Lightroom Panorama Projections: Spherical vs Cylindrical vs Perspective

Lightroom’s panorama merge offers three projections. Spherical maps the frames onto the inside of a sphere and suits very wide, tall or multi-row panoramas. Cylindrical maps them onto the inside of a cylinder and suits wide single-row panoramas. Both keep vertical lines upright in a level panorama and bend other horizontal lines; they differ in how they treat the top and bottom of the view. Perspective flattens them onto a plane, keeps all straight lines straight, and suits architecture and narrower panoramas, at the cost of heavy stretching at the edges. The right choice depends mostly on how wide your panorama is and whether it contains straight lines that must stay straight.

This page explains what each projection does to your image, how to choose between them, and how the other options in the merge dialog interact with the projection you pick. For shooting the frames in the first place, see what a panorama is and how to create panoramas in Lightroom.

Why a Panorama Needs a Projection at All

When you turn the camera on a tripod to shoot a panorama, you are recording a slice of a sphere of view around you. A print or a screen is flat. There is no way to flatten part of a sphere without distorting something, the same problem mapmakers face with a globe. A projection is simply the rule Lightroom uses to unroll that curved view onto a flat rectangle, and each rule chooses a different thing to keep accurate and a different thing to give up.

The wider the panorama, the more the choice matters. For a two-frame merge covering 70 degrees, all three projections look similar. For a 180 degree sweep, they look completely different, and one of them (Perspective) may not work at all.

Spherical vs. Cylindrical vs. Perspective at a Glance

• Spherical: What stays straight: Vertical lines (in a level panorama) and the horizon. What bends or stretches: Horizontal lines above and below the horizon curve; the top and bottom are compressed rather than stretched. Best for: Very wide or tall panoramas, multi-row merges, full circle views. Width it handles: Any, up to a full 360 by 180 degrees.
• Cylindrical: What stays straight: Vertical lines everywhere, and the horizon. What bends or stretches: Horizontal lines above and below the horizon curve; the top and bottom stretch if the view is tall. Best for: Wide single-row landscapes and cityscapes. Width it handles: Any horizontal width, including 360 degrees, with modest vertical coverage.
• Perspective: What stays straight: Every straight line. What bends or stretches: Edges and corners stretch more and more as the view gets wider. Best for: Architecture, interiors, flat facades, narrow panoramas. Width it handles: Comfortable up to roughly 100 degrees; never 180.

Spherical Projection

Spherical projection treats the frames as if they were pasted on the inside of a ball with the camera at its center, then unrolls that ball so that equal angles across the scene take up equal distances in the image, both horizontally and vertically. Because it spaces angles evenly in both directions, it can hold a view that is very wide and very tall at the same time, up to a full 360 by 180 degree sphere. Only content close to straight up or straight down gets stretched sideways.

The trade-off is that straight lines curve. If the camera was level, the horizon stays straight and vertical lines stay vertical, but a roofline above or below the horizon bows into an arc, and the bending gets stronger toward the top and bottom of the frame. Tall subjects near the top or bottom also look slightly squashed, because spherical gives every degree of elevation the same height. In open landscapes without many straight lines, this barely shows.

Choose spherical when: you shot two or more rows, the panorama covers a lot of sky and ground as well as width, you are merging a full circle, or Lightroom cannot merge the set with the other projections. It is also the safest first choice when you are not sure, because it rarely fails.

Cylindrical Projection

Cylindrical projection treats the frames as if they were wrapped around the inside of a can with the camera at its center. Unrolled, the horizontal direction is spaced evenly by angle, just like spherical, but the vertical direction is projected flat. That keeps every vertical line vertical, which is why trees, people, poles and the sides of buildings look natural.

Two things give. Horizontal lines that are not on the horizon curve, so a long fence close to the camera or the edge of a road bows up or down. And because the vertical direction is flattened, a panorama with a lot of height starts to stretch near the top and bottom edges: clouds overhead and the ground at your feet grow taller than they should.

Choose cylindrical when: the panorama is a single horizontal row, it is wide (anything from about 120 degrees to a full circle), and it contains vertical subjects you want upright, such as a skyline, a forest edge or a mountain range with people in the foreground. For most classic wide landscape panoramas, cylindrical is the projection that looks the way people expect.

Perspective Projection

Perspective projection, also called rectilinear, flattens the frames onto a single plane, the same way an ordinary non-fisheye lens draws an image. Every straight line in the scene stays straight in the result, whether vertical, horizontal or diagonal. That makes it the natural choice for buildings, interiors, bridges and anything built with right angles.

The cost rises steeply with width. A rectilinear image stretches objects more and more the further they are from the center, so the edges of a wide perspective panorama look smeared and enormous, and the merged file needs a heavy crop. The stretch grows without limit as the view approaches 180 degrees, so a perspective projection can never show a full half circle. When a set is too wide, Lightroom may refuse to merge it in Perspective, or produce a bow tie shaped result with most of the image lost to the crop. The lens distortion page explains the same edge stretching in single wide-angle frames.

Choose perspective when: straight lines are the point of the picture and the panorama is narrow, roughly two to four frames shot with a normal or short telephoto lens. A common use is stitching a few frames to get a wider or higher-resolution view of a facade than a single wide-angle lens could give without converging lines.

Which Projection for Which Scene

• Wide landscape, single row, 120 to 360 degrees: Cylindrical. Try Spherical if the sky or foreground looks stretched.
• Multi-row panorama or one with lots of sky and ground: Spherical.
• Full 360 degree view: Spherical, or Cylindrical if it is a single row.
• Building facade, interior or bridge, under about 100 degrees: Perspective. See architecture photography for keeping verticals straight in camera.
• City skyline: Cylindrical keeps the towers upright; Perspective only if the panorama is narrow.
• Real estate and room views: Perspective for one wall or a narrow view; Cylindrical for a wide room where slight curvature of horizontal lines is acceptable. Real estate photography covers how wide is too wide for interiors.
• Not sure: Click through all three in the merge dialog. The preview updates in seconds, and the right answer is usually obvious once you see them side by side.

Still shooting the frames? How to create panoramas in Lightroom walks through capture and the full merge from start to finish.

How to Choose a Projection in Lightroom

1. Select all the frames of the panorama in the Library or Develop module.
2. In Lightroom Classic, choose Photo > Photo Merge > Panorama, or press Ctrl+M (Windows) or Cmd+M (Mac). The cloud-based Lightroom has the same merge under its Photo menu.
3. In the merge dialog, click Spherical, Cylindrical or Perspective and watch the preview.
4. Adjust Boundary Warp, Fill Edges or Auto Crop (below) to deal with the empty edges.
5. Click Merge. When the source files are raw, the result is a new DNG file that keeps raw editing latitude, so you can still adjust white balance and recover highlights afterward.

Boundary Warp, Fill Edges and Auto Crop

Every projection leaves an irregular outline with empty, transparent areas around the edges. The merge dialog gives you three ways to deal with them, and they behave differently with each projection.

• Boundary Warp stretches the merged image outward until it fills the rectangle, from 0 (no warp) to 100 (fully filled). It keeps more of the picture than cropping does, but it adds its own bending. It works well on Spherical and Cylindrical landscapes, where a little extra curvature in clouds or hills is invisible. On a Perspective architecture panorama it can bend the very lines you chose Perspective to keep straight, so use it lightly there.
• Fill Edges fills the transparent areas with invented content based on the surrounding pixels. It works for sky, water and grass, and fails on detailed or patterned areas. Check the filled edges at 100 percent before keeping them.
• Auto Crop trims the result to the largest clean rectangle. It is the most honest option, but on a wide Perspective merge it can throw away a large part of the image.

A practical combination for landscapes is Cylindrical or Spherical with Boundary Warp somewhere around 50 to 100, then a final crop by eye. For architecture, Perspective with Auto Crop and little or no warp.

Shooting Habits That Make Any Projection Work Better

• Overlap each frame by a third to a half. More overlap gives the stitching more shared detail to match, especially with wide lenses.
• Lock exposure, white balance and focus. Use manual mode and manual focus so every frame matches; Lightroom blends small differences, but large ones show as bands.
• Rotate around the lens, not the tripod. Turning the camera around its no-parallax point stops near and far objects shifting against each other between frames. Parallax explains why this matters most when there is a close foreground.
• Level the tripod base. A tilted base makes the horizon climb or fall across the frames, which every projection then has to bend back.
• Shoot verticals. Turning the camera to portrait orientation gives more height, which leaves room for the projection and crop.

Common Mistakes

• Forcing Perspective on a wide sweep. The edges balloon and most of the image is cropped away. Switch to Cylindrical.
• Using Cylindrical on a multi-row panorama. The sky and foreground stretch tall. Spherical handles height far better.
• Cranking Boundary Warp on architecture. It undoes the straight lines you chose Perspective for.
• Blaming the projection for parallax errors. Ghosted or broken objects near the camera come from rotating around the wrong point, not from the projection. No projection fixes them.
• Judging only the preview. Zoom to 100 percent on the merged file and check seams and filled edges before you delete the source frames.

Try This: One Panorama, Three Projections

Take a wide panorama you have already shot, ideally one with a horizon and at least one building or tree in it. Open the panorama merge and click through Spherical, Cylindrical and Perspective with Boundary Warp at 0, then at 100. Take a screenshot of each of the six previews and put them side by side. Look at three things in each: the horizon, the vertical edges of the building or tree, and how much image survives. Ten minutes of this teaches the differences faster than any explanation.

Frequently Asked Questions

What is the difference between spherical and cylindrical panoramas?

Both space the scene evenly from left to right, so they handle wide panoramas well. The difference is vertical: cylindrical projects the vertical direction flat, so the top and bottom of a tall view stretch, while spherical spaces the vertical direction evenly by angle, so it handles tall and multi-row panoramas without that stretching but squashes the top and bottom slightly. In a level panorama both keep vertical lines upright and both curve horizontal lines away from the horizon.

Which Lightroom panorama projection is best?

There is no single best one. Cylindrical is the usual choice for wide single-row landscapes, Spherical for very wide, tall or multi-row panoramas, and Perspective for architecture and narrow panoramas where straight lines matter. Try all three in the merge dialog, since the preview shows the result in seconds.

Why can Lightroom not merge my panorama in Perspective mode?

The panorama is probably too wide. A perspective projection stretches the edges more and more as the angle of view increases and cannot represent 180 degrees at all, so very wide sets either fail or produce an unusable shape. Use Cylindrical or Spherical, or merge fewer frames.

Should I use Boundary Warp?

For landscapes, usually yes: it keeps image area that cropping would throw away, and the extra bending is rarely visible in natural scenes. For architecture, use little or none, because it curves straight lines. Compare it with Auto Crop on each panorama.

Can I change the projection after merging?

No. The projection is baked into the merged DNG. To try a different one, select the original frames and merge again. Your source frames are untouched, so nothing is lost.

Can Lightroom merge HDR panoramas?

Yes. Lightroom Classic has an HDR Panorama option in the same Photo Merge menu, which merges bracketed exposures and stitches them in one step, with the same three projections. What is HDR explains when bracketing is worth it.