Author Topic: Eye Relief  (Read 58 times)

scamcackratge

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Eye Relief
« on: December 27, 2017, 12:32:44 AM »
Hello,

I am new to astronomy and I am adding eyepieces and have a question.  It seems to me that EP's using a longer eye relief are a bit more comfortable to work with.  I do not have to move my attention around as much to view and that I have significantly less blackout.

Are longer eye relief EP's more comfy in general?

Thanks.



coachroninil

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Re: Eye Relief
« Reply #1 on: December 30, 2017, 02:47:32 AM »
Quote
Hello,

I'm new to astronomy and I am adding eyepieces and have a question. It seems to me that EP's with a longer eye relief are a bit more comfortable to use. I don't have to move my eye around as much to view and I have less blackout.

Are longer eye relief EP's more comfortable in general?

Thanks.

There are two answers for this.

1/ Eyeglass wearers appreciate the extra eye relief, especially if they have a condition that cant be corrected by adjusting the focus on the eyepiece.

2/ Personal choice. I love long eye relief, just because I do. Other observers have no such preference. Unless you wear glasses try whatever sounds good and go from there in terms of preference.

David Williams

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Re: Eye Relief
« Reply #2 on: January 04, 2018, 04:10:19 AM »
I think most find that there's a threshold, the 3 mm of eye relief a 5 mm Plossl provides is almost always too little. And 20 mm is almost always enough. Somewhere between those two, is the threshold between not enough and enough. For me, that's around 10-12'mm with 15 mm being preferred.

As was noted, eyeglasses changes the equation.

Jon

Travis Vega

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Re: Eye Relief
« Reply #3 on: January 10, 2018, 04:26:45 PM »
Your question is very subjective, as is mentioned in the other replies.

I wear eyeglasses, now, so for me 20mm or slightly more is preferred, but I can goto 15mm in a pinch, if I have to.

Before wearing glasses (or when I used to wear contacts), I preferred 8mm-15mm, as I found it very comfortable to put my eye in close.

Best you can do is try a few different ones and see what you find to be comfortable.

Longer focal length eyepieces tend to typically have longer eye relief. Along with that, some people like to 'look around' in the eyepiece, some don't. It really all comes down to each person's comfort and what experience they like to have at the eyepiece.

ds

John Abreu

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Re: Eye Relief
« Reply #4 on: January 18, 2018, 08:11:37 AM »
Quote
Hello,

I'm new to astronomy and I am adding eyepieces and have a question. It seems to me that EP's with a longer eye relief are a bit more comfortable to use. I don't have to move my eye around as much to view and I have less blackout.

Are longer eye relief EP's more comfortable in general?

Thanks.

Most people find excessively short eye relief uncomfortable. As to how much is enough for comfortable viewing, that's very much a personal preference thing.

Excessively long eye relief actually increases blackouts for some people, but that only tends to be a problem in very long focal length eyepieces.

I like long eye relief (I like the option of view with glasses as I have astigmatism issues in addition to significant levels of myopia). I really wish someone would bring out a quality, but still reasonably affordable line of 60-70-degree eyepieces with a usable 20mm of eye relief. I have a set of Meade HD-60s (about 17mm of eye relief), and they are OK, but not really comfortable with glasses for me. I also have a bunch of Vixen LV LERs (20mm eye relief), but while I'm perfectly happy with 45-50-degree AFOV fields for planetary viewing, something wider would be nice in the longer focal lengths. I was hoping the ES-62 line would be Explore Scientific's version of Tele Vue Radians, but, alas, this turned out not to be the case.

kerolero

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Re: Eye Relief
« Reply #5 on: January 20, 2018, 01:19:38 PM »
I would assume that most comments that reference eyeglasses are made with the idea that the user is wearing them while doing visual astronomy... I wear glasses (trifocals), but take them off when doing visual astronomy...

Oh... I prefer a lot of eye relief... my eyepieces are 15mm with the exception of 2 which are 10mm for a planetary zoom and 19mmfor one of the wider ep's

Richard Ross

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Re: Eye Relief
« Reply #6 on: January 20, 2018, 08:32:31 PM »
Yes, as mentioned above very long eye relief causes more blackouts and issuesin my experience than what some consider "short" eye relief.

Somewhere around 12mm eye relief, perhaps as much as 15mm and as little as 10mmis what I prefer in short to mid focal lengths. Once the focal length exceeds about 25mm,somewhat longer eye relief becomes acceptable, although it often requires some sort of extension piece to make it comfortable to use.

One of the things I dislike about long eye relief is that it is more difficult to exclude reflections from my cheek, bridge of my nose, and eye from the eyepiece.This includes at dark sites where bright stars, planets etc. all provide enough general reflection at ~90 degrees off axis that they brighten the backgroundin the eyepiece. The way it is most noticeable is with an H-Beta filter on a 2" eyepiece because it darkens the background so much. If I don't carefully cup around my eye or use some sort of hood, then the image is often washed out.

Sean Meyer

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Re: Eye Relief
« Reply #7 on: January 21, 2018, 03:52:14 AM »
This is great info. I don't wear glasses so I don't have that requirement. I've been concerned about dropping $$$ on an EP that I end up not liking. The reason I came to the impression that I liked longer eye relief is due to a pair of Denk 32MM plossels that came with a Binotron I bought. Very pleasant viewing.

I'd like to add EP's for planetary/lunar viewing and it seems many people like Takahashi Abbes or Brandon. Both have mid-teens eye relief, slightly less than the Denk plossel.

Dan

Freddy Banks

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Re: Eye Relief
« Reply #8 on: January 23, 2018, 04:35:34 AM »
Quote
Hello,

I'm new to astronomy and I am adding eyepieces and have a question. It seems to me that EP's with a longer eye relief are a bit more comfortable to use. I don't have to move my eye around as much to view and I have less blackout.

Are longer eye relief EP's more comfortable in general?

Thanks.

For me, yes. For you, maybe not.
My shortest eye relief is 12mm and that 's plenty close enough for me.

Bino viewing is an entirely different experience. Comparing bino and mono viewing doesn't work very well.

Michael Ritchie

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Re: Eye Relief
« Reply #9 on: January 25, 2018, 08:21:02 PM »
Dan,If you can go to a local star party or public viewing event you can try different eyepieces on a variety of objects. Ask questions and see if can can view through different types and focal lengths of eyepieces. Amateur astronomers are usually very willing to share their knowledge.Personally I am near-sighted and have astigmatism so I wear glasses all the time. However, when I'm viewing I only wear my glasses when I'm finding things with the Telrad. I prefer not using my glasses even at low power and putting up with the astigmatism which is minor. At higher magnification, with a smaller exit pupil, the astigmatism isn't noticeable. I prefer keeping the eyepiece closer to my eye. I like using ortho's because they are so sharp and don't mind the eye relief if the eyepiece is 6mm (4.8mm e.r.) or larger. My UWA's are very comfortable for me also. It's a personal matter so try before you buy if you can. You can also buy eyepieces used on CN Classifieds and Astromart and resell them for about the same price if they don't work out.

Jose Lukeson

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Re: Eye Relief
« Reply #10 on: January 26, 2018, 05:50:16 AM »
Quote
I would assume that most comments that reference eyeglasses are made with the idea that the user is wearing them while doing visual astronomy... I wear glasses (trifocals), but take them off when doing visual astronomy...

Oh... I prefer a lot of eye relief... my eyepieces are 15mm with the exception of 2 which are 10mm for a planetary zoom and 19mmfor one of the wider ep's

I take my glasses off too, or rather, flip them up onto my forehead using an elastic band.

I like 12-20mm eye relief. I require a good eyecup if 20mm though. The 9mm Morpheus with 20mm eye
relief and a flimsy eyecup didn't work out for me. Getting a stiffer replacement eyecup from Agena fixed
that problem.

Ryan Fletcher

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Re: Eye Relief
« Reply #11 on: January 30, 2018, 01:21:51 PM »
Hizohsix, I think that you need to say what you like to view since that determines the type of eyepiece that is best. Generally speaking a good Plossl is a good eyepiece to use. However, at higher magnification or short FL, they don't provide very good eye relief and additionally they have narrow fields of view. For the moon it is nice to have a wide field of view to take in the entire scene. You should expect to have a collection of eyepieces providing magnifications of 50, 100, 150, 200, and 250. You may also want to go for a lower magnification if you like wide fields of view. This is however just a general recommendation as to the magnifications you will want to have. For general planetary and moon viewing the 150 mag works for average seeing. But when seeing is really good you will need 200 mag or on exceptionally good nights 250 or 300 mag.

I think it is best to start with Plossls as they perform very well. A good Barlow such as the Televue X2 is also good to have as it allows you to get increased mag on those very good nights. I like the type 1 Naglers that you can get used in the classifieds as a way to get good wider field eyepieces. However, if you can tolerate the narrow field of view, a Televue Plossl with a Televue Barlow works very well.

ulpehaco

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Re: Eye Relief
« Reply #12 on: January 31, 2018, 06:35:11 AM »
One other thing- eyepieces with plenty of ER tend to have larger eye lenses. This can also add to the more comfortable feel of using the eyepiece. For me at least, it is easier to look through a lens the size of a nickel compared to a lens opening like you might see on a 5mm plossl (which is more the size of a soda straw).

I wear glasses so about 90% of my eyepieces and binoculars offer 20mm (or more) of eye relief.

Dennis Collins

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Re: Eye Relief
« Reply #13 on: February 02, 2018, 02:55:49 PM »
Hello Penarin. Your post makes sense to me. Could be why they seem more comfortable. Hmmm.....

schorerabhat

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Re: Eye Relief
« Reply #14 on: February 08, 2018, 09:41:03 PM »
Eye relief is not just desirable if you wear glasses while observing - it's a necessity. There are many eyepieces on the market that I cannot even consider buying because their eye relief is less than the 20mm minimum that I need.