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#1 xcy

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Posted 24 November 2012 - 02:14 PM

How common is seeing floaters and how does this affect the ability of people at the eyepiece, especially when observing planets or the moon?

#2 csrlice12

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Posted 24 November 2012 - 02:26 PM

The older you are, the more likely to have floaters. Dirt and stuff just get into your eyes over time. I have a few "permanent" floaters in my left eye from laser surgery.

#3 MikeBOKC

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Posted 24 November 2012 - 02:31 PM

Floaters are pretty much universal for folks past 55-60. As our eyes age the vireous matter lining the inside of the eyeball dries some and flakes away. Over time two things usually happen -- you get used to them and your eye's sensory nerves basically tune them out, and they tend to settle out some. The only time to be worried about floaters is if you have a sudden dramatic increase in the number of floaters accompanied by light flashes at the corner of your field of view. That can indicate a possible detached or detaching retina. Otherwise it's all part of aging and most people adapt to them fairly well, with no issues using telescopes, binoculars, microscopes, etc.

#4 kkokkolis

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Posted 24 November 2012 - 02:46 PM

All people have floaters, starting quite early in life. The solution is a larger exit pupil. You still see them but they are reduced in size and obstruct a minimal proportion of the FOV. An exit pupil of 5-1mm or 5-2mm (24-10mm eyepiece for an f/5 system) still provides a lot of options.

#5 FirstSight

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Posted 24 November 2012 - 02:52 PM

How common is seeing floaters and how does this affect the ability of people at the eyepiece, especially when observing planets or the moon?


Having internal floaters inside one's eye is, as others have suggested, in part a function of accumulated internal debris inside people's eyes that occurs with aging (particularly past around 40 to 50 years old).

HOWEVER, the visibility of floaters (which makes them a problem for planetary or lunar viewing) is also a function of how small the exit pupil is that a given focal-length eyepiece produces in a given focal-ratio telescope. Floaters begin to become noticeably visible for a majority of people by around 0.5mm exit pupil size, but the threshold varies from person to person with some having problems by around 0.7mm or so and some able to tolerate even smaller exit-pupils than 0.5mm without significant interference.

The reason problems with floaters are associated with planetary or lunar viewing is that achieving the higher magnifications desired for studying detail often requires using a short-enough focal-length eyepiece that the key ratio:
exit pupil = (eyepiece focal-length) / (telescope f-ratio)
...produces a result near or smaller than 0.5mm. For example, in my Televue NP101 (focal-length 540mm, f-ratio apx. 5.4), a 3.5mm eyepiece gives 154x and an exit pupil of 0.65mm, but a 2.5mm eyepiece, which brings magnification to 216x gives an exit pupil of 0.46mm, which is right on the threshold of causing problems for planetary viewing for me.

THE REASON visible floaters cause such problems, especially for planetary detail, is that the scale of the visible floaters is often similar in scale to the angular size of more detailed features the observer wishes to see by using a magnification that makes them more easily visible, but for the floaters.

#6 DaveJ

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Posted 24 November 2012 - 03:23 PM

How common is seeing floaters and how does this affect the ability of people at the eyepiece, especially when observing planets or the moon?


As others have already mentioned, quite common indeed. However, there is a one-word solution to tremendously reduce their effect: binoviewers! I've got horrible floaters - the result of fifteen eye surgeries including 10,000 laser burns to treat diabetic retinopathy, cataract surgery in both eyes, posterior capsulotomies both eyes and a relatively recent hemorrhage. Now, when I tell you binoviewers can definitely help with floaters, it is a true statement. Without binoviewers I wouldn't be seeing much of anything. The human brain is capable of taking sub-par images from each eye and miraculously creating a composite view that far exceeds that capable from either eye alone. I'm amazed every time I experience the phenomena. :cool:

#7 Starman1

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Posted 24 November 2012 - 04:10 PM

Dave,
The best argument for binoviewers ever.

#8 kkokkolis

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Posted 24 November 2012 - 04:45 PM

That thing about binoviewing and binocular vision in general is absolutely true. The brain diminishes the differences between the two eyes when stacking images.

#9 faackanders2

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Posted 24 November 2012 - 05:54 PM

Floaters are common in high power eyepieces. Need exit pupil of >1mm to get rid of floaters. So normal and low power get rid of floaters, as well as binovieres and binoculars cancel individual eye errors.

See Royal Canadian Handbook eyepiece chapter.

#10 Eddgie

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Posted 24 November 2012 - 08:46 PM

60 Years old and I see floaters at anything smaller than about 2mm exit pupil.

One of the many reasons I prefer a larger aperture for planets is that not only can I get a much brighter for a given magnification, but the exit pupils usually eliminate the issue of floaters.

But since I started binoviewing, I have not really had anymore problem with floaters.

And they work better for planets anyway I think.

#11 faackanders2

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Posted 24 November 2012 - 09:03 PM

60 Years old and I see floaters at anything smaller than about 2mm exit pupil.

One of the many reasons I prefer a larger aperture for planets is that not only can I get a much brighter for a given magnification, but the exit pupils usually eliminate the issue of floaters.

But since I started binoviewing, I have not really had anymore problem with floaters.

And they work better for planets anyway I think.


binoviewers are best for bright objects.

single eyepiece is best for dim and/or wide TFOV or multiple objects.

#12 jeff heck

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Posted 25 November 2012 - 12:45 AM

I have trained myself to observe with my non-dominate eye. No floaters or astigmatism, as well as making the object appear brighter.

#13 Keith

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Posted 25 November 2012 - 12:56 AM

I have some floaters, and have had them for years, I am only 37 and spent a good deal of time out on the water in my late teens-early 20's, without sunglasses. FISH ON! Also had tinitus since I was 17. I learned the best thing to do is protect what is left. I rarely go outside without sunglasses for the last 8 years since I have been back in the hobby, and I have been an earplugs guy for 20 years, I never get near a drummer without them.

#14 xcy

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Posted 25 November 2012 - 03:59 AM

I know the advantages of using a binoviewer, but if one sees floaters when not using any optical aid, why shouldn't see them with a binoviewer?

#15 pogobbler

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Posted 25 November 2012 - 04:43 AM

I know the advantages of using a binoviewer, but if one sees floaters when not using any optical aid, why shouldn't see them with a binoviewer?


As I understand it, viewing with a binoviewer is similar, in a broad sense, to stacking multiple photos to weed the noise out of the signal. The brain can take the signals from each eye and, to an extent, take what's common between them-- the image of the planet-- and discard what's not common-- the floaters, which would be unique to each eye. From my experience with my own binoviewer, this works pretty well.

To me, floaters are a great justification for binoviewing and for using a large aperture, as well, which would give a larger exit pupil for a given magnification as compared to a smaller aperture.

#16 Mirzam

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Posted 25 November 2012 - 07:34 AM

Another vote for binoviewing from someone with severe floaters. Only for lunar and planetary viewing is it really essential. DSO's don't present the same problems. (At least not yet).

JimC

#17 Paul G

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Posted 25 November 2012 - 10:00 AM

I have massive floaters, including a large one in each eye at the center of the fov. Binoviewers are a godsend, but since the two central ones overlap I have to flick them out of the way repeatedly while observing.

I've looked into eliminating them. Pulling high g's can shove them downward, but it would take a ride in a jet fighter to pull enough g's to move them. The risk is that if there is a filamentary connection between a floater and the retina it will cause a retinal tear. I haven't been able to hitch a ride on a US fighter but the Russians sell rides so it can be done.

They can be sucked out through a fine needle, but there are enough potential complications that I have been unable to find a surgeon who would risk it for what they consider a trivial reason.

There is an ophthalmologist who zaps them with a laser. I figured he was a quack since he was the only one doing it five years ago and he still is the only one doing it, but turns out my ophthalmologist knows him well, said he is legit and a pretty sharp guy. Supposedly the plasma ball that forms when the laser vaporizes the floater protects the retina from the laser itself, but my ophth said the problem is the shock wave that whacks the retina, can cause retinal hemorrhage and/or detachment.

Binoviewers are the safest solution.

#18 Eddgie

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Posted 25 November 2012 - 12:36 PM

single eyepiece is best for dim and/or wide TFOV or multiple objects.


Best for you perhaps, but lately I have been doing almost 100% of my viewing with binoviers. On deep sky of course floaters are not a problem, but I find that observing with Binoviewers has become more enjoyable than observing with mono-vision.


So, it is really a personal preference and nothing more. We all get to use what we like best.
Perhaps the view is a bit dimmer, but I find it much more immersive than mono-vision.

#19 faackanders2

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Posted 25 November 2012 - 01:46 PM

single eyepiece is best for dim and/or wide TFOV or multiple objects.


Best for you perhaps, but lately I have been doing almost 100% of my viewing with binoviers. On deep sky of course floaters are not a problem, but I find that observing with Binoviewers has become more enjoyable than observing with mono-vision.


So, it is really a personal preference and nothing more. We all get to use what we like best.
Perhaps the view is a bit dimmer, but I find it much more immersive than mono-vision.


If you cant find/see the dim object with binoviewers, try single eyepiece and you may be able to see it. Or select an object you can just barely see in binoviewers and notice how much brighter it is with single eyepiece.

Agree 100% bright objects look great in binoviewers with dual eye advantage.

#20 Sarkikos

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Posted 25 November 2012 - 02:13 PM

Keith,

I have some floaters, and have had them for years, I am only 37 and spent a good deal of time out on the water in my late teens-early 20's, without sunglasses. FISH ON! Also had tinitus since I was 17. I learned the best thing to do is protect what is left. I rarely go outside without sunglasses for the last 8 years since I have been back in the hobby, and I have been an earplugs guy for 20 years, I never get near a drummer without them.


Protect your eyes and protect your ears. Good advice for anyone at anyone age.

I have some tinitus, probably from standing too close to jack-hammers when I was younger. But luckily at 56 I still have excellent hearing ... maybe because I never went to a rock concert and always hated loud music? :thinking:

I have floaters in both eyes, which make observing bright objects at much less than 1mm exit pupils irritating. Yes, binoviewers help. Another good idea is to keep the eyes as close as possible to photopic when viewing the planets and Moon. Look at the reflection on a white sheet of paper from a bright white flashlight every so often when observing. That will do wonders for visual acuity, so you won't need to bump up the magnification so much, and can get by with a wider exit pupil.

On the other hand, when I'm looking at deep sky objects - or planets when less than about 7 arcsec - I don't notice eye floaters. Then I can push the power higher.

For the last ten years or so, I've been wearing sunglasses everytime I step outside. My eyes can still deeply dark adapt and the pupil can dilate to over 7mm. One of the worst things amateur astronomers can do to their eyes is go outdoors without wearing good sunglasses.

Mike

Disclaimer: Don't use white light when viewing deep sky objects and never use a white light at a dark site! :rules:

#21 Eddgie

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Posted 25 November 2012 - 03:27 PM

I do not at all dispute what you say. I have been observing for 40 years and have owned 40 or so telescopes and dozens and dozens of eyepieces, and of course I know that I am loosing a bit of brightness with the Binoviewers.

But I like the view better.

A year ago, I would not have wanted to believe that binoviewing could be more enjoyable, but now I find much less joy in mono-viewing.

Is the view "better" in mono? Maybe for you, but no longer for me. I don't think I could go back now.

#22 DaveJ

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Posted 25 November 2012 - 04:31 PM

Is the view "better" in mono? Maybe for you, but no longer for me. I don't think I could go back now.


A big giant +1

#23 sopticals

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Posted 25 November 2012 - 06:57 PM

I know the advantages of using a binoviewer, but if one sees floaters when not using any optical aid, why shouldn't see them with a binoviewer?


To me, floaters are a great justification for binoviewing and for using a large aperture, as well, which would give a larger exit pupil for a given magnification as compared to a smaller aperture.


Absolutely :bow: true.

#24 Sarkikos

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Posted 25 November 2012 - 07:40 PM

My personal preference is to binoview only the Moon and bright planets. For deep sky, I use three types of eyepiece: Baader Hyperion Zoom for most objects, to dial in the optimum image scale and perceived contrast; wide fields for the big stuff or large groupings of objects; mostly orthos and such for the really faint fuzzies. But the Baader Zoom is in the focuser most of the time.

I don't binoview deep sky. I've never seen floaters when observing anything other than the Moon and bright planets. For me, binoviewing DSO dims the image too much. But that can be a good thing when looking at planets and the Moon.

Mike

#25 Ed D

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Posted 26 November 2012 - 09:12 AM

+1 for binoviewers mitigating floaters, especially for planetary and lunar.

Ed D






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