Selecting the best lens to use for a panorama affects many aspects of the final file. Besides obviously affecting the vertical field of view, the file size (in pixels) will be determined. This will then be a major factor in compressing the file for final delivery. The following chart lists the common lenses used & their vertical field of view (in portrait orientation), along with a graphical representation of the final image's aspect, it's size in actual pixels as well as megabytes (uncompressed). The panorama is a complete 360°, using the standard source images of 512 x 768.
| Lens | Vfov | Aspect Image | Pixels | Megabytes |
|---|---|---|---|---|
| 14mm | 104° |  |
2208 x 740 | 4.67 |
| 15mm | 100° | |
2496 x 768 | 5.48 |
| 18mm | 89° | |
2880 x 752 | 6.20 |
| 20mm | 84° | |
2976 x 768 | 6.54 |
| 24mm | 74° | |
3456 x 752 | 7.44 |
| 28mm | 66° | |
3936 x 752 | 8.47 |
| 35mm | 54° | |
4416 x 756 | 9.55 |
| 45mm | 44° | |
6144 x 760 | 13.36 |
| 50mm | 40° | |
6144 x 764 | 13.43 |
It seems that normal lenses more than 28mm become inefficient for QTVR. You would think that the widest angle lens available would be the best choice all the time, but there are things to consider. Mainly, the ultra wide angle lenses generally show more image than desired for outdoors. For outdoors QTVR, which is primarily of objects that are far away from the camera, a 24mm - 28mm lens would be a good choice. There are also issues of compression (relating to the appearance of near and far objects, not file compression such as Sorenson), though that becomes more pronounced with telephoto lenses. If you could only use one lens for all panoramas, a 20mm lens would probably be the one get.
UPDATE: The method explained below has become obsolete since Apple released the QuickTime Active/X control. It is still listed here for reference. You should now used the <OBJECT> tag within web pages for Internet Explorer users on the Windows platform. Full details can be found on Apple's QuickTime Active X Plugin page.
Once Microsoft updated it's media player for Windows to version 6.4, by performing a standard installation, users will be changing the default application which plays .mov files from QuickTime to MediaPlayer. MediaPlayer currently does not handle QTVR tracks, and if it can play the file at all, it will only play the tiles track in a linear manner. Generally, MediaPlayer will not support the codecs used for QTVR, and will attempt to download a compatible codec from Microsoft's web site. If this fails, then the user will receive an error message. This is obviously not what we want!
Changing the preferences of MediaPlayer would return control back to QuickTime, and it's easy to do. Normally, MediaPlayer can be launched from the "Run..." button on the "Start" menu by simply typing in mplayer2. Otherwise, the default location on a Windows machine is in the "C: Drive", in the "Program Files" folder, in a folder named "Windows Media Player", with the filename of mplayer2.exe.
Once MediaPlayer is open, selecting "Options..." from the "View" menu will bring up the Options window. The last tab, "Formats" should then be selected, which will display a list of media that MediaPlayer will handle. Scrolling down to the last item on the list will find "QuickTime file", which we want not checked (Personally, I uncheck everything, except the first three items, the Windows Media specific formats, because I let QuickTime Player handle all the others). After making sure that the "QuickTime file" item is unchecked, click "Ok" to close the Options window. MediaPlayer can then be closed.
If you want to confirm that QuickTime can handle all the files types, open "Control Panel" from the "Settings" button on the "Start" menu. Find and open the "QuickTime" control panel. Select "File Type Associations" from the drop down menu. Make sure that everything is checked, including the "Notify me..." option. Close this control panel when finished. Now QuickTime Player should be in control again.
MediaPlayer is taking over .mov files on web pages as well. To address this issue, you can use a special attribute of the QuickTime 4 Plug-in. The attribute is QTSRC, and it represents the actual file you want the plug-in to open. It was originally designed for use with the new RTSP streaming format, but can help us with this problem. The only problem with this is that it requires QuickTime 4 or later, it will not work with QuickTime 3.
Simply create an image file of any size, and save it in TIFF format, Named with the extension .qti. Upload that file to your web site with your QTVR movies, and compose your EMBED tag as follows:
<EMBED SRC="dummyfile.qti" QTSRC="realqtvr.mov" ...add any other attributes that you need.
Because the .qti mime type is handled by the QuickTime Plug-in, and MediaPlayer doesn't take over this file type, QuickTime will present the file correctly.
You could use this same technique to force other content such as Flash movies or standard JPEG or GIF images to be opened with the QuickTime plug-in. Check out my MediaPlayer Test page to see this in action.
