Diopter setting (1 Viewer)

Roy C · Mar 23, 2019

On my recent eye prescription for distance glasses my right eye is +1.75 and my left eye is +2.25 (meaning my right eye is stronger by 0.50 I think). Does this mean that in theory the Diopter setting on my Binos should be minus 0.50 to compensate for the right eye being stronger than the left?

WJC · Mar 23, 2019

Roy C said:
On my recent eye prescription for distance glasses my right eye is +1.75 and my left eye is +2.25 (meaning my right eye is stronger by 0.50 I think). Does this mean that in theory the Diopter setting on my Binos should be minus 0.50 to compensate for the right eye being stronger than the left?

Nope. Your dioptric strength changes throughout the day. It is a good baseline but is affected by fatigue, alcohol, caffeine, drugs, and even water.

It is imperative that you learn to STARE and let the bino do its job. Focus until it is sharp for you—while just staring—and note your dioptric settings. You may use that as a STARTING POINT in the future. The numerals should matter a lot less than the ACTUAL focus. Very few diopter scales are accurate, anyway. :cat:

Bill

Roy C · Mar 23, 2019

WJC said:
Nope. Your dioptric strength changes throughout the day. It is a good baseline but is affected by fatigue, alcohol, caffeine, drugs, and even water.

It is imperative that you learn to STARE and let the bino do its job. Focus until it is sharp for you—while just staring—and note your dioptric settings. You may use that as a STARTING POINT in the future. The numerals should matter a lot less than the ACTUAL focus. Very few diopter scales are accurate, anyway. :cat:

Bill

Thanks for that Bill. Does that mean that you should keep checking the diopter setting each time you go out ?
What exactly do you mean by learning to STARE :eek!:

PYRTLE · Mar 23, 2019

As the man says, it can vary from day to day. I'm diabetic and the diopter settings can change from birding first thing in the morning through to say again late afternoon. Some days the binos just snap into sharpness, whereas others they just wont work. I use a Zeiss FL 8 x 32 most of the time. Also, whether you choose to wear spectacles or not when using optics, makes a difference, well, certainly to me.

Roy C · Mar 23, 2019

PYRTLE said:
As the man says, it can vary from day to day. I'm diabetic and the diopter settings can change from birding first thing in the morning through to say again late afternoon. Some days the binos just snap into sharpness, whereas others they just wont work. I use a Zeiss FL 8 x 32 most of the time. Also, whether you choose to wear spectacles or not when using optics, makes a difference, well, certainly to me.

Thank you, although I have prescription glasses for driving I cannot see any difference with glasses on or off when using Binos so do not bother wearing them out in the field.
Also I have tried setting the diopter at say + 1 and -1 and cannot tell any real difference, it all looks sharp to me once in focus. BTW I am using a Swaro 8x32.

WJC · Mar 23, 2019

Roy C said:
Thanks for that Bill. Does that mean that you should keep checking the diopter setting each time you go out ?
What exactly do you mean by learning to STARE :eek!:

You realize, of course, if I tell you this, I’m gonna hafta killya! That’s okay, though, we have a profusion of Brits, anyway.

— I think the attachments will explain much of what you want to know.
— Suppose you’re looking at a killdeer at the edge of your yard and then go to the pterodactyl a half mile away. You will probably note that your focus had to change quite a bit and that the numerals are as useful as a steering wheel on a stone.
— Many people think those diopter settings are supreme and, because of your prescription, that’s what their bino should be set to ... wrong! Those settings change with distance—and several other factors—and unless you’re buying into all that “autofocus” crap, you need to rely on the actual focus, regardless of the numerals.

Finally, I’m too tired to killya myself. How about I send Guido and the boys over around 4:00 p.m., tomorrow. Will that work for you? :cat:

Bill

Roy C · Mar 23, 2019

WJC said:
You realize, of course, if I tell you this, I’m gonna hafta killya! That’s okay, though, we have a profusion of Brits, anyway.

— I think the attachments will explain much of what you want to know.
— Suppose you’re looking at a killdeer at the edge of your yard and then go to the pterodactyl a half mile away. You will probably note that your focus had to change quite a bit and that the numerals are as useful as a steering wheel on a stone.
— Many people think those diopter settings are supreme and, because of your prescription, that’s what their bino should be set to ... wrong! Those settings change with distance—and several other factors—and unless you’re buying into all that “autofocus” crap, you need to rely on the actual focus, regardless of the numerals.

Finally, I’m too tired to killya myself. How about I send Guido and the boys over around 4:00 p.m., tomorrow. Will that work for you? :cat:

Bill

So if I am reading it right then you should re-check your diopter setting if shooting from a big different distance from that which it was set (or if I had a bad nights sleep or a few strong coffee's or a maybe a beer or two :-O) If this is so then I will be spending more time checking and adjusting the diopter setting than actually watching the birds :-C
Thanks for your help anyway Bill, Guido and the boys will not be needed.

WJC · Mar 23, 2019

Roy C said:
So if I am reading it right then you should re-check your diopter setting if shooting from a big different distance from that which it was set (or if I had a bad nights sleep or a few strong coffee's or a maybe a beer or two :-O) If this is so then I will be spending more time checking and adjusting the diopter setting than actually watching the birds :-C
Thanks for your help anyway Bill, Guido and the boys will not be needed.

Hi, Roy:

Nope. Don't over think it; everything on the bino need not be quantified. Problems sought after will ALWAYS be found. Let them find you! It's their job. :cat:

Bill

PYRTLE · Mar 23, 2019

Not really, in use, I'd look through the bins in the morning and only adjust the dioptre if I didn't "feel" the image was crisp and bang on. If required I'd adjust accordingly and then lock it in for the rest of the day and just use the main focus wheel.

jring · Mar 23, 2019

Hi,

same here, often when I grab a pair which I had used some days ago, the image is not quite right and when I check the diopter setting, i.e. if the image is sharp for each eye, it's off a little bit - which is quickly corrected.

Joachim

WJC · Mar 23, 2019

PYRTLE said:
Not really, in use, I'd look through the bins in the morning and only adjust the dioptre if I didn't "feel" the image was crisp and bang on. If required I'd adjust accordingly and then lock it in for the rest of the day and just use the main focus wheel.

Your dioptric settings change in tandem ... NOT independently! Once set, the center wheel is ALL you should need for any distance.

Bill

NDhunter · Mar 23, 2019

Roy:

Tell us, are you wearing your glasses when viewing ? I did not see that above. So if so, your
correction should help equalize the diopter, but when viewing without glasses you will have to adjust
of course.

Jerry

PYRTLE · Mar 23, 2019

Jerry,
Post # 5 suggests glasses not used when using binoculars.

WJC · Mar 23, 2019

PYRTLE said:
Jerry,
Post # 5 suggests glasses not used when using binoculars.

Dioptric problems alone ... no.
MILD astigmatism ... maybe.
Strong astigmatism ... always.

Being fascinated by the study of optics since the age of 8 and aligning my first bino for money at 19 it is sometimes easy for me to forget that which is sub-basic for me may be a new or strange concept for others. :cat:

Bill

Steve C · Mar 23, 2019

As regards staring, what I have always done is routinely forced my eyes to relax. You can feel a palpable relaxation effect along your temples and over the scalp. Often times when comparing two or more binoculars, or when the diopter is not yet just right, or if the collimation is maybe a bit off, or maybe when a binocular and your eyes are not going to play well together, our eyes take over and try to arrange the view. Often the stress is related to poor conditions for viewing, or maybe I just don't feel real well, the stress will really tighten up the facial muscles associated with eye movement. After a while, just stopping every so often and forcing my eyes to relax seems to work. Maybe just keeping relaxed is equivalent to just staring.

WJC · Mar 24, 2019

Steve C said:
As regards staring, what I have always done is routinely forced my eyes to relax. You can feel a palpable relaxation effect along your temples and over the scalp. Often times when comparing two or more binoculars, or when the diopter is not yet just right, or if the collimation is maybe a bit off, or maybe when a binocular and your eyes are not going to play well together, our eyes take over and try to arrange the view. Often the stress is related to poor conditions for viewing, or maybe I just don't feel real well, the stress will really tighten up the facial muscles associated with eye movement. After a while, just stopping every so often and forcing my eyes to relax seems to work. Maybe just keeping relaxed is equivalent to just staring.

Hi, Steve:

BINGO!

I just tell folks if they want to enjoy a nice, trouble-free image, stop whining and learn. :cat:

Bill

PS would you post a PDF on CN for me?

Steve C · Mar 24, 2019

Bill,

PM sent

WJC · Mar 24, 2019

Steve C said:
Bill,

PM sent

Roger that.

BC

Troubador · Mar 24, 2019

I am diabetic like Pyrtle and occasionally find that I need to readjust the diioptre. I wear spectacles all the time because although I can see fine through the binos without them my long distance vision isn't good enough to find all the subjects I want to point the binos at. Also, being a little astigmatic I do need some correction for this so it does improve the view via the binos although for me not significantly. Keeping the spectacles on all the time minimises inconvenience and maximises performance. Being aware of necessary changes in the dioptre setting just adds to this but I only attend to this if I find the view demands it, I don't routinely repeat the dioptre unless I feel I need to.

Lee

Roy C · Mar 24, 2019

Thank you for all the comments folk, all good stuff :t::t::t:
Just to clarify, I have no problem with viewing through my Binos or the diopter setting. Being a newby to the world of binoculars (well decent ones anyway) I was just just curious if there was any correlation between the diopter on a pair of binos and a eye prescription.

The one thing I have gleamed from all the postings is that it is not just a case of setting the diopter and forgetting it as a lot of stuff on the web would suggest. Being a bird photographer it makes complete sense to me that light level and distance can make a difference.

p.s went out with my heavy birding camera gear yesterday (worn bandoleer fashion) and my Binos around the neck and the set-up was great. Thanks again for all your help guys.

Diopter setting (1 Viewer)

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