Friday, July 17, 2015

PLAYING AROUND WITH PANORAMAS

There are two new features included with the latest version of Lightroom.  One is HDR (high dynamic range), which I have experimented a bit with previously: http://skepticphoto.blogspot.com/2015/06/st-josaphats-in-hdr.html.  The other is a panorama function.  In this second application two or more shots can be stitched together to show more of a wide-angle view.

Before I tried this technique in the field, I thought I should practice a bit at home, so here is a panorama of our living room.


There are some issues to keep in mind when trying this technique.  First, there needs to be a significant overlap between shots.  When I tried stitching shots with only about a 10% overlap, things tended to get confused.  A 30% overlap seems safer.  Second, one needs to be careful regarding exposure levels between shots.  I generally use aperture priority for most of my shots.  And it is true that the apertures need to be consistent between the shots (so that depth of field doesn't change from one shot to the next).  But if aperture priority is used, the overall lighting from one shot to the next can vary significantly, fooling the camera's autoexposure system.  This can create shots that have differing exposures, which will be obvious when the shots are stitched together.  My solution is to establish the level of exposure, both aperture and shutter speed, and then switch to manual mode for the panorama shots.

So here is an effort I attempted during my most recent visit to the Wisconsin State Capitol.


I believe this was composed of three different shots and represents about 120 degrees of angle.  (The two skylit corridors are actually at right angles to each other.)  I thought the technique worked well in this circular setting.

Later I visited one of my favorite local venues, the Basilica of St. Josaphat.  Here the results were distinctly "mixed."  One of my early efforts was a five shot sequence covering a full 180 degrees.  That did not work.  I reduced the sequence to three shots and got the following.


Frankly this looks a bit weird, as the pews across the back are actually parallel, not at an angle to one another.  I consider this a failure.  I took a couple more panoramas from the back corner of the nave to get the following.



These were both three shot sequences, the first taken in landscape, the second in portrait.

I also wanted to try the technique on a dome shot.  First, here is a typical single dome shot.


And here is a three shot panorama of the dome.


Perhaps I could stretch this a bit more with practice.  One anomaly that I noticed is that the dome in the second, panoramic shot is not circular.  I tried to correct this in post processing but couldn't figure out how.

While I was at St. Josaphat's I took a few more traditional shots.  Here are a few of those.





One more comment regarding this panorama technique.  The files created are extremely large.  It is a slow process creating the panoramas and seems even slower in working with the files once created. But I do see myself working on this technique more in the future.

John

1 comment:

  1. Was fin ally able to read your captions and found the final one very interesting. Much talent is shown in your photos

    ReplyDelete