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Focal length for panos

PostPosted: Mon Oct 13, 2008 11:28 pm
by robert
I've been trying to figure out which lens/focal length to use for panos. I have a panosaurus head which means stitching is generally pretty easy, but I want to be able to have my panos look different than just a centre crop of a really wide angle. This is because I generally dont print bigger than A3 and my 10-22 on a 400D can print with as much detail as I need.

Looking at the angle of view on a 1.6x camera the following horizontal/vertical angle of view:
50mm = 26'/17'
10mm = 97'/74'

Assuming only one row and shooting in portrait it would take almost 6 images (5.7 x 17'=97) @50mm to equal a centre crop of a 10mm in landscape.

How do people use panos/stitching to do something that they couldnt with a really wide angle and subsequent centre crop. Do people do panos with their widest lens or what?

I have printed some panos about 900mm x 250mm but I dont just want to be able to produce big prints- I want to capture things I cant with just one image.
Hope this isnt too confusing- maybe you could just give your thoughts on which FL you use for panos.

Robert PS on reflection maybe it is that the stitched images do yield significantly better prints at A3 size than a single image...

Re: Focal length for panos

PostPosted: Tue Oct 14, 2008 9:02 am
by DaveB
robert wrote:Looking at the angle of view on a 1.6x camera the following horizontal/vertical angle of view:
50mm = 26'/17'
10mm = 97'/74'

Assuming only one row and shooting in portrait it would take almost 6 images (5.7 x 17'=97) @50mm to equal a centre crop of a 10mm in landscape.

Including 20-30% overlap?

How do people use panos/stitching to do something that they couldnt with a really wide angle and subsequent centre crop. Do people do panos with their widest lens or what?

At the moment I'm generally only doing single-row panos. I do panos for several reasons (mainly with 1.6x bodies so far):
  • It provides much higher-resolution results than a single frame.
  • It avoids the distorted edges of the image circle projected by a WA lens (the 10-22mm is one that suffers towards the edges, although compensating for the chromatic aberration in the RAW converter does wonders for the whole image!).
    By using a good zoom lens away from its extreme focal lengths (closer to a "sweet spot" in the zoom) and overlapping the shots, the edges can be MUCH higher quality.
  • I've done a huge pano of the flamingo-filled shore of Lake Manyara (Tanzania) using a 400mm lens. In that case a single frame that covered the scene would only provide less than one pixel per flamingo! And the empty sky and foreground would contribute nothing.
  • I've done panos using a 300mm lens: that was simply to get a higher-res file than I could by cropping a single frame.
Generally I use my 17-40mm or 24-105mm lenses, and while I used to set the focal length so I maximised the vertical pixels by just covering the interesting vertical area (in the case of a horizontal pan) these days I try to take into account how wide I'm going to pan, what aspect ratio final image I want, and thus how high it needs to be.

Re: Focal length for panos

PostPosted: Tue Oct 14, 2008 9:15 am
by big pix
....... the 2 lens I am using for pano's ATM are 50mm 1.8 Nikon Prime, and 24mm PC lens.......... on a D300 body

Re: Focal length for panos

PostPosted: Tue Oct 14, 2008 6:43 pm
by Matt. K
Some of the biggest panos ever produced were taken with the longer focal length lenses. IE 200mm to 300mm. This reduces overall distortion and makes for easier and more accurate stitching.

Re: Focal length for panos

PostPosted: Thu Oct 16, 2008 6:15 pm
by Killakoala
What Matt said, but for overall ease of use, about 24-28mm will sit you nicely in between the distortion versus
flat' look area. A better alternative would be about 70-90mm with 3 levels of height as well as length. It gets more complicated doing it that way but how accurate do you want your panos to be?

Re: Focal length for panos

PostPosted: Fri Oct 24, 2008 12:07 am
by bwhatnall
This has got to be the biggest Pano I have ever done, I have been experimenting with them lately.

Image

I shot it using 24 images at 30mm on my Nikon 18-135. This lowered the distortion that I got. The field of view is almost 180 degrees, though I cropped a bit as you loose corners. It was taken in two rows, starting at the bottom left, panning to the bottom right, then moving the camera up 3/4 of a frame, and panning to the left again.

The main tip I have with panoramas is to shoot with your camera in portrait orientation, this gets rid of almost all distortion when photoshop stitches afterwards, and use photoshop CS3 for stitching, best software I have used yet.

Re: Focal length for panos

PostPosted: Fri Oct 24, 2008 11:22 am
by Yi-P
I use 50 or 85mm lens for panos.

A 137MPix panorama from a build up of lots of 85mm FOV shots made wide angle possible:
CLICK For Image

Re: Focal length for panos

PostPosted: Fri Oct 24, 2008 11:39 am
by gstark
bwhatnall wrote:I shot it using 24 images at 30mm on my Nikon 18-135.


The main tip I have with panoramas is to shoot with your camera in portrait orientation, this gets rid of almost all distortion when photoshop stitches afterwards


Well, it's not PS that's bringing in the distortion though, but your use of a lens at a wide angle.

I'm not convinced that the 18-135 is the best lens for this task, either: the focal length setting may be liable to change as you move the camera through its vertical and horizontal range to capture the images that you need within this process, and that can introduce a totally different form of "distortion" across your images, making it also more difficult to stitch.

It would be better to do this using longer prime, which of course would mean more images, and more stitching. But it would give you far greater granularity, better accuracy at the time of shooting, much greater detail, and less to zero distortion as you stitch.