# Luminous Landscape Forum

## Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: davewolfs on May 29, 2009, 02:09:44 pm

Title: How much field of view when using shift lenses for Panos
Post by: davewolfs on May 29, 2009, 02:09:44 pm
Hey everyone,

I'd like to know, how much more coverage you get when doing a maximum shift in each direction with say a 24mm or 17mm tilt shift lens.  If there is an online calculator I'd appreciate the link.

Thanks,

Dave
Title: How much field of view when using shift lenses for Panos
Post by: JeffKohn on May 29, 2009, 03:10:02 pm
The math is pretty basic, you just have to factor it based on sensor size, since 10mm shift is a greater relative increase on DX compared to full-frame.

For instance with 16x24mm sensor, stitching with 10mm horizontal shift in each direction results in an image of roughly 16x44mm (a bit less after cropping to clean up the stitch), or about an 85% increase in horizontal FOV.
Title: How much field of view when using shift lenses for Panos
Post by: davewolfs on June 03, 2009, 09:09:49 pm
Thanks for the response.  Sorry if this is a dumb question, but take the following scenario.  If you are using the shift functionality of the lens for stitching panoramas if I had my camera placed on a sliding rail and I were to shift the camera 12mm vs shifting the lens 12mm, would I be able to expand my FOV by the same amount using either method?
Title: How much field of view when using shift lenses for Panos
Post by: Kirk Gittings on June 03, 2009, 11:19:09 pm
There is a quality factor involved. I do these shifts every day almost for clients. A full shift in both directions with the current 24 t/s (not the one coming) will give you significant fall off in the corners requiring some cropping. So measuring the effective FOV is not that straightforward. I also have a 6" sliding platform, but rarely use it as it contributes very little to the field of view.
Title: How much field of view when using shift lenses for Panos
Post by: BernardLanguillier on June 04, 2009, 07:46:39 am
Quote from: davewolfs
Thanks for the response.  Sorry if this is a dumb question, but take the following scenario.  If you are using the shift functionality of the lens for stitching panoramas if I had my camera placed on a sliding rail and I were to shift the camera 12mm vs shifting the lens 12mm, would I be able to expand my FOV by the same amount using either method?

No.

- moving the camera has almost no effect on FOV
- shifting the lens results in a movement of the projection of the scene on the sensor by that amount and should be thought about in angular terms.

Regards,
Bernard
Title: How much field of view when using shift lenses for Panos
Post by: AlanG on June 04, 2009, 10:38:13 am
When I did panos with the 24 TSE, I used a sliding rail to re-center the lens axis after shifting. So it did not contribute to a wider field of view. I have since found that panos work much better by using a pano head and then making a rectilinear pano. (Planar mode in Autopano.) This easily works for up to 120 degree wide panos.  Wider panos can be stitched in spherical mode and then may be somewhat corrected using the warp tool in CS4.

I posted examples below. The first one used a 16mm lens tilted up with the camera in a vertical position shooting 4 frames.  The convergence was corrected in Autopano. No single shot camera could have produced this perspective. (I was very close to the building. The foyer shots illustrate a spherical image where the curve was mostly corrected via the warp tool and a wider one that curves.
Title: How much field of view when using shift lenses for Panos
Post by: dasams on June 14, 2009, 04:15:31 pm
Quote from: JeffKohn
The math is pretty basic, you just have to factor it based on sensor size, since 10mm shift is a greater relative increase on DX compared to full-frame.

For instance with 16x24mm sensor, stitching with 10mm horizontal shift in each direction results in an image of roughly 16x44mm (a bit less after cropping to clean up the stitch), or about an 85% increase in horizontal FOV.

Taking this a step further, let's compare the *horizontal* angle of view of a 24 mm lens with and without stiching.  The stated *diagonal* AOV is 84 deg which applies to a full frame sensor.  By my trig, the horizontal AOV is 73.7 deg.  If the lens is shifted 10mm in each direction and then stitched, the result would be equivalent to a photo taken with a sensor that is 24mm tall and 36+20=56mm wide and the horizontal AOV would be 98.8 deg.  This corresponds to a lens with a 15.4 mm focal length which would have a diagonal AOV of 109 deg.  For comparison, the AOV of a 14 mm lens is 114 deg while a 17 mm is 104 deg.  That help?  Dave
Title: How much field of view when using shift lenses for Panos
Post by: davewolfs on June 15, 2009, 12:03:29 pm
Quote from: dasams
Taking this a step further, let's compare the *horizontal* angle of view of a 24 mm lens with and without stiching.  The stated *diagonal* AOV is 84 deg which applies to a full frame sensor.  By my trig, the horizontal AOV is 73.7 deg.  If the lens is shifted 10mm in each direction and then stitched, the result would be equivalent to a photo taken with a sensor that is 24mm tall and 36+20=56mm wide and the horizontal AOV would be 98.8 deg.  This corresponds to a lens with a 15.4 mm focal length which would have a diagonal AOV of 109 deg.  For comparison, the AOV of a 14 mm lens is 114 deg while a 17 mm is 104 deg.  That help?  Dave

The first post states that the increase in FOV is relative to the shift in MM.  So for example, a FF Sensor that is 24x36 experiencing a 10mm shift in both directions is an increase of approx 56%.  So that said, wouldn't the increase in the horizontal field of view be 56% by shifting both ways with a 24mm lens, therefore a 24mm lens which normally has a FOV of 73.7 deg results in having a horizontal FOV of 114.97 deg?
Title: How much field of view when using shift lenses for Panos
Post by: dasams on June 15, 2009, 05:08:33 pm
Quote from: davewolfs
The first post states that the increase in FOV is relative to the shift in MM.  So for example, a FF Sensor that is 24x36 experiencing a 10mm shift in both directions is an increase of approx 56%.  So that said, wouldn't the increase in the horizontal field of view be 56% by shifting both ways with a 24mm lens, therefore a 24mm lens which normally has a FOV of 73.7 deg results in having a horizontal FOV of 114.97 deg?
The angle of view and the physical width it captures are not linearly related.  For example, if you are standing 10 ft in front of a brick wall with a 24 mm lens, you'll be able to capture 15ft of the wall.  Increasing the capture by 56% to 23.4 ft requires an AOV of 98.9 deg, not 114.97 deg.  The wider the angle, the more nonlinear the relation between angle and the amount of capture.  dave
Title: How much field of view when using shift lenses for Panos
Post by: AJSJones on June 15, 2009, 11:09:02 pm
Quote from: davewolfs
Hey everyone,

I'd like to know, how much more coverage you get when doing a maximum shift in each direction with say a 24mm or 17mm tilt shift lens.  If there is an online calculator I'd appreciate the link.

Thanks,

Dave
Here (http://www.cambridgeincolour.com/tutorials/tilt-shift-lenses1.htm) is an online calculator that seems to do (some of) what you need

Cheers
Andy
Title: How much field of view when using shift lenses for Panos
Post by: JeffKohn on June 16, 2009, 10:18:47 am
Quote from: davewolfs
The first post states that the increase in FOV is relative to the shift in MM.  So for example, a FF Sensor that is 24x36 experiencing a 10mm shift in both directions is an increase of approx 56%.  So that said, wouldn't the increase in the horizontal field of view be 56% by shifting both ways with a 24mm lens, therefore a 24mm lens which normally has a FOV of 73.7 deg results in having a horizontal FOV of 114.97 deg?
My post was misleading, the proportional relationship holds for the equivalent focal length, not the actual field of view. (Which makes sense if you think about it, since we know focal length and FOV are not directly proportional).

For instance if I use my 24mm TS-E on a DX lens, I can take 3 vertical shots with 10mm shift in-between, and end up with a capture area of roughly 24x36mm, which just happens to be the same as if I had taken a single 24mm shot with a full-frame camera. Which also means the FOV would be the same as if I had taken a single 16mm shot on DX.