kinda dumb pano question

Was thinking the other night about trying a panoramic shot at a historic rail terminal in NJ. But I started thinking about the 2 furthest points of the shot, the left and right edge of the photo.

I had wondered instead of using the same focal length for the entire frame and having the sides drop off and become farther away, would it be possible to change focal lengths for the shots that go away from the center?

Something like for example, instead of doing maybe 50mmx50mmx50mmx50mmx50​mm. Maybe have 75mmx65mmx50mmx65mmx75​mm. Is this even possible or worth trying?

If you think about it for a moment, you will realize that there would be absolutely no way to match up adjacent photos that were made with different focal lengths (unless you cropped the ones that were taken with a shorter focal length to match the ones taken with the longer focal length).

In making a single panoramic photo you match up features in adjacent images to blend them as one image.

i know you match up or overlap usually by 1/4 or 1/2 a shot. But it was something i had thought about quickly and didn't think about certain things. But it answers my question that it can't be done.

2005GLI wrote in post #3129211
But it answers my question that it can't be done.

There are other ways to remove the "bulging in the middle" effect. One way is to shoot at a 50mm plus focal length which will reduce the effect. 80mm to me is best as it will give you a natural line of sight.

The other way if shooting below 50mm is to try the fish eye lens correction trick: You basically distort your end result to correct the "fish eye" effect you got after blending.

This approach has many pitfalls, namely:

1) The left and right sides become stretched
2) The middle becomes squashed
3) You lose top and bottom detail

But a way around the problems is to do two panos, half and half of the scene. Do the fish eye correction and then merge the two panos, after correction, together.

You may also want to do a muli-row pano because of the detail you lose at the top and bottom. Always shoot in portrait when doing a pano.

This is an example of a one-step pano being corrected. If this was three separate panos, I could correct with much less of a distortion and then blend the three panos together.

Make sense?

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I shoot 180 degree panos with my 70-200 at 70mm in portrait mode. You will have to avoid parallax.

I highly recommend Panorama Factory for processing them.

cosworth wrote in post #3129389
I shoot 180 degree panos with my 70-200 at 70mm in portrait mode. You will have to avoid parallax.

Ah, can't fix those they are intended to look that way. Agree about getting a Pano Head.

cosworth wrote in post #3129389
I highly recommend Panorama Factory for processing them.

Same recommendation here.

Can't fix? Nothing to fix, they look natural.

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Sorry Jason, missed the 70mm part I meant where the subject matter is quite close and one is doing a 180 degree pano.

Nice pano by the way, did you use an ND Grad with that? Nice blending.

Yeah a cokin ND. It is a bit overkill on this shot however.

Cool, gives me faith in using my ND Grads in panos too (off to Italy in a month). Did you use a 2-stop ND Grad? Doesn't look like it needed a grad filter. Like the idea of the tops of trees in the foreground.

The mountain tops were blending into the sky too much. Once I got the rig set up it wasn't really needed. Plus there was this ugly cloud darkening the trees by then too.

why shoot a pano in portrait? If tomorrow is like what today was im going over to the station. Only bad part is, you are not allowed to use a tripod on any transit property. So i gotta find myself a pole to lean against. I thought about the monopod, but i really dont want to be hassled at all if someone does say something to me.

2005GLI wrote in post #3132173
why shoot a pano in portrait?

Because you get more "height" in your final pano and more space to work with. It may take more shots but is worth it in the end.

I did my night shot, in earlier post, like this. See how the corrected image is shorter, this is what it would have looked like if I had initially shot in landscape.

Try it. Shoot exactly the same scene, without changing the focal length, in portrait and in landscape. Join them and see which one has more height.

2005GLI wrote in post #3127082
I had wondered instead of using the same focal length for the entire frame and having the sides drop off and become farther away, would it be possible to change focal lengths for the shots that go away from the center?

Something like for example, instead of doing maybe 50mmx50mmx50mmx50mmx50​mm. Maybe have 75mmx65mmx50mmx65mmx75​mm. Is this even possible or worth trying?

SkipD wrote in post #3127319
If you think about it for a moment, you will realize that there would be absolutely no way to match up adjacent photos that were made with different focal lengths (unless you cropped the ones that were taken with a shorter focal length to match the ones taken with the longer focal length).

No it's not worth trying.

You can vary the focal length as you shoot the the different photos. I actually did this by accident once. I was using a zoom lens on a tripod and I must have accidentally zoomed between shots as I rotated the camera to the next position. I didn't even notice that I'd done it until I saw the end result: Autostitch stitched the photos together without any complaints whatsoever.

But the reason it's not worth trying is that Autostitch stretches some of the pictures to make sure that the corresponding details line up. What you get is something like this:

xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx
xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx

And then you effectively have to crop the ones taken with the shorter focal length (the 3 on the left here), as SkipD observed. (Or you can leave it as is, but it looks strange!) When I get home I'll see if I can find my accidental experiment to show you.

Here it is, for your amusement. The pano is comprised of 9 photos; the first 5 shots were at f=24mm, and the last 4 were at f=21mm. AutoStitch didn't complain at all.

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