Re: Slit width - Distance to fim plane

[Peter Sanders <peters@xxxxxxxxxxxxxxx>]

Robert Durn wrote:
> 
> Hello to all,
> Does any one have any thoughts or answers to how wide a slit should be and
> how far it should be from the film plane? I have been building a camera with
> a 24mm Nikon lens using 120 film stock and a 1mm slit placed 10mm from the
> film plane.
> I still can't get a really sharp image even at f16. The film transports
> around a drum omega style and has an image of 149.5mm for 360 degrees.
> Also, I know that the rule says 2 x focal length x Pi or 150.796mm but is
> 149.5mm close enough?
> 
> Can any one help?
> Many thanks, Rob Durn Stockport UK
> 
> also at Robert.Durn@xxxxxxxxxxxxxxxxxxxx

I have also made a rotation camera with a drum for the 120 film. 
The slit wide is 0.75 mm and the distance to the film plane is 13 mm.
The first photo's I have made has the same problem, not in focus.
My mistake, I start the exposure of the film at the rong side on the
film.
Not at the backside of the film but left-right rong.
I forgot the lens makes an image up-side down
Now I rotate the drum in the other direction and al the images are in
focus.
www.huizen.dds.nl/~sandersp
The test exposures on black and white photo paper seems oke.

Peter Sanders, Amsterdam