Shooting the raw frames : 無料・フリー素材/写真
Shooting the raw frames / selkovjr
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | These are all the shots I was able to make during a minute-long stop at a traffic light. I was hand-holding the camera and did not have time to aim well. The result is a very haphazard set of frames. One of the shots was even done at a different focal length. There is no way they can be stitched automatically. But this is a good case to demostrate that even badly shot frames can be assembled into a reasonably good panorama. Before we start discussing frame-stitching, I must say a few words about how the pictures were taken.Camera settingsA few important camera settings are required for good photography and for image development. I check these settings every time I go out or do anything that will reset the camera's configuration. - make sure the clock is current - the file format is set to raw - the ISO speed is at the lowest setting - the viewfinder shows the histogramThese settings are good for all kinds of photography, but are essential for making good panorama shots.On the siteI mostly shoot in automatic mode, unless I need to do something extraordinary. In the early days, I used to lock exposure while taking panoramic shots; now it is not noly unnecessary, but can even hurt. It is often difficult enough to pick a good exposure for a single frame; picking a good exposure for a 180-degree field of view can be infinitely more difficult. My camera stores 12 bits of lightness in each channel; image manipulation occurs in a 16-bit space; we have some wiggle room for exposure adjustment after the fact. That's why I always have a histogram view in my viewfinder -- I want all frames to encode as much information as possible, without any losses either on the dark or on the bright side.Ideally, a panorama is shot off a tripod; even more ideally, using a panoramic head (which I don't have). But hand-holding is possible, too, especially if there are no obvious features like trees or fences in close range, which would betray a parallax. This is a series of hand-held shots that blended without a single glitch into a 206-degree field of view.Two things to watch while making a single-row panorama: - adjacent frames must overlap by 30-50% (the more, the better) - they should be as close to level and in as good a vertical alignment as possibleIf, while still at the scene, I suspect I have shot a frame out of alignment, I shoot another frame or several at approximately the same angle of aim to cover the possible gaps. One more thing to watch when the light is unsteady or when things are blown across by a strong wind -- clouds and their shadows: - make consecutive shots as quickly as possibleThe closest separation between the shots I ever got was about 11 seconds — the time it takes for me to aim and shoot, plus the time the camera spends writing the raw file (which takes much longer to store than a compressed image). That is not good enough to shoot the rolling waves at a close range, for example. Situations like those will require creative editing later. Knowing this, it may be useful to shoot many extra frames, hoping that the waves will be approximately in sync in a sufficient number of frames.Next: Raw file storage |
| 撮影日 | 2010-08-03 18:13:02 |
| 撮影者 | selkovjr , Chicago, Illinois |
| 撮影地 |