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For artwork photography, I want to have the painting "perfectly" parallel to my camera sensor, in order to improve sharpness and reduce the amount of post-processing in my workflow.

Are there dedicated tools available to achieve this ?

The camera grid is usually too large to get precise results, and I gave a try to the mirror technique (you put a mirror in at the center of the artwork, if you see your lense in it from the viewfinder or screen then you got the right alignment), but it is a pain to set up and I found the results as imprecise.

I was suggested a tilt-shift lense but I feel the issue of relying on my eyes within the viewfinder will be the same.

Spirit levels may help but couldn't fix the horizontal angle between the two vertical planes.

I was thinking about a 4 points laser rangefinder to be mounted on the camera, does something like that exist ?

Note that I can usually move the artwork (placing it flat on the floor might work for small pieces, but not for larger ones, though).

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  • \$\begingroup\$ Just found this question to which mine might be a duplicate. I have to read it once rested tomorrow. \$\endgroup\$
    – Skippy le Grand Gourou
    Commented Mar 2, 2020 at 0:47
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    \$\begingroup\$ One can use a precision total station, like a Sokkia SRX1 to align the the subject, presumably a flat surface, to a projected point that is exactly perpendicular to a desired point on the flat surface. I've actually done this to set up a lens testing protocol. \$\endgroup\$
    – doug
    Commented Mar 3, 2020 at 23:05
  • \$\begingroup\$ @doug That's totally out of my budget but this option is probably the closest to what I imagined, thanks for this input ! \$\endgroup\$
    – Skippy le Grand Gourou
    Commented Mar 7, 2020 at 22:35

5 Answers 5

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I am a simple man and I like to have simple solutions.

I would not find parallelism. I would find the center.

You need a nonelastic thread (cotton for example), one tip pen and one assistant or two.

  1. Paste one end of the thread next to one corner of the painting. Or have another assistant holding it.

  2. Put the assistant holding the spool of thread on the opposite corner of the painting and start to unroll the thread from the center to the front of your camera.

  3. Cut the thread and find the exact center of it folding in half and mark it with the pen.

  4. Do the measurements again but this time the camera lens needs to be exactly on the marking.

  5. Do the measurements again with the same cord but the other two corners of the painting and adjust the position of the camera if needed.

You now have the lens at the "exact" center of the painting.

  1. Frame and level the best you can.

You can, of course, use a laser meter or something, especially for big artwork, just do not fire the laser to the painting, especially if it is an antique.

Put the cap on your lens and fire at it. Paste a sheet of paper on it so the laser reflects nicer on it.

An additional tip: use the longest focal length you have or the longest one you can use in the room you are in.

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    \$\begingroup\$ Well, that sure is a neat trick (a similar process was suggested here), but I don't think it really goes in the way of optimizing my workflow… And I will probably go nuts after a few artworks of different sizes in a row. \$\endgroup\$
    – Skippy le Grand Gourou
    Commented Mar 2, 2020 at 13:43
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A tube placed on the surface of the artwork can provide alignment. If the far end of the tube (smaller) is perfectly centered within the opening of the tube (larger); then the camera must be perfectly aligned with the tube, and therefore with the surface the tube is on.

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A quick and easy method is to put a mirror where the target will be (you can also possibly cover the target with aluminum foil), and scribble a cross at its center.

You then look into you viewfinder, and put two things at the center:

  1. the reflection of your lens in the mirror
  2. the cross on the mirror

#1 alone guarantees parallelism. #2 centers the camera FOV

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  • \$\begingroup\$ Thanks for the input, but I already tried this setup and as mentioned in the question I wasn't very satisfied with it, I felt it was quite imprecise. Maybe it was just my setup which was wrong (I was in a rush when I tested) I may give it another try in better conditions. \$\endgroup\$
    – Skippy le Grand Gourou
    Commented Mar 2, 2020 at 13:51
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Maybe the most reliable way would be to shoot the artwork on the floor anyway.

I mentioned in the question that it wouldn't work for larger artworks. However, thinking about it, mounting the camera on a giraffe boom (or whatever the actual name is) would allow to photograph quite large artworks.

Having both the canvas and the sensor parallel to the ground allows to make full use of the two axis of a spirit level. There may still be an angle between the sensor and the subject, but this angle being around the lense axis it's the easiest to correct by eye.

An additional advantage of this method is that it's easy to put a white or colored cloth behind the painting and therefore maybe allow autocropping in post.

However, this method might not be very convenient for large artworks unless using a wide angle lens. A painting with a length (not width) of 1 m would require a distance (i.e. height) of 1.40 m with a 50 mm lens on a full frame sensor, or 1.70 m with a 40 mm lens and an APS-C sensor, which would be impracticable without an articulating screen.

Note that I didn't try this method yet.

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We have one of these https://www.versalab.com/PARALLEL.html

It works pretty well for getting things aligned but the laser is not super powerful. Currently looking at options for something better.

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