In my free time, I sell lots of items on eBay with a variety of different sized items. I am currently designing four "picture chambers", which are basically four different sized cardboard boxes with different dimensions (length, width, height).

However, my goal is to use the same image lens and sensor for all four of these photo chambers.

I am trying to come up with the optimal lens parameters (focus distance, CoC, Focal Length and F/#) that will work for all of these chambers.

The four chambers have different heights (300mm, 350mm, 400mm, 450mm) and my goal is to have the camera mounted directly above (top-down). The items that I am imaging can range in height from just a few mm, to ~200mm.

My current approach is to specify the range of my focus distance and then calculate the near and far DOFs from there. I get confused when I throw in the horizontal and vertical Fields of View and I was wondering if anyone has general tips or methods to ensure that the lens I choose can work across all of the four different chambers.

  • 2
    \$\begingroup\$ SInce FoV involves both focal length and sensor size, what size sensor are you planning on using? Also, from what distance are you planning on shooting? \$\endgroup\$
    – Michael C
    Sep 17, 2017 at 22:01
  • \$\begingroup\$ I plan on using a 1920x1080 sensor with a pixel size of 3um. The distance that I am shooting is about 100mm to 300mm. \$\endgroup\$
    – Gary
    Sep 17, 2017 at 23:20
  • \$\begingroup\$ So you're saying the sensor is 5.76mm × 3.24mm? \$\endgroup\$
    – scottbb
    Sep 18, 2017 at 2:45
  • \$\begingroup\$ Your subject varies between flat and 20cm deep? You wish to have or maintain image sharpness with a subject distance of 30cm? You prefer to have a vertical "copy" set-up? \$\endgroup\$
    – Stan
    Sep 18, 2017 at 2:57
  • \$\begingroup\$ Do you really need four different chambers that are so close in size? \$\endgroup\$
    – Caleb
    Oct 18, 2017 at 16:00

1 Answer 1


If your objective is images that be mainly viewed on a computer screen by prospective buyers, your depth-of-field calculations can be greatly relaxed. I suggest a circle of confusion diameter computed as 1/1000 of the focal length. Thus if an 80mm lens is mounted, the COF would be 0.08mm etc. For this application you might get away with 1/900 of the focal length or perhaps even courser. Anyway, depth-of-field calculations are based on subjective things that may or may not be applicable. Also, all depth-of-field table, online computers and math formulas are calculated for object distances only on the lens axis. You are on your own if you are worrying about depth-of-field calculations for object placements near the borders of the area being imaged. In other worlds, you are entering into the realm of trial-and-error and tables and charts will only be guesstmates and likely for your application you can loosen them.


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