Best lens to photograph a large flat object

Question

I need to accurately photograph mood boards. These are large (4x8 feet, 120x240 cm in my case) white or black boards with photographs, material swatches, pantone swatches pinned to them.

The goal is to have the ability to re-print them elsewhere (we have offices on 3 continents that need to use these boards) so that the prints are a reasonably accurate reproduction of the original ones.

I can't scan these boards (too large) or make multiple copies (too much work).

I can easily take multiple pictures, and color-adjust them and stitch them together automatically, but I'd like to have to take as few shots as necessary.

Good hints are here, but I'd probably like to have a higher resolution.

Are lenses a good way to achieve that, once I've maxed out on camera resolution?

Answer 1

I would say you want a telephoto lens. If you want a scan-like image, being far away with a long lens is your best bet, as it will preserve the rectilinearity of your subject. I don't know exactly how long a lens you'd need to get no noticeable distortion, but if it were me I would use my 100mm prime.

Edit: another option would be to shoot with a wide angle lens and correct the distortion in post. I'm not sure how much of a difference it makes for the quality, but it would make it easier to light and require less space.

Answer 2

I have several answers.

1) Use whatever lens you want (or can). You are limited not by a lens, but on the actual space you have in front of your board.

If you have the board on a tight space, you will probably need a wide angle lens, but if the board is on the middle of a manufacturing plant, you can use a telephoto lens to minimize spherical distortion. Just the proper focal length to have all on one shoot.

2) Several shoots Panorama aproach.

Let us think that you have enough space, for example 4 m. infront of the bard, and you could shoot it with a 35 mm lens on a croped sensor.

If you instead shoot that with a 100 mm lens panning and tilting, and then compositing them in Hugin for example, you are increasing the real megapixels on your final file, that can be used to mantain detail in the printed copies.

Spherical correction

There are two options to avoid spherical distortion.

a) Aumenting the distance to the board. I would say arround 3 or more times the longest side of the board (2.4x3 = 7.2 mts)

b) Correcting it in post production.

Aditional factors

There are a lot of factors you need to consider. Using a color reference chart (color checker), shooting in raw, good iluminants, good ilumination angles, good print quality, a proper color managed workflow.

Answer 3

A macro lens will be the best option, because macro lenses have very good corner to corner sharpness and very little distortion.

Any macro lens will do, however choose one with at working distance best suite to your use, my guess will be around 60mm or so.