Panoramas

[FiestaRed]

A great number of my images are panoramas, usually between four and six shots done in portait. I normally gauge the turning angle for panoramas by moving the camera round two notches on the scale marked around my ballhead. Today I used a 70-200 lens at 150mm instead of the 24-70 I always seem to turn to and the image wouldn't stitch together. I'm guessing that the extra length on the lens meant that I moved the camera to far of an angle.

Would using a nodal rail help providing I offset the camera the correct distance when I use the longer lens? That way I could still move the camera the same two notches on the ballhead.

 

[Kodiak Qc]

Would using a nodal rail help providing I offset the camera combo the correct distance when I use the longer lens?

Yes Mike but getting the right length is critical!

I realise that I MISUNDERSTOOD the OP!

 

[StewartR]

Would using a nodal rail help providing I offset the camera the correct distance when I use the longer lens? That way I could still move the camera the same two notches on the ballhead.

No.

The issue here is to do with the angular field of view - in other words how much you rotate the camera between shots, not which point you rotate it about.

Let's imagine you're using your 24-70mm lens at 50mm, in portrait orientation, on a full frame camera. Your field of view is 27° wide, which means that if you rotate the camera by 27° between frames they will butt up against one another with no overlap. In practice you want a bit of overlap, so you might want to rotate the camera by (say) about 20° between frames. If that's two notches on the ballhead, that implies each notch equates to about 10° of rotation.

But when you shoot at 150mm on a 70-200mm lens, your field of view is obviously much narrower. In fact it's only 9° wide. So you need to rotate the camera much less between frames than previously. Even one notch on the ballhead, which we've estimated might be about 10°, would be too much and would leave you with frames that don't overlap.

Does that make sense?

Fancy panoramic heads like the Nodal Ninja are only required when you have objects in the panorama which are close to the camera. In that situation it's important to avoid parallax errors, and the way to do that is to rotate the camera around the nodal point. But for landscape panoramas, where everything is at a reasonable distance, parallax isn't a big deal and you can even shoot hand-held.

 

[FiestaRed]

No.

The issue here is to do with the angular field of view - in other words how much you rotate the camera between shots, not which point you rotate it about.

Let's imagine you're using your 24-70mm lens at 50mm, in portrait orientation, on a full frame camera. Your field of view is 27° wide, which means that if you rotate the camera by 27° between frames they will butt up against one another with no overlap. In practice you want a bit of overlap, so you might want to rotate the camera by (say) about 20° between frames. If that's two notches on the ballhead, that implies each notch equates to about 10° of rotation.

But when you shoot at 150mm on a 70-200mm lens, your field of view is obviously much narrower. In fact it's only 9° wide. So you need to rotate the camera much less between frames than previously. Even one notch on the ballhead, which we've estimated might be about 10°, would be too much and would leave you with frames that don't overlap.

Does that make sense?

Fancy panoramic heads like the Nodal Ninja are only required when you have objects in the panorama which are close to the camera. In that situation it's important to avoid parallax errors, and the way to do that is to rotate the camera around the nodal point. But for landscape panoramas, where everything is at a reasonable distance, parallax isn't a big deal and you can even shoot hand-held.

Thanks Stewart, that makes perfect sense. I never even gave a thought to the field of view difference between the two lens. Thanks for a very clear explanation, brilliant.

 

[StewartR]

Thanks Stewart, that makes perfect sense. I never even gave a thought to the field of view difference between the two lens. Thanks for a very clear explanation, brilliant.

You're welcome. Thanks for the thanks.

 

[Craig_85]

@StewartR has got it.

Nodal slide makes jack difference at longer focal lengths, only really a benefit with wide angles and part of the image being closer to camera.

 

[Terrywoodenpic]

Why even bother with notches on the ball head.
Use live view on a DSLR.
Take your first shot. look at the image, and note an object about a quarter of the way in from one side .
swing the lens to fit the same object on the edge of the other side, and take another shot
Repeat till every thing is covered.
If any object is close to you, take an extra shot that gets it all in in one go, so that you do not get stitching problems through parallax.
(it makes no difference if the overlap varies.)

QED.
Nodal slides can be useful for setting the non rotation point. (nodal point), but are not necessary except when close objects are included, especially with wider lenses.

 

[FiestaRed]

Why even bother with notches on the ball head.
Use live view on a DSLR.
Take your first shot. look at the image, and note an object about a quarter of the way in from one side .
swing the lens to fit the same object on the edge of the other side, and take another shot
Repeat till every thing is covered.
If any object is close to you, take an extra shot that gets it all in in one go, so that you do not get stitching problems through parallax.
(it makes no difference if the overlap varies.)

QED.
Nodal slides can be useful for setting the non rotation point. (nodal point), but are not necessary except when close objects are included, especially with wider lenses.

Using the notches on the ballhead has in the past (using the same lens) always given me better, more accurate results for stitching than using live view. On this occasion though and through my own daft and very basic mistake it let me down.

 

[Terrywoodenpic]

Using the notches on the ballhead has in the past (using the same lens) always given me better, more accurate results for stitching than using live view. On this occasion though and through my own daft and very basic mistake it let me down.

I have no idea why you had a problem using live view as it makes no difference to the stitching software. PTGui and PTAssembler do not even have problems if you change orientation or focal length, shot to shot.
However, mostly I shoot mine hand held outside, using the viewfinder freehand. I have never had a problem doing it this way, even when Shooting moving subjects and people in the shots. Modern stitching programs make light work of such things. However programs like photoshop / lightroom are very restrictive. And would blow a fuse.
When shooting interiors with close objects or combining exposure fusion. Is when I break out the tripod and panoramic head.