We had one in a previous incarnation of my department. The present building is, sadly, not suitable.
If there are physics labs in the Uni, they should have proper blackout facilities for light experiments. Even the LEDs on alarm sensors will spoil the effect. Hopefully, one of the rooms will have a decent view and a suitable wall to project onto or a place to fit a screen. Then you need to work on getting them to agree to you making a hole in their blinds.... Petzval's formula will give you the optimal diameter of pinhole for sharpness. d=2times the square root of f times lambda d = diameter f = focal length (pinhole to image plane, mm) lambda = wavelength of light (nm) [choose something from the middle of the visible spectrum, about 500] Hole needs to be as clean and round as possible, to reduce higher order diffraction effects. You may need to both make the hole in something that you attach to a bigger hole in the blind (for cleanliness of edge) and make the hole bigger than optimal to reduce the acclimatisation time required to view the image. World pinhole day in April...... > On 10 March 2017 at 15:17 Mark Roberts <[email protected]> wrote: > > > I'm thinking of making a room-sized camera obscura as an experiment > for my Digital Photography I class. Anyone ever tried it? > > -- > Mark Roberts - Photography & Multimedia > www.robertstech.com -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
