Basics of Panoramic & Mosaic Image Making

Written by Ernesto Santos on 31 December 2015.

You see an outdoor scene that strikes you. It is so compelling and inspiring that you want to somehow fit it all into your photograph. Your first instinct is to grab your widest lens and position your camera so that all the features of that glorious landscape are in the frame.

You do your best to make sure you get a good exposure and sharp focus. Done! A triumph! You go home beaming and you anxiously open the image file on your computer. Once open you are immediately disappointed. What happened to that awe-inspiring vision? The light looks right, and it is tack sharp, but the overall effect is underwhelming to say the least. So what happened? Pretty simple, your image is the victim of lens focal length characteristics and how our eyes and brains perceive what has been captured as a digital image.

By using a super wide-angle lens to get as much of the landscape within the frame as possible certain things happen optically, and with our physiology, that work against all our efforts to make that compelling image. For one, wide-angle lenses have the propensity of making far-away objects look smaller than they do to our eyes. That beautiful snowcapped mountain in the distance looks inspiring in real life through our eyes, but when captured on the camera sensor, with lenses considered wide-angle in focal length, that same mountain shrinks in size relative to the foreground. It also now looks much farther away. This phenomenon also affects objects and features in the mid-section of the frame, although to a lesser degree. Lastly, things in the immediate foreground look disproportionately larger and somewhat elongated. This effect is even more pronounced when the shot is taken from a low angle, close to the ground.

When we look at a photograph our eyes and our brains follow a process to analyze and interpret what we are seeing. This process involves looking for things to focus on, commonly called anchor points. In addition, as our eyes scan the image our brain wants to create a narrative, a story which helps stir our emotions helping to round out the experience. Framing a wide-angle scene where there is a lot of detail to process, compounded by our noble but misguided attempts to fit it all in, is what quickly leads to uninspired imagery. Successful landscape photographers know this and tailor their efforts to avoid these pitfalls.

This article isn’t necessarily about how to change your approach regarding framing and perspective, but to go through the basics of using a different photographic image format to help you avoid that cluttered and chaotic look. By changing the format of the image to a wide panoramic style or by building a composite image called a mosaic, using several rows and columns of pictures, we can have our cake and eat it too.

WHAT IS A PANORAMA AND MOSAIC?

A panorama, according to Google search definitions is: “An unbroken view of the whole region surrounding an observer.” I think that is a pretty good description. I’m often asked how wide should a panorama be? And what are the rules of proportion? Well, I wish I could rigidly say it has to be at least three times as wide as it is tall. That is actually a nice proportion but it doesn’t work in every situation. Here are a few guidelines I like to follow.

Include only visual information that adds to the image. In fact, this is a good thing to think about with all manner of photography.
Try to attain that all-important narrative. Don’t extend the boundaries of the panorama image just to make it wide. More so than standard, single-frame imagery a panorama asks a lot of the viewer – he/she must visually scan a lot of information. Keep it interesting, don’t go wider than you need to, tell a story, and stir the emotions.
Take into consideration how big the image will be when processed. This is especially important if you plan to make a big print to hang on your wall.
A word on very long panoramas. Do you really want to make something that at a distance looks like a long, thin ribbon? These might be appropriate in a historical, documentary, or surveying context, but not so much as fine art photography. Remember that the wider the image, the closer you have to get to the print to see detail.

Mosaics are simply one image made from a composite of many frames stacked in rows and columns. These tend to have a more traditional aspect ratio akin to single frame images but because they are made of several, sometimes even hundreds of frames, they can have incredible resolution. If you want to silence the pixel peepers once and for all, show them a mosaic made with a 36 megapixel camera consisting of just four rows and four columns. The resolution of even this modest size will blow them away.

PC-Nikkor 35mm f/2.8 AI-S, ca. 1980 PC-E Nikkor 24mm f/3.5D ED Tilt-Shift Lens, current model

LENSES

It doesn’t take specialized camera lenses to make really great panoramas and mosaics. Any high-quality lens for your camera will do, but I do have my favorites. A surprising thing is that you can make great images with short telephoto focal lengths. You don’t always need to reach for your wide-angle lens. Personally, my favorite general purpose focal length is 35 mm for a full frame 35 mm DSLR. But I also commonly use a mid-range zoom like a 24-70 mm and a short telephoto like a 70-200 mm. Of course, any of the fixed-focal prime lenses can be used as well. By the way, that 35 mm lens I like to use is a perspective control shift lens. The shift capability of this lens allows me to always keep the camera level and perpendicular to the ground, eliminating distortion created by tilting the camera up or down to place the horizon where I want it. Instead of tilting the camera, the shift function raises or lowers the lens components and allows me to shift the image circle hitting the sensor up or down, which gives me the ability to place the horizon as needed. These lenses are not an absolute requirement but they sure make things easier.

CAMERAS

While you can make composites with just about any type of camera it is preferred to use a DSLR. These cameras usually are easier to set to manual mode and also allow fixed, manual focusing. You need to set the exposure manually so that it does not change as you pan the camera across the scene. Using any of the auto modes would change the exposure values from frame to frame causing differences in exposures and making frame blending in post processing very difficult. You also need to focus so that you use the exact same focus point from frame to frame. This means turning off auto focus and using the focus ring on your lens.

TRIPODS and PANNING EQUIPMENT

There are a myriad of tripods and specialized panorama panning heads in many price points. Due to the brevity of this article I do not have the luxury to list them all here. The basics dictate that you get a sturdy tripod with fully adjustable legs and a solid base. You will also need, at the very least, a ball head that can pan and tilt (tilting for mosaics only). Here is where it can quickly get confusing since there are very basic accessories, some extremely sophisticated panning heads, and everything in between. I highly recommend that you study these accessories carefully and inform yourself of how they work before purchasing. In all honesty, I have never used a specialized panning/tilting head. I prefer a simple kit that is light, and is easy to pack and set up. It includes a Really Right Stuff (RRS) panning clamp that attaches to my standard Arca-Swiss style ball head clamp and pans independently, not requiring the use of the panning function of my ball head. I also use a simple 7 ½ inch rail to set the camera/lens combination at the position relative to the center of the tripod/panning point so that there is little to no effect of parallax. This optical center of the lens/camera is correctly referred to as the “no-parallax point” or “entrance pupil”. This is NOT the same as the incorrectly used, but popular term, “nodal point”. Using a panning clamp and an adjustable rail along with my PC-Nikkor 35 mm shift lens I have a pretty solid and fast package for panoramas and simple two to four row mosaics.

Six-shot, two row, three column mosaic at 35 mm focal length - Canyonlands NP - Utah

SOFTWARE: PUTTING IT ALL TOGETHER

There is a lot of stitching software out there that can help you combine your series of panorama and mosaic frames into a dazzling final product. Some are easy to use; others are quite complicated and versatile. Here is a short list of some of the more popular programs.

AutoStitch – Mostly an automated process as the name implies. Very easy to use.
Hugin – Extremely powerful open source program that is “free”. Comes with lots of tools.
AutoPano Pro – Very advanced. Can even process HDR panos and mosaics. Supports fish-eye lenses.
PanaVue ImageAssembler – There are three versions available for beginners to advanced pano makers. Pick the one that suits your needs and you don’t have to pay for tools you won’t be using.
PTGui – Probably the granddaddy of them all. Also very powerful and really good at fixing inconsistencies of tilted and rotated frames (photographer error in the field) to produce excellent results.

Of course, there is also the built-in Photomerge tool in Photoshop. When it first came out in Photoshop CS3 it was marginal at best. Now it is much improved and can probably tackle 85 to 95% of most panoramas and mosaics taken. Incidentally, Adobe Photoshop Lightroom also has this tool.

I learned to hand stitch panoramas using Photoshop and layer masks a long time ago when I saw a tutorial on-line by National Geographic photographer Bruce Dale. I still use this technique exclusively today, but then again I don’t make many multiple row and column mosaics. It is also the preferred method used by the dean of nature photography, John Shaw. While I don’t have the scope in this article to go through the step-by-step process I use I can give you the basics. I hope to present the details of my method in a future tutorial.

Hand Stitching in Photoshop

Open all frames of the panorama or mosaic in Adobe ACR.
Select the middle frame of your series of images, or the one that shows a representative exposure. Now select all the other remaining frames so that the adjustments you make on the middle frame are also automatically applied to the whole series. Remember that exposure values, tone, color, and saturation levels must be identical for all frames.
When done making adjustments open the series in Photoshop.
Create a new blank canvas that has the dimensions to hold all frames in the series. In other words, if your panorama consists of three frames from a camera with a resolution of 6,000 pixels wide by 4,000 pixels tall, make the new canvas at least 18,000 pixels by 4,000 pixels. I actually make it a little larger in height so I have some headroom if the images don’t line up exactly at their edges – which is the case most of the time.
Drag and drop the series of images starting from left to right onto the blank canvas. Each frame will be placed on its own layer.
Zooming in I then drag the images to align them with the frame in front of it.
Starting with the second image from the left and every subsequent image thereafter, I create a layer mask. I then use a soft brush at varying opacity settings to paint the left edges away so that they blend seamlessly into the image in front of it. At this time I also inspect the exposure values from frame to frame and make levels adjustments to each frame so that the exposure is smooth and consistent across the panorama or mosaic.
When done blending the seams I flatten all layers in the image, straighten if necessary, and crop to clean up the edges.

Four-shot horizontal panorama at 35 mm focal length - Death Valley NP - California

SHOOTING TECHNIQUES

Lastly, let’s talk about how to shoot a simple panorama and a two row mosaic.

Survey the scene you intend to shoot in terms of a panoramic or mosaic aspect ratio. As I noted earlier, my standard is three to four horizontal frames across for a panorama and two to three rows, and three to four columns for a mosaic. If you prefer shooting with the camera in the portrait (vertical) position six to nine frames across is usually good. The placement of objects in the frame is totally an artistic decision on your part, but I try to stay away from placing prominent objects close to the margins. This tends to make the image look uneven or “heavy” on one side. The eye will want to continually anchor on that point, preventing a thorough scanning of the image. All other common compositional tips work with panos too. Leading lines, S curves, patterns, tension, asymmetry, etc., all have their place in composite imagery.
Once you’ve established your spot set your tripod so that it is as level as possible. Many tripod models these days have a bubble level in the base, I recommend you use it; it will make things much easier during the shooting process.
Set your camera on your ball head using a rail and pano head so that the camera/lens entrance pupil is sitting right on panning point.
Now it is time to level the camera. Most panning clamps, rails, and pano heads come with built in bubble levels as well. If yours doesn’t have one you can use a bubble level that attaches to the hot shoe of your camera. The latest DSLR cameras also have a leveling tool in the menu system. This can also be used in place of a bubble level.
Set your camera’s exposure mode to Manual. Turn off Auto Focus. Set the exposure for the brightest area of the scene, and make a test shot. Check your histogram to make sure you are not blowing out the highlights. Now take a test shot of an area with the most shadow. Note the histogram. Here is where you will have to evaluate the test shot results and determine if you need to adjust the exposure so that one single exposure setting will accommodate the highlights and the shadows the best across the series of frames.
Now that you have the correct exposure you can concentrate on determining how much panning you want to do; where the image will begin on the left and where it will end on the right. Pan the camera using your panning device, whether it is the ball head base, a panning clamp, or a pano head. Now you have to determine how much overlap you need from frame to frame. An easy way to do this is to use the viewfinder grid in your camera’s viewfinder if your camera has one. If it doesn’t you will have to use the markings on the panning base. Using the viewfinder gridlines you simply start with the camera at the left-most side and note where the right-most grid line falls. Look for a feature in the landscape along that line where you can now place the left-most grid line as you make the first pan. Repeat this process through the entire scene until you arrive at the right-most boundary of your composition and note how many frames you will be shooting. For mosaics you will have to shoot all the rows for that panned position before continuing to the next pan position.
Finally, focus the lens manually using the focus ring on the lens, and take the sequence of shots making sure the camera is panned carefully so as not to disturb its level position and that you don’t accidentally move the focus setting. It is a really good idea to use a remote shutter release and mirror lockup in this situation as well to minimize the effect of camera shake.

If you would like to learn how to arrive at the entrance pupil of your lens(es) there are many tutorials on the web, so many, that I felt it would be better that I let you explore those resources on your own. By the way, not too long ago I posted an article where I explain how to use Nikon’s Virtual Horizon feature combined with long focal length lenses to virtually eliminate, in some situations, the need for all that I have taught you here. If you are interested, the article can be found here.