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04-22-2018, 06:30 PM - 1 Like   #1531
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Sunrise over Fort Churchill, Nevada. Seven landscape frames stitched in Lightroom.


04-23-2018, 10:41 PM   #1532
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QuoteOriginally posted by kh1234567890 Quote
Looks like you enjoyed your visit to Canberra - I was too lazy to get out of bed for any of the balloon festival.
04-27-2018, 09:01 AM - 3 Likes   #1533
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Another shift panorama, this time using the Rokinon (Samyang) 24mm tilt/shift. Two exposures, not quite full shift left + right:



There's definitely some vignetting out at the edges when fully shifted; this has been corrected somewhat in post.
04-27-2018, 10:59 AM   #1534
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QuoteOriginally posted by baro-nite Quote
Another shift panorama, this time using the Rokinon (Samyang) 24mm tilt/shift. Two exposures, not quite full shift left + right:



There's definitely some vignetting out at the edges when fully shifted; this has been corrected somewhat in post.
Notable to me: 1) no evidence the vignetting was retained on the overlapping sections; 2) the program did a good job blending the water.

04-27-2018, 12:10 PM   #1535
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QuoteOriginally posted by WPRESTO Quote
Notable to me: 1) no evidence the vignetting was retained on the overlapping sections; 2) the program did a good job blending the water.
By shift panorama I mean I used lens shift rather than camera rotation, hence the entire panorama is a single crop from the lens's actual image circle. So, no vignetting band in the middle. I did use a stitching algorithm (in Affinity Photo) rather than simple abutment, both to blend the water across the join and because this lens doesn't have a tripod mount, so shifting means the lens moves rather than the camera, hence some small parallax effect.
04-27-2018, 12:57 PM   #1536
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QuoteOriginally posted by baro-nite Quote
By shift panorama I mean I used lens shift rather than camera rotation, hence the entire panorama is a single crop from the lens's actual image circle. So, no vignetting band in the middle. I did use a stitching algorithm (in Affinity Photo) rather than simple abutment, both to blend the water across the join and because this lens doesn't have a tripod mount, so shifting means the lens moves rather than the camera, hence some small parallax effect.

But, unless I'm not visualizing properly, you are still combining two images in PP with the possibility of some vignetting on the right corners of the left image, and the left corners of the right image. Correct?
04-27-2018, 02:15 PM   #1537
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QuoteOriginally posted by WPRESTO Quote
But, unless I'm not visualizing properly, you are still combining two images in PP with the possibility of some vignetting on the right corners of the left image, and the left corners of the right image. Correct?
I think not; the two exposures are recording side-by-side sections of a single image circle. The result should be the same as though I made a single exposure with an xpan-sized (i.e., 24x60mm) sensor.
04-27-2018, 03:24 PM   #1538
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QuoteOriginally posted by baro-nite Quote
I think not; the two exposures are recording side-by-side sections of a single image circle. The result should be the same as though I made a single exposure with an xpan-sized (i.e., 24x60mm) sensor.

So you did not combine two images in PP? Never mind. I'm afraid this discourse isn't profitable. The image turned out very well indeed, and that is what matters.

04-27-2018, 07:27 PM   #1539
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QuoteOriginally posted by WPRESTO Quote
So you did not combine two images in PP? Never mind. I'm afraid this discourse isn't profitable
If so it's only because I'm not explaining myself well. Not the first time that's happened! I'll try again, in case it's helpful to you or anyone else reading.

Most stitched panos are made with an ordinary lens, rotating the lens/camera unit between exposures. Each exposure will have the same pattern of vignetting, and this can be problematic when combining exposures, for the reason you point out.

A shift lens has a larger image circle, allowing one to extend the field of view by shifting the lens laterally, relative to the camera, rather than rotating the lens and camera as a unit. Each exposure will have a different vignetting pattern, because the optical axis of the lens hits a different point on the sensor based on how the lens is shifted. That pattern will be asymmetrical unless the lens is in its neutral (unshifted) position.

In the example above, I made one exposure with the lens shifted about 12mm right of the zero point. This exposure, of the right-hand half of the scene, shows vignetting along the right edge. Then I shifted the lens 24mm left (to 12mm left of the zero point) for the second exposure. This exposure, of the left-hand half of the scene, shows vignetting along the left edge. It's a little confusing (for me, anyway) to think about because a lens projects an inverted image, but by shifting the lens right the sensor picks up more of the left side of the image circle (where the vignetting is stronger), which corresponds to the right side of the subject.

Had I taken a single exposure with zero shift, it would be identical to the above result were you to crop 20% off the right and 20% off the left.

Hope that helps!
04-28-2018, 02:55 AM   #1540
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Pinhole Panorama

Had a play today with a body cap pinhole. Pretty boring subject matter (our backyard) but an interesting experiment. This is 5 vertical frames stitched with Panorama Pro
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04-28-2018, 04:57 AM   #1541
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I do understand the method as I have used a shift lens since way back in the film days, obviously not for panos back then. I have used a tilt/shift in the digital era (=Samyang 24mm) but only to get enormous DOF, not to generate a pano nor to straighten verticals. I was assuming there might be some darkening of all four corners regardless of the shift. It would seem that the "good" corners are moved far enough toward the center of the circle of confusion that there is no vignetting in them. IN THEORY, using shift to generate a pano would cause a little bit of around-the-edge perspective change because of parallax for objects very near the camera position, which rotating the system around the lens' nodal point would not. I doubt very much that such a parallax shift could be detected or would cause problems when stitching (might cause a nearby slender vertical, such as a tree or sign post, to be rendered imperceptibly wider). In theory, if you do not rotate the system around the nodal point when taking multiple exposures for a pano, the parallax changes may generate double images of nearby slender verticals during stitching, but I have made many multi-file panos hand-held and have never detected such a phenomenon.
04-28-2018, 07:21 AM - 2 Likes   #1542
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Agreed that parallax is a non-issue for the vast majority of cases. I think you'd need to have obviously straight lines (e.g., architectural features) in the near foreground for this to become at all noticeable.

Even though it's unlikely to be an issue with the kinds of panos I do, I still try to avoid it. Partly to make it a habit, in case I do ever need it; partly just because it is easy to do and I enjoy learning about such things. Nodal-point rotation solves the problem entirely, as does a shift lens with a tripod mount (i.e., shift the camera relative to the lens rather than the other way around).

---------- Post added 2018-04-28 at 10:33 AM ----------

Same subject, another two-shot shift pano, but this time vertical shift (camera still in landscape orientation). Also using tilt for Scheimpflug focusing.



Pentax K-1, Rokinon tilt/shift 24/3.5
04-28-2018, 12:02 PM - 5 Likes   #1543
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K1 + Venus Laowa 12/2.8

04-28-2018, 05:29 PM - 3 Likes   #1544
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5 image vertical panorama of the Paris Casino Eiffel Tower. Now if we could only eliminate all the tourists except for me.

04-30-2018, 01:24 AM - 2 Likes   #1545
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Stitched panorama of the Florence skyline from atop the cathedral, using the Sigma 17-50mm f/2.8. Cross-posted to the Sigma thread.


Florence panorama 2
by Jonathan MacDonald, on Flickr
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