Pano stitching with shift lenses

[DaveB]

Has anyone here experimented with stitching images made by shifting a lens?
For example the following image made using a 40D and the 24mm Canon tilt/shift:



The lens was shifted to the left, to the middle, then to the right. The camera was shifted an equal distance in the other direction (sliding in the QR clamp) to eliminate any parallax issues. The 3 images were then overlaid and cropped in Photoshop.
The major problem I'm having at the moment is controlling the chromatic aberration (for example Lightroom's chromatic aberration controls assume the lens's image circle is centred on the sensor). Has anyone here tried anything similar?

[gstark]

Hi Dave.

Short answer from me on this one is no, but ....

The lens was shifted to the left, to the middle, then to the right. The camera was shifted an equal distance in the other direction (sliding in the QR clamp) to eliminate any parallax issues.

Last week we were playing with the new Nikkor 45 f/2.8 PC on a D700 body, but just doing the usual stuff. We'll be posting something from that shortly, to show one of the uses that you can put a PC lens to.

That leads me to my question: could you please elaborate upon your technique here for us? What you were doing, and why? What were the outcomes you were wanting to achieve? I think that what you're doing is somewhat unusual - even with a PC lens - and I'm sure that there are others who may also be interested to learn from your expertise in this.

[DaveB]

could you please elaborate upon your technique here for us? What you were doing, and why? What were the outcomes you were wanting to achieve?

Just to achieve a particularly wide image. Essentially, if the lens stays in the same position and we move the sensor across the image circle we can get a bunch of overlapping images that need no distortion to blend into a composite panorama. Because the shift lens doesn't have a tripod mount it (rather than the camera) moves when shifted, and we have to move the camera in the opposite direction to move the lens back to the same position.

The only complication I'm having is controlling the lens' chromatic aberrations (I have to do it in Photoshop after layering rather than in the RAW converter).

[gstark]

Thanks, Dave.

So, essentially, it's a variation on the typical pano technique that one might employ, but you're using the lens to get the varying points of view.

Sort of a variation, too, on how the ultra-wide MFs work.

Cool.

[big pix]

Dave, here is a sample of just a 3 shot pano stitched in PSCS3. I shot this as a test just after getting my 24-mm T-S . I have not seen any of the problems that you have en-counted but will have a much closer look. I have done a few of these, but for clients........ have you tried different f stops, as I found f 11 & f 16 to give the sharpest results.



3 shot pano using D300 Nikor 24-mm TS lens. One shot to the left, one in the middle and one to the right

[DaveB]

By the way, this is the centre image of the three:


That's how much you see with 24mm on a 1.6x body. As you can see the shift lens can give us a much wider view. Normally for this type of app I'd use a vertical format (which can be done easily using an L-plate) and shift the lens along the "short" axis of the sensor. This time I was just lazy (it was just a test shot outside college).
These shots were at f/8.

[DaveB]

Dave, here is a sample of just a 3 shot pano stitched in PSCS3.

Nice job. With a scene like that (with no significant foreground elements) you don't even have to shift the camera!

[big pix]

I have done quite a few panos using the 24 mm shift lens, but for clients, with no problems........ some with quite defined foregrounds

....... have you tied stitching using another program rather than Light Room

[DaveB]

have you tied stitching using another program rather than Light Room

Lightroom doesn't stitch. I usually use Photoshop CS3: sometimes PtGUI.

[radar]

Dave,

interesting topic and I see that Bernie has piped up.

I have also done something similar with the Nikkor 28mm PC-E lens. Instead of doing it on the horizontal, I did it on the vertical. I did a panorama, I think of 7 images, then shifted the lens up halfway, did the 7 images and did this one more time. This was done on a levelled panning base with the lens positioned on its nodal point. In the end I wasn't all that happy with the results but that was more due to my screwing up the exposure. Now that I have improved my post-processing skills, I will go and revisit that image and see what I get.

Forgot to mention, I use PTgui for the stitching.

cheers,

André