Photogrammetry tutorial 4: bulky stuff

Previously, I had much to say about photographing specimens that you can move around and nicely place on a turntable. However, the world of vertebrate palaeo holds many specimens that do not fit into that category. Specimens that just generally do not fit at all, anywhere. Specimens like sauropod sacra, huge chunks of fossilized and therefore rock-heavy bone that you need a forklift to move. Beaten only by sacra with still-attached ilia. Oh, and obviously beaten by stuff too heavy to move at all placed in storage so that it is barely accessible. Like hips with a shelf right above them. Like this one:

Vernal_hip01

As you can see, the next shelf isn’t far above. Luckily, there is some room, and there are aisles on both sides. This is in the Utah Field House of Natural History State Park Museum. The layout in the photo below (AMNH Big Bone room) is much worse, because the specimen is facing the wall:

AMNH_bigbone

How did I deal with the rather suboptimal conditions in Vernal?

First of all, I took photos with long exposures. The light wasn’t too bad, as there were long banks of fluorescent lights down both aisles, and behind me (on the photo above) there was a row of those gloss white painted collection cabinets that do such a neat job of reflecting light. So there was light coming in from many directions, and the shadow thrown by the shelf above wasn’t as hard as it could have been. But the level was, overall, rather low. Long exposures meant that I needed to use a tripod, which had the added benefit of “allowing” me to fiddle with the tripod until I got the perfect composition for each photo. It takes forever, compared to speedy hand-held shots, but in the end that time is easily compensated for by the lower number of photos needed, because each photo is better composed.

A specimen in confined quarters – and being very close to the ground is a confinement in that sense, too – requires a lot of variability in the tripod. Check out what I did to get good shots from a low angle, in order to capture as much of the lower edges and ventrally directed surfaces of the sacrum:

Vernal_hip02

Yup, that looks pretty contorted! But it allowed me to take photos like this:

Vernal_hip03

Look how nicely the surfaces on the underside show up!

So, how do you photograph such huge immobile specimens?

Ensure good lighting

In the case shown above, there was no need to bring additional lights. However, be prepared to set up a few lamps and use white cardboard as reflectors to light up the lower surfaces of the specimen.

Use long exposure times and a tripod

well, duh!

Take hand-held HDR shots

a contradiction to the last statement? No! To properly document the top of the specimen you may need to combine both methods. Or, in fact, take sets of photos of the complete specimen with both methods. Also, do not be afraid of taking the camera off the tripod and pressing it against the bottom surface of the next higher shelf to hold it steady; this gives you excellent top-down shots. or even use the flash!

Vernal_hip04

This is a HDR shot, for which I held the camera under the next-higher shelf and aimed blindly.

Select views to maximize the coverage of the specimen’s surface

This may mean hanging a sandbag from your tripod as a counterweight and sticking the camera between the shelves! Most tripods have a small hook for this purpose.

If you follow these rules you will likely get pretty good results!

Vernal_hip06

Vernal_hip05

Vernal_hip07

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About Heinrich Mallison

I'm a dinosaur biomech guy working at the Museum für Naturkunde Berlin.
This entry was posted in 3D modeling, photogrammetry, photography. Bookmark the permalink.

8 Responses to Photogrammetry tutorial 4: bulky stuff

  1. Pingback: Sauroposeidon in perspective–too much perspective | Sauropod Vertebra Picture of the Week

  2. Nima says:

    What species are the hips in the Vernal pictures? The squat flat pelvis that you took multiple pictures of for the 3D model looks like a titanosaur, and the taller thinner one on the green pallette next to it looks like a camarasaur… just my guesses. Are the species identified?

  3. Ollie says:

    Hi there, Thanks heaps for taking the time to explain this process. I’m just about to roll my sleeves up and give it a go, so all the tips and tricks that I can find are greatly appreciated :-)
    Cheers,
    Oliver.

  4. Pingback: Photography and illustration talk, Part 12: Stereo and 3D | Sauropod Vertebra Picture of the Week

  5. Pingback: Photogrammetry tutorial 6: building a model from the photos | dinosaurpalaeo

  6. Pingback: How to Make Your Own 3D « paleoaerie

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