On 26-10-2014 14:19, clipka wrote:
> Am 26.10.2014 10:22, schrieb Thomas de Groot:
>> On 26-10-2014 9:54, Stephen wrote:
>>> On 26/10/2014 08:13, Thomas de Groot wrote:
>>>> But, it is the reason why on goggles, the baseline /is/ extended.
>>>> Consider also those military stereoscopic viewers. From my own
>>>> experience with stereoscopic viewers used for aerial photographs,
>>>> extending the baseline makes objects appear like billboards.
>>>
>>> Would that not be more of the "telescopic" effect of the lens's used?
>>>
>> Hmm... I am not sure how much the lens influences the effect indeed. My
>> guts tell me it is the baseline mostly, but then who would rely on his
>> guts? :-)
>
> Actually it is a combination of the telescopic effect of the lens -
> which enlarges the viewed objects in the horizontal and vertical - and
> the /absence/ of (sufficient) baseline extension - which would emphasize
> the depth cues accordingly.
>
> For instance, in 20x binoculars I think you'd ideally need a baseline of
> around 12m; obviously this would make such devices very impractical to
> carry around, so that's not done.
>
...but which is achieved for instance with aerial photographs used for 
cartographic photogrammetry, with baselines of hundreds of metres.

Thomas

Post a reply to this message