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I have a Kaidan Spherical head that I use most of the time, but it is much bigger and weighs more than 6 pounds (this is orig QPS1, current version is lighter) vs. the 2.5 pounds weight of the Magic Arm. For those not familiar the Magic arm is basically is device with an elbow joint, and then a ball joint on each end which gives pretty much free movement where you want. All three joints are tightened at one point - the elbow. The friction model, show here I think is easier to work with, vs. the lever model which I'm told is either tight or loose.
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| Above is a multi row QuickTime VR object showing the setup. The red line represents the rotation of axis; the blue line the horizon of the shot; and the green dot the nodal point. I have the Magic Arm mounted to a Bogen 3001 tripod. Camera in this case is Sony F707 with 0.6x lens (roughly 25mm equiv). This is important to note because on this model the center post can rotate. Once I setup the camera for a row of photos I just turn the center column for the other shots. I keep it at low point to assure height consistency. As you can see this is not perfect but seems to work with very few flaws. It takes a little getting used to the setup, may help to have a short doll rod with height marked from tripod head to nodal point, and a level. I am also thinking of making paper angle indicator to help me line up shots within a row, as some else has suggested for monopod solution a compass would work (attached to top of center column) This is not as accurate as using Kaidan head and also takes me about one minute to reset the camera for another row, but for hiking I think it is worth the trade off. Obviously won't be great if very dynamic subjects. If there is a lot of cloud movement then I would shoot the shots angled up right after I shoot the horizon level. Since I am shooting spherical shots it does not matter if my horizon shot is not level; the accuracy of the nodal point is more important. If you are only shooting single row being level is more critical to maximize the vertical FOV of your final pano. I also expect that you would have to manually stitch each image since shot placements won't be accurate enough for premade shot template. (What about when I don't want to use a tripod at all) (F707 lens correction using PanoTools) (How to attach Magic Arm to Tripod) |
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This is my first test using the Magic Arm setup. I did inside to test how much of a problem nodal point flaws will be. Outside in large landscape will be more forgiving. I stitched this in Realviz Stitcher. Its interface works really well for panos when the photos are not at even increments and are rotated, really nice GUI (once ver3.5 is out I can control stitch blending with masking). I could export each photo to layered Photoshop file to hide stitching flaws but I have not in the sample. All I have done outside of stitcher is to adjust levels, contrast etc.
Requires QuickTime 5 to view, may put up alternate java version at later date. |
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The image above shows raw and adjusted settings for Sony F707 with Sony VCL-MHG07 wide angle lens using PanoTools settings of *The Picture below shows results with my new numbers for pano tools revised on 05.11.02 The red image is test grid as raw computer file, the other image is overlay of corrected photo, as the ghost shadow shows its not perfect, but its getting pretty close. here are the new numbers. (d=1.095, c= -0.0825, b=0.003, a=0) |
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For those interested the following numbers are what I came up with for correcting the Sony F707 with only the built in lens set at wide angle setting (d=1.05, c= -0.045, b=0, a=0) |
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| A Note on Handheld panos |
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In bright lighting this is fine, the trick here is not to rotate around your body, but to rotate around nodal point (near front of lens). The way I do this is to stick my left foot forward (I'm looking through lens with left eye). My foot is pretty much under the front of camera lens. then I rotate around the around the front of my foot (and lens). I've only done this for single row but its always worked well.
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Above is a macro shot of the stud on Magic arm and the top of the center column of Manfrotto/Bogen tripod center column. This is the ideal mounting condition where the center column has 3/8" male threads to match the 3/8" female threads on the Magic Arm stud. The female threading is deep enough that the stud can clamp down tight against the center column and give a nice strong attachment. I have also attached to a Bogen monopod with the dual 3/8" and 1/4" threading. Seemed to fit fine, but did not give a good field test. (for those not familiar with it the 3/8" threading recesses to reveal a 1/4" thread.
Another important tripod selection issue is a rotating center post (mine is a 3001). This lets you rotate the camera without adjusting the magic arm. I have the post down at low setting to keep height consistent but this is good idea anyway to avoid torque with off center weight. It seems that the typical use of the Magic Arm is to position lights, not hold a camera, and in that situation people seem to use a clamp which in which the whole stud fits, not using the threading. When I purchased the retailer told me will not fit tripod, but Bogen (who was right) told me otherwise. FYI - I purchased through B&H but I'm sure many other places sell it as well. |
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| inertia-llc home page contact me posted by David Goldwasser, 04.18.02; modified 09.06.04 |