>Last I checked Mr. Dusariez is a subscriber to this list. He might be >able to help with your book search.
Yes Michel has e-mailed me and is trying to get hold of a copy for me > > I have built a camera based loosely based on the idea have a > > look - malcam.fucx.co.uk However it was full of faults and is very > > haphazard. >Didn't have any luck with this URL. try again? http://malcam.fucx.co.uk/ just checked it . Let's try an ASCII diagram: > > > Side View: > | > | > | > | <-------------------Film plane > | > | |------------| > |( ) wheel ( ) <------ Rubber O-ring > | |------------| > | | > | | <------- Fixed Shaft > | | > =========[]| |[]========== <-- Camera Body > | | > |------------| > | __ | > | < > | <----- Tripod mount > | > < | > |____< >____| > >The tripod mount, shaft, wheel and O-ring are all fixed. The film >contacts the O-ring, and the camera is the only part free to move. As >such, when the film translates through the camera it pulls the camera body >around the wheel. Hope this helps a bit. Yep it helped, i understand the slit concept it was just where the disc was placed and how it worked. If you get to my site you can see my 'odd' interpritaion of the larscan idea. > > > My plan is to build a larscan that takes 24hrs to rotate using two > > polarizing filters controlled by a microprocessor and a small motor to > > control exposure. Any thoughts on this idea? > >Exposure in a slit camera is controlled by rotational speed, slit size, and >lens aperture. A 24 hour rotation is really slow, necessitating a very >small slit size, really small aperture, and/or as it sounds modulating >the light using crossed polarizers. Yes the relative shutter speed is 4 minutes so it will probably need some nutral density fitltration as well as a small apature. Doing a quick test with two polarizers and a spot meter and theres about 15 stops between the two extreams. >Not too sure what you are trying to >do so don't really know how to approach the design. Well the idea is to be able to record a day from midday to midday in a single flat image with a view to capturing the movments of tides. >One problem with >panoramic cameras is keeping the exposure consistent across the strip of >film. I'd assume that this would be a BIG problem with a 24 hour exposure >unless you are in an artificial environment where you can control the >illumination. Also, my gut feeling, for what it is worth, is that you may >need better control of the camera rotation and film translation speeds >than what you can probably get with the Larscan design. yes this is becoming apparent i think the use of friction will cause banding problems at such a low rate of turn. I am considering useing a chain along the underside of the camera and a stationary cog instead of the disc. >If you are >already talking about microprocessor control it would probably make sense >to consider using stepper motor control of both the camera rotation and >film translation. I'm unsure about stepper motors and what they do? Any good links would be appreicated > >What do you have in mind for the controlling microprocessor? A laptop, an >embedded controller, or maybe a basic stamp <http://www.parallaxinc.com/>? Just a simple PIG processor which will read voltage from a photo cell inside the camera and adjust the pol filters to keep nthe voltage constant, this is somthing which my father, who is an electronic engineer will help me with. Cheers for the help Gareth _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp _______________________________________________ Cameramakers mailing list [EMAIL PROTECTED] http://rmp.opusis.com/mailman/listinfo/cameramakers
