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Unexpected effect from a Dioptrx or was I dreaming?

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#1 John Rogers

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Posted 30 May 2020 - 06:55 PM

I had heard of the Televue Dioptrx and read some reviews, but none really grabbed me with a "you gotta try this!" message. 

As a result of a low-ball bid on eBay, I recently had the opportunity to try one.   By simply holding it over the eyepiece while observing the Veil Nebula.  I rotated the Dioptrx and was very pleased to see the flared stars become pinpoints across the field of view of the 31mm Nagler.

However, I also noticed that the contrast of the Veil improved as well.  Thinking I might be imagining things, I moved the Dioptrix in and out of the light path.  The nebula definitely appeared more prominent across the entire field with the Dioptrix in place.

Has anyone else experienced this?


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#2 wrnchhead

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Posted 30 May 2020 - 07:37 PM

It seems that it would, considering the light is froperly directed to where it should go. I am going to look this product up.

#3 wrnchhead

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Posted 30 May 2020 - 07:40 PM

Ok TV says
“1. You're more likely to see a sharper, higher contrast image, because:

A. The Dioptrx is always completely aligned to the eyepiece optics, eliminating aberrations from a decentered mismatch of eyeglass power and astigmatic axis.

B. Dioptrx can be rotated to exactly compensate for the astigmatic axis angle in real time, since both head angle and age can vary your eyesight astigmatic angle.

C. Dioptrx likely has better multi-coatings than eyeglasses, and certainly is better in transmission and reflection reduction than uncoated eyeglass.”
Interesting.
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#4 J A VOLK

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Posted 30 May 2020 - 07:42 PM

I use one - big improvement with exit pupils of 4mm and above for me.  My guess is the improvement is because the Dioptrix is working, not any filtering effect.  For fun, put the Dioptrix in the worst orientaion and see if this is still true for you. 

 

An FYI for those with the ES 30mm 82 - remove the eyecup, open the Dioptrix wide and it fill fit!


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#5 Jon Isaacs

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Posted 31 May 2020 - 12:22 AM

I use one - big improvement with exit pupils of 4mm and above for me.  My guess is the improvement is because the Dioptrix is working, not any filtering effect.  For fun, put the Dioptrix in the worst orientaion and see if this is still true for you. 

 

An FYI for those with the ES 30mm 82 - remove the eyecup, open the Dioptrix wide and it fill fit!

 

For those using a Dioptrix, it would be helpful to include how much correction yours provides. 

 

Jon


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#6 RichA

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Posted 31 May 2020 - 12:35 AM

I had heard of the Televue Dioptrx and read some reviews, but none really grabbed me with a "you gotta try this!" message. 

As a result of a low-ball bid on eBay, I recently had the opportunity to try one.   By simply holding it over the eyepiece while observing the Veil Nebula.  I rotated the Dioptrx and was very pleased to see the flared stars become pinpoints across the field of view of the 31mm Nagler.

However, I also noticed that the contrast of the Veil improved as well.  Thinking I might be imagining things, I moved the Dioptrix in and out of the light path.  The nebula definitely appeared more prominent across the entire field with the Dioptrix in place.

Has anyone else experienced this?

 Any smearing of an object diminishes brightness and contrast.  Extended objects.  Non-extended objects become extended and their brightness drops.  Nice that it confers benefits in both cases.



#7 MartinPond

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Posted 31 May 2020 - 06:50 AM

What they said (about smearing/contrast).

 

Just one added detail:  there are many tiny stars as well,

   and together they generate a greying background when smeared.

   So...not just the target objects..


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#8 Jon Isaacs

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Posted 31 May 2020 - 07:20 AM

 Any smearing of an object diminishes brightness and contrast.  Extended objects.  Non-extended objects become extended and their brightness drops.  Nice that it confers benefits in both cases.

 

For an extended object, it depends on the objects brightness as the eye has poor resolution of dim objects.  

 

Try focusing on the moon.. viewing the moon through a filter, a standard 100,000:1 solar filter.

 

Jon



#9 SteveG

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Posted 31 May 2020 - 01:02 PM

I had heard of the Televue Dioptrx and read some reviews, but none really grabbed me with a "you gotta try this!" message. 

As a result of a low-ball bid on eBay, I recently had the opportunity to try one.   By simply holding it over the eyepiece while observing the Veil Nebula.  I rotated the Dioptrx and was very pleased to see the flared stars become pinpoints across the field of view of the 31mm Nagler.

However, I also noticed that the contrast of the Veil improved as well.  Thinking I might be imagining things, I moved the Dioptrix in and out of the light path.  The nebula definitely appeared more prominent across the entire field with the Dioptrix in place.

Has anyone else experienced this?

I spent a couple of years trying to figure out why every low power eyepiece I bought gave me crappy views. I don’t even know how I finally stumbled on Dioptrx, but it was a real eye opener for me. Fortunately my astigmatism isn’t getting any worse, so I’ve purchased (3) Dioptrx at 1.0 for my various low-power eyepieces. What Dioptrx did you get, and does it match your eyeglasses prescription?



#10 faackanders2

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Posted 02 June 2020 - 10:48 PM

I spent a couple of years trying to figure out why every low power eyepiece I bought gave me crappy views. I don’t even know how I finally stumbled on Dioptrx, but it was a real eye opener for me. Fortunately my astigmatism isn’t getting any worse, so I’ve purchased (3) Dioptrx at 1.0 for my various low-power eyepieces. What Dioptrx did you get, and does it match your eyeglasses prescription?

astgmatism would be worse with low power large e

xit pupil eyepieces,


Edited by faackanders2, 02 June 2020 - 10:48 PM.


#11 John Rogers

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Posted 02 June 2020 - 11:38 PM

I spent a couple of years trying to figure out why every low power eyepiece I bought gave me crappy views. I don’t even know how I finally stumbled on Dioptrx, but it was a real eye opener for me. Fortunately my astigmatism isn’t getting any worse, so I’ve purchased (3) Dioptrx at 1.0 for my various low-power eyepieces. What Dioptrx did you get, and does it match your eyeglasses prescription?

My prescription is for 2 diopters and I purchased a 3.0 Dioptrx.  I am toying with the idea of equipping all of my Televue eyepieces with a 2.0 Dioptrx and creating a "for my use only" set of eyepieces.



#12 SandyHouTex

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Posted 03 June 2020 - 12:01 PM

The dioptrix is the best thing Televue ever did for us older amateurs.

 

The Paracorr is second, for all amateurs.


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#13 hoof

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Posted 03 June 2020 - 04:18 PM

An FYI for those with the ES 30mm 82 - remove the eyecup, open the Dioptrix wide and it fill fit!


I use my ES 30mm UWA for night vision with the TNVC and it works, due to this very fact. Works well, though it’s a huge eyepiece for only viewing 43 degrees ;)

#14 SteveG

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Posted 04 June 2020 - 07:52 PM

My prescription is for 2 diopters and I purchased a 3.0 Dioptrx.  I am toying with the idea of equipping all of my Televue eyepieces with a 2.0 Dioptrx and creating a "for my use only" set of eyepieces.

Just curious, why the 3.0 if your prescription is 2.0?

 

I've found that the Dioptrx works exactly as advertised, and matching the CYL of my viewing eye produced perfectly corrected results.


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#15 ewave

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Posted 04 June 2020 - 08:37 PM

Sometimes I've often wondered if the Dioptrx can unexpectedly correct some astigmatism inherent from the eyepiece, either under or over correcting, depending on the prescription of the Dioptrx vs the inherited eyepiece astigmatism. Does Don P's EP chart have a column for inherent astimatism for at least some identified EPs?


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#16 John Rogers

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Posted 04 June 2020 - 09:23 PM

Just curious, why the 3.0 if your prescription is 2.0?

 

I've found that the Dioptrx works exactly as advertised, and matching the CYL of my viewing eye produced perfectly corrected results.

It was an eBay pickup for about half of the cost of a new one.  Since my prescription was three years old, I assumed that it would be a little worse.  As it turns out, I recently got a new prescription and it hasn't changed at all.

 

Now I have a couple of 2.0s on order for the two eyepieces with the largest exit pupils.  So, I will soon determine if it is worth keeping the 3.0.


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#17 213Cobra

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Posted 05 June 2020 - 03:47 AM

It was an eBay pickup for about half of the cost of a new one.  Since my prescription was three years old, I assumed that it would be a little worse.  As it turns out, I recently got a new prescription and it hasn't changed at all.

 

Now I have a couple of 2.0s on order for the two eyepieces with the largest exit pupils.  So, I will soon determine if it is worth keeping the 3.0.

My prescription cyl is also 2.0; however that is really a daylight spec. For astro purposes I found the 2.5 DioptRx to be optimal. Generally, you will need a bump from your eyeglasses prescription for truly tight stars through DioptRx.

 

Phil


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#18 Ernest_SPB

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Posted 05 June 2020 - 04:32 AM

People! 

Televue Dioptrx is just a frame for lens that corrects astigmatism of observer eye. Nothing more. If it picked up with correct cylinder diopters it can improve image as well as eyeglasses. It requires shorter eye relief and better aligned to eyepiece optics, nothing more.



#19 SteveG

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Posted 05 June 2020 - 11:30 AM

People! 

Televue Dioptrx is just a frame for lens that corrects astigmatism of observer eye. Nothing more. If it picked up with correct cylinder diopters it can improve image as well as eyeglasses. It requires shorter eye relief and better aligned to eyepiece optics, nothing more.

Yes, we know this.




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