Lens Calibration for Samyang 7,5mm F:3,5 M4/3 (Sort of..)

[mikmak]

Trying to do the impossible calibration of a fisheye lens. It is not perfect, but i am rather satisfied with the result. I have calibrated it with hugin and several testpictures inluding some testshots from the net. It was not very succesfull I'm afraid so instead i used the FF values for the Canon 15mm Fisheye as a base, and adjusted the values in ASP for the best visual result - and this worked much better than my other attemps.

This should be usefull for all M4/3 Cameras from Olympus and Panasonic.

Lens information to 'profile_micro43.txt':

begin lens
group: micro43
multiplier: 2.0
aperture: 3.5
calibrated: true
menu_lens: Samyang 7.5 mm f/3,5 Fisheye
cal_abc: 0.0 0.023453 -0.024743 -0,412565
end

Lens information to 'profile_olympuslenstable.txt':
0 0 0|Samyang 7.5 mm f/3,5 Fisheye

The reason for the 0.0 in focal lenght and in 'profile_micro43.txt' and 0 0 0 in 'profile_olympuslenstable.txt is that the lense is 100% manual - no electronics what so ever.

Before:

120213_OMD_1702.jpg

After:

120213_OMD_1702_1.jpg

As allways - Any comments and corrections is welcome
Per

[grubernd]

i have that lens and never had the nerve to go through de-fishing it for ASP
although i knew it would be worth it for certain pictures.
especially if you use a square crop.

awesome result, thank you very much for sharing.

an example from an uncropped image:

grubernd_230068-7871_w1.jpg

grubernd_230068-7871_v2_w1.jpg

[-cr]

I'm using the following parameters with this lens instead:
cal_abc: 0.0 0.049 -0.069 -0.45
Still not perfect, but imo better.