My binos make me sea sick

[Bender]

I struggled for a while with my current binos as they leave me with a distinct feeling of sea sickness when panning around for halve an hour or so.

Now I started to appreciate the flexibility my small 8x42 binos give me so I am now trying to find a model that might be better suitable.

To be fair, I rather susceptible as I don't really get on in cars, boats, planes etc so other people using my Bino's would probably be fine.

What kind of distortion could cause the sea sickness feeling and which model might be good for me to enjoy longer stints under the sky.

[FLO]

Your binocular is misaligned, probably only slightly. 

I don't know which binocular you have so please don't take this as criticism but this is usually a problem with cheap binoculars. When a binocular is clearly misaligned (double vision) you wouldn't even try to use them. But if the misalignment is only slight our eye muscles can pull the image back into line. But doing so causes eye-strain, headaches and even nausea. When you see someone pause when using a binocular to blink and rub their eyes the binocular is probably slightly misaligned. Unfortunately most budget binoculars are misaligned out-of-the-box. 

HTH, 

Steve 

[BinocularSky]

Just to add to what Steve said, you can easily check if it's misalignment by using a different coloured filter over each eyepiece (anaglyph glasses, Quality Street cellophane wrappers (clean!), etc.) to look at the night sky. If the image in each side is a different colour, the visual system thinks they are different objects and doesn't try to merge them. Either that, or defocus the right eyepiece dioptre, so that one side the stars look like big blobs; see if the focused star looks dead centre of the defocussed one (not so good a method, IMO).

Another thing that can cause nausea is "rolling ball" effect -- the image appears to "roll" across the field of view as you pan; it is usually counteracted by introducing a small amount of pincushion distortion into binoculars. Some people are much more sensitive to it than others.

[Bender]

Thanks Steve and Stephen. I just tried the color filter test (blue on the left side and red on the right side)

When looking at a star, closing my eyes and opening them, it seemed that for a fraction of a second the red star jumped considerably to the left side of the blue one.

The defocusing test was more difficult to assess, but when defocusing the right side it seemed the sharp star was more on the right side if the refocused disk

We are talking about my new Leica Trinovids here, so I would be disappointed if they would indeed be out of collocation.

I must say they felt right from the beginning somewhat odd but I couldn't put my finger on it.

[FLO]

We are talking about my new Leica Trinovids here, so I would be disappointed if they would indeed be out of collocation.

They are an excellent binocular so well worth having repaired

[Bender]

Hmm, not sure if I do something wrong. I subjected my new Opticron WP HR 8x42 to the same color filter test and it seems to me that the blue star is doing some jumping and then quickly merging with the red one when opening my eyes.

I don't hope the are not properly collimated as well

[Bender]

Just an update. I repeated the filter exercise today, looking at thin branches. I could not see two separate branches.

Could the split second divergence of the star image last night be more down to my eyes than a faulty bino ?

[FLO]

If you are seeing a view that begins slightly double, but quickly merges into one, that might be your eye correcting binocular misalignment. But Leica Trinovids are well-made premium binoculars and it is possible you have a 'lazy eye' that takes a while to align. I am not confident offering advice on eyesight, I think it best you book an appointment with your optician for a checkup  

HTH, 

Steve 

[BinocularSky]

If the red and blue merge easily, then collimation is probably acceptable. The initial separation may be due to your closed eyes relaxing as if looking at something a different apparent distance away than the binocular image appears. If you really want to check critically, use Pleiades's crossed Bahtinov method, which will even show separation of images even if collimation is not perfect but is well within industry-standard tolerances. Of course, the only reliable way to test if the collimation is within acceptable limits is to use a proper optical bench.

And yes, it could be your eyes , especially if the same thing happens in all binoculars.

(Edit: X-posted with FLO-Steve)

[Bender]

Thanks guys, I notice when changing from left (main observating) to right eye in mono on my telescope that it takes a lot longer with the right eye to focus so it could well be my eyes . But I give the method from Stephens link a go