Help finding a converging lens with focal length of several feet

I am building a large camera obscura.

Can anyone suggest where or how to obtain a lens with a focal length
of several feet (for less than $200)?

I am open to unique suggests - taking apart existing set-ups,
interesting aberration, ect.

Thanks
Dave

.

Relevant Pages

  • Re: New Rx
    ... 20 feet is termed optical infinity. ... properly focused with the same lens power that provided clear vision ... I switch to my distance glasses only for driving. ... No. you measure the prescription at 20 feet which gives the lens ...
    (sci.med.vision)
  • Re: Overheard on the scanner
    ... 10 feet x 10 feet. ... size on a single plate ... To put the same six-footer in the frame with my 500mm lens, ... related to the diameter of the aperture (i think to the square, ...
    (rec.arts.sf.fandom)
  • Re: Hyperfocal distance
    ... The hyperfocal distance is obviously located somewhere between near ... > manually set the focus point on the lens given a set 50mm lens at F4 so I ... If you have a DoF of 4.6 to 5.4 feet, ...
    (rec.photo.digital)
  • re:Why is ONLY 20/20 Vision so important?
    ... of the eye. ... This optimal distance was decided at 20 feet. ... A lens put in front of your eye, being contact lens or eyeglasses will ... focus point to where it should be for the best vision possible. ...
    (sci.med.vision)
  • Re: Xtreme photography - looking for inspiration/ideas
    ... around with long daylight exposures. ... Get a lensbaby or super fast lens for shallow DOF to go with that ND ... lens at 3 feet away wide open, ... obvious - I haven't pushed my lenses to their limits, ...
    (rec.photo.equipment.35mm)