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The Hyperion Experiment

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#1 Miranda2525

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Posted 25 February 2020 - 10:10 PM

Hi.

 

I am in no way an expert on eyepieces. I am a casual observer with the same interests as many others. 

 

I bought a used 21mm Baader Hyperion a while back. I had two extra 14mm Baader fine tuning rings in my eyepiece case from even further back. I added one 14mm fine tuning ring to the 21mm Hyperion as I wanted just a bit more magnification. It needed a bit more "in focus"since adding the fine tuning ring, so I added an adapter which makes it parfocal to the rest of my eyepieces, which was a bonus, and there is no longer a need for "in focus" and re-focusing the focuser.

 

The 21mm by itself is fairly nice, but once I added the fine tuning ring, it made the field stop look sharper and it cleaned up the "soft look" of the 21mm when used alone w/o the fine tuning ring, (it had slight edge of field brightening).

I then bought a 10mm Baader Hyperion, and when using it alone, there was a substantial amount of edge of field brightening, and the field stop was not in focus, so I tried an experiment.

 

I added a 14mm fine tuning ring, and an empty filter cell and now the edge of field brightening is gone, and the field stop now looks to be in focus. Eye placement has also become a bit easier on both the 21mm and the 10mm Hyperions. 

 

I just wanted to share my experience and little "experiment" I tried with both the 21mm and the 10mm Baader Hyperions, which worked out really good. If any of you have those two eyepieces, you could try this to see if you like them better. Once I added both the 14mm fine tuning rings to both, and a empty filter cell to the 10mm, I have just left them that way, and don't plan on changing them back. 

Make sure to do the switch in a dust-free environment, as you don't want any dust or debris to get in between the Smythe lens and the body of the eyepieces. Do it as fast as possible also, to avoid dust or debris as well.

 

I made sure to use a air blower bulb on the inside of the Smythe lens and bodies of both eyepieces to make sure there is no dust, etc in between the lenses.

 

I have since tested both eyepieces on star clusters. The 21mm is sharp out to about the 80% point with mild astigmatism near the field stop. the 10mm was pretty much sharp out to the edges. I tested both using my 10" Orion XTi without using a coma corrector and both were perfect in the Orion ED 100.


Edited by Miranda2525, 26 February 2020 - 07:56 AM.

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#2 SeattleScott

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Posted 26 February 2020 - 12:06 AM

Very interesting. So dies this decrease the effective AFOV? I mean you are eliminating EOFB and reducing edge softness so it seems like maybe this is accomplished by reducing AFOV. Or are you changing the magnification/focal length of the eyepieces? So the 10mm really acts like something else?

Scott

#3 Starman1

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Posted 26 February 2020 - 12:20 AM

Very interesting. So dies this decrease the effective AFOV? I mean you are eliminating EOFB and reducing edge softness so it seems like maybe this is accomplished by reducing AFOV. Or are you changing the magnification/focal length of the eyepieces? So the 10mm really acts like something else?

Scott

Adding spacers changes the focal lengths in the same way moving a Barlow farther away from the eyepiece does.

The 21mm becomes a 17.6mm with the 14mm spacer.

The 10mm becomes an 8.4mm focal length and the additional filter spacer changes that to 10% less, or 7.6mm (rounded off).

 

Eye relief changes.  As to whether AF changes, it shouldn't, but sometimes re-spacing a Smythe lens has unpredictable results.


Edited by Starman1, 26 February 2020 - 12:23 AM.

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#4 SeattleScott

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Posted 26 February 2020 - 01:33 AM

Thanks that helps a lot. So not necessarily the answer to plugging the gap between the 8 & 13 LVWs.

Scott

#5 Ernest_SPB

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Posted 26 February 2020 - 02:19 AM

Eye relief changes.  As to whether AF changes, it shouldn't, but sometimes re-spacing a Smythe lens has unpredictable results.

More spacing (from negative prefocal component to lenses in EP body) - a bit shorter eye relief. Easy to calculate. For short focal EP the effect is neglectable, for long focal - can be measured.



#6 ngc7319_20

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Posted 26 February 2020 - 06:17 AM

Very interesting.  Moving the Smythe lens (effectively a Barlow lens) farther out will reduce the diameter of the light beam (pupil diameter) at the field stop and through the rest of the eyepiece.  This can only improve the sharpness.  It may also modify the field curvature, so it better matches your particular scope.



#7 25585

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Posted 26 February 2020 - 07:16 AM

Like your thread title Miranda. waytogo.gif

 

Can you measure what the new eye relief is please?



#8 luxo II

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Posted 26 February 2020 - 07:18 AM

So not necessarily the answer to plugging the gap between the 8 & 13 LVWs.

The SSW 10mm “plugs the gap” nicely as it’s wider and sharper than the LVWs.

I sold my LVWs while worth something, when I found better alternatives at half what the LVWs fetched. Good eyepieces don’t need to be larger than handgrenades, nor the size of coke bottles.

Edited by luxo II, 26 February 2020 - 07:25 AM.

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#9 25585

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Posted 26 February 2020 - 07:23 AM

I have LVWs. My FL plug is a Pentax XW 10mm, but a Morpheus 9mm is as good.


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#10 Miranda2525

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Posted 26 February 2020 - 07:57 AM

Very interesting. So dies this decrease the effective AFOV? I mean you are eliminating EOFB and reducing edge softness so it seems like maybe this is accomplished by reducing AFOV. Or are you changing the magnification/focal length of the eyepieces? So the 10mm really acts like something else?

Scott

Funny you asked this question. When adding the 14mm fine tuning ring to the 10mm, it feels like a wider apparent field of view. 


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#11 Miranda2525

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Posted 26 February 2020 - 09:19 AM

Like your thread title Miranda. waytogo.gif

 

Can you measure what the new eye relief is please?

I would measure it, if I knew how, lol. It feels like about 17mm.


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#12 chrysalis

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Posted 26 February 2020 - 10:27 AM

BTW - depending on your scope, you can REMOVE the Smythe lens and get a pretty nice 32.2mm EP as a result.

 

hyperion stuff.jpg



#13 Starman1

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Posted 26 February 2020 - 10:34 AM

I've done that, but the eyepieces have serious lateral astigmatism when you use them that way.

Perhaps at f/8 or longer?


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#14 Miranda2525

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Posted 26 February 2020 - 11:16 AM

I've done that, but the eyepieces have serious lateral astigmatism when you use them that way.

Perhaps at f/8 or longer?

True. Not good at all that way.



#15 Miranda2525

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Posted 28 February 2020 - 01:36 AM

Like your thread title Miranda. waytogo.gif

 

Can you measure what the new eye relief is please?

So, I just measured the eye relief using a flashlight and I left the rubber eyecup off. There's a post about doing this here on CN. I got 15mm on the button. Great if you don't wear glasses and you leave the eyecup off. I leave mine off when using it, and it is very comfortable.  If you wear glasses, you will lose a few mm because the eye lens is slightly concave and it is recessed a few mm.  

 

The eye relief measurement with the flashlight was done using a 14mm fine tuning ring and an empty 2" filter cell added to the eyepiece. I get 145x magnification now, instead of 110x if it was native at the 10mm setting. I timed the eyepiece alone and got 110x, which is close, but not perfect due to some distortion in the eyepiece.


Edited by Miranda2525, 28 February 2020 - 01:41 AM.

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