why in UWA 82 svbony eyepieces all suddenly stay black

[Ser]

Telescope N 130/650 Explorer-130PS AZ-5! In complect original eyepieces 10mm and 25mm! I bought svbony 82 degrees 6-9-15-20 oculars! So such problem: "I don't know what's wrong with those SVBONNY eyepieces! I look with one eye in svbony eyepiece! Suddenly it feels like I blinked with other eye (that don't see in eyepiece, it realy stay black not like turn off, but slowly closed like eyebrow close eye) and all in ocular stay suddenly black (like my another eye don't let me see with eye what see in eyepiece)! And everything stays black (in that black moment i try watching inside eyepiece around) until I take my eye off the ocular! I don't understand that moment when it stay black! Look-look for example minute, and suddenly someone say "your eye tired and need sleep". With original 10mm and 25mm eyepieces not such problem!”

[Franklin]

You have to hold your eye in exactly the right place to see through these super-wide field eyepieces.

[Ser]

i try my eye turn around! don't help me!

How i need to see in ocular? i just in astronomy 2 nights! ))

[Ser]

25 minutes ago, Franklin said:

You have to hold your eye in exactly the right place to see through these super-wide field eyepieces.

i try my eye turn around! don't help me!

How i need to see in ocular? i just in astronomy 2 nights! ))

[Franklin]

Try holding your eye further away from the eyepiece and try to keep it central.

[Ser]

Just now, Franklin said:

Try holding your eye further away from the eyepiece and try to keep it central.

hmmm - i think that rubber top in eyepieces needed to hold eyebrow exactly on ocular...  Away from ocular - i will need to focused focuser again?

[Ser]

3 minutes ago, Franklin said:

Try holding your eye further away from the eyepiece and try to keep it central.

how cm away i need hold my eye?

[Franklin]

1 minute ago, Ser said:

hmmm - i think that rubber top in eyepieces needed to hold eyebrow exactly on ocular... 

Not necessarily, the rubber eyecup should be adjustable. Try twisting it up so it keeps your eye further away from the lens.

[Franklin]

2 minutes ago, Ser said:

how cm away i need hold my eye?

Depends on your eyesight. Just take the eyepiece out of the telescope and hold it up to your eye, aiming at a bright sky or lit ceiling and move it slowly away from your eye until you see a nice clean circle of light. That's the correct eye position to have when using in your scope.

[Ser]

9 minutes ago, Franklin said:

Try holding your eye further away from the eyepiece and try to keep it central.

and why with original 10mm and 25 mm wild angle oculars not such problem?

i try answer myself: because in that wild angle i see all "picture" with eye and don't trying to turn it around?

[Franklin]

1 minute ago, Ser said:

and why with original 10mm and 25 mm wild angle oculars not such problem?

Your eye can take in about 65 degrees so with the extra wide angle eyepieces you need to look around to see the whole vista but if you move too much you get blackouts. When I first looked through 83 degree eyepieces I hated them but I learnt how to look through them and now I love them.

[bosun21]

The eyepieces you have (red and black) are actually 68 degrees AFOV. You just need to try them in daylight and with your eye central to the eyepiece very slowly move your head back until you see the image in a bright perfectly circular disc. It sounds as though you have never looked through an eyepiece before but don’t be put off as you will soon get the hang of it.

[Ser]

1 minute ago, Franklin said:

Your eye can take in about 65 degrees so with the extra wide angle eyepieces you need to look around to see the whole vista but if you move too much you get blackouts. When I first looked through 83 degree eyepieces I hated them but I learnt how to look through them and now I love them.

ha-ha-ha - i hate them too ! ))))))

1. with original (not written angle) - Wild Angle only - so they for example 60 degrees or smaller and with them i see all "picture" and don't try look around! Here all i understand!

2. can explain how, if i will try stay away 1 cm with eye from ocular, how to look around with eye? )

[bosun21]

1 minute ago, Ser said:

2. can explain how, if i will try stay away 1 cm with eye from ocular, how to look around with eye?

Move your eyeball not your head.

[Ser]

ok! thanks for all! i get answer! 

I was start thinking about getting Svbony oculars back to Aliexpress! ))

[Ser]

realy help me! i ask astroshop managers that question - they answer that don't know and maybe oculars bad quality! So with yours help will try again and will turn eye away!

[Franklin]

17 minutes ago, Ser said:

can explain how, if i will try stay away 1 cm with eye from ocular, how to look around with eye?

You're not looking in the eyepiece, you're looking at an image formed by the eyepiece and that image is formed a little way outside of the eyepiece lens. You'll get the hang of it once it's clicked.

[Elp]

As a general rule, the higher the power of the eyepiece (lower the number), the eye relief of the eyepiece becomes less and less, so your eye needs to be closer to the eyepiece when using high power eyepieces. You cannot keep your eyes far away from the eyepiece if it is not a long eye relief eyepiece.

Having read your post a few times, I suspect your issue is similar to what I experience, I cannot keep my non viewing eye closed for very long and the view from my viewing eye gets impacted. Try keeping both eyes open and cover your non viewing eye with your hand, this makes it slightly more comfortable than closing one eye all the time. Some people use an eye patch to do this rather than using their hand.

With wide angle eyepieces to get the whole FOV, your eye needs to be fairly close, or close to touching the eyepiece via the eyecup, you won't get the whole FOV any other way, especially if it's an 82 degree one.

[Ser]

3 minutes ago, Elp said:

As a general rule, the higher the power of the eyepiece (lower the number), the eye relief of the eyepiece becomes less and less, so your eye needs to be closer to the eyepiece when using high power eyepieces. You cannot keep your eyes far away from the eyepiece if it is not a long eye relief eyepiece.

Having read your post a few times, I suspect your issue is similar to what I experience, I cannot keep my non viewing eye closed for very long and the view from my viewing eye gets impacted. Try keeping both eyes open and cover your non viewing eye with your hand, this makes it slightly more comfortable than closing one eye all the time. Some people use an eye patch to do this rather than using their hand.

With wide angle eyepieces to get the whole FOV, your eye needs to be fairly close, or close to touching the eyepiece via the eyecup, you won't get the whole FOV any other way, especially if it's an 82 degree one.

yes! i one moment i found that that black appears much later when i hold closed other eye with hand !

[John]

As @bosun21 says above, the eyepieces you have, the 6mm, 9mm, 15mm and 20mm, are around 68 degrees, not 82 degrees.

 

 

 

 

 

 

[Ser]

my telescope with original 10mm and 25 mm: https://www.astroshop.eu/telescopes/skywatcher-telescope-n-130-650-explorer-130ps-az-5/p,55150

and svbony from alexpress (i hope don't get forum block because of link): https://www.aliexpress.com/item/32840105236.html

ups - they realy 68 degrees... sorry (when i bought i much think about 82... )

[Ser]

16 minutes ago, Elp said:

Having read your post a few times, I suspect your issue is similar to what I experience, I cannot keep my non viewing eye closed for very long and the view from my viewing eye gets impacted. Try keeping both eyes open and cover your non viewing eye with your hand, this makes it slightly more comfortable than closing one eye all the time. Some people use an eye patch to do this rather than using their hand.

i need to keep not-used eye OPEN?

if i will use patch (because difficult use hand all time) - with patch possible to keep eye OPEN, or eye goes CLOSED because of patch?

[John]

Ideally you should close or cover the non-observing eye. 

Looking through a telescope does take some practice, whatever eyepiece is being used.

[RT65CB-SWL]

Hi @Ser and welcome to SGL. 

Eye placement is key when using wide angle (WA) and ultra-wide angle (UWA) e/p's. with short focal lengths. I also would get the same effect as you described when using a TeleVue 6mm Radian [they are 58^o AFOV] with my Meade ETX-105. 

I have and use the Svbony 'Goldline' [66^o] and 'Redline^' [68^o]... they are 6mm too! 

 

Edited August 28, 2023 by RT65CB-SWL