Curved Horizon

[PatR]

I've shot over 2000 image files with the CGO3+ and not seen such horizon distortion.

 

[FlushVision]

I've shot over 2000 image files with the CGO3+ and not seen such horizon distortion.

Me neither. While there is some distortion in my images (there has to be, that's the nature of the beast) I can't see any obvious distortion with my eyes. I was doing a coastal flight last week and as I look at the horizon I see no noticeable curve.

 

[BroVari]

Then I am guessing that you guys have the early version of CGO3+ with 98 degree lens.

 

[FlushVision]

Then I am guessing that you guys have the early version of CGO3+ with 98 degree lens.

Yep. Pre-ordered and one of the first available in the U.K. delivered to me 1st June 2016.

 

[PatR]

Have three cameras. One from May last year, one from December last and one January this year. The December camera has a PixAero lens though.

 

[AH-1G]

here are two examples using my H, the first is the large body of water flat Mt. Dora Lake no curvature, the second is a church 30 degree down angle and curvature.

 

[kd4pbs]

Field curvature will only be apparent on horizontal lines the farther up or down from the center of the screen vertically. Field curvature will only be apparent on vertical lines the farther left or right from the center of the screen horizontally. So, if the horizon is dead center, with an equal amount of sky and land above and below the horizon, it doesn't matter how much distortion the lens introduces; it will always be perfectly flat.

 

[AH-1G]

hmmm

Field curvature will only be apparent on horizontal lines the farther up or down from the center of the screen vertically. Field curvature will only be apparent on vertical lines the farther left or right from the center of the screen horizontally. So, if the horizon is dead center, with an equal amount of sky and land above and below the horizon, it doesn't matter how much distortion the lens introduces; it will always be perfectly flat.

AhHa

 

[kd4pbs]

My mistake... I am using incorrect terminology.
Indeed it's called "Geometric distortion" as I originally stated. "Field curvature" is related to the focus plane, where items from center to edge can have a different focus point.
Here's a great page on the subject...
Distortion - imatest
As you can see, the farther from center the horizontal and vertical lines, the more the distortion.

 

[PatR]

Indeed. Doing some experiments with that I was able to generate images with different levels of distortion.

 

[Air Intel]

Call Yuneec and explain this to them. Take a couple of still pictures to assist your explanation, presuming the horizon is presented the same way. Looks like you might have gotten one of the original lenses that were changed to eliminate that. The CGO3+ does not provide a curved horizon.

My CGO3+ does also has a curved horizon. Is there a physical fix for this do you know? Shouldn't have to use software to fix it later. Drone was only purchased 6 months ago! I have sent the drone in for repair of the st16 so I'm wondering if this is also something they can fix whilst its already there? Or is it due to the wide angle lens and can't be changed?
Thanks!

 

[Fred Garvin]

Just the nature of such a short lens. Get up to 24mm and it’s much, much less. 28mm and beyond it’s not really an issue. Once you drop below 18mm it starts to become very noticeable.

 

[thetrecker]

@AH-1G i am guessing reading this that we have different lenses and i have a newer 1 why i have more curvature on my horizon
i purchased the drone second hand was told not flown much ( looked like new when i got it ) and only about 6 mouths old so around april / may 2017

have found a fix for lightroom if anybody would like it @Air Intel need to extract and put into the folder C:\Program Files\Adobe\Adobe Photoshop Lightroom 5.7.1\Resources\LensProfiles\1.0 or equivalent

or C:\Users\[USERNAME]\AppData\Roaming\Adobe\CameraRaw\LensProfiles\1.0

example

 

[Air Intel]

Cool, thanks @thetrecker !

 

[AH-1G]

@thetrecker
I didn't know there were different lenses for the H.
Purchased mine March 2016

 

[Fred Garvin]

Thanks for that profile! Got one for the C23?

 

[thetrecker]

@thetrecker
I didn't know there were different lenses for the H.
Purchased mine March 2016

thats why i love forums lots of info ( only just read the whole of this thread to get that info )
so according to this i would imagine you have 98 degrees and mine would be 115 degrees
so now i am looking for a cheep old cgo3+ lol as i like your pics

Well, depends on when you bought your typhoon. I have 2 CGO3+ cameras and one of them (older - bought in may 2016) has almost no distortion, and the newer one (may 2017) has much much wider angle of the lens. I have contacted yuneec about high distortion of the newer camera, they told me that in the new cameras they install a lens with 115 degrees angle and in the older cameras they installed a 98 degrees lens. That's why there is that difference and they claim it is normal and I agree because 115 degrees is pretty wide.

 

[thetrecker]

Thanks for that profile! Got one for the C23?

sorry Fred i found this on a different forum its is homemade by somebody so might still need work maybe somebody with better now how could convert it to a c23 using it as a base to start ??

 

[Fred Garvin]

I’ve never created one, but I don’t think they’re that hard to do. I’ve got a couple macros I made for my D810 and D7200 that apply to each image during import....they do lens profiles and remove CA, plus fill out a bunch of meta fields with common info.