infinite on my Optolyth 100 but it doesn't...|=(|
Well, it does when using the BS 1.6x barlow, resulting in an equivalent 6.8mm ep, so producing 92.5x on the Optolyth. It´s not an ep for eye-glass users like me since the eye-relief is reduced.
Will have to only use it with the TMB92+Nikon FSA-L2 combo http://www.birdforum.net/showthread.php?t=175297 - tests just started and for now I just post a photo of the HW on the Optolyth...
 

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David,
Looks like a very good combo. I too was in search of a wide field zoom scope. I tried the Nikon FSA-L2 also but with a Tak FS60. I didn't like the results I got and ended up going in another direction. I also tried making a zoom scope out of a zoom camera lens and the Ethos 17. It worked OK as long as I didn't use an image erector. After trying many scopes and EPs I ended up with a Vixen ED114 + Denk power mag switch + Leitz 30mm 88 degree. Also use this combo with my ED50 with outstanding results. The Leitz and the Nikon ED50 is by far my favorite low power viewing option. Quite a bit better then the 8x Nikon EII bins I have. I sure hope one day there is a 80-100 degree zoom eyepiece made. Heck even a constant 72 degree 8-24mm zoom would be nice. I doubt these kinds of designs are even feasible without being extremely big and expensive to make.
 
Sorry I should have been more clear with my post. I like to see a long FL wide field zoom. Something around the 20-24mmm range on the low power side. I actually had one of those speers zooms for a while. I never cared for it too much though and sold it. The dang thing was way too long. I had a bit of trouble with blackouts as well. Even though the view was nice and sharp. It also seemed like the contrast wasn't up to par with my other EPs.

Back to 100 deree EPs I can't wait to try out the new explore scientific 25mm 100 degree EP. If it ever becomes available that is.
 
JBT said:
I tried the Nikon FSA-L2 also but with a Tak FS60. I didn't like the results I got and ended up going in another direction.
Click to expand...
What you didn't like on that combo, besides being long? Field curvature of the FS60? The much cheaper 65mm 4 lens Chinese telescopes have flat fields and excellent colour correction. As I need "power" I had to go to a larger aperture telescope - if wasn't the use of the binoviewer the f6.5 versions would be good for the 100º monoviewing...
Wide field zooms still are only 2x. The Leica is 60-80º and the new Meopta has constant 66º AFOV. Nikon could reply to the Kowa LensScope and to the new Swaro X line with a version of a >95mm lens and a improved version of the FSA_L2 for visual use with the EDG eyepieces and the HWs, resulting on constant 72º and 102º AFOV 3.5x zooms ...o:D
 
I don't know the exact numbers but when I used the FSA-L2 with the Tak60 it increased the Taks FL too much for my liking. It turned my 20x EP into about a 30x EP. The short side of the FSA's FL is 500mm if I remember correctly and I think if I had used the FSA with a scope with a FL around 500mm I don't think I would have notice very much change in the mags. I don't know for sure though if this is why I saw the magnification increase.

Other then that I liked the FSA as an image erector but I wanted to keep my lower mags below 20x. Since then I've got a scope with a FL of 600mm so I might buy another FSA and try it out with the scope but the dang thing is so dang expensive.
 
More about the HW

When trying to decide if I would get a Ethos SX 4.7 clone - there are from TS/Skywatcher/Lunt Engineering/... I tested again the Nikon HW 12.5 on the Optolyth.
I had forgot that it reaches focus using the BS 1.6x barlow cell and found that the useful AFOV with eye-glasses is higher than I previously mentioned. If without the barlow the useful AFOV for me is about 65º (but it doesn't reach focus at the infinite both on the Optolyth 100 and Pentax PF100), with the barlow the eye-relief increases and the useful AFOV is >90º on both models. From Kimmo contact with the Kowa 1.6x extender, I remembered to use 2 BS 1.6x barlow cells and it reaches focus giving a increase factor of 2.7x on the Optolyth and 2.6x on the PF100. However the useful AFOV decrease a bit but still >85º, and the resulting image seem a bit dim, when compared to the XW5 - the HW coatings seem to pair better with the PF100 since the resulting image have more light and contrast than in the Optolyth 100 - to be tested on field and to compare resolutions...
With the EiC10 it doesn't reach focus, with or without barlow cell, on both models.

Anyone tested/uses one of Ethos clones in a spotting scope?

By the way, I was considering to replace the HW by a Doctor 12.5 but changed opinion... Just remembered that if the Docter reaches focus on the Kowa 88, the HW also should reach without barlow!...
 
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110º eyepieces!...

Just did a test comparing wide AFOV eyepieces http://www.pt-ducks.com/cr-telescopes.htm#Test%20of%205mm%20eyepieces that includes an Ethos clone with 110º. If the usable eye-relief for eye-glass users is reduced (as expected), I was surprised by the comfort of using it without eye-glasses (besides the 110º...), and by the fact that I obtained the same resolutions with or without eye-glasses - I have strong astigmatism...
Will update the text after field use but it can take several months since my duck season is ending, only will restart in June and Summer isn't the best season to test optics...
By the way also included a Baader Morpheus 4.5 that is the wider AFOV eyepiece suitable for eye-glass users and also liked it a lot...;)
 
DRodrigues said:
- if there was a 5mm version I might be tempted to ordered it but my bad experience with the Radian 4mm showed me that in a 630mm birding scope I'm pushing the limits too much...
Click to expand...

157.5X is quite a bit. I'm hoping me Celestron M2 100ED, 540mm, will be able to handle 4mm/135X. If not I'll drop down to 4.5/120X and give that a whirl.

Surely the 5.5mm/98X will have no issues.
 
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Esbaa92_5

Using the right adaptors and a Baader Hyperion 2.25 barlow cell with the ES92_12 I got a ESBAA92_5, in a 1.25" format... :king:

Photos within some days at cr-telescopes at http://www.pt-ducks.com, replacing the Nikon HW12.5 with barlow cell,s but for now see how it looks on a spotting scope!

www.pt-ducks.com moved from hosting company so you should refresh the site link when viewing it - today I finally moved all site...
 

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The 4mm SLV was fine though at 50* not hardly wide. After successfully using a Luminos 82* 15mm/36X [26mm field stop] as feeder monitor I ordered a Meade 100* 10mm/54X.

At 110* SX only offers a 3.7 & 4.7 which for my 5.4 scope comes to 146X and 115X. I am intrigued by 146X as that represents about the top end on a 100mm objective astronomically wise leaving a 0.685 EP.

I wonder how the moon would look under those parameters.
 
For observing the moon, the 146x might be useful.
For daylight birding, I would go for the 115x. Are you thinking on the Ethos SX or on their clones?
 
Right now I'm only thinking of any 110*. I have a Meade 100* 10mm, 54x in the Regal, coming next week. I'll want to evaluate its performance before considering 110*.

But, the Tele Vue Ethos SX represents the creme de la creme, so perhaps I could justify the cost on one eyepiece. In all honesty I'm not sure if I could tell the difference twixt it and a clone on me lowly non-alpha spotter. |:D|
 
Well, the Meade MWA 100* 10mm/54X came in and I like it. The fov isn't that much smaller than the Luminos 15mm/36X. Mostly have used it to watch the bird feeder, but I did play around on soaring birds.

The little cone on the Luminos was small and this is a mite smaller, but the extra 18X is nice. I'm waiting for another sliding plate to arrive so I can mount to the 516 head.

In the meantime I'm using the small MHXPRO-2W and though making a game stab it is near limit in load. The transfer bar that came w/scope is set for horizontal viewing and it's too time consuming and troublesome to switch the center of gravity back and forth.

Quite a handful w/o sliding plate capacity. Still, it was nice to see them at the higher magnification even if locating them and maintaining them framed within fov was challenging at times. Weighs in around 3/4 lb.
 
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