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The dark side of the eyepiece

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#1 jc_colorado

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Posted 24 October 2020 - 03:31 PM

Ok, so while I have been in the hobby off and on for 15 years I have only ever had one premium eyepiece  which is a 24 Pan besides what came with my Orion 10 EQ .  I just bought some Radians this past week and I only had about 30 minutes with them due to the cold and incoming drizzle.  I had a hard time getting my eye in just the right place to see through it.  Keeping my eye there also seemed liked a chore.  I don't have this issue at all with my 24 Panoptic.  Can someone break this down as to why this is happening?  I am looking to invest in some DeLite and/or Delos eyepieces in the near future, but I really don't like this effect.  What is the difference between the Radian and the Panoptic that I only experience it in the Radian?   What do I need to look for in other eyepieces to avoid this?  I hope to get some more time with them tonight and will play with the eye relief extension a bit more and hopefully not have to fight the eyepiece so much.  Thank you for your insight.

 

Using in:

Zhumell Z8 1200mm f/4.7

Orion Atlas 10 EQ 1200mm f/4.9


Edited by jc_colorado, 24 October 2020 - 03:37 PM.


#2 SeattleScott

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Posted 24 October 2020 - 03:42 PM

The radian has 20mm ER. It is designed for glasses. If you don’t wear glasses then you may have difficulty finding and keeping the sweet spot. Consequently it has an adjustable eyecup that you can raise to guide your eye to the correct position if not wearing glasses. Generally speaking, with long ER eyepieces, you want eyecup down if wearing glasses or eyecup up if not wearing glasses. This is somewhat universally true. I wouldn’t call it a defect of the radians but just something to get used to with long ER eyepieces. With a 6mm Ortho you don’t have to worry about raising an eyecup. You probably won’t have the option. But with long ER it is something you need to factor in.

That being said some long ER eyepieces are a little more finicky than others. Personally I haven’t used the TV long ER eyepieces.

Scott
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#3 CeleNoptic

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Posted 24 October 2020 - 04:02 PM

Radians should have built-in Pupil Guide - Instajust, check out TeleVue instruction 

 

 https://www.televue....nstructions.pdf

 



#4 jc_colorado

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Posted 24 October 2020 - 04:07 PM

Thank you.  So is this purely a result of eye relief so if I want to avoid this in the future I just need less eye relief?



#5 25585

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Posted 24 October 2020 - 04:08 PM

Ok, so while I have been in the hobby off and on for 15 years I have only ever had one premium eyepiece  which is a 24 Pan besides what came with my Orion 10 EQ .  I just bought some Radians this past week and I only had about 30 minutes with them due to the cold and incoming drizzle.  I had a hard time getting my eye in just the right place to see through it.  Keeping my eye there also seemed liked a chore.  I don't have this issue at all with my 24 Panoptic.  Can someone break this down as to why this is happening?  I am looking to invest in some DeLite and/or Delos eyepieces in the near future, but I really don't like this effect.  What is the difference between the Radian and the Panoptic that I only experience it in the Radian?   What do I need to look for in other eyepieces to avoid this?  I hope to get some more time with them tonight and will play with the eye relief extension a bit more and hopefully not have to fight the eyepiece so much.  Thank you for your insight.

 

Using in:

Zhumell Z8 1200mm f/4.7

Orion Atlas 10 EQ 1200mm f/4.9

Delites are easy and painless to use. Radians were torture. Try a 9 or 11mm Delite, and prepare to become addicted.



#6 havasman

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Posted 24 October 2020 - 04:14 PM

I wear contacts to observe and also find long eye relief eyepieces difficult and inconvenient to use. It's pretty common. I have 1 Delos but it's lockable adjustable eye guard works VERY well to give a reference point for eye location.

You can likely recover what you spent on the Radians. Try a T6 Nagler. They're different from Radians and for me much better ergonomically.


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#7 jc_colorado

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Posted 24 October 2020 - 05:48 PM

Thanks.  Between the DeLite, Delos, and Nagler which would you recommend?  I am looking for something in the 6-8mm, 10-13mm, and probably 17.3mm Delos.

 

What eye relief would you recommend to avoid searching for the object in the eyepiece while avoiding the blackout area?



#8 SeattleScott

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Posted 24 October 2020 - 05:54 PM

For not wearing glasses I think 10-15mm is a good target for ER. Adjustable eyecups help assure it will work well, especially if closer to the 15mm end.
The other issue is keeping the eye lens outside the eyelash blast radius to keep the glass cleaner. There it is helpful to be at least 10mm if not 15mm, depending on the length of your lashes.

Scott

Edited by SeattleScott, 24 October 2020 - 05:56 PM.


#9 TOMDEY

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Posted 24 October 2020 - 05:57 PM

You guys are experiencing mass hysteria. The Radians and Delites are 1st-order equivalent... same AFOV, same form and fit, same adjustable pupil guide, same top diameter, same rollover rubber eyecup, same eye relief... same everything! I'd say you just aren't reading Al's instruction regarding eye placement. The Radian also has that perforated disc that you can insert or not, depending on how you feel that night. It sounds like you are like most people who (subconsciously) think that you gota cram your eye right up to the hardware, a rookie mistake... rather than floating behind it... finding and memorizing where the exit pupil is... floating in space.

 

Keep in mind that getting the pupil of your eye in the right place is inherently difficult. You need to get the xyz of your eyeball correct to a millimeter or so in, and hold it there, while looking in. If you don't provide something to hold onto (ergo chair, ladder with railings), all bets are off. The difficulty is not the eyepiece, it is you! The manufacturers can only do so much... the rest is on your side of the fence!    Tom

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#10 Jon Isaacs

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Posted 24 October 2020 - 06:00 PM

The 16 mm Type 5 and the type 6 Naglers have around 12 mm of eye relief.  If You have eye placement issues with 20 mm of eye relief, these will probably do the job.

 

But I'd spend some time with the Radians. There is a learning curve and in a month you may find you really like 20mm of eye relief.  For whatever reasons, I accommodate most any amount of eye relief naturally but find 16mm-18 mm most comfortable.

 

Jon


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#11 John Fitzgerald

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Posted 24 October 2020 - 06:02 PM

Radians work fine if you raise the eye cup to the proper level.  Delites work a bit better,  and the eye cup adjustment is better.  Which Radians do you have?



#12 BillP

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Posted 24 October 2020 - 06:09 PM

Thank you.  So is this purely a result of eye relief so if I want to avoid this in the future I just need less eye relief?

Not all long eye relief eyepieces have this issue.  With the Radians though they are quite sensitive to proper eye placement.  You can mitigate much of it if you are judicious about setting the Instajust to the proper height when using them, and also observing seated as this allows you to maintain a steadier head position.  Using the pupil guide that came with them also help -- if you look at the DeLites the pupil guide is basically built into the eyepiece instead of being an accessory so it is a lesson learned from the Radians.  The eye guard height on the DeLites also locks which is another lesson learned as the Radian's Instajust never stays put between observing session.

 

Anyway, on other lines with long eye relief they are not as sensitive as what you are experiencing with the Radians.  Examples would be XWs, Delos, DeLites, Morpheus, others.


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#13 jc_colorado

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Posted 24 October 2020 - 06:11 PM

Thanks for continued feedback.  

 

Tom, I probably still do fit into the rookie classification due to the infrequency of use and the limited experience of varying eyepieces.  

 

Being that Radian, DeLite, and Delos all appear to have 20mm of eye relief I guess I should not expect any difference in the viewing experience as it pertains to eye placement and experiencing blackout?

 

Being that the Panoptic has 15mm of eye relief does this alone explain why I don't experience this "problem" with my 24mm Pan?

 

I hope to put some more consistent time in at the scope going forward so that should help a lot as well.



#14 ed_turco

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Posted 24 October 2020 - 08:16 PM

The radian has 20mm ER. It is designed for glasses. If you don’t wear glasses then you may have difficulty finding and keeping the sweet spot. Consequently it has an adjustable eyecup that you can raise to guide your eye to the correct position if not wearing glasses. Generally speaking, with long ER eyepieces, you want eyecup down if wearing glasses or eyecup up if not wearing glasses. This is somewhat universally true. I wouldn’t call it a defect of the radians but just something to get used to with long ER eyepieces. With a 6mm Ortho you don’t have to worry about raising an eyecup. You probably won’t have the option. But with long ER it is something you need to factor in.

That being said some long ER eyepieces are a little more finicky than others. Personally I haven’t used the TV long ER eyepieces.

Scott

Uncle Al's 40mm Plossl is a stinker.
 



#15 f74265a

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Posted 24 October 2020 - 08:17 PM

The 16 mm Type 5 and the type 6 Naglers have around 12 mm of eye relief. If You have eye placement issues with 20 mm of eye relief, these will probably do the job.

But I'd spend some time with the Radians. There is a learning curve and in a month you may find you really like 20mm of eye relief. For whatever reasons, I accommodate most any amount of eye relief naturally but find 16mm-18 mm most comfortable.

Jon


Agree that the nagler t6s are a good option if you prefer something that will plug and play with 24 pan. Sometimes when I’m lazy and don’t feel like messing around with eye cups I observe with the 24 pan, 13t6 and 5t6 for no fuss low, medium and higher power
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#16 jc_colorado

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Posted 24 October 2020 - 08:33 PM

I do not wear glasses when viewing so I guess I don’t need that much ER.
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#17 Miranda2525

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Posted 24 October 2020 - 09:00 PM

Delites are easy and painless to use. Radians were torture. Try a 9 or 11mm Delite, and prepare to become addicted.

I've had and used a 6mm Radian. Torture? Far from it. I had no problems using the 6mm Radian without glasses and not even use the pupil guide or have the rubber eye cup or the housing upwards.

 

It's all about setting your eye and "hovering" at just the right place, (if you don't like to use the rubber eyecups or have the top part upwards on some eyepieces like Radians, Delites, Delos, etc). Also, I think the ones who have eye placement problems using long eye relief eyepieces are just not used to it and they DO NOT SIT DOWN while observing.

 

Of course, using the rubber eye cups flipped up or having the top body part of the housing screwed / placed upwards is even better for some. The only time I really have the rubber eye cups on my eyepieces upwards is when using nebula filters for maximum effect, or if stray light is near, so I can block it off.

 

Sitting down while observing is paramount to getting rock-steady views.


Edited by Miranda2525, 24 October 2020 - 09:08 PM.

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#18 jc_colorado

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Posted 24 October 2020 - 09:19 PM

The sitting down could very well be part of the problem.  I had just received them, I had a small window of time, and it was freezing, and I was not sitting down.  There is a high light cloud deck, I will try it again before the snow starts...


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#19 jc_colorado

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Posted 24 October 2020 - 09:53 PM

ok, so I don't know what the difference is, but I tried both sitting and hunching with the dob.  I didn't have any issues tonight.  Sitting was much easier and nicer on my back, but I didn't struggle at all.  I used the 8mm Radian and had some decent views of Mars, Saturn, and Jupiter.  Seeing wasn't great, but enjoyable.


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#20 f74265a

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Posted 24 October 2020 - 10:53 PM

An adjustable astronomy chair improves the experience with using almost any eyepiece. With standing it is hard to stay really stable over an exit pupil of only about 0.5 to 5mm for long. I highly recommend one
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#21 BillP

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Posted 24 October 2020 - 11:30 PM

I've had and used a 6mm Radian. Torture? Far from it. I had no problems using the 6mm Radian without glasses and not even use the pupil guide or have the rubber eye cup or the housing upwards.

Granted that you had no problems.  But many many people did.  I was one of them.  I had all the Radians from 18mm to 4mm for a good amount of time.  I always viewed sitting.  Would have been nice to use the instadjust if it ever worked properly, but it would always move down with the slightest pressure so never stay put.  I never did use the pupil guides.  I would classify how they made my eyes feel as torture also.  After some time I got the hang of them and did not have the positioning issue anymore.  But when I switched to the XWs my eyes immediately told me that they had been tortured for the past few years as in comparison it now felt like my eyes were in a spa with the XWs.  The Radians caused a lot of eye strain for me I guess as when I switched I could not believe how much better my eyes just felt while observing!

 

The DeLites are better IMO in every single way compared to the Radians.  TV fixed all the Radian issues in the DeLite (sharpness, color neutrality, lack of lateral color, an eye guard that works, pupil guide integrated into the build, and 2 extra degrees of AFOV to boot!!


Edited by BillP, 24 October 2020 - 11:33 PM.


#22 TOMDEY

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Posted 24 October 2020 - 11:37 PM

I just realized that precious few astronomy books or equipment manuals actually say anything about how to address an eyepiece. You'd think it comes naturally, but not so. In our optics labs, all of the techs, most of the engineers, some of the scientists, and none of the bosses know how. When introduced to an eyepiece on some piece of equipment, the proper technique is:

 

>get permission from the custodian

>get comfortable

>he tells you what you should expect to be seeing

>eye open, on-axis, slowly move in until the field fills

>go farther in till you lose some field

>back off and settle in... making a mental note of where the pupil is, relative to the hardware

>he will show you the adjustments etc. and it's off to the races

 

Many viewers have crazy long eye relief... gun sights, scale readings, med exam instruments. The eye relief can sometimes be a couple of feet!

 

Come to think of it... Al Nagler's Apollo scene simulator was like that! The user's head is in the pupil, with the projector on the other side of the window!

 

~click on~ >>>

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#23 BKSo

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Posted 25 October 2020 - 04:41 AM

I just realized that precious few astronomy books or equipment manuals actually say anything about how to address an eyepiece.

What if the eyepiece in question doesn't have a field stop (say if it is a DIY job)?


Edited by BKSo, 25 October 2020 - 05:28 AM.


#24 izar187

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Posted 25 October 2020 - 05:17 AM

You guys are experiencing mass hysteria.

 

-------------------------------------

 

Yeah, but it's an eyepiece forum.


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#25 25585

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Posted 25 October 2020 - 05:57 AM

I've had and used a 6mm Radian. Torture? Far from it. I had no problems using the 6mm Radian without glasses and not even use the pupil guide or have the rubber eye cup or the housing upwards.

 

It's all about setting your eye and "hovering" at just the right place, (if you don't like to use the rubber eyecups or have the top part upwards on some eyepieces like Radians, Delites, Delos, etc). Also, I think the ones who have eye placement problems using long eye relief eyepieces are just not used to it and they DO NOT SIT DOWN while observing.

 

Of course, using the rubber eye cups flipped up or having the top body part of the housing screwed / placed upwards is even better for some. The only time I really have the rubber eye cups on my eyepieces upwards is when using nebula filters for maximum effect, or if stray light is near, so I can block it off.

 

Sitting down while observing is paramount to getting rock-steady views.

I had Radians, I have Delites. Comfort of use, wearing glasses, standing or sitting with the Delites is divine and their optical quality is superior to the Radians.

 

While there may be a technique to 80°+ AFOV viewing, both Radians and Delites are mere low-60s AFOV. As such, they should be instantly user-friendly out of the box, for everyone in all situations. The Delites excel, Radians fail.


Edited by 25585, 25 October 2020 - 05:57 AM.



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