Would binoviewers be useful?

[Merlin999]

I have mentioned before that my eyesight is not great with areas of my retina being damaged. I do find it hard to see faint light so I was wondering whether binoviewers would help by delivering light to both my eyes.

My youngest daughter also said she finds it uncomfortable just viewing with one eye.

But I am not sure how they work, especially in terms of EPs. Do they just sort of sit on top of the EP?

Do you think binoviewers would help me? If so are there better makes than others out there? Any idea how much I would have to pay?

Thanks in advance.

Stephanie

[Rusty Strings]

I'm sure binoviewers would improve your view, the downside is that they fit between the focuser and eyepiece and as a result you have to have two indentical eyepieces.

[pvaz]

I have not used a Binoviewer so I can't advice on that. However there are a few cheap options to improve observing with one eye. The main thing is to observe with both eyes open and cover the eye you're not using. I find that when you close one eye you squint the other and this causes the view to become much worst.

So here are the options:

1) Cover the other eye with your hand.

2) Use a pirat "thingy" (can't name it in english but this is what I mean )

3) Use a large black cloth or towel. It cuts any stray light and you can pull one side closer to the eye you're not using. Just remember to leave a bit of an opening so your breath won't fog the EP.

I tried all but now use the 3rd method which I find more efficient. Without any exaggeration, I found that observing with both eyes open improved my views greatly then investing out on expensive EPs. (Of couse if you can do both then the better. )

[weso]

i got one of those big furry hats with ear flaps, i just turn it sideways on almost so one of the flaps covers an eye. nice and warm also

[Merlin999]

Thanks pvaz and Weso, I'll try covering my eyes with a towel or something similar safe in the knowledge that I'm not going to look too silly.

Hi Rusty springs, I am sorry to be such a newbie but I don't really follow how the binoviewer would use two EPs. Unless the binoviewer slots into the scope with no EP, and then the two EPS fit within the binoviewer, one in each side leading to each eyepiece in the binoviewer if you see what I mean?

Stephanie

[oldfruit]

That`s exactly how it works. you put the binoviewer in first, then 2 eyepieces of the same focal length, so you look through like you would with binoculars

[Trevor-Austin]

I used to have binoviewers but didn't find them as good as a single eyepiece surprisingly. Much easier on the eye and eyestrain though!

[Merlin999]

Thanks Oldfruit. Yikes, I managed to presuade hubby to buy one Revelation EP set which was over my budget (though a great buy), but I think I have zip chance of persuading him to let me get two sets. So some new EPs and a binoviewer will set me back, gulp, that much. Hmm may have to scratch the idea of binoviewers....

Trevor, after what I've just said, glad I was to read your post to say you didn't find them terribly good.

Maybe when I win the lottery (which is unlikely as I never do it) I'll buy some new EPs and a binoviewer. Until then, I think I'll try the towel method. Much cheaper and proof that Douglas Adams was right about the usefulness of towels.

Stephanie

[Trevor-Austin]

That might have been part of my problem, I didn't have quite as good pairs of eyepieces as I did singles.

And they were only the Antares binos so that probably had an effect on quality too.

[astroimpulse]

i got one of those big furry hats with ear flaps, i just turn it sideways on almost so one of the flaps covers an eye. nice and warm also

Genius!

Like pvaz I use a cloth but the hat idea is quality Two for the price of one

[Merlin999]

I've just realised weso I already have a furry hat with flaps. I'll save my towel for other purposes and try out your hat idea next time! And my youngest daughter also has a hat like that so hopefully that should make it easier for her, though she does also have a pirate eyepatch from an old Halloween costume (thanks pvaz) which would also do the trick!

Goodness knows what our neighbours are going to think!

Thanks weso.

Stephanie

[The Warthog]

I suffer from diabetic retinopathy, and have had more than 16 laser sessions, as well as having both lenses replaced, and I suffer from Grave's disease which gives me vertical double vision and made the use of binoculars impossible until the doctors sorted out a pair of glasses for me. I'm about 1.5 mag behind everyone else in being able to see stars. On top of that I live in an area that is almost as light polluted as downtown Toronto, and I don't Know why I bother some nights.

I have found that the brain does a pretty good job of covering those parts of the visual field that are missing. when I am looking through any of my scopes I see lots of interesting stuff, but I have found that younger, experienced observers can see things in my own scope that I cannot. The Leo triplet is a case in point; I could only barely make out two of the three. Still, when I am looking at something reasonably bright, it looks marvellous.

The binoviewer is an expensive solution to the problem. if you want a full range of eps you must buy two of each, and unless you have unlimited funds this will limit the quality of your ep choices. Also, if you wish to add 2" eps you will be back to one eye. You can get variable Barlow and a filter slide for the binoviewer, but again, ££. Also, the binoviewer delivers half thelight from the objective to each eye, so that while you do derive some advantage from using both eyes you ultimately have no more light. I got a lot of this gen from a long discussion with a Denkmeier salesman a few years ago.

The solution I have decided upon is raw aperture, which is why I have an 11.5" mirror sitting on my bookcase waiting for me to build a telescope around it. 1f you increase the diameter of your scope by half, you gain a magnitude. It may be less expesive to double the size of your objective than to buy all the things you need to add a binoviewer, at least if you have a dob.

You can reduce the discomfort of using one eye by covering the other or if your back garden is dark, by just not closing the other eye.

Good luck with whatever you decide.

[Merlin999]

Thanks Warthog that was a very informative post and I really appreciate you telling me about your eye condition.

I have retinitis pigmentosa which progressively kills cells in the retina. This leads to large gaps in my field of vision. Another issue is that when the cells are dying, they give very bright flashing lights which my brain manages to mostly ignore though I have little vision in bright sunlight and also little in the dark. The flashing lights are really annoying when looking through the telescope.

This is why I rely on my hubby to steer the telescope for me. He is also able to see much fainter objects through the scope than I am. Though I do manage to get fantastic views of Jupiter.

Interesting that only the same amount of light is delivered when you add a binoviewer. I was wondering that since the damage to my eyes is not symmetrical and as you say the brain does a marvellous job trying to fill in the blanks, whether providing both eyes with light would let my brain construct a fuller picture.

However, I think all this wondering may be slightly moot anyway as I hadn't realised you need two sets of EPs which makes the cost prohibitive for me.

I think overall it isn't worth it for me. Thanks everyone for the advice.

Stephanie

[glowjet]

Stephanie, try taking one lens of an old pair of dark sunglasses out and try that, might help you keep both eyes open.

John.

[Merlin999]

Thanks John. I'll have a hunt around and see if I can find an old pair of sunglasses: I'm sure I have some somewhere.

Stephanie

[The Warthog]

Stephanie, try taking one lens of an old pair of dark sunglasses out and try that, might help you keep both eyes open.

John.

What a superb Idea! I think I'll share that one around. You could even paint over the lens.