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basic binos stuff please (1 Viewer)

jape

jape

Well-known member
new to birding and binoculars i have been reading the threads but most is way beyond what i want to know.

1. mine have a knurly wheel for focus, works fine
2. they also have an adjuster on RH eye which i assume of course equates diferent eyes!

question, if i set 2., the RH eye should it stay set if i alter 1.

In other words if the RH eye seems to lose that tuning as i do 1.,, is it natural eye effect or, if as i assume whatever the final focal distance is, the relative difference in the binoculars would stay same, does it mean the binoculars need some other fixing.

ahem, well, seems i explained it ok, you tell me!
 
Well, the usual process is to focus on something (perhaps 30' away or more) with only the left eye, (right eye shut) using the focus wheel. The binoculars will now be focused for that eye.
Then, close your left eye, and adjust the dioptre (the individual adjuster on the right hand barrel) to get your right eye in focus (on the same object, naturally)
Any differences between your eyes should now be catered for, and when you open both eyes - voiia!! Hopefully.....
 
Jape,

Sounds like you have a normal focal control setup:

The large centered focus wheel (1) adjust both left and right barrels equally.
The right adjuster (2=Diopter) controls focus of just the Right barrel.

If your binos are working properly, you should be able to make the following focal steps to get an equal overall focused view:

A. Pick a static target around 10 to 20 meters away (road signs, license plates, large text, leaf details, etc.)
b. Using the large focus knob (1), adjust for a sharp focus in the left barrel (helps if you block the right barrel view).
c. Without touching the large focus knob, use the right barrel diopter adjuster (2) to get a sharp focus in the right barrel (helps if you block the left barrel view).
d. Check your normal binocular view to determine equal focus clarity on the same target.
e. If all are working and set properly, the large focus knob should now give you an equally sharp focus from any target that is close or far away!

If you are following these steps and are still having issues getting a consistent equal focus, then you may have problems with either of the focus mechanisms. What brand and model of binoculars are you using?

Ted
 
thank you both. my bad explanation, sorry.

i get very good focus and dioptre adjustment
sometimes though after that, when i alter the large focus wheel, the focus in my right eye has drifted.
i wondered if that was usual, to have to adjust dioptre regularly.
happy to do so.
 
Can be down to the type of binocular, some porro prisms, those with the front lenses offset from the eyepieces, with the eyepieces joined by a bridge, sometimes can focus unevenly if the bridge is slightly wobbly. Those claiming to be waterproof can be particulary prone to this.

If it isn't mechanical then if your binoculars are badly adjusted to the width between your eyes, any slight movement of the binoculars can change the apparent focus of one eye. It happened to me yesterday (my excuse - I was in a hurry).

These are the 2 most common reasons I have encountered - there are bound to be others.

It might help if you name the binoculars you are using, I have inexpensive binoculars that cost well under £100 that function perfectly, so cost on its own (within reason) shouldn't be a factor.
 
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hi. they are inexpensive camlink langham 8x25 and i love 'em. light, easily adjustable and perfect for my situation.

the dioptre adjustment changing as i used the centre focus was all i had noticed as it takes time and that means lil birdie sometimes gone. i think it maybe i hold them badly.

i will try holding them differently so i can be sure it isnt inadvertently altered by me.

they are straight line design and get up to the eye quickly, i will keep my right hand away from the dioptre adjuster now. thanks again all.
 
Jape I have taken a look at a pic of these binos and it looks as though the very prominent dioptre adjusting ring might be quite easy to accidentally move. If you find this is happening you could try putting a big rubber band around it, wrapping it around several times with the first wrap on the ring and the next wraps progressively onto the barrel below. Plastic adhesive tape like insulation tape would also work but would be a right faff to shift if you needed to adjust the dioptre again whereas you could pull the rubber band to one side or just take it off and then replace it after the adjustment. The only downside to the rubber band is that it might be easy to shift the ring and alter your setting when you are wrapping the rubber band around it.

Lee
 
With internal focus binoculars, particularly cheap ones there is stiction often in one barrel. Some never give good focus.

Even the common 50mm Chinese monoculars in 10x, 12x, 15x and 20x suffer this and are difficult to focus.
They are available in 8 or more brands for identical products.
Despite the glowing ads that most of them are high class optics.
They aren't and some have astigmatism also.

I have a Helios AM something roof prism binocular which also does this.

Normally, high class binoculars have fewer problems regarding focus and diopter issues.
But not always.

P.S.
At such a low price I am surprised they work at all.
What I have done with such binoculars is to go through 20 looking across the road, and buy the best 3 and let other people buy the fair and the bad ones.
 
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thankyou binastro. i had no preconception about binos as i was happy years ago with $10 plastic ones for what i wanted. (redhead down the road ... no, actually hunting with bow to just tell details of ground).
now i am watching birds these are remarkable and suit me very well for purpose. they gather good light so i can identify colours which are not there for naked eye. when i get them just right the image leaps at me in 3D with clarity. i am certainly very happy with them. i think i had a bad grip that meant as i folded them slightly in or out my finger was turning the dioptre knurl.
i cannot imagine paying thousands when these are so good for what i need, backyard and across the park.
 
Lee, grip adjustment has done the job but if it re-occurs i shall try your idea, thank you.
i had already got into habit of left hand focus but now use right and that has cured it.
 
Maljunulo said:
At the risk of being labeled an insufferable snob, the problem with cheap optics is that they are.
Click to expand...

“There are good optics and there are cheap optics but there are no good, cheap optics.”—Leif Robinson, former editor of S&T magazine

Bill
 
there are good redheads and there are cheap redheads but there are no good, cheap redheads.
actually, that is wrong but i thought i would transmogrify the concepts to explore the logical semantics.
i conclude you are wrong.
and i have a pair of good, cheap optics as well
now one day i may enjoy superlative examples if i am fortunate
afterall, everything is relative (except redheads who shouldn't be related) to experience, need and fortune.
 
some weird bloke very kindly sent me some reading about 'focussing'.
simple, straightforward and commonsense that has that extra unwritten verity you perceive from the words that only comes from honest experience and a form of misunderstood modesty hidden by brash humour.
applied
success
thank you
 
paddy7 said:
So i take it you're sorted, right?;)
Click to expand...

yes thank you. learned a lot very quickly thanks to help from people here.

next question: the image is not perfectly round or oval when comfortable with my eyes.
i assume this is my head shape/measurement across eyes?
the centre of the image is good, crisp and even has enough depth of field to give an almost 3D effect but the edges are figure of eight and blurry not that it worries me as what i see is all sharp within effective vision area. just wondering if other binocular types or designs give a wider view so a shift of eye rather than binos sees more. i would be happy to pickup the terminology so please correct me.
 
jape said:
yes thank you. learned a lot very quickly thanks to help from people here.

next question: the image is not perfectly round or oval when comfortable with my eyes.
i assume this is my head shape/measurement across eyes?
the centre of the image is good, crisp and even has enough depth of field to give an almost 3D effect but the edges are figure of eight and blurry not that it worries me as what i see is all sharp within effective vision area. just wondering if other binocular types or designs give a wider view so a shift of eye rather than binos sees more. i would be happy to pickup the terminology so please correct me.
Click to expand...

This is caused by curvature of field. The image may start getting soft 1/3 to ½ the distance off axis. Sometimes the image may hold together all the way to the edge of the field. The aberration can only be corrected by greatly stopping down the system or in using an inverse aberration know as ... $$$$!

Bill
 
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