photo etc blog: 2010

I wanted a cheap single-row pano head, so I searched DIY pano heads on the web.
Among many of DIY pano heads that I've found these were interesting.

Victor van Dijk's DIY pano head using stock Manfrotto parts.

Peter Reimer's DIY pano head that uses a ballhead mounted upside down.

Spherical Panoramas :: Equipment

Erik Krause's DIY pano head that also uses upside down ballhead

Pan/Tilt Panorama-Head

My Plan:

Upside down ballhead idea seemed great as it could be very inexpensive, if you already own a ballhead with separate pan lock, and the camera can be rotated around lens nodal point instead of orbiting around the center of the tripod. Yet you keep the convenience and stability of your ballhead.

Unfortunately I don't own a ballhead with separate pan lock.

I ended up ordering a panning base and Manfrotto sliding plate

The panning base will be placed on top of the ballhead, and the sliding plate will be mounted on the panning base to position the camera off-centered so that the lens' nodal point concided with the center of the panning base. Well, that's the plan.

I've been working on lens correction recently. More speicifically correcting distortion.

One of my cheap lenses has a strong mustache distortion at the wide end. Just like this:

So, I tried PTLens, an inexpensive and popular lens correction tool. It did an OK job. Though I could still see mustache distortion after PTLens treatment. Of course, I wasn't happy.

Then I decided to use Hugin to solve this problem. When you create a panorama using Hugin, often times you get a lens profile as a by-product along with a beautifully stitched panoramic image, if you used Hugin's optimizer. Since I had not used this cheap wide angle lens for panorama, I didn't have its lens profile yet.

So, naturally I carefully determined the non-parallax point of the lens at its wide end of focal length. Shot a 360 panorama with the lens. I chose my living room for this little photo shoot where there are a lot of straight vertical lines. The aperture was set f/11 and I focused at hyperfocal distance.

Loaded images into Hugin. Manually created vertical control points. Ran control point detector. Then the rest is just same as a usual stitching process. In the end, I got a decent lens profile that's tailored for my own copy of the lens.

Move your mouse pointer over the image to see 'corrected' image.