メインウィンドウ：レンズ設定タブ
（Main Window: Lens Settings tab）
このページには、パノラマ撮影に使用されたカメラとレンズのパラメータが含まれています。ほとんどの設定はPTGuiによって自動的に決定され、これらの設定を変更する必要はほとんどありません。Lens Settings tab（レンズ設定タブ）は、Advanced mode（詳細設定モード）でのみ表示されます。 シンプルモードでは、Project Assistans（プロジェクトアシスタント）は、レンズタイプ、視野、焦点距離のパラメータのコピーを表示します。継ぎ目の無い（シームレスな）パノラマを作成するには、ソースイメージを再配置（remapped）する必要があります（他にもworpedと呼ばれます）。これは透視変換と見ることができます。ソース画像のパースペクティブは、生成されたパノラマのパースペクティブに変換されます。 適切な変換のために、PTGuiはあなたの写真を撮るために使用されたレンズを知る必要があります。 2つの重要なパラメータは、レンズのタイプと視野です。いくつかのレンズタイプがサポートされています。 レンズの種類がわからない場合は、直線（通常）のレンズが最も適しています。
This can be seen as a perspective transformation: the perspective of the source images is transformed into the perspective of the generated panorama. For a proper transformation, PTGui needs to know what lens was used to take your pictures. The two key parameters are the type of lens and its field of view.
Several Lens types are supported. If you don't know the type of your lens, it most likely is a rectilinear (normal) lens.
(Horizontal) field of View: This is the viewing angle (in degrees) between the leftmost point and the rightmost point in your images.
For rectilinear (normal) lenses, the field of view can theoretically never be more than 180 degrees, and most practical lenses have a horizontal field of view of 80 degrees or less. Other lens projections can have a horizontal field of view of up to 360 degrees.
For rectilinear lenses you can instead provide the focal length and the multiplier parameters. The multiplier (which is often called crop factor) is defined as the diagonal of a full frame 35mm sensor divided by the actual sensor diagonal. Please note that the relation beween the horizontal field of view, focal length and multiplier depends on the aspect ratio (i.e. portrait vs. landscape) as well. PTGui bases the calculation on the aspect ratio of the first image in the project.
For example, if lens focal length is 28 mm and focal length multiplier is 1.6, the HFOV could be 30 degrees if the first image is in portrait orientation and 44 degrees if it is in landscape orientation.
Nearly every digital camera records the focal length of the lens into the 'Exif' header of the image file. By pressing the EXIF button, the lens parameters are initialized from the EXIF information in the first image (if available).
You can use the Lens Database to store and later retrieve the parameters of your lens. Please note that the lens database is initially empty; it is only used for your own data. The lens database stores the Lens Type, Field of view, a, b and c parameters. Save To Database copies the values from the Lens Settings tab into a record in the database; Load From Database copies the 5 values from the lens database back to the 5 fields in the Lens Settings tab.
The Advanced lens settings include:
Lens correction parameters (a, b and c): these parameters can be used to correct imperfections of your lens, such as barrel distortion. This will much improve the alignment of the images in the panorama. It's not necessary to provide these values; PTGui determines them automatically when running the Optimizer.
Mathematical background: a, b and c constitute a third order polynomial, mapping pixels according to the following formula:
rsrc = a*rdest4 + b*rdest3 + c*rdest2 + (1-a-b-c)*rdest
where rsrc is the radius between the source pixel and the center of the image, and rdest is the output radius. rsrc and rdest are scaled such that the value 1 corresponds to max(width,height)/2 of the image.
rsrc = a*rdest4 + b*rdest3 + c*rdest2 + (1-a-b-c)*rdest
where rsrc is the radius between the source pixel and the center of the image, and rdest is the output radius. rsrc and rdest are scaled such that the value 1 corresponds to max(width,height)/2 of the image.
Shift parameters (d and e): these parameters shift the source picture by the given number of pixels. You can use these parameters to correct for off-center CCDs in digital cameras. If the geometrical center of the lens is left from the actual image center, enter a positive value for Horizontal Shift. Likewise for Vertical Shift: if the lens center is above the image center, enter a positive vertical shift value. Again it's not necessary to enter values here by hand; instead tell the opimizer to optimize the lens shift and the resulting values will be filled here.
Another use for the shift parameters is stitching 'flat' images together (when no perspective correction is needed), for example when stitching aerial photographs, or stitching partial scans of an image which would otherwise be too large for a scanner. In such a case, you would mark all images as having individual shift parameters (see below) and set the shift parameters to the pixel offset positions of each image in the final stitched image.
Shear parameters (g and t) can be used to correct skew in the image. Shear only occurs in flatbed scanners, if the CDD is not exactly mounted perpendicular to the scanning direction. Digital cameras don't exhibit shear so these values should be kept at 0.
If you know the values for your scanner, enter them here. Otherwise you may let the optimizer calculate them for you.
If you know the values for your scanner, enter them here. Otherwise you may let the optimizer calculate them for you.
Usually all images in your panorama are taken with the same camera/lens. But if this is not the case, PTGui allows you to enter individual settings for some or for all images. Use Individual Lens Settings to indicate that one or more images have individual settings for Lens Type, Field of View, a, b and c. The lens parameters for each image can then be set in the Image Parameters table.
In the same way, Individual Shift Settings and Individual Shear Settings indicate which images have individual settings for Shift and/or Shear.