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

AfterShot Pro General Questions & Getting Started Forum
Post Reply
FalCT60
Posts: 153
Joined: Wed Feb 15, 2012 11:29 am
operating_system: Windows XP Pro
System_Drive: C
32bit or 64bit: 32 Bit

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

Post by 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... :roll:

Regards,

J.-Luc
FalCT60
Posts: 153
Joined: Wed Feb 15, 2012 11:29 am
operating_system: Windows XP Pro
System_Drive: C
32bit or 64bit: 32 Bit

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

Post by FalCT60 »

Well, after a few days, I'm not satisfied at all... :cry:
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 ? :shock:
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. :evil:
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. :oops:
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
Moderator
Posts: 1675
Joined: Thu Jan 12, 2012 1:38 pm
operating_system: Linux
System_Drive: N/A
32bit or 64bit: 64 Bit
Video Card: FirePro 4900
Monitor/Display Make & Model: NEC PA301w, ColorMunki
Location: München
Contact:

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

Post by 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
Send bugs to the Monkey // AfterShot Kickstart Guide // sRGB clipping sucks and Adobe RGB is just as bad
Bibble since 2005 // W7 64 on quad Phenom // Ubuntu 14.4 on quad i7 and dualcore AMD // Images
FalCT60
Posts: 153
Joined: Wed Feb 15, 2012 11:29 am
operating_system: Windows XP Pro
System_Drive: C
32bit or 64bit: 32 Bit

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

Post by FalCT60 »

Hello Afx,

I first used the old method, but the results were... awfully bad! :evil:
Then I upgraded to new version and used the gui.
But, then again, very hard to get acceptable results. :cry:
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. :oops:

J.-Luc
FotoLars
Posts: 35
Joined: Thu Jan 12, 2012 11:58 am
operating_system: Linux
System_Drive: X
32bit or 64bit: 64 Bit
motherboard: Intel D975XBX2
processor: Intel QuadCore Q6700
ram: 8 GB
Video Card: NVIDIA Quadro NVS 295
Hard_Drive_Capacity: 8 TB
Monitor/Display Make & Model: 2xDell 30", 5120x1600 (2x2560x1600)

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

Post by 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.

The former text in this very reply has been deleted.
Post Reply