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— Panoramas: Evil Flaws —

Panorama Flaws

Flawed Stitching — Inattention
PTGui makes such a good job that you forget that there might be stitching flaws. This panorama (original size 8310 x 4155 pixels) looked very good. The flaws were discovered only later and the panorama had to be re-done. Your customer would have seen the flaw at once — such is human malice: others notice your flaws long before you do.

pano

The stitching error is between the last series of exposures at 300° and the second one at 0° (the first one was the zenith). The area is framed in the picture above. The flawas are not noticable in this size, of course.

flaws

Above, details in original size. Left, from the flawed version; and at right the perfect version. After it was clear where the flaws occured, a couple of control points had to be set. Actually, there were none and I should have seen this right from the start.

Think about it: it really pays to scrutinise whether all seams have got enough control points. The time to add some control points is much shorter than starting the project anew. Do not forget that others will see the flaws more readily than you do. When a panorama is finished, take the time to look at it closely. It will spare you from some possible embarrassment later.

Flawed Stitching — Wind
One single flaw was discovered when the HDRI-panorama «Tight Space» was scrutinised: at the seam beween the zenith and the 300° photographs.

flaws

The detail below at left shows the first stitching version where the flaw was noticed. The panorama was stitched anew after missing control points were added manually. The centre picture shows the success. More control points were added and aligned between the zenith and the 300° shots with great care. The detail at right shows the result.

flaws

This flaw cannot be removed with all patience because the common places in the pictures consist of twigs only, which had moved between the photographs. The flaw was finally retouched using a graphics application.

Blending Flaws — Light
During the time of twilight (dawn, nightfall), the lighting condition change rapidly. A LDRI panorama can be photographed within one minute. For this HDRI panorama, 5 minutes elapsed from the first to the last shot.

flaws

The picture shows the sequence how the panorama was photographed. The change of light during dawn and dusk accelerates towards the equator and it is faster at sea level and at places with a flat horozon. Here, we are at 6,560 ft above sea level in the mountains at a geographical latitude of 46° and twilight proceeds rather slowly. Nevertheless, 5 minutes are already visible.

flaws

The detail shows where the first, second and last photographs join. The picture was excessively contrast enhanced to show the flaw. The seam between the zenith and the 300° shot and the seam between the 300° photo and the 0° one could not be properly blended because the difference in light is too pronounced.

As long as the sun is above the horizon, such problems will not be encountered.

 
  © 2004 - 2018 by Horo Wernli.