Re: Double depth

[T3D Larry Berlin <lberlin@xxxxxxxxx>]

john bercovitz:
>>There are various rules for the maximum allowable depth in a 
>>scene.  Seems like the best ones have to do with the maximum 
>>amount of parallax on the film and that that amount is usually 
>>about 1/30 of the focal length of the system.  
>>
>>For miniature format with the usual 35 mm lenses, this works 
>>out to about 1.2 mm of parallax.  If a scene has a lot of depth 
>>in it, some people will crop the mask a similar amount for 
>>"double depth".  Does this cause viewing problems?  I think I 
>>can see where it would be a problem for projection because the 
>>window would be really close, but what about in a hand viewer?
>>
>>The reason I ask is that I just calculated the way I set the 
>>window in my medium format viewer and it's at about 4' (1.2 m) 
>>which is approximately double depth.  I have no problem with it.  
>>I haven't heard of anyone having a problem with it.
>>
>>So if double depth isn't a problem, where does this limit to 
>>the amount of a depth in a scene come from?

I'm not sure I understand the use of the term *double-depth*. What is the
relationship between the amount of parallax in the image and cropping of the
window?

Larry Berlin


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