Help: What binocular eyepiece correction should I use?

I can't work out what eyepiece correction to use on my binoculars.

I think the binoculars are a bit crap and have some play in the
front-back position of the eyepieces. If I can made a nominally
correct setting then the slight movement would occur around that
correct value.

My spectacles prescription is quite astigmatic:
(R) -0.25 -3.00 x5 (L) -0.75 -3.50 x175
For reading add 1.00

What dioptre correction setting should I use on the right eyepiece?

Thank you.

Chris


-----

If the actual binoculars make any difference to this, then here are
the binoculars I would use the correction on. I don't wear
spectacles when using the binoculars.


8x30 porro prism
10x50 porro prism

9x21 roof prism

Chris S <(E-Mail Removed)> wrote in news:Xns9AAE845658262451E7A@
127.0.0.1:

> What dioptre correction setting should I use on the right eyepiece?
>
> Thank you.
>
> Chris
>

1- Focus the eye that does not offer diopter correction.
2- Adjust the correction on the other eye so what you see is in focus.



--
Scott
Reverse name to reply

"Mike Tyner" <(E-Mail Removed)> wrote in
news:(E-Mail Removed) :

>> What dioptre correction setting should I use on the right eyepiece?
>
> I think the technical answer is about +0.75 but it's almost
> negligible, compared to 3 or more diopters of uncorrected astigmatism.
>
> Scott's right. Better to set it empirically. The markings could be
> off, the prescription could be off, and you might not prefer the exact
> center of Sturm's interval when you focus.
>
> -MT, OD
>
>
> "Chris S" <(E-Mail Removed)> wrote in message
> news:Xns9AAE845658262451E7A@127.0.0.1...
>>I can't work out what eyepiece correction to use on my binoculars.
>>
>> I think the binoculars are a bit crap and have some play in the
>> front-back position of the eyepieces. If I can made a nominally
>> correct setting then the slight movement would occur around that
>> correct value.
>>
>> My spectacles prescription is quite astigmatic:
>> (R) -0.25 -3.00 x5 (L) -0.75 -3.50 x175
>> For reading add 1.00
>>
>> What dioptre correction setting should I use on the right eyepiece?
>>
>> Thank you.
>>
>> Chris
>>
>>
>> -----
>>
>> If the actual binoculars make any difference to this, then here are
>> the binoculars I would use the correction on. I don't wear
>> spectacles when using the binoculars.
>>
>>
>> 8x30 porro prism
>> 10x50 porro prism
>>
>> 9x21 roof prism
>>
>
>


The the astigmatism, you might prefer binocs with good eye relief, so you
just wear your glasses.


--
Scott
Reverse name to reply

Mike Tyner wrote:
>> What dioptre correction setting should I use on the right eyepiece?
>
> I think the technical answer is about +0.75 but it's almost negligible,
> compared to 3 or more diopters of uncorrected astigmatism.
>
> Scott's right. Better to set it empirically. The markings could be off, the
> prescription could be off, and you might not prefer the exact center of
> Sturm's interval when you focus.

Wouldn't you say +.50? Then adjust focus empirically?

Dave

On Fri 30 May 2008 15:29:01, Mike Tyner wrote:
>>
>> What dioptre correction setting should I use on the right
>> eyepiece?
>
> I think the technical answer is about +0.75 but it's almost
> negligible, compared to 3 or more diopters of uncorrected
> astigmatism.
>
> Scott's right. Better to set it empirically. The markings could be
> off, the prescription could be off, and you might not prefer the
> exact center of Sturm's interval when you focus.
>
> -MT, OD
>


Mike, I wish it were so straightforward as just setting the eyepiece
correction empirically. Unfortunately, there seems to be too much play
to keep a setting.

It's hard, until I make further eyepiece adjustments, to know if the
image was as good as it could have been. After I have made that
adjustment then movement due to play is probably close to max!

I guess I'll try +0.75 (or +0.50 as suggested by Dave Bell) and then
vary the setting a little.

On May 30, 8:00*am, Chris S <defa...@default.invalid> wrote:
> I can't work out what eyepiece correction to use on my binoculars.
>
> My spectacles prescription is quite astigmatic:
> * (R) -0.25 -3.00 x5 * (L) *-0.75 -3.50 x175 *

If you want clear vision you will need to get eye relief shields on
the eye piece and wear your glasses. Your problem is the large amount
of astigmatism and binoculars can only be adjusted for sphere, which
is minimal in your case compared to the astigmatism.

Dr Judy
(Birder/sailor with astigmatism who always wears her glasses with
binos)