Re: [tech-3d] Re: blueprint

[Peter Homer <P.J.Homer@xxxxxxxxxxxxx>]

>thanks for your help. I was trying to use blueprint paper in a sterio 
>pinhole camera. I figured that since about 10 minutes under a regular 
>light can ruin a pice of the stuff it should work. A 53 hour exposure 
>yielded only evidence of a light leak. Oh well, mabe a roll of 
>electrical tape and about a month...

Perhaps you could also try the light sensitive paper used in sunlight recorders. I am thinking of the type which use the pinhole principal not the glass sphere which magnifiies the suns rays. They have a scale for hours printed on them but I seem to remember that the paper is impregnated with the blue sensitive material so you may be able to use the back. They are simply developed in water which washes out the blue except where it has been exposed to light. Normaly there is just a streak produced by an actual pin hole image of the sun where the light must be fairly intense, when the sun is not  visible there is no mark but as the suns image moves it does not expose any spot for very long. A long exposure of a static scene may produce an image. Because these paper strips are intended to to wrapped around the inside of a cylinder they are in rectangular format which should be convenient for a stereo pair. We used to have such equipment at work but at the moment I cannot find it !
for any further information.  P.
J.Homer   




-------------------------- eGroups Sponsor -------------------------~-~>
eGroups eLerts
It's Easy. It's Fun. Best of All, it's Free!
http://click.egroups.com/1/9698/8/_/520353/_/972903070/
---------------------------------------------------------------------_->