I Took That!

Blog by Jim Everett

http://www.itookthat.com

Blog Support Notes

CREATING STUNNING PANORAMAS

Presented by Jim as a guest on The Lab With Leo Laporte TV Series

G4 Tech TV Canada, and How To Channel Australia

http://www.labwithleo.com

We look at a few techniques and tips about how to create great panoramas simply and with a relatively low-cost approach.

Panoramas have always fascinated people. Some of the early approaches to creating panoramas involved cameras with very wide lenses, or lenses that moved and painted the image on the film. In fact, high-end panoramas are still done this way.

These days, with digital photography, creating panoramas is much simpler. And the latest software automates the stitching process of blending a series of images together to create a much bigger single image.

Of course, there is an enormous range of software available from around $30 to $1,000 - even free programs. Some programs do the stitching automatically, and even balance exposure and align pictures that are lessthan perfect. Others provide complicated sets of tools with steep learning curves to allow for full manual alignment and stitching.

We're going to look at the automatic tools, and emphasize the art of taking the pictures so that the images are at their best for these tools to work with.

Why create a panorama?

- To create a total sense of horizontal expanse, such as a sweeping view

- To capture a very wide subject when you can't get back far enough

- To show a big picture that has close-up details

- To create a sense of being there, such as with a street scene

- To capture a very tall subject, with a vertical panorama

- Because it's fun and a really cool thing to do

Key factors when capturing a panorama:

- Equal exposure on each image that is part of the panorama (especially the sky)

- The correct amount of overlap, between 15% and 50% depending on the subject

- Keeping the horizon horizontal and at the same level in the picture

- Using the optimal focal length for the image to avoid distortion, yet provide coverage

- Keeping the camera on the same axis for all the shots

Choose subjects that will work well as a panorama:

- Avoid extremes of lighting from one side to the other

- Look for interesting elements to create a subject or anchor

- Check from left to right that everything will fit in each frame while keeping the same horizontal plane

Key techniques when taking a panorama:

1. Use a tripod if you can. However, in my experience, the most inspiring panoramas have presented themselves when I don't have a tripod.

2. Choose a focal length that is the equivalent of a normal lens or even a little more telephoto. Wide-angle lenses can create distortions in

perspective, and are more likely to give you vignetting, or dark corners which are a nightmare to correct later. If you can’t get the top and bottom parts in, turn your camera to a vertical format and take overlapping shots that way.

3. If your final picture contains both near and far objects, you’ll need to use a small aperture so that both the close objects and the horizon will be in focus.

4. If your entire panorama is at a distance, and you're using telephoto and hand-holding, you’re better opting for a fast shutter speed.

5. Decide if you want to shoot in a jpeg or RAW. Jpeg will give you a small file, and one that is pre-optimized and easier to stitch later. Choosing RAW allows you more control over exposure later, but also gives you larger files; which may be a challenge if you have a slow machine when it comes to stitching.

6. Determine the optimal area of the final picture that you want to have correctly exposed and in focus.

7. Lock your focus and exposure on this area for all the shots.

8. Position your body so you are facing the final shot, at the right hand end of the panorama.

9. Keep your feet still and twist your body back to the point where you will start. Ensure you have extra top and bottom for cropping.

10. Take the first picture, allowing about 30% more on the left-hand side than you will need in the picture.

11. Take a note of some of the landmarks or key points in your image towards the right hand side, that will guide you in the next step of overlap.

12. Keeping the horizon level, and at the same height, move to the next image, an overlap around 20 percent. Use the key points that you remember from the previous shot. Again, take a note of some key points on the right hand side.

13. Continue this until you have completed the entire panorama, with a little bit of spare subject on the right hand side of the last image.

*** GOOD TIP: Make sure that nothing really important is at the very top or very bottom of the picture. When you stitch these, you often lose areas at the top and bottom when the software corrects for perspective.

Preparing to stitch the images to create a single panorama

First, decide whether your panorama is for screen viewing on a computer, or whether you'll be making a print with it. If it for screen viewing, decide whether you want the entire panorama to show on a single screen, or do you want a panorama that the viewer will need to scroll across. If you're making a print, what size would your final print be?

Based on the megapixels of your camera, will the final image have sufficient resolution to create the print as is, or will you need to boost the size? Generally speaking, it is best to boost the size once you have finished the stitching and final corrections. For boosting image size, I typically use Genuine Fractals from On One software (www.ononesoftware.com). Adobe Photoshop CS3 (www.adobe.com) also has sophisticated algorithms for boosting image size.

If your subject was very dark, and you boosted the ISO rating on your camera, you're likely to get more digital noise. Or if you're using a

camera with a sensor that creates a lot of noise, then you'll also need to de-noise it.

The best time to de-noise is before you do anything else to the image. Most software image programs like Photoshop have a de-noising function. I prefer to use a third party product such as Noise Ninja from PictureCode (www.picturecode.com). Be careful not to overdo noise reduction, or you'll lose details, and end up with an image that looks plastic.

Choosing your panorama software

The three that I will talk about today are Photoshop CS3 with its Photomerge function, and two lower-cost options - DoubleTake (www.echoone.com) and Calico from Kekus (www.kekus.com). These are both in the $20 to $30 range, and do an excellent, stand-alone job with most images. Even when the images are not perfect, both of these have their strengths for correcting variations.

As with any work involving on-screen display, or print output, it is vital that you have your display calibrated and color-corrected.

Now for the stitching

If any of your images are less than perfect for the panorama, it is better to correct them before you start stitching. Things to correct include: making sure your horizon is horizontal, correcting any lens distortions (including vignetting) and equalizing the exposure if you forgot to lock it went taking the shots. The standalone application, or Photoshop plugin, LensFixCI from Kekus, is a very handy and quick way of automatically correcting your image for the particular make and model of lens that you used for each shot. Do this after noise reduction, but before loading into the panorama software.

Also, if some of the shots have areas that are washed out, or deep shadow areas, you may want to try working on these before you start stitching. There are no absolute rules, and often I will do finishing touches in the final assembled image. The hardest thing to fix once the panorama is made is the sky. This is why it's important to lock the exposure, so the sky is equally exposed across the whole panorama.

You can either drag all your images to a window, as with Calico and DoubleTake, or add them as files or a folder through a browsing dialog box in Photoshop: File>Automate>Photomerge.

DoubleTake has a number of correction and adjustment controls built in. These allow you to rotate and line up your horizon, adjust exposure, finetune the placement of images for better alignment of points, and create an optimal crop when you finish. DoubleTake allows you to save your file as TIFF, PNG, PDF, QuickTime VR and jpeg, but not as Photoshop. Where images have exposure variations, or noticeable vignetting, DoubleTake is not as strong as the automatic fix in Calico.

Calico offers fewer image adjustment controls, is a better speed choice when images are more correct to start with, and seems to do a better job of combining images that have exposure variations and vignetting. It allows you to save a file as TIFF, jpeg and Photoshop with layers (for further adjustments), as well as choosing your method of interpolation, and exposure equalization. Calico has the ability to stitch multiple rows of images. Kekus, the developer of Calico, also offers other sophisticated tools for manual creation.

Photomerge in Photoshop offers a number of different stitching and blending options. For most purposes, the automatic function is the one used. It is simpler, does a better job, and requires no fixing. Photoshop creates a panorama with a combination of layers and layer masks. It actually chops the images and dovetails them together after aligning a selection of location points. If you try and move the layers after the stitching has occurred, they will look as if they are being pulled apart like a cookie being broken. But you can still work with the layers and masks for fine-tuning.

When you save your panorama, you may be offered the choice of saving with layers, or in different formats. If you have the "Save As Layers" option, I would probably do that and then “Save As” that version often as a flattened Photoshop version for printing. Remember when you save as a jpeg, you do lose some quality in detail each time you save as.

You now have a Photoshop file which you treat as you would any other image file for printing. The difference is that you need a sheet or roll of paper that is long enough to accommodate the width of the panorama. You may find that some printers have a limitation on the width of panorama you can print (meaning the length of the paper it will feed through).

Each printer maker has different setups for panoramas, so you need to make sure you have the proper driver installed and follow the instructions carefully. Not all manufacturers write instructions that make it easy to print a panorama. However, if you persevere, the end results will be worth it.

For large panoramas, you may want to send your file to a lab. A Toronto firm, Silvano Imaging (www.silvanoimaging.com), is about to offer a service that will print panos up to 51" x 150'0" (that's 130cm x 45metres). Try and e-mail THAT file (they have an FTP server, or you can send on a disk).

Finally, practicing your new skill

Go and play with some local pano-friendly subjects. Get some practice in now so you'll be ready when that amazing panorama opportunity presents itself in the future!

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