Creating the best synth starts with the right photos. This guide will help you understand how to take the best photos for Photosynth. Reading it could save you from taking a few hundred pictures only to find out later that Photosynth won't put them together the way you imagined.
You can also download this guide as a pdf: The Photosynth Photography Guide (1MB)
Got more time?
Start by standing in the center of the room with your camera zoomed wide. Spin around, taking overlapping shots as you go. Make sure successive photos are overlapped by at least 50%. Depending on how wide your lens goes, you'll probably need to take 15-30 photos to go all the way around.
To give the room a good 3D model, you should next shoot overlapped shots from each of the corners. For saturation coverage and the most reliable reconstructions, shoot from the centers of each wall as well.
Finally, walk around the room shooting the interesting details. Make sure that all your close-ups have ―approach shots‖ providing intermediate sizes of the object you're closing in on. For example, if you're photographing a wall of paintings, and you want to zoom in on a single painting, you'll need to have a few intermediate images to help Photosynth put the whole thing together. See the photos below.
A good rule of thumb is to never move more than half the distance to your subject without taking an additional shot. Similarly, never increase your focal length by more than a factor of 2 without taking an additional shot.
Move in on the subjects that interest you, but make sure you don't move more than 50% of the way in without taking an additional shot.
Copyright Christine Gedye 2008. Used with permission of the artist.
So, remember to:
If you take overlapping shots of a 2D surface at different scales, Photosynth will create a detailed synth of the result. Move the camera so that it's always facing the subject head on. You don't need to shoot it from different angles, although it doesn't hurt if you do.
Shooting a 3-D Object
It's important to get lots of overlap around an object and to walk around it. To get a great synth around a convex object (such as a vase), you'll want to take a photo approximately every 15 degrees, so it takes at least 24 photos to get around a vase perfectly. If your object is not completely convex, you'll need even more.
Make sure that the center of the object is in the middle of the picture, and that the picture frames the entire object. Be sure to include close-ups. This technique can be used for a full circle around an object, a small arc or anything in between.
Want to Use a Turntable?
If you have an object that is small enough to be rotated in front of the camera on a turntable, you should be able to make a fantastic synth with a beautiful navigational 'halo'. If you don't have a photographic turntable, get creative – a plastic kitchen turntable (also known as a 'Lazy Susan') works just fine. Here are the rules for using a turntable:
Now comes the easy part. Take a photo, then rotate the object no more than 15 degrees, then take another photo. Repeat until you have rotated the object through 360 degrees. There is no need to be exact in the amount of rotation between shots, but you should be aware that the 15 degree rule assumes fairly convex shapes. If you have an object with lots of deep narrow cavities, or has lots of complex overlaps, you'll want to shoot with less than 15 degrees of separation.
Going Around Corners
To be safe, you need at least 9 images to go around an exterior corner. In the example below there are solid matches between adjacent images (e.g.: Images 1/2), average matches between pairs that are 2 apart (e.g.: 4/6) and not many between images that are 3 apart (e.g.: 4/7).
Like to process your photos?
If you're the kind of photographer who likes to adjust color or contrast before you share your work, go for it. Photosynth is remarkably resilient to different color casts, and dynamic ranges. If you want to remove red-eye or fix other imperfections in a part of a photo, don't hesitate.
On the other hand, the following operations will confuse Photosynth, and should be avoided if you want a decent reconstruction.
What NOT to do
Avoid drastic angle and scale changes – a close-up of a sign may not stitch in if the only other photo of it is 100 feet away.
What NOT to shoot
There are some subjects that Photosynth just doesn't like. Here are some examples of what works well ('Synthy') and what doesn't:
Ready to get going?
Now that you know what works and what doesn't, you're ready to get started. Don't be discouraged if your first synth doesn't come out as well as you'd hoped. Before long you'll get a feel for the variety of photos that will make the best synth. The most important thing to remember is: have fun!