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greater contrast and colour depth with eyes away from eyepiece (1 Viewer)

SeldomPerched

Well-known member
Can anyone explain this? It may be something you all know already and I'm just late to the party.. I could have posted this in any make of bins forum but since I first noticed it with the 8x42 SLC that I have been using for the last month or two, the Swarovski forum gets the honour...

The discovery is a simple one but a not too technical or mathematical explanation would be nice to have. Regardless of how far in or out the eyecups are adjusted, I noticed that by moving my face and eyes back a bit, so there in an inch or so gap between me and the eyecups, the colour becomes more saturated, more contrasty. It looks as though veiling glare is introduced when my eyes are closer to the instrument. This is regardless of how I normally place the bins to my face, i.e. brow or eyesockets. By introducing some extra distance in the form of a gap, the magic happens.. and as mentioned the amount of 'screw-out' of the eyecups does not affect this.

After this accidental discovery I tried the same with a pair of something quite different, Zeiss 8x32 T*FL and got the self-same effect.

Why?

Tom
 
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giosblue

Well-known member
Can anyone explain this? It may be something you all know already and I'm just late to the party.. I could have posted this in any make of bins forum but since I first noticed it with the 8x42 SLC that I have been using for the last month or two, the Swarovski forum gets the honour...

The discovery is a simple one but a not too technical or mathematical explanation would be nice to have. Regardless of how far in or out the eyecups are adjusted, I noticed that by moving my face and eyes back a bit, so there in an inch or so gap between me and the eyecups, the colour becomes more saturated, more contrasty. It looks as though veiling glare in introduced when my eyes are closer to the instrument. This is regardless of how I normally place the bins to my face, i.e. brow or eyesockets. By introducing some extra distance in the form of a gap, the magic happens.. and as mentioned the amount of 'screw-out' of the eyecups does not affect this.

After this accidental discovery I tried the same with a pair of something quite different, Zeiss 8x32 T*FL and got the self-same effect.

Why?

Tom

The SLC I bought came with the Swarovski winged eyecup. The previous owner reckons they have a huge effect, much better. What you are experiencing is the opposite. You're letting more light in. I don't know, if it works for you, go with it.
 

SeldomPerched

Well-known member
The SLC I bought came with the Swarovski winged eyecup. The previous owner reckons they have a huge effect, much better. What you are experiencing is the opposite. You're letting more light in. I don't know, if it works for you, go with it.

Strange, isn't it? It certainly isn't an ideal hold to keep the bins steady with just hands in contact. I discovered it by accident. I just wish I could undiscover it!

Tom
 

elkcub

Silicon Valley, California
United States
Tom,

In normal use, a binocular is designed for the exit pupil to be placed coincident with the eye's pupil. When the instrument is separated from the eye's pupil, light rays coming from the outer edge of the binoculars' eye lens are cut off which results in the field of view being reduced and the remaining rays restricted to the center where there are fewer aberrations. You observed some of the effects, but there is also an increased depth of field.

Ed
 
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SeldomPerched

Well-known member
Tom,

In normal use, a binocular is designed for the exit pupil to be placed coincident with the eye's pupil. When the instrument is separated from the eye's pupil, light rays coming from the outer edge of the binoculars' eye lens are cut off which results in the field of view being reduced and the remaining rays restricted to the center where there are fewer aberrations. You observed some of the effects, but there is also an increased depth of field.

Ed

Thank you, Ed, and that fits with how it seemed. It was as you say an effect of outer rays. To me they seemed to veil the image and make it seem brighter - to the detriment of colour saturation.
 

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