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ES82's, Tele Vue Dioptrx, and Astigmatism

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#1 evil16v

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Posted 26 November 2012 - 10:56 PM

I'm in the market to upgrade my eyepieces (and eye-wear)and would like to discuss a few interrelated issues I am looking at.

First...I am really sold on The ES82's, as I have recently viewed through some comparable Naglers (according to some here)recently. I can't really afford the Naglers @300 odd a piece. But there is one feature Televue has that is desirable to me... The Astigmatism-Correcting Lenses. Has anyone tried to fit the Dioptrx to an ES82? Is it possible? I'm not apposed to turning an adapter ring of sort, if it is configurable. I don't know how the Dioptrx "lock" to the eyepiece. Is it an O-ring by chance?

I have an Astigmatism in both eyes of 1.5, according to a phone call to the optometrists office i got my last pair of glasses from. They made no mention of any other correction. I believe I am having problems viewing through my 9mm Plossl (Eye-relief is 6mm). I can't quite get close enough to focus w/my glasses on, and feel like i am missing out with my glasses off. Do you guy think i am really having that much issue with that amount of astigmatism? Below are the eye relief specs on the ES82s. Should I just use glasses with the increased eye-relief of the 82's?

4.7mm 14mm

6.7mm 14mm

11mm 15mm

14mm 15mm

18mm 13mm

24mm 17mm

30mm 21mm



Next week, I am getting another eye exam for a new pair of glasses. My current pair now are polycarbonate corrected by 1.5,and have an Anti glare coating that i am not sure i like. The 3 year old coating started delaminating a year or so ago, and scratches REALLY easy. Do you guys use coated Glasses? anything special i should ask for? I need to Decide what I want next week, when I order the new ones.

#2 cjc

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Posted 27 November 2012 - 03:50 AM

There is a table on the Teleview site giving the exit pupil where astigmatism becomes an issue. Dioptrix Table. For 1.5 dioptres you should not not notice astigmatism in focus with eyepieces giving an exit pupil of less than about 1.5mm, so of less than about 9mm focal length for your F/5.91.

The Explore Scientfic eye relief figures do not correspond with my experience of usability, probably because they are true eye relief figures from the centre of the last lens which is, in some cases, deeply recessed and concave. I found the 14mm to be unusable with spectacles even with a fully dark adapted eye. The 8.8mm is acceptable to me and the 4.7mm marginal at best.

I use spectacles most of the time for viewing except from critical viewing of planets at high magnifications. I have found polycarbonate in the past to be fragile. I now have multifocal spectacles with high index glass lenses (not possible in the US perhaps), but have that these do not work well for astronomy, because of the constraints on head angle. I have had a special pair of astronomy spectacles made with lenses quite close to my eye with one viewing lens on infinity and the other set close for handling equipment and viewing charts, etc.

#3 SteveG

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Posted 27 November 2012 - 01:52 PM

I too would like to know if I can fit a Dioptrx on the ES eyepieces. My preference would be with the 68 degree widefields, as the longer eye relief is necessary. We need someone to remove the rubber eyeguard, and with plastic calipers measure the diameter of the slot where the rubber eyeguard resides. The Dioptrx uses a twist compression ring to fix it into this slot.

I have 1.0 correction and currently use the Dioptrx with a Pan 27 and a Pan 22. These combo's work perfectly. I'm hoping to figure out a way to attach a Dioptrx to my 34mm Meade SWA.

#4 evil16v

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Posted 27 November 2012 - 06:35 PM

There is a table on the Teleview site giving the exit pupil where astigmatism becomes an issue. Dioptrix Table. For 1.5 dioptres you should not not notice astigmatism in focus with eyepieces giving an exit pupil of less than about 1.5mm, so of less than about 9mm focal length for your F/5.91.

The Explore Scientfic eye relief figures do not correspond with my experience of usability, probably because they are true eye relief figures from the centre of the last lens which is, in some cases, deeply recessed and concave. I found the 14mm to be unusable with spectacles even with a fully dark adapted eye. The 8.8mm is acceptable to me and the 4.7mm marginal at best.

I use spectacles most of the time for viewing except from critical viewing of planets at high magnifications. I have found polycarbonate in the past to be fragile. I now have multifocal spectacles with high index glass lenses (not possible in the US perhaps), but have that these do not work well for astronomy, because of the constraints on head angle. I have had a special pair of astronomy spectacles made with lenses quite close to my eye with one viewing lens on infinity and the other set close for handling equipment and viewing charts, etc.


I missed that!!! I really appreciate the link. That is very useful, need to know info for a person with Astigmatism.

I wonder if my Astigmatism has worsened over the last 3 years. That would mean i am on the ragged edge with the 9MM EP. The ES8.8 would put me over the line. Not good.

Thanks for the info on the ESs and eye wear too!

#5 evil16v

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Posted 27 November 2012 - 06:51 PM

I too would like to know if I can fit a Dioptrx on the ES eyepieces. My preference would be with the 68 degree widefields, as the longer eye relief is necessary. We need someone to remove the rubber eyeguard, and with plastic calipers measure the diameter of the slot where the rubber eyeguard resides. The Dioptrx uses a twist compression ring to fix it into this slot.

I have 1.0 correction and currently use the Dioptrx with a Pan 27 and a Pan 22. These combo's work perfectly. I'm hoping to figure out a way to attach a Dioptrx to my 34mm Meade SWA.


X2

#6 russell23

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Posted 27 November 2012 - 09:12 PM

There is a table on the Teleview site giving the exit pupil where astigmatism becomes an issue. Dioptrix Table. For 1.5 dioptres you should not not notice astigmatism in focus with eyepieces giving an exit pupil of less than about 1.5mm, so of less than about 9mm focal length for your F/5.91.

The Explore Scientfic eye relief figures do not correspond with my experience of usability, probably because they are true eye relief figures from the centre of the last lens which is, in some cases, deeply recessed and concave. I found the 14mm to be unusable with spectacles even with a fully dark adapted eye. The 8.8mm is acceptable to me and the 4.7mm marginal at best.

I use spectacles most of the time for viewing except from critical viewing of planets at high magnifications. I have found polycarbonate in the past to be fragile. I now have multifocal spectacles with high index glass lenses (not possible in the US perhaps), but have that these do not work well for astronomy, because of the constraints on head angle. I have had a special pair of astronomy spectacles made with lenses quite close to my eye with one viewing lens on infinity and the other set close for handling equipment and viewing charts, etc.


I missed that!!! I really appreciate the link. That is very useful, need to know info for a person with Astigmatism.

I wonder if my Astigmatism has worsened over the last 3 years. That would mean i am on the ragged edge with the 9MM EP. The ES8.8 would put me over the line. Not good.

Thanks for the info on the ESs and eye wear too!


Definitely you want to experiment with it. I have 1.25 diopters of astigmatism. I've found that a 1.4mm exit pupil is just bothersome enough that I prefer glasses still. Below 1.2mm astimatism is no longer a problem for me.

Dave

#7 ji4m

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Posted 27 November 2012 - 10:42 PM

I only have the 16mm eyepiece, but the width of the slot is 29.0mm with an axial length of 3.5mm. The top ring is 31.9mm wide and 1.35mm thick.

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#8 cjc

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Posted 28 November 2012 - 02:56 AM

The 4.7mm and 8.8mm have the same top dimensions as the 16mm, and as I recall the 14mm does also. I guess they all do up to 16mm.

The 16mm is very marginal with spectacles for me, like the 4.7.

#9 SteveG

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Posted 28 November 2012 - 01:15 PM

I missed that!!! I really appreciate the link. That is very useful, need to know info for a person with Astigmatism.

I wonder if my Astigmatism has worsened over the last 3 years. That would mean i am on the ragged edge with the 9MM EP. The ES8.8 would put me over the line. Not good.

Thanks for the info on the ESs and eye wear too!


You may have this backwards. You scope, at f6, delivers about a 1.5mm exit pupil with a 9mm eyepiece. This is the cut-off point, or smallest exit pupil where you would likely notice astigmatism. Shorter focal lengths would show less - or none. It's the longer focal lengths that will show your astigmatism.

Oh, and after 3 years you could be off on your astigmatism. I would get it checked. I'm currently waiting on buying another Dioptrx until my next eye exam.

#10 evil16v

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Posted 28 November 2012 - 08:03 PM

Thank you. That kinda gives me a benchmark.

I have an eye appointment next week. I'll have all the current specs and maybe a discussion about this with the doc by this time next week.

#11 evil16v

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Posted 28 November 2012 - 08:06 PM

I only have the 16mm eyepiece, but the width of the slot is 29.0mm with an axial length of 3.5mm. The top ring is 31.9mm wide and 1.35mm thick.


This is exactly what I needed! Thank you!

Now i need the nagler/dioptrix specs.

#12 evil16v

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Posted 28 November 2012 - 08:09 PM

The 4.7mm and 8.8mm have the same top dimensions as the 16mm, and as I recall the 14mm does also. I guess they all do up to 16mm.

The 16mm is very marginal with spectacles for me, like the 4.7.


OK... now we know those! This is just getting better. thank You!

#13 evil16v

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Posted 28 November 2012 - 08:42 PM


I missed that!!! I really appreciate the link. That is very useful, need to know info for a person with Astigmatism.

I wonder if my Astigmatism has worsened over the last 3 years. That would mean i am on the ragged edge with the 9MM EP. The ES8.8 would put me over the line. Not good.

Thanks for the info on the ESs and eye wear too!


You may have this backwards. You scope, at f6, delivers about a 1.5mm exit pupil with a 9mm eyepiece. This is the cut-off point, or smallest exit pupil where you would likely notice astigmatism. Shorter focal lengths would show less - or none. It's the longer focal lengths that will show your astigmatism.

Oh, and after 3 years you could be off on your astigmatism. I would get it checked. I'm currently waiting on buying another Dioptrx until my next eye exam.


:foreheadslap:

Your right... I do. Now this makes better sense. Now I understand how the 'Eye Pupil Size vs. Age' chart on the TV site relates to this. I now understand why they suggest this is a lesser issue as we age.

I also now see why everyone is talking about longer focal Length EPs. The only two EPs i have yet, are the 9mm and the 30mm. Now, trying to remember... I go back and fourth with my glasses, but i think a majority of the time I have glasses on with the 30mm. It has pretty good eye relief. The 9mm not at all. That must be why i singled out the 9mm. So at this point, the 8.8 would in fact be better, and more so, the 6.7 and 4.7. I think I have it! Thank you for straightening me out on that! I'm just getting started so I have a lot to learn.

#14 evil16v

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Posted 28 November 2012 - 08:51 PM

This thread has good some useful info... particularly posts #6 and #11.

'Only one Dioptrx'

Apparently, an O-ring will make a dioptrx fit an ES 100* 20mm EP. I kinda wondering if that would work on an ES82*.I don't have dimensions on those.
I have a selection O-rings in a couple different size formats to try (i.e. metric vs. iso).

#15 evil16v

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Posted 10 December 2012 - 02:49 AM

Ok time for an Update:

I went to the optometrist and he did change my prescription a bit. I discussed the Dioptrix with him and he said go for the 2.0.

the prescription:

side sphere cyl axis dist pd
OD -.50 -2.25 005 34
OS -1.00 -1.75 020 34

I went with Trivex lenses and hoya EX# anti-glare.


Still need the nagler/dioptrix Dimensions. Anyone?
\
Long Eye-Relief Tele Vue Eyepieces that Accept DIOPTRX™
Plössl 55, 40, 32mm
Radian 18, 14, 12, 10, 8, 6, 5, 4, 3mm
Panoptic 41, 35, 27
Delos all
Nagler Type 4 22, 17, 12mm
Nagler Type 5 31, 26,
Ethos all

I may have to sit on this for a while anyway... Christmas is starting to kill the budget...

#16 SteveG

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Posted 10 December 2012 - 03:13 PM

The inside diameter of the Dioptrx is 43.5mm loose, 41mm tight. I believe it will fit the ES 68 deg 28mm.

#17 Starman81

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Posted 10 December 2012 - 11:47 PM

The inside diameter of the Dioptrx is 43.5mm loose, 41mm tight. I believe it will fit the ES 68 deg 28mm.



I ordered a DIOPTRX to use on my Ethos. I'll try it on my ES68 28mm when it comes in and let you know.

#18 evil16v

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Posted 12 December 2012 - 03:27 AM

Thanks guys!!

#19 Starman81

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Posted 17 December 2012 - 11:49 PM

The inside diameter of the Dioptrx is 43.5mm loose, 41mm tight. I believe it will fit the ES 68 deg 28mm.



I ordered a DIOPTRX to use on my Ethos. I'll try it on my ES68 28mm when it comes in and let you know.


For those who were wondering, DIOPTRX fits just fine on the ES68 28. Personally, I am fine with the ER and wearing my glasses with the ES68 28.

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#20 Dave Ittner

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Posted 18 December 2012 - 01:24 AM

Interesting, does it screw into the top? Is it securely attached?

#21 Starman81

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Posted 18 December 2012 - 07:34 AM

Interesting, does it screw into the top? Is it securely attached?


Yes and yes.

#22 Dave Ittner

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Posted 18 December 2012 - 09:11 AM

Thanks. I hope to look through a Dioptrx one of these days.

#23 fvandrog

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Posted 18 December 2012 - 09:48 AM

Interesting, does it screw into the top? Is it securely attached?


Yes and yes.


Thanks for the useful info -- I am tempted to get a once my ES eye pieces arrive. I hesitated a while before buying them, considering to go for TV because of the Dioptrix, but the price difference was just too big.

F.

#24 SteveG

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Posted 18 December 2012 - 01:39 PM

The inside diameter of the Dioptrx is 43.5mm loose, 41mm tight. I believe it will fit the ES 68 deg 28mm.



I ordered a DIOPTRX to use on my Ethos. I'll try it on my ES68 28mm when it comes in and let you know.


For those who were wondering, DIOPTRX fits just fine on the ES68 28. Personally, I am fine with the ER and wearing my glasses with the ES68 28.


Thanks Starman - Looks like a perfect fit! I wish ES had the same upper barrel diameters on the other 68 deg eyepieces.

#25 SteveG

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Posted 18 December 2012 - 01:41 PM

Interesting, does it screw into the top? Is it securely attached?


Sort of. The Dioptrx is 2-peices, that have a compression style fitting that tightens when you twist the 2 pieces together.






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