Samyang 8mm Tests – Field of View
It’s been a week since I bought my Samyang 8mm Fisheye. Reasons why I bought the lens in Nikon mount is to be able to use it both in Canon and Nikon AND because it will offer a wider field of view in a Nikon DX.
Here are some shots to show how the field of view of the lens looks in Canon and Nikon APS-C cameras.
Though the framing are not exactly the same, it is noticeable that the field of view is much wider on the Nikon camera than it is on a Canon camera. (Canon has a crop factor of 1.6 while Nikon has 1.5). There is also flare as the sun is in the picture.
The barrel distortion of fisheyes may not always work and the picture can be turned to rectilinear using the Lightroom profile for Nikon 10.5mm fisheye lens.
Here is how the “corrected” pictures appear:
For comparison, here is a shot of an ultrawide rectilinear lens (Canon 10-22mm):
The straightened image for Nikon is still wider than the Canon’s and both are wider than the Canon 10-22 at 10mm. However, the left and right sides of the pictures are much much softer due to the stretching of the picture.
Compared to Samyang, there is a less noticeable flare (reddish hexagon on the third tricycle). I’m not sure if this is due to better flare control or because the sun is not directly in the picture (compared to Samyang).
To get better average resolution in the straightened picture, the Samyang straightened image can be cropped (to remove soft corners). Here is the same picture as the one above (Canon mount) cropped with same FOV as Canon 10-22mm at 10mm.
However, corners are not the same as those shot with the rectilinear lens:
The corners of the Canon 10-22mm are much sharper. However, the ones from Samyang are also good considering that picture was de-fished (stretching the pixels at the corners) and cropped heavily (will have far fewer pixels from the 18MP of 7D than the crop of the rectilinear lens).
*All images shot without Lightroom correction (except for defishing).
Pretty Obvious Conclusions:
1. Samyang 8mm Fisheye provides wider field of view on Nikon DX than on Canon APS-C (due to Canon’s slightly smaller sensor size) . Hmmmm, might get a Nikon DX body.
2. Defished fisheye image from Samyang is still very wide, wider than the widest rectilinear lens from Canon (10-22) and probably even wider than the widest rectilinear APS-C lens (Sigma 8-16mm). However, left and right corners will be much softer due to stretching of pixels necessary in defishing but center will be sharper.
3. If rectilinear images are needed, a rectilinear lens is still better. The defished image can be a substitute, esp. if the output will be small and corner sharpness are not primary concern but it will not be better.
Now, where to get the money for a Nikon DX body…