3

I’m building an ultra large format camera to take sheets of photo sensitive paper up to 3 meteres wide, although will start shooting with paper 2.4m x 1.2m.

If there any exisiting lenses that can be found for this purpose? Of course pinhole will do, but at this size optimal pinhole will be about f/1200, hoping to find something faster if possible.

I’m hoping to have infinity focus when lens is 2-4meteres from paper, although can adjust this if necessary

Hoping for anywhere between 40-74 degree angle of view horizotonally, preferring 74 degrees.

  • Dpreview.com has this story about a lens for camera obscura use, which sounds ballpark what you need. There's a link to the company there. I have, however, no personal knowledge of this product at all. – StephenG Jun 4 '18 at 0:24
  • I am planning to try one of these; although I think the angle of view is more telephoto then I want. Unless I make my camera even bigger.... – Malcolm McCaffery Jun 4 '18 at 1:10
  • The limiting factor will likely be the diffraction limit of whichever lens you choose (assuming you select a lens which is sufficiently expensive to reach its diffraction limit.) A lens with performance sufficient to reach the maximum resolving power of sensitive paper at that image circle is nearly impossible (think litho lenses) So long tent pole is what resolution you want on the paper? Would 10 lp/mm do it? – PhotoScientist Jun 4 '18 at 5:22
  • While ideally I would like best resolution possible I realise sacrifices will need to be made...ideally a lens option could produce more detail then a laser drilled pinhole. I think 10 lp/mm would be fine... – Malcolm McCaffery Jun 4 '18 at 5:37
  • I do not know, but probably you could dissasamble some old lenses to make an arrange of your own. Just an idea. – Rafael Jun 4 '18 at 6:37
1

I think you can buy a refracting astronomical objective lens. Size the focal length based on the diagonal measure of the largest print you will be making. As an example, to project a 2.4 X 1.2 meter print, search for a 3000mm achromatic refracting telescope objective.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.