Lens calibration : Nikkor 20mm f/2.8 AI-S / Nikon D700

[FalCT60]

Me again, with data for the Nikkor 20mm f/2.8 AI-S lens.
Once again, they might slightly differ from what could be found by experts.

Code: Select all

begin lens
group: nikonSLR
multiplier: 1.0
aperture: 2.8
calibrated: true
menu_lens: Nikkor 20mm f/2.8 AI-S
cal_abc:  20 0.005067 -0.003084 -0.038441   
#cal_abc: 20 0.250 0.731 -0.606
end

On the commented line are data I found once when I hadn't understood the process. To be tested, just for fun...

Regards,

J.-Luc

[FalCT60]

Well, after a few days, I'm not satisfied at all...
What I did : I took 2 pictures of buildings from a high point of view, loaded them into Hugin, set 12~15 "normal" points and entered the results into ASP.
At this step, the results were not acceptable at all, so I manually tuned them within ASP lens correction plugin.
It took about an hour before I could find the result acceptable (it took six times more for the Tokina, see other post).
But, now, I don't like the results at all. And I don't understand why I have to correct the values Hugin has computed. Oughtn't they are OK as is ?
Last week, I tried to calibrate my Nikkor 500mm f/8 Reflex... the values Hugin returned resulted in worse corrected pictures than those not corrected.
Whatever the method I use (Hugin or GML Camera Calibration Toolbox), I can't get good results. There must be something I don't understand at all.
So, be very careful with both the calibration data I posted : don't rely on them. I hope I can post correct values soon.

Regards,

J.-Luc

[afx]

Which method are you using? The old Hugin tutorial or the new calibrate_lens_gui ?
The gui results work perfectly in AS (same results as in the calibrate_lens_gui corrected preview), but first you have to get the silly gui to work, that's what I am currently struggling with. It seems to be very picky about the lines it accepts.

cheers
afx

[FalCT60]

Hello Afx,

I first used the old method, but the results were... awfully bad!
Then I upgraded to new version and used the gui.
But, then again, very hard to get acceptable results.
I even tried GML tool http://graphics.cs.***/en/science/re ... ration/cpp, but there it seems that I didn't understand anything at all.

J.-Luc

[FotoLars]

Hi!

EDIT:
Please have a look at this thread, http://forum.corel.com/EN/viewtopic.php?f=90&t=45815, for a complete guide concerning calibration of lenses.

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