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Eye relief and floaters?

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#1 erin

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Posted 06 August 2018 - 11:58 AM

Hi everyone! I have tried to find a answer to this question and can't seem to....

 

Do eyepieces with shorter focal lengths but with more eye relief (like an AT Paradigm or BST Flat Field) help with floaters? I have a hard time viewing Jupiter with my 6 and 8mm plossls because of those pesky things. I know that exit pupil is the main thing that affects how annoying the floaters will be and that a telescope's aperture can help with that. I just wondered if more eye relief has any affect too? 

 

I have heard that binoviewing helps with floaters too.

 

Thanks! 



#2 RAKing

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Posted 06 August 2018 - 12:08 PM

I am not sure eyepieces with more eye relief will help with the floaters per se, but they might make the viewing more comfortable, which might allow you to sit and wait for the floaters to move away.

 

Binoviewing helped me because all of my floaters were in the left eye (my main monoviewing eye).  Adding the right eye for viewing cleared things up a lot.

 

It takes a while, but my floaters have now "calmed down" and I hardly notice them any more.

 

Cheers,

 

Ron


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#3 MartinPond

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Posted 06 August 2018 - 12:11 PM

It's the exit pupil, basically.

As it gets small compared to the floaters, the diffraction/light-up gets worse..

 

The smaller eye relief will have other issues, like dust on a tiny final surface,

  but for floaters they will be similar..

Another reason for not puhsing the power too hard, I suppose, unless the aperture is bigger.

 

When it comes to surface floaters, washing and toweling the face can make a massive difference.


Edited by MartinPond, 06 August 2018 - 12:12 PM.

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#4 Aleko

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Posted 06 August 2018 - 12:23 PM

For me it doesn't matter what the eye relief or the AFOV is.  Floaters are a problem the smaller the exit pupil. Whether a 5mm ortho or a 5mm XW or a 5mm Nagler, the problem is the same.

 

As mentioned above, there are two solutions...

 

BINOVIEWER.  It helps. I can use higher power than with just one lens before the floaters get too bad. I guess the brain, to a point, merges the images and allows you to see more detail. But only to a point. Eventually floaters become a problem even with the binoviewer.

 

APERTURE.  After years of going up the ladder with more aperture, the last several years I've been using smaller scopes.  For planetary and lunar, I'm ready to start scaling the ladder again.  More aperture allows more magnification before the image gets too dim. More aperture and magnification means that a pesky floater might only ruin a portion of a planet image instead of the whole thing.  My experience lately is that aperture makes more of a difference on floaters than a binoviewer.

 

Of course, larger aperture with a binoviewer would be best. smile.gif


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#5 25585

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Posted 06 August 2018 - 12:27 PM

Hi everyone! I have tried to find a answer to this question and can't seem to....

 

Do eyepieces with shorter focal lengths but with more eye relief (like an AT Paradigm or BST Flat Field) help with floaters? I have a hard time viewing Jupiter with my 6 and 8mm plossls because of those pesky things. I know that exit pupil is the main thing that affects how annoying the floaters will be and that a telescope's aperture can help with that. I just wondered if more eye relief has any affect too? 

 

I have heard that binoviewing helps with floaters too.

 

Thanks! 

I am not so much troubled by floaters these days, but my eye reflected back onto the eyepiece eye lens surface.

 

Used to own a 13mm Nagler 1 which caused that. Distancing my eye as much as possible helped with both floaters and reflection to some a certain extent. Worth a try.



#6 AstroBruce

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Posted 06 August 2018 - 12:36 PM

16" scope, 200X, 2mm exit pupil. Aaaaah.

 

Bruce



#7 erin

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Posted 06 August 2018 - 12:56 PM

Thank you all for your help! 

 

It's worth trying out all your suggestions...except aperture at this point....

 

No more new scopes for me for a while. Better eye relief eyepieces on the other hand....

 

That being said, 16 inches of aperture does sound like a great solution. waytogo.gif


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#8 buddy ny

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Posted 06 August 2018 - 01:01 PM

Hi everyone! I have tried to find a answer to this question and can't seem to....

 

Do eyepieces with shorter focal lengths but with more eye relief (like an AT Paradigm or BST Flat Field) help with floaters? I have a hard time viewing Jupiter with my 6 and 8mm plossls because of those pesky things. I know that exit pupil is the main thing that affects how annoying the floaters will be and that a telescope's aperture can help with that. I just wondered if more eye relief has any affect too? 

 

I have heard that binoviewing helps with floaters too.

 

Thanks! 

Bino - viewing is he way to go if the floaters are bad

Using my Baader Mark - V,, has fixed , like 90% of my issues with floaters 

my Abbes 4-6mm were the worst. My Nag22mm T4  is the best   when it come to the annoyance of floaters 

peace 

B


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#9 Codbear

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Posted 06 August 2018 - 01:10 PM

It's not just the aperture, but focal length as well if you want higher power without going down to the single digit range. I start to run into floater problems with my 16" f4.5 when I try and use my 8mm Ethos, and have a lot of floaters with my 3-6mm zoom.

 

However, when I use my new Celestron 14" Edge, I get over 2x my bang for the buck in magnification because of the 154" FL. I can use my 17mm Ethos with no floaters, compared to an 8mm Ethos on my 16" with floaters to get the same magnification.


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#10 AstroBruce

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Posted 06 August 2018 - 01:44 PM

It's not just the aperture, but focal length as well if you want higher power without going down to the single digit range. I start to run into floater problems with my 16" f4.5 when I try and use my 8mm Ethos, and have a lot of floaters with my 3-6mm zoom.

 

However, when I use my new Celestron 14" Edge, I get over 2x my bang for the buck in magnification because of the 154" FL. I can use my 17mm Ethos with no floaters, compared to an 8mm Ethos on my 16" with floaters to get the same magnification.

That's great, if it works for you. I've done the same test. I see no difference.

 

Bruce



#11 wky46

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Posted 06 August 2018 - 08:39 PM

I gotta get a pair of binoviewers. Been reading more how they really help

 

Wanna push the mag up so bad on those rare nights 

 

I’d be happy with 200X but <150X is about the max I can reach before the floaters get too noticeable 



#12 Jon Isaacs

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Posted 07 August 2018 - 09:54 AM

It's not just the aperture, but focal length as well if you want higher power without going down to the single digit range. I start to run into floater problems with my 16" f4.5 when I try and use my 8mm Ethos, and have a lot of floaters with my 3-6mm zoom.

 

However, when I use my new Celestron 14" Edge, I get over 2x my bang for the buck in magnification because of the 154" FL. I can use my 17mm Ethos with no floaters, compared to an 8mm Ethos on my 16" with floaters to get the same magnification.

 

At F/4.5, an 8 mm eyepiece provides a 1.78 mm exit pupil,  at F/11, a 17 mm eyepiece provides a 1.55 mm exit pupil.  The focal length of the scope only incidental,  it's really about the exit pupil. 

 

A small exit pupil is a tiny beam and is easily blocked. For a given magnification , a larger aperture provides a larger,  brighter exit pupil.  Binoviewers work because there's a much smaller chance that both eyes will be affected in the same part of the view so the brain can fill in the missing pieces in one eye using what it sees in the other eye .

 

Jon


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#13 Disciplus55

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Posted 07 August 2018 - 11:49 AM

Hi There,

I wrote it down on another thread already, there is one way to actually minimize floaters : don’t look down, don’t tilt your head down, and here is why : eye globes are... globes, covered of liquid, and floaters float on that liquid, and gravity does its job with floaters : they go to the bottom of the globe mostly, so, if you tilt your head down and point your eyes down to the eyepiece, floaters go down, right in front of your retina. If instead you sit, turn the diagonal 90 degrees left or right, and have your eyes pointing horizontal, you will have much less floaters in the way between your retina and the eyepiece... as simple as that ! :)


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#14 Ralph Steudtner

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Posted 07 August 2018 - 01:42 PM

There is only 1 true solution to serious floaters in your eyes. I documented my experience with floater surgery in a thread entitled “Eye Floaters In The Eyepiece” dated April 3, 2014. I am happy to say that 4 years later I am still floater free and my eyesight is better than 20/20. The surgery is not for everyone and does carry some risks, but if your floaters are serious enough as mine were, it is worth considering.
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#15 Starman1

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Posted 07 August 2018 - 01:54 PM

It's not just the aperture, but focal length as well if you want higher power without going down to the single digit range. I start to run into floater problems with my 16" f4.5 when I try and use my 8mm Ethos, and have a lot of floaters with my 3-6mm zoom.

 

However, when I use my new Celestron 14" Edge, I get over 2x my bang for the buck in magnification because of the 154" FL. I can use my 17mm Ethos with no floaters, compared to an 8mm Ethos on my 16" with floaters to get the same magnification.

That doesn't make sense.

The 8mm eyepiece in the f/4.5 scope yields an exit pupil of 1.78mm.

The 17mm eyepiece in the SCT yields a 1.55mm exit pupil.

The floaters problem in the 17mm in the 14" should be worse, not better.

 

Edit: just saw post #12.  obviously on the same wavelength.lol.gif


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#16 Codbear

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Posted 07 August 2018 - 01:59 PM

At F/4.5, an 8 mm eyepiece provides a 1.78 mm exit pupil,  at F/11, a 17 mm eyepiece provides a 1.55 mm exit pupil.  The focal length of the scope only incidental,  it's really about the exit pupil. 

 

A small exit pupil is a tiny beam and is easily blocked. For a given magnification , a larger aperture provides a larger,  brighter exit pupil.  Binoviewers work because there's a much smaller chance that both eyes will be affected in the same part of the view so the brain can fill in the missing pieces in one eye using what it sees in the other eye .

 

Jon

So the question is Jon and Don...why does my 14" Edge show fewer floaters even with a smaller exit pupil?

 

Two possibilities come to mind, and please weigh in on the second one:

 

1. I did not do a side-by-side and have only used the 16" twice since I got my Edge (super convenient with a 

permanent setup), and I simply may have not had as many floaters on the Edge nights.

 

2. My 16" dob GSO mirror is the one in a million jackpot. Rob Teeter told me when I bought the scope used from him that it was an exceptional mirror, and provided the test showing 1/14th wave pv. While I love my new 14" Edge for its convenience compared to the dob (I have a rare muscle disease, so even wheelbarrowing the 16" can be daunting on some nights) as well as what I would call very good optics, it's tough to beat the sharpness of the view through the dob.

 

Both comparisons were made on the Moon at about first quarter. So is it the extra 31% light-gathering power of the dob that illuminates the moon more, showing more floaters, or might it be that I might squint a bit to have to try just a bit harder to see finer Moon detail through the Edge compared to my wide open eyes on the dob, somehow affecting the floaters?


Edited by Codbear, 07 August 2018 - 02:02 PM.


#17 erin

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Posted 07 August 2018 - 03:42 PM

Hi There,

I wrote it down on another thread already, there is one way to actually minimize floaters : don’t look down, don’t tilt your head down, and here is why : eye globes are... globes, covered of liquid, and floaters float on that liquid, and gravity does its job with floaters : they go to the bottom of the globe mostly, so, if you tilt your head down and point your eyes down to the eyepiece, floaters go down, right in front of your retina. If instead you sit, turn the diagonal 90 degrees left or right, and have your eyes pointing horizontal, you will have much less floaters in the way between your retina and the eyepiece... as simple as that ! smile.gif

Thanks for the tip! I will give it a try. 



#18 erin

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Posted 07 August 2018 - 03:45 PM

There is only 1 true solution to serious floaters in your eyes. I documented my experience with floater surgery in a thread entitled “Eye Floaters In The Eyepiece” dated April 3, 2014. I am happy to say that 4 years later I am still floater free and my eyesight is better than 20/20. The surgery is not for everyone and does carry some risks, but if your floaters are serious enough as mine were, it is worth considering.

Hi Ralph, I did stumble on that thread. I am so glad the surgery worked for you! My doc checked out my eyes pretty thoroughly and is not at all concerned. So I won’t consider that route yet, but your experience is very encouraging. It might be that I have had them and started noticing them thanks to using my scopes. I have a group of little circles that are right in the center of my field of view. They are so annoying!



#19 Starman1

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Posted 07 August 2018 - 05:08 PM

The eye is filled with a vitreous humor, the consistency of petroleum jelly.

Floaters are small agglomerations of protein that can form from cells detaching from the retina or any other parts of the eye.

Essentially, small pieces of flotsam and jetsam that are suspended in the viscous material.  They don't necessarily float or fall to the bottom.

In a vitrectomy, where the vitreous humor is removed and replaced with a saline solution, the floaters are removed along with the vitreous humor.

Any new floaters that would detach would likely go to the bottom of the eye due to the lower viscosity of the replacement fluid.

Unfortunately, a vitrectomy is almost immediately followed by the formation of cataracts in the lens, so often a lens replacement is done at the same time as the vitrectomy.

My wife had a vitreal detachment occur that leaves "gauze curtains" to appear in her vision--fortunately not in the center 30° of field.  This puts her at risk for a retinal detachment

and makes her a good candidate for a vitrectomy + lens replacement.  She's waiting until her cataracts progress further.

 

As for floaters and eye relief, there isn't a relationship.

But, for the visibility thereof, I guess it all depends what you view.

Floaters are most visible on the Moon, often visible on the planets, but almost never visible on other objects.


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#20 erin

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Posted 07 August 2018 - 08:38 PM

Thanks for all the info Don. Your poor wife—that sounds rough. I have a friend whose retina either did detach or was very close to it. She is fine now, but what an ordeal.



#21 25585

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Posted 13 August 2018 - 05:17 AM

The eye is filled with a vitreous humor, the consistency of petroleum jelly.

Floaters are small agglomerations of protein that can form from cells detaching from the retina or any other parts of the eye.

Essentially, small pieces of flotsam and jetsam that are suspended in the viscous material.  They don't necessarily float or fall to the bottom.

In a vitrectomy, where the vitreous humor is removed and replaced with a saline solution, the floaters are removed along with the vitreous humor.

Any new floaters that would detach would likely go to the bottom of the eye due to the lower viscosity of the replacement fluid.

Unfortunately, a vitrectomy is almost immediately followed by the formation of cataracts in the lens, so often a lens replacement is done at the same time as the vitrectomy.

My wife had a vitreal detachment occur that leaves "gauze curtains" to appear in her vision--fortunately not in the center 30° of field.  This puts her at risk for a retinal detachment

and makes her a good candidate for a vitrectomy + lens replacement.  She's waiting until her cataracts progress further.

 

As for floaters and eye relief, there isn't a relationship.

But, for the visibility thereof, I guess it all depends what you view.

Floaters are most visible on the Moon, often visible on the planets, but almost never visible on other objects.

I think it depends on the brightness of an object being viewed to an extent. Looking for centre stars in a magnified bright planetary is more exasperating with floaters, for example.


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#22 Ohmless

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Posted 13 August 2018 - 03:07 PM

I was having issues with floaters when using high magnifications with my 4" f/10 refractor.  Since then I have switched to a 6" f/5 with binoviewers and the change was night and day.  No problems with floaters for my anymore(for now).  Maybe if you can't go with a larger scope you can find one that just has a shorter focal ratio or try the binoviewer option if you simply don't want to use lower power eyepieces(inherently a larger exit pupil.)


Edited by Ohmless, 13 August 2018 - 03:09 PM.


#23 erin

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Posted 13 August 2018 - 04:26 PM

Thanks Ohmless! I am definitely thinking of going to binoviewers, especially for planets. The worst for me is Jupiter. I do see them on the moon, but the moon is big enough that I can get around them. The floaters are perfectly placed right over Jupiter, so making out details is tricky at high mags, as you said.


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#24 Paul G

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Posted 13 August 2018 - 04:33 PM

I've had them as long as I can remember. Two prominent ones near the center of my fov look like giant spiders, one in each eye. They are bad enough I have to flick my eyes to the side repeatedly to read the newspaper. The flick is temporary as they float back into their normal position.

 

Some things I've tried:

 

-- binoviewer works great, the brain fills in the missing data with good data from the other eye. When my two spiders superimpose there still is a brown spot so I still have to flick but it is much better than monoviewing.

 

-- Get a retinal surgeon to aspirate them with a fine needle. I have yet to find someone who is willing to take the associated risks for what they consider a trivial problem.

 

-- Pull really high G force to shove them down to a lower permanent position. Roller coaster isn't enough. Tried to hitch a ride on an F15 or F16, couldn't make it happen. Was considering a trip to Russia where cash can get you a ride in a fighter jet but my ophthalmologist discouraged me. He said it would work, but often times a floater may have a filametary attachment to the retina in which case it would rip the retina when the floater was shoved down.

 

-- An ophthalmologist on the net offers to zap floaters with a laser, claims the resulting plasma ball that occurs when the floater is vaporized protects the retina from the laser. Small floaters disappear completely, larger ones are replaced with small fragments. Five years ago he was the only person offering this procedure, today he is still the only one doing it which makes me suspicious; if it were really effective/safe others would be offering the service by now. I asked my ophthalmologist if the guy was a quack and he said no, he went to medical school with him, he's a sharp guy, but the risk of the procedure isn't the laser hitting the retina, it's the shock wave produced by the little "explosion" that whacks the retina and can cause bleeding and/or detachment. He didn't recommend it.

 

-- He told me if I live long enough the vitreous will liquefy and the floaters will sink out of sight. I'm 65, not sure how much longer that will be and if I'll be around to enjoy floater free observing.

 

Like Bette Davis said, getting old ain't for sissies!


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#25 Starman1

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Posted 13 August 2018 - 07:45 PM

"Live long enough" probably means 100 years or more.

My next door neighbor got floaters bad when he was in his 50s.  He's in his 90s now, and he told me they're slowly going away.

Egads.




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