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Author Topic: Oblique Camera 12mm on Wingtra Gen II  (Read 1653 times)

Costas

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Oblique Camera 12mm on Wingtra Gen II
« on: February 08, 2022, 12:58:48 PM »
I have Wingtra Gen II drone equipped with an Oblique Sony a6100(wide lens).

The pictures does not contain any info about Focal Length and F-Stop in exif. (all numbers are 0 when imported in Agisoft)

The camera specs state that it has 12mm lense, APS-C sensor. The focal Length is 12mm (18mm equivalent for 35mm). F-Stop is set at 4.5 in the lenses ring (no software option in camera menus).

So the questions are:
1) In Camera Calibration settings what should i choose? Is it Frame or Fish Eye?
2) Can i add this numbers (specs) in Agisoft myself and how? If yes should i add the 12mm or the 18mm equivalent to 35mm?
« Last Edit: February 08, 2022, 01:00:38 PM by Costas »

Darko

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Re: Oblique Camera 12mm on Wingtra Gen II
« Reply #1 on: February 11, 2022, 11:25:05 PM »
Hi,
I've been using this setup for a long time on my hexa drone. It is perfect lens. You should choose FRAME camera. it is not Fisheye lens. The only thing you should touch in the Camera Calibration is "Rolling Shutter" option that has to be checked. Just leave the rest to Agi to calculate it by itself.
When shooting choose the Manual setup and set it up to Auto ASA with the Exposure set up to 1/1000 and in summer time close the aperture to 5.6 and you'll get the best out of it. In the winter time when light is not that bright you can open it more up to it's widest opening. In that case you'll get some blurry corners but otherwise the picture will be perfect.
Good luck with your Wingtra!!

Costas

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Re: Oblique Camera 12mm on Wingtra Gen II
« Reply #2 on: February 14, 2022, 05:46:30 PM »
Darko, thank you for you info.

The settings i used are the ones that Wingtra says to use as default. Some of them are:
aperture between 4 and 5.6 (i suppose it's the 4.5)
Exposure: 1600
Exposure composition: -0.3
ISO: Auto

I tried a test project before i got your answer and i indeed tried the Frame Camera setting but I didn't enable the Rolling Shutter. I thought that the camera had a mechanical Shutter. Don't ask me why, i just forgot to check the shutter type on this camera. :-)  Maybe because the other camera i use on Wingtra is the Sony RX1R II which has a mechanical shutter.

Anyway the results are pretty good (see pic) and the accuracy is about 1cm for X,Y and 5cm for Z at 3gsd without Ground Control Points.

Thank you for pointing out about Rolling Shutter.
Another question is about the "Adaptive Camera Model Fitting". I choose to not use this feature in Alignment and on Optimising. I have not tested yet with this option ON. Do you use it or you leave it unchecked?