Ask the VR Photography Experts

Q: I’m trying to shoot panoramas of car interiors and have run into a number of problems. I have a Sony Cybershot DCS F55V camera with a 0.7x wide angle adapter, Kaidan Quickpan III spherical head with universal mount, and RealViz Stitcher software.

How do you lock the exposure levels on the Cybershot camera? How do you mount the camera inside the car and where should you position it. And what is the best way to light the car? I’m experimenting with simply covering the windows with sheets.

A: There are lots of different ways to shoot interiors like this, some better than others. I have a suspicion that you will have a difficult time doing them successfully with the camera you describe. I am not familiar with the Sony DCS F55V, and don't know whether you can actually control exposure manually with it, nor whether the 0.7x wide angle adapter is acceptable for stitching alignment (barrel distortion is often a problem with supplemental adapters). However, necessity is the mother of invention and we often do our best work when we have less than we think we need.

Of utmost importance, you need to have a camera that has, at the very minimum exposure, lock capability, so you can lock the exposure at a given setting when you shoot the panoramic sequence. True manual exposure is better. (Note that some digital cameras claim to have manual exposure, but it is simply a manual compensation -- plus or minus up to two stops -- of the camera's auto exposure system. This is insufficient, as the camera will continue to change its exposure with each shot.)

In terms of mounting the camera inside the car, you need to first choose where you (or your client) want the view to be from. Many photographers put the camera in between the two front seats, as it's easier to position (you can often use a tripod on the floor of the vehicle) and this gives a better view of the back seats in the panorama. Personally, I prefer to shoot these from the driver's-eye view, which is dead center in the driver's seat. This is where most purchasers of a car will be spending most of their time (nobody really sits in a car astride the emergency brake lever or stick shift).

Putting the camera on a tripod in this position is problematic at best, because the tripod legs interfere with so much of the seat below. I found it was best therefore, to support the camera on a boom arm which comes in through the driver's window. This gives the camera an unobstructed view in every direction in the interior, except for the support arm in the window. This is easily retouched out, especially if you are compositing an exterior view into the window areas anyway. You may also be able to do this through a removable sunroof, if available, but it's better to do it through the window, since you know that EVERY car has a driver side window available. Make sure the boom arm and stand are stable, as you don't want the camera position to move even slightly during the shooting sequence. You'll also want to trigger the camera remotely via a cable release or other mechanism, so you don't have to be inside the car when you shoot. The weight of a person on one side of the car or another will shift its position slightly, and image alignment between frames of the sequence can become a problem.

If capturing a view of the full back seat are from this position is important, consider doing a second shot with the driver's seat headrest removed, which you can either composite or layer (as a semi transperent view) in post production. This gives a nice effect, as it shows the position of the headrest, but the view toward the back of the car is not completely blocked by it.

Lighting is best done with the most diffuse (soft) light possible. Taping diffusion material over the outside of the windows works quite well, especially if you are planning to composite an exterior scene into the window areas later on. This technique presents some problem with a "glow" around the window edges, but can be minimized if you also tape some dark backing strips over the outside of the diffusion material around the window edges, so not so much light is hitting the edge areas.

Additionally, you will find that some areas of the interior will be too dark, such as the floor in the recesses of the driver and passenger leg rests. This is not generally a problem if the vehicle's carpeting is fairly light (gray or tan), but these spots become "black holes" with black or dark carpeting. In these instances, hiding a small slaved strobe or fill light under the front seats can fill in these areas quite nicely (don't overdo it, and if you use continuous or "hot" lights, watch out for heat buildup).

Note, if you are using bed sheets over the windows, that most linens are not pure white and will wind up giving the interior an unfavorable color cast (most likely a bluish or yellowish color). You might be able to fix this in post production (after the complete panorama has been assembled). However, it's better to actually buy a roll of photo grade diffusion material and use it over the windows (cut it to the sizes you need), since these rolls are completely neutral in the color balance.

I also like to turn the panel (and sometimes the interior) lights on in the vehicle when shooting, as it tends to improve the contrast and look of the panel. Usually this requires that you shoot in a controlled light studio where you can burn the panel light exposure in for about 4 seconds and have the ambient light remain dark except for the firing of the strobe lights. This however, may be a more complicated technique than you want.

Q: I liked your suggestion of shooting a car interior with the camera on a boom arm coming through the driver’s window. However, with many cameras, this seems impossible due to the the center of gravity of the camera not being in the same spot as the nodal point of the lens. When the camera is positioned to rotate around the nodal point, the off-center weight of the camera forces it to “flop” downward during shooting. How do you prevent this?

A: Good point. And one which reminds me of further details.

I shot the first automotive VR interiors for Toyota's 1996 and 1997 product lines, and since we were the first to do these, we had to develop the techniques from scratch. We shot with a Nikon F3 film camera and a heavy Nikkor 8mm fisheye lens.

The key element in bringing a camera in on a boom arm through the window is that you shoot the panorama sequence with the camera rotating about a horizontal axis, rather than the normal vertical one. This also requires that the pan head be capable of being locked into each detent position so that the off-axis weight of the camera/lens doesn't keep pulling it out of position. Unfortunately, most commercial pan heads don't have this capability, as the manufacturers seem to assume that all panoramas will be shot with the camera rotating around a vertical axis. This is an unfortunate oversight in my opinion, but it probably isn't a pressing concern for the average photographer.

To solve this problem, we simply drilled a small hole through the rotation collar of the pan head and then drilled matching interior holes for every detent position we needed. Then, we slipped a small steel pin through the aligned holes to lock the head in each position as we shot. The pin kept the head from rotating, even with the off-axis weight of the camera pulling against it.

You *can* rotate the camera without being inside the car simply by keeping the driver side window open and reaching through the window to remove the pin, rotate to the next detent and reinsert the pin again (you can lift up the diffusion material over the window when you need to reach in) . Of course, with the larger vehicles, it helps to have long arms <grin>. However, it is possible to open a passenger or back door in between each shot to access the camera if you have to. The car will return to it's original position after you get back out of it and close the door again. If you do this, make sure you don't adjust or move anything else inside that might cause other alignment problems. Of course, you also have to be extremely careful not to bump the boom arm or stand that it rests on during the process. If you do, it's best to restart the shooting sequence completely, as you will never be able to realign everything perfectly.

I found the hardest vehicles to shoot and light properly were the convertibles, because it was so difficult to keep the soft interior lighting we wanted without getting significant lens flare from the broad light sources above. Cars with sunroofs were much easier, particularly if the sunroof was not too big. The other cars that were difficult were the very small sports cars with black interiors, because there was very little room to get lights positioned properly, and the contrast range of the scene without supplemental lighting went quickly beyond the ability of the film to capture it.

For general reference, we averaged about two car interiors per shooting day, and the entire shoot took about 10 days the first year and about a week the second. The result however, became Toyota's leading advertising method (via their web site). Toyota tracked that these VR scenes led to more actual test drives (getting their potential clients in for a test drive at a dealership is the best way to get them to buy a car) than any other advertising mechanism they used. This is also why today, almost every car company uses VR to show its products on their web site. (Most of the U.S. automotive photography today is done in either Los Angeles or Detroit, as that's where the major hubs of the automotive industry are located).

- Scott Highton