Eye relief differences in different people?

[badhex]

Hello all,

This might be a stupid question but is there much variance in how much eye relief a person needs (not counting glasses wearers)? I tend to find with some EPs with decent ER (so far, Morpheus 4.5mm, APM 24mm, possibly the new APM superzoom although untested at night) that I have to hover a bit above the eyecup to get the full field vs blackouts.

I get that there would be minor differences due to face shape but you'd think it would be tiny amounts, and I don't feel like I've seen many reports of this for these particular EPs for other people. I've had to put extension rings on all of my Baaders for example - it's not like my eyes are bulging out from my head or anything! 😂

[SthBohemia]

Fascinating question- As I don't have a huge EP selection probably not the best person to reply-However, as regards blackouts the TeleVue Radian 10mm, and Rini 50mm are somewhat, lets say, more exacting regarding head placement and remaining perfectly (almost) still while observing.

While Russell EP's, old Kellners AND an acromatic Huygenian are 'user friendly'.

 

[vlaiv]

I guess there is some variation.

Not sure how much, but I can name two factors that will change eye relief and depend on person.

First is any sort of dioptre.

As we get older - we get farsighted, and although we might not need glasses in everyday life or just for observing - we don't all have same ideal focus position when observing relaxed.

Change of focus position will change eye relief somewhat.

Second thing of course is position of eyes with respect to eye sockets. Some people have gentler facial features / less pronounced bones / eye sockets - and others are different in that respect.

[badhex]

Yeah it's a weird one. I do need to get my eyes tested as it's been a couple of years, but last time I had it done they said it was better than 20/20 or whatever system it is now. 

Maybe I've just got a weird face! 

[SthBohemia]

1 minute ago, badhex said:

Maybe I've just got a weird face! 

Doubt it. I was reading a forum link a couple of weeks ago within CloudyNights, which was worded almost identically to yours, but cannot remember the name of the link.  CloudyN is just SO huge!

[Zeta Reticulan]

It seems to me generally that EP's corrected for faster scopes tend to have more eye placement issues than those not so well corrected. There are exceptions of course.

I find the 13mm eye relief on my 19mm Panoptic virtually perfect, and with no other issues. It is 'only' 68 degrees FOV though.  It's not surprising it's one of my most used eyepieces. The 82 degree 19mm Luminos is also comfortable to view through. However, it is better suited to slower scopes. 

The ES 18mm, also 82 degrees, is much better corrected than the Luminos. Although, in use, the ability to rapidly evolve a compound eye might be an advantage. Another factor with modern eyepiece fads is the need for original equipment manufacturers to pander to the 'Magoo Mob'. A lot of manufacturers seem to believe that they won't be able to sell eyepieces that don't have an eye relief anywhere between about 20 millimetres and 6 metres. 

Edited August 4, 2022 by Zeta Reticulan
Universal translator malfunction

[RT65CB-SWL]

17 hours ago, SthBohemia said:

Fascinating question- As I don't have a huge EP selection probably not the best person to reply-However, as regards blackouts the TeleVue Radian 10mm, and Rini 50mm are somewhat, lets say, more exacting regarding head placement and remaining perfectly (almost) still while observing.

While Russell EP's, old Kellners AND an acromatic Huygenian are 'user friendly'.

 

Assuming you purchased your TeleVue Radian new, did it include a pupil guide in the box? [image and instructions below].

TV Radian Eyepiece Instructions.pdf

I too would get a blackout when using my 6mm Radian with my ETX105 before I added/re-modded the rear end/visual back.
Using the supplied pupil guide should eliminate it. 

Edited August 5, 2022 by Philip R

[Mr Spock]

An interesting topic. I've always been surprised how easy I find using a 4mm orthoscopic. It has tiny eye relief but it doesn't seem to matter.

[RT65CB-SWL]

On 04/08/2022 at 21:20, Mr Spock said:

An interesting topic. I've always been surprised how easy I find using a 4mm orthoscopic. It has tiny eye relief but it doesn't seem to matter.

Same here too!
My Ortho’s are Circle-T 6 & 12.5mm... plus a 0.965" / 6mm (used with the 0.965” to 1.25" adaptor, as shown in the second image). 

Apologies for the quality of the images, as they were taken with my Go-Pro clone.

Edited August 6, 2022 by Philip R

[Zeta Reticulan]

I like my 4mm ortho's, but for prolonged observing sessions alternatives can be good. The 4mm Tak' ortho is surprisingly ergonomic to use.

Unfortunately Tak' have ceased making their ortho's.

[Don Pensack]

It is not unusual, in fact it is ordinary, for people who don't use glasses to find the eye relief of long eye relief, glasses-compatible, eyepieces to be excessively long

when used without glasses.

Many eyepieces have roll-up, or slide-up, or click-up eyecups to pull the eyecup out farther away from the eyepiece to help hold the head in place at the longer distances to the lenses.

Others, like the Morpheus, include an eyecup extender, and yet still others sell an after-market extender.

There is nothing unusual in your having a bit of difficulty holding your eye in place at a large distance from the eyepiece.

 

Many amateur astronomers have been getting steadily older, and the number of posts criticizing eyepiece makers for not having enough eye relief for glasses has been steadily climbing

over the years--to the point where, now, it is almost folly to introduce a new line of eyepieces that are not compatible with glasses.

The makers, though, do need to address usability by the non-glasses wearers.

 

Even with glasses, there is a profound difference from person to person, and some glasses wearers can use as little as 16mm of eye relief, and others need up to 24mm.

How deep-set your eyes are and how far away the lens is from the eye enter into the picture of a need for eye relief.

Even a lot of people who do not wear glasses complain about short eye relief eyepieces being "uncomfortable".

 

Make sure you observe while seated--that makes holding your eye in place much easier.

 

[badhex]

11 hours ago, Mr Spock said:

An interesting topic. I've always been surprised how easy I find using a 4mm orthoscopic. It has tiny eye relief but it doesn't seem to matter.

I also seem to manage okay with a 6mm BCO, although I wouldn't call it comfortable exactly. You'd have thought that if I do have "physiologically extended eye relief" (that's it, I'm coining it PEER. You heard it here first folks) then it would apply to all EPs. Or maybe it does, and some people have it even worse with their orthos! 

[badhex]

10 hours ago, Don Pensack said:

It is not unusual, in fact it is ordinary, for people who don't use glasses to find the eye relief of long eye relief, glasses-compatible, eyepieces to be excessively long

when used without glasses.

Many eyepieces have roll-up, or slide-up, or click-up eyecups to pull the eyecup out farther away from the eyepiece to help hold the head in place at the longer distances to the lenses.

Others, like the Morpheus, include an eyecup extender, and yet still others sell an after-market extender.

There is nothing unusual in your having a bit of difficulty holding your eye in place at a large distance from the eyepiece.

 

Many amateur astronomers have been getting steadily older, and the number of posts criticizing eyepiece makers for not having enough eye relief for glasses has been steadily climbing

over the years--to the point where, now, it is almost folly to introduce a new line of eyepieces that are not compatible with glasses.

The makers, though, do need to address usability by the non-glasses wearers.

 

Even with glasses, there is a profound difference from person to person, and some glasses wearers can use as little as 16mm of eye relief, and others need up to 24mm.

How deep-set your eyes are and how far away the lens is from the eye enter into the picture of a need for eye relief.

Even a lot of people who do not wear glasses complain about short eye relief eyepieces being "uncomfortable".

 

Make sure you observe while seated--that makes holding your eye in place much easier.

 

Thanks for detailed reply Don. As mentioned I've had to use extenders on a number of EPs - the Morpheus I own plus I'm going to do the same to the APM 24mm UFF and now, since managing a quick first light last night, also the APM Superzoom.

The Superzoom was the worst of those for in terms of eye positioning. I will need to play around with the extensions but I was able to fit a whole finger's width between my eye and the end of the eyecup! 

I swtiched to seated observing a while ago and it is a lot more enjoyable overall, beyond just eye positioning! 

Edited August 5, 2022 by badhex

[badhex]

After a lot of faffing about trying different permutations, I believe I've fixed the ER issue for my APM Superzoom and Morpheus 4.5mm:

I ended up with a Baader M43 extension plus Morpheus eyecup for the APM. The Morpheus 4.5mm needed a couple of extra mm on top of the extension + eyecup, so I found some silicon hair bands which work pretty well until I can find a more suitable o-ring.

Last job is to fix the APM 24mm UFF but in waiting on the remaining extension and eyecup. 

Edited August 5, 2022 by badhex

[JeremyS]

4 hours ago, badhex said:

After a lot of faffing about trying different permutations, I believe I've fixed the ER issue for my APM Superzoom and Morpheus 4.5mm:

I ended up with a Baader M43 extension plus Morpheus eyecup for the APM. The Morpheus 4.5mm needed a couple of extra mm on top of the extension + eyecup, so I found some silicon hair bands which work pretty well until I can find a more suitable o-ring.

Last job is to fix the APM 24mm UFF but in waiting on the remaining extension and eyecup. 

Is it this one Joe part 2954250? https://www.baader-planetarium.com/en/hyperion--morpheus-m43-extension.html

[badhex]

3 hours ago, JeremyS said:

Is it this one Joe part 2954250? https://www.baader-planetarium.com/en/hyperion--morpheus-m43-extension.html

That's the one Jeremy. There is also a rubber eyeguard with a metal M43. You get one of each supplied with the Morpheus, which were already in use on the 17.5mm and 4.5mm so I bought an additional three extensions and two rubber eyeguards so I could muck about with different options. 

[badhex]

Turns out the Pentax XW also has an M43 thread available, although thankfully I have no issues with ER on my 10mm XW so I don't have to resort to this monstrosity 😱

[badhex]

Quick update on the ER experiments, I managed to test both EPs under the stars, and the spacing is perfect on both the Morpheus 4.5mm and the Superzoom. Makes a huge difference to comfort when using the EPs! 

[Louis D]

1 hour ago, badhex said:

Quick update on the ER experiments, I managed to test both EPs under the stars, and the spacing is perfect on both the Morpheus 4.5mm and the Superzoom. Makes a huge difference to comfort when using the EPs! 

Maybe we need to petition Baader to include several thin M43 sized O-rings for fine tuning the eye cup height as you did on the 4.5mm Morpheus.  They already include the useless clip for the eyepiece holster that's supposed to be used for tactile nighttime identification of eyepieces, so why not include something actually useful that costs pennies/pence in volume?

[Zeta Reticulan]

Baader eyecups have always been weird.

I finally managed to put a far less annoying one on my old 14mm Morpheus a couple of years ago.

Even then you have to be careful if you try to roll it down. If the rubber accidentally detaches from the metal collar there is a lot of grease. 

[badhex]

23 minutes ago, Louis D said:

Maybe we need to petition Baader to include several thin M43 sized O-rings for fine tuning the eye cup height as you did on the 4.5mm Morpheus.  They already include the useless clip for the eyepiece holster that's supposed to be used for tactile nighttime identification of eyepieces, so why not include something actually useful that costs pennies/pence in volume?

Agreed! Maybe I'll use my best Deutsch and send them an email 🙂

[badhex]

59 minutes ago, Zeta Reticulan said:

Baader eyecups have always been weird.

I finally managed to put a far less annoying one on my old 14mm Morpheus a couple of years ago.

Even then you have to be careful if you try to roll it down. If the rubber accidentally detaches from the metal collar there is a lot of grease. 

Did yours come with the winged version attached already? Both my Morpheus' came with the standard eyecup attached to the metal collar, with the winged version just as the rubber part.

[Zeta Reticulan]

1 hour ago, badhex said:

Did yours come with the winged version attached already? Both my Morpheus' came with the standard eyecup attached to the metal collar, with the winged version just as the rubber part.

Mine is quite old and had the original winged eyecup. I bought the 'wingless' eyecup a few years later. I think these are now bundled with the entire range. IIRC the Morpheus were fairly new (and a lot cheaper lol) when I bought mine. 

[bosun21]

I only use the extension piece on two of my six Morpheus eyepieces. The 4.5mm and the 6.5mm. I find all the others to be just fine and comfortable the way they are. 

[Don Pensack]

On 08/08/2022 at 06:52, Zeta Reticulan said:

Baader eyecups have always been weird.

I finally managed to put a far less annoying one on my old 14mm Morpheus a couple of years ago.

Even then you have to be careful if you try to roll it down. If the rubber accidentally detaches from the metal collar there is a lot of grease. 

Huh?  The rubber is glued to the threaded ring, and there is no grease at all.