Editing equirectangular panoramic images can be challenging, especially near the zenit (top) and nadir (bottom) due to the heavy distortion in those areas. A practical solution is to convert the equirectangular image into cube faces, which represent the six sides of a cube (front, back, left, right, top, bottom). This format allows for easier and more precise editing. Once the modifications are complete, the cube faces can be reassembled into a seamless equirectangular panorama.
This guide outlines the complete process using PTGui:
🧊 Step 1: Load the Equirectangular Image into PTGui and convert to Cube Faces
Open PTGui.
In the "Extras" menu, select the option to convert to cube faces.
Add the equirectangular image, set the Jpeg-Quality to 95 if you are using Jpeg, and click "Convert"
🖼️ Step 2: Edit the Cube Faces
Open the six undistorted cube face images in your preferred image editor and apply the necessary edits to the relevant face(s), such as removing a tripod from the nadir or retouching the sky in the zenit.
Save the edited images with the same filenames.
🔄 Step 3: Reassemble the Cube Faces into an Equirectangular Image
Open PTGui.
Load the six edited cube face images. You can simply drag and drop the cube face images from the explorer.
The images are automatically aligned for equirectangular output in the PTGui editor:
3. Go to the "Create Panorama" tab.
4. Choose your desired output resolution and click "Create Panorama".
Converting an equirectangular panorama into cube faces provides precise control over editing problematic areas like the nadir and zenit. PTGui simplifies this workflow, enabling seamless transitions between projections and accurate reassembly of the final panorama. This method is particularly effective for high-quality virtual tours, 360° photography, and professional post-processing tasks.
Thinking a step further, what you really need is the 15,3mm lens reported by PTGui:
As someone who's always appreciated Sigma for their forward-thinking designs, innovation and engineering excellence, I was genuinely pleased to see them take the idea of the CUBE FACE LENS and created one. With its 15,3mm focal length, its perfectly suited for capturing seamless panoramas.
Expect cheap Chinese clones to hit the market soon.
🔗
Reportedly, this lens can focus from 0,2m to 1AU (astronomical unit), so you can have the sun perfectly in focus.
Because sometimes, the best way to solve a problem … is to avoid it entirely in the first place. The 15,3mm cube face lens captures the world in exactly 90° intervals. Just six clean shots stitched with pixel-perfect seamlines, and leave the fisheye theatrics at the door.
Spokane, Washington, nestled along the Spokane River in the eastern part of the state, is known for its rich history, vibrant arts scene, and stunning natural surroundings. Named after the Spokane Tribe, 'Children of the Sun' in the Salish language, the city reflects deep indigenous roots and natural beauty.
All pictures and panoramic images are taken with 1/1000s f/5,6 ISO 100/21° f=7,5mm, unless noted otherwise.
🏥 UW
Our journey begins at the University of Washington School of Medicine's Spokane campus, where the first panorama captures the academic heart of the city.
Spokane's green centerpiece, once the site of Expo '74, is now a vibrant public space full of history and movement. Bridges connect the city to Havermale Island, where some panoramas were taken.
The view here spans from the upper Spokane Falls to the Pavilion, capturing the park's dynamic blend of nature, architecture, and community life.
This particular panorama proved trickier than expected. Without a tripod, aligning the frames by hand made it difficult to maintain precise rotation around the nodal point, which is essential for perfect stitching. I even added an extra frame to help with stitching, but small imperfections remain.
Still, the result captures the essence of the scene, even if a few pixels had a mind of their own. Sometimes, the story behind the image is part of the image itself.
The Spokane River winds through the city, carving its path through stone and story alike. Along its banks, trails, bridges and parks invite exploration. The panoramic images captures the river's flow near one of its quieter bends, where reflections of sky and trees ripple across the surface.
Framed by Steel: A View Through the Bridge
River bend
Sunlit Walk Along the Water
More Pictures Along the Riverside
A single dead tree stands between the walkway and the riverbank. Its bare branches reaching skyward in contrast to the lush greenery around it.
Why did it die? Was it disease, drought, or simply age?
Its presence adds a quiet tension to the scene, a reminder that even in places full of life and movement, stillness and decay have their place too.
Spokane offers a wide spectrum of hotel experiences, like a roulette wheel of hospitality. On one end, you've got places like the Ramada by Wyndham, where the décor is "early abandonment", the guests are... let's say colorful, and the rooms come with a complimentary layer of grime. On the other end, there are sleek 4-star hotels that promise luxury but sometimes deliver lukewarm service and Yelp reviews that read like cautionary tales. And in the middle? The classic 3-star American hotel, where breakfast includes a waffle machine, questionable eggs, and the lingering scent of disappointment. Choose wisely, or at least pack your sense of humor.
We were lucky. Tucked into a quiet neighborhood, our apartment served as a perfect base for exploring the city. With morning light filtering through the windows and the scent of pine in the air, it offered a peaceful retreat.
Our journey ends where we first arrived, and we leave Spokane behind with memories captured in light and lines.
Spokane International Airport welcomes visitors with a mix of regional charm and modern convenience. The terminal's open design and surrounding pine-dotted landscape offer a first glimpse of the Inland Northwest's character.
The windows facing the airfield are tinted with a subtle blue hue, and be corrected by adjusting the white balance (photos were taken using the sunlight white balance setting).
Forty minutes later, we rolled into Seattle and the Spokane chapter came to a close, pixels packed, panoramas pending, and the last bit of sunlight archived in RAW.
The AstrHori 6.5mm f/2 Fisheye Lens is a manual focus Circular Fisheye Lens for APS-C cameras with a 192° field of view.
Best general setting is at the 1m mark and f/5.6. This puts everything from near to infinity in focus.
The AstrHori 6.5mm Fisheye Lens fills the entire APS-C sensor with its 192° field of view, unlike the Laowa 4mm Circular Fisheye, which projects a 210° image circle that does not fully cover the frame.
AstrHori 6.5mm
Laowa 4mm
However, with only 192° of coverage, the AstrHori 6.5mm makes it difficult to capture a full 360x180° panorama using just two images. In contrast, the Laowa 4mm performs much better in this regard thanks to its wider 210° field of view.
Example 360x180° panorama with two pictures using the AstrHori 6.5mm Fisheye Lens:
1/800s f/5,6 ISO 100/21° f=6,5mm
Both images must be perfectly aligned using a nodal point adapter. If the camera is even slightly off-axis, parallax errors can occur, which may lead to visible stitching artifacts like this because of the missing overlap:
A 360x180° panorama created from only two images relies solely on control points along the left and right edges. Unlike multi-image panoramas using 6+Z+N shots1, there is no flexibility for adjustment in other areas of the frame.
To improve the quality of a 360x180° panorama, three images should be taken at 120° intervals with the camera slightly tilted upward, along with an additional Nadir (bottom) shot to cover the ground area and eliminate potential shadows.
1/1000s f/5,6 ISO 100/21° f=6,5mm
The three slightly upward-tilted shots capture the sky seamlessly, while the Nadir takes care of the floor details:
But this only yields a final resolution of 8k by 4k. A two-shot fisheye panorama is 7k by 3.5k, which is already quite limited. In contrast, a full-frame fisheye panorama captured using 6+Z+N gets 16k by 8k.
All resolutions are based on a 20MP camera.
Surprisingly sharp in the corners for such an affordable lens. A clear improvement compared to the old Zenitar, which was my first fisheye lens and handled sharpness like it was optional and felt more like a Cold War relic than an optical instrument.
Not sure how the Peleng even compares, but for a circular fisheye on full-frame cameras at that time, it seems better suited for museum display than modern photography.
1/800s f/5,6 ISO 100/21° f=6,5mm
And nice sunstars:
1/800s f/5,6 ISO 100/21° f=6,5mm
Only a Circular Fisheye can capture this:
1/400s f/5,6 ISO 100/21° f=6,5mm
With the focus set to its minimum distance, the leaf is actually touching the front element of the lens. This is one of the drawbacks of this lens: you cannot make those funny fisheye closeup shots. The Laowa 4mm is much better in this regard with its extreme close focus capability.
1/800s f/5,6 ISO 100/21° f=6,5mm
More examples shot with the AstrHori 6.5mm lens on a Nikon Z30:
1/800s f/5,6 ISO 100/21° f=6,5mm
1/640s f/5,6 ISO 100/21° f=6,5mm
1/640s f/5,6 ISO 100/21° f=6,5mm
1/800s f/5,6 ISO 100/21° f=6,5mm
1/800s f/5,6 ISO 100/21° f=6,5mm
1/800s f/5,6 ISO 100/21° f=6,5mm
1/1000s f/5,6 ISO 100/21° f=6,5mm
1/1000s f/5,6 ISO 100/21° f=6,5mm
1/1000s f/5,6 ISO 100/21° f=6,5mm
1/1000s f/5,6 ISO 100/21° f=6,5mm
Summary
✅ AstrHori 6.5mm: Best for general fisheye photography, great sharpness, sunstars, and APS-C coverage.
✅ Laowa 4mm: Best for minimal-shot 360x180° panoramas and creative close-up fisheye fun.
✅ TTArtisan 7.5mm: Best for general 360x180° panoramas.
❌ AstrHori 6.5mm: Not ideal for close-ups or minimal-shot panoramas.
❌ Laowa 4mm: Weaker in flare resistance.
❌ TTArtisan 7.5mm: Beware the lens cap: it has a mind of its own and occasionally makes a break for freedom. Even with a fix in place. A true escape artist.
6+Z+N refers to a common panoramic shooting technique used with full-frame fisheye lenses: six horizontal shots taken in portrait orientation around a central point, plus one shot each for the Zenith (top) and the Nadir (bottom) views. ↩
It’s finals week for spring quarter at the University of Washington (UW), and graduation celebrations are just beginning. The weather is good, and with the UW campus full of open spaces and interesting buildings, it’s the right time for panoramas and for capturing every pixel from zenith to nadir.
All panoramas photographed that day were taken without a tripod using a Nikon Z30 with a 7.5mm Fisheye Lens. In the library, this was necessary anyway, since photography is allowed but tripods are not permitted in the UW Libraries.
Red Square
This panorama captures Red Square, a central open space on the University of Washington campus known for its iconic views and architectural surroundings.
Suzzallo Library stands as one of the University of Washington’s most iconic buildings, with its grand Gothic architecture lending a timeless presence to the campus landscape.
The Statue of George Washington stands at the west end of Red Square, a longstanding symbol of the university’s heritage and a familiar landmark for students and visitors alike.
The Suzzallo Library and the Statue of George Washington are partially visible in the background, adding a subtle sense of place and history to the scene.
The Quad is a beloved green space on campus, especially known for its breathtaking cherry blossoms each spring and its peaceful, tree-lined walkways year-round.
It’s probably called The Quad because it was easier than explaining That Big Square Where Everyone Takes Cherry Blossom Pics. Besides, calling it The Quadrangle sounds like a spell Hermione would cast right before finals.
Airplane spotted cruising at tree level. Must be a scenic route.
Smith Hall and Miller Hall
Smith Hall and Miller Hall stand side by side along the edge of the Quad, their classic collegiate architecture framing the space with a sense of tradition and academic purpose.
Denny Hall, the oldest building on campus, stands with timeless elegance, its Romanesque architecture marking the historic beginnings of the University of Washington.
The School of Art and the School of Music sit near the edge of campus, where creativity and performance shape a vibrant cultural presence within the university’s academic landscape.
In panoramic imaging, particularly in architectural or urban settings, a common source of stitching artifacts occurs when prominent structures such as building façades are captured in separate frames rather than as a whole within a single exposure. This segmented capture approach increases the risk of misalignment during the stitching process, often resulting in visible seam lines that disrupt the continuity and geometry of key architectural features.
In this panorama, the two building façades are each captured in separate frames but have been (green) masked to ensure that no seam line intersects the primary architectural elements, preserving structural integrity in the final composite.
School of Art
The School of Art combines creativity and academic depth, giving students a place to study classic forms like drawing, painting, and sculpture.
The Communications Building houses the university’s journalism and communication programs, offering students a dynamic space to explore media, storytelling, and public discourse.
Drumheller Fountain sits at the center of Rainier Vista, offering a stunning reflection of Mount Rainier on clear days and serving as a scenic focal point surrounded by some of the campus’s most iconic buildings.
Rainier Vista is a grand, tree-lined axis that stretches from Red Square to Drumheller Fountain, offering a sightline to Mount Rainier on clear days and serving as one of the campus’s most iconic visual corridors.
The Rainier Vista Northeast Bridge spans a key pedestrian route near the end of the vista, offering elevated views of Drumheller Fountain and the surrounding landscape while connecting key parts of the campus with ease and elegance.
The bridge to Husky Stadium provides a vital pedestrian link between the main campus and the athletic complex, guiding fans and students alike across Montlake Boulevard with sweeping views of Union Bay and the stadium’s iconic silhouette.
Equirectangular projection of the information sign.
1/1000s f/5,6 ISO 100/21° f=7,5mm
Rectilinear projection of the information sign.
Viewpoint 2
Within a minute, the weather shifted from sunny with clouds to overcast and windy.
Panorama Timestamps:
Time
Weather
Action
09:45:18
⛅
09:45:21
⛅
09:45:24
⛅
09:45:27
⛅
move the bicycle
09:45:45
☁️
again move the bicycle
09:46:10
☁️
09:46:12
☁️
09:46:15
☁️
remove the camera from the nodal adapter1 and prepare for the nadir2
09:46:27
☁️
The forecast was ⛅ until noon. This is what the actual weather turned out to be:
The panorama vividly captures the swift weather change, with the shadow gradually fading in the final pictures, creating an eerie emptiness.
And the Cybertruck nearly obscured Mount Rainier.
After last week’s abrupt stop due to clouds and wind, I finally got the chance to pick up where I left off. Today couldn’t have been more different—clear skies, warm light, and perfect conditions for capturing the panoramas I had planned.
The elders say the sky speaks to those who listen. I stood on sacred ground, raised my hand to the wind, and the eagle came—gliding from the sunlit heights, answering the silent call of the tribe. In that moment, the spirit of the sky revealed itself, and I captured its flight in a single frame.
In moving traffic, it's always possible that vehicles are only partially captured. To prevent this, multiple shots were taken, which were also used to reduce the number of vehicles on the road. In this case, not all images are fully connected to each other via control points. Only the original images are.
The duplicate images are then linked only via control points. This makes everything much simpler.
View from the other side of the canal.
1/1000s f/5,6 ISO 100/21° f=7,5mm
GPS map
To create the GPS map in cPicture, select the pictures with GPS data and click the map icon in the toolbar.
To get all panoramic images with GPS, enter the following in the search box at the upper right:
360x180.jpg %gps=1
This search performs two functions:
360x180.jpg matches all panorama images with filenames ending in this pattern. Adjust this part if a different naming convention is used.
%gps=1 filters for images that contain GPS metadata.
After the search completes, select all images from the search result to display on the map.
For landscape-style panoramas, a nodal adapter on a tripod isn't necessary. However, with close objects like the guard rail, a nodal adapter is recommended. ↩
In panorama photography, the nadir is the point directly below the camera. PTGui's viewpoint correction makes handheld nadir pictures easy to stitch. ↩
This panorama was captured from 7 vantage points on the observation platform.
Almost like The Tower Panorama.
A total of eight images were used to create the panorama. One additional shot (#4) was taken moments later to capture a boat that had just entered the scene. Since this image was slightly out of alignment, it was registered to the first frame using control points and selectively masked to seamlessly integrate the boat into the final composition.
