Re: [hugin-ptx] Re: Simple lens calibration

On Sat 09-Jan-2010 at 13:31 +0100, Wolfgang Hugemann wrote: So I basically suggest 1) to use modern faccades as suitable targets Yes the tutorial doesn't have all the possible methods: the simplest is to stitch a panorama, you can also correct perspective of a rectangular object like a buil

Re: [hugin-ptx] Re: Simple lens calibration

I have just worked out a stable and rather simple way to determine the lens correction parameters. I uploaded the example image, the corrected image an the Hugin project file to www.unfallrekonstruktion.de/imagemagick/Olympus_C2500L.zip The Olympus C2550L is an older prosumer zoom camera with a q

Re: [hugin-ptx] Re: Simple lens calibration

On Mon 04-Jan-2010 at 09:29 +0100, Wolfgang Hugemann wrote: > >The solution was to activate the check box "Edit script before >optimising" and reset the start vector to (0, 0, 0) again. The >optimisation then converged to the correct values. > >This hint should be given in the tutorial, because my

[hugin-ptx] Re: Simple lens calibration

There is an undo button. I use it often when an optimization failed. It's hard to know if it failed without looking at the preview, and you have to accept the optimization to do this. On Jan 4, 12:29 am, Wolfgang Hugemann wrote: > > I have located the pto file for the project and have uploaded it

Re: [hugin-ptx] Re: Simple lens calibration

> I have located the pto file for the project and have uploaded it, you > should find it here tute.pto?gsc=__lf2AsAAACSWoUVkYFVtD9bujJphFH7>. > In case this link gets mangled, look for lens-cal-tute.pto. > > Hope this helps. Indeed, it did. By co

[hugin-ptx] Re: Simple lens calibration

Hullo Wolfgang, On Jan 4, 5:46 am, Wolfgang Hugemann wrote: > > The tutorial method is only really stable with lots of lines in the > > scene (or multiple photos). > > If that is the only reason for my problems, it should probably be > mentioned exactly on that page... I lost hours by trying to r

[hugin-ptx] Re: Simple lens calibration

Hi Tom, Tom Sharpless wrote: > Did your calibration image set cover 360 degrees? No, this was a a-b-c calibration only. I left the FOV fixed > It seems to me that if you use multiple images for calibration, then > the correct focal length or fov becomes a critical parameter (which is > not

[hugin-ptx] Re: Simple lens calibration

The box would be the lens housing, the lens itself consists of a certain number of glass elements with air between those. In most cases there is second box behind box #1: the camera body, also filled with air. If the whole combination is surrounded by water it's either a underwater camera or broke

[hugin-ptx] Re: Simple lens calibration

2009/2/25 Carl von Einem : > > Yes, but a different medium (water instead of air) is used at one > surface of the glass. That's where the angle of the light ray changes. Oh you mean the lens is inside a box ? I thought that the lens would be in the water. regards mick --~--~-~--~~--

[hugin-ptx] Re: Simple lens calibration

Hi Pit On Feb 26, 4:03 am, Pit Suetterlin wrote: >   Hi Oskar, > > I tried the several-lines method for calibrating my lens, and it indeed worked > quite nicely. > > Oskar Sander wrote: > > > sorry for waking up an old thread. > > > I'd like to use this method to calibrate a UW camera set-up.  T

[hugin-ptx] Re: Simple lens calibration

Hi Oskar, I tried the several-lines method for calibrating my lens, and it indeed worked quite nicely. Oskar Sander wrote: > > sorry for waking up an old thread. > > I'd like to use this method to calibrate a UW camera set-up. That is, > a camera in a housing with a wide angle lens attache

[hugin-ptx] Re: Simple lens calibration

Yes, but a different medium (water instead of air) is used at one surface of the glass. That's where the angle of the light ray changes. Carl Mick Crane wrote: > I assumed refraction was the issue but wondered why the calibration > would be different underwater. It is light falling on the lens

[hugin-ptx] Re: Simple lens calibration

I assumed refraction was the issue but wondered why the calibration would be different underwater. It is light falling on the lens in both cases. Regards Mick On 25 Feb 2009, at 16:39, Carl von Einem wrote: > > Put an empty drinking glass on your kitchen table. > > Fix a laser pointer so

[hugin-ptx] Re: Simple lens calibration

Put an empty drinking glass on your kitchen table. Fix a laser pointer so it aims from a higher point on one side of the glass to the table surface on the other side of the glass. Eventually mark the spot where the laser pointer hits the table. Fill your glass with tap water and watch the beam b

[hugin-ptx] Re: Simple lens calibration

2009/2/25 Oskar Sander : > the purpose with the calibration foul be to be able to correct > individual images using Fulla (and maybe directly in Lightroom > eventually) but also to have a starting value when stitching linear > panoramas of wreck sites. Why does it need to be underwater to calibr

[hugin-ptx] Re: Simple lens calibration

sorry for waking up an old thread. I'd like to use this method to calibrate a UW camera set-up. That is, a camera in a housing with a wide angle lens attached on the housing. Obviously this set-up is very much different from the camera on land so I need to do it in the pool, so I need to plan th