Correcting Fisheye images with PTLens Photoshop plug-in.
Due to the size of the sensor in DX format cameras, an 8mm fisheye lens will not produce a circular image. FX format cameras, on the other hand, have a bigger sensor and therefore will produce a fully circular image.
If you are shooting with an 8mm fisheye lens on a DX format cameras, you will always have dark corners in your picture that require adjusting in order to de-warp the image to a full frame, just as a ‘full frame fisheye’ such as 10.5mm would do. You may simply crop the image but that way you will lose a considerable amount of picture and the image will still remain distorted. Alternatively, you may use the lens correction options in Adobe Photoshop or Lightroom 3, but these offer limited control over the image.
PTLense Photoshop plug-in is a simple and powerful plug-in which also works as standalone software and you will definitely find it useful when working with your fisheye images. The plugin is available to download as a trial version (both Windows and Mac) that has complete functionality, but will only process 10 images. For $25, you can also purchase the licence via PayPal, which is a pretty good deal in my opinion.
Once you download the software, you can use it as standalone software or Photoshop plug-in. Just move the plugin to the Photoshop plugin folder and restart Photoshop. As shown below, the plugin should appear under Filter/ePaperPress/PTLens.
Once you open your picture in Photoshop, just go to Filter and select PTLens. Next the plugin window will open where you can work on your image. PTLens offers several adjustment options as highlighted below.
If you are working with an image taken with an 8mm Fisheye lens, make sure you select the ‘Fisheye’ option in the ‘Correct’ box. Next, the ‘Fisheye’ box on the left will activate where you can correct your image. In order to get rid of the dark corners in your picture, you will have to adjust the ‘Distortion’ slider to a desired level and then zoom in by adjusting the ‘Crop’ slider. You can also rotate your image and adjust the horizontal and vertical position which is extremely useful.
PTLens also offers correction of Perspective, Chromatic Aberration and Vignetting that can be useful while working with pictures captured with an ordinary lens.
The effect of correcting the Fisheye distortion can be seen below.
Thanks for reading and good luck with your photography.