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I need guidance on a mirrorless camera, to be set-up on the ceiling of large plans.

The plans cannot be hanged vertically on a wall for a technical reason. They have to be flat on a table not even inclined. So camera has to be ontop of the table taking pics from a Birdseye view.

Plans are around. 130cm x 90cm large.

Lense has to be light as with gravity focus would be effected.

Quality has to be good to be able to read even faint notes in pencil on the old papers.

Which camera and lense would you recommend and why? I am thinking that camera should be setup approximately 1.5 meters from the surface of the table.

Leli Agius
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  • Re: lens creep (which is mostly about zooming movement, not focusing - but you're using a macro prime for this, right?), please see: Possible to lock focal length on zoom lens? (SELP1650) They work just as well for loose focusing rings as they do for zoom rings. But if you're going mirrorless and considering a modern lens designed for mirrorless, the focusing ring is usually just an electronic movement sensor that instructs the camera where you want to focus. The camera then moves the lens focusing element using focus-by-wire. – Michael C Mar 16 '21 at 09:10
  • And if you really want to go high end... but some of the concepts used in such systems can be applied using more mundane equipment. – Michael C Mar 16 '21 at 09:15

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I have had to do exactly what you are attempting. Although the documents I was imaging were not quite as large. 80cm x 60cm or so. The problem you will run into is one of getting all the detail in one shot. I took several overlapping photos methodically from upper left moving to the right in as many rows as needed. Mine were old handwritten taped together pages of a family tree we were trying to preserve. Hopefully your documents are single layers and there won't be tape stains, offsets, mismatches, hard to read folds etc. I took the individual images and stitched them back together in PS. The results were acceptable. If you have a large number to try this on I would highly suggest building a platform, well lit with rails running above it that you can slide your camera along while keeping the same height. Reducing the amount of work you will need to do later. Fine writing in pencil is hard to capture from 1.5 meters away. As far as the focus and gravity, a little blue painters tape or a wide rubber band works. Check on youtube for large document scanning. Plenty of good examples. I would have built my own but I only had a few to capture. Good Luck!! Jeff

Jeffrey Hall
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To do what you want even, high quality lighting is much more critical than what camera you use.

If you need to minimize geometric distortion and maintain high sharpness from edge to edge use the longest focal length prime Macro lens you can use in the space you have available.¹

¹ Since you didn't reveal how much space is between your mounting point and the document(s), telling us document size doesn't help much, as that is only half of the equation,

Michael C
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  • I'm Flexible with the height. If someone recommends a lense to me that needs to be fixed at let's say 90cm from the surface i would adjust the system to this height. I need guidance on best type of lense for such task – Leli Agius Mar 17 '21 at 08:15
  • @LeliAgius to compute angle of view one must take into consideration lens focal length and sensor size. To convert that to linear dimensions, one must also take into account distance. Without those three variable, it's just a shot in the dark for anyone to recommend a specific lens without knowing what size sensor you're working with and what height will be practical for you to work with. The best type of lens for this use case is in the answer: a long focal length prime (no zoom) optimized for macro work with plenty of flat field correction included in the lens design. – Michael C Mar 18 '21 at 02:55
  • For more, please see: Why is the Tamron 90mm 2.8 marketed as Macro and not as a “portrait” lens? – Michael C Mar 18 '21 at 07:08
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Recommendations:

  1. A lens with autofocus to deal with the potential for focus creep.
  2. A camera that allows full control from a tethered computer to avoid fiddling with the controls of a camera in an awkward location and to allow aligning the subject with the camera rather than vice versa.
  3. A camera that allows continuous external AC power to avoid changing batteries in a ceiling mounted camera.
  4. Rigging a “goal post” from two C-stands, a piece of speed rail, a camera platform (rather than a tripod head) and various clamps, pins, and other ordinary rigging hardware designed for professional studio and cinema use.
  5. Use of a mirror to align the camera parallel to the work surface. Place the mirror on the work surface below the camera. When the mirror reflects the center of the lens into the center of the picture the surfaces are parallel.
  6. If the project is temporary, consider renting equipment rather than purchase.
Bob Macaroni McStevens
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