Photos and P4 Pro: can we reduce distortions?

[Bucho]

For a client I realize a mission of photographic shots from a P4 Pro over a river, the camera pointing at -90 °.
The customer is generally satisfied with the result, however the edges of the photos seem distorted (the tree trunks on the edges of the photos do not appear vertical but a little oblique: are these distortions what is called "flash eye"?) .
I attached an example of a photo, below.
Is it possible to affect the camera settings (ISO, exposure, shutter speed, ...) to reduce distortions?
Or can we reduce these distortions by resuming the photos under PhotoShop, PaintShop or other application?

 

[Jim Roof]

What you are seeing is not a distortion. The trees near the edge of the photo are appearing in the photograph just as they would appear to a person viewing the scene from the same location as the camera.

There is a complex issue of 'mental imaging' that is also at play here. If you were sitting in a perch that was 400 feet above the trees, your BRAIN would KNOW that the trees were vertical and your BRAIN would NOT see them as 'leaning back' from the center of the photograph. However, the cameras does not have a brain to make that determination and the image itself does not contain the mental decoding that the eye performs naturally. That is why you see the trees, completely accurately photographed, and wonder why they appear to be leaning back.

You cannot fix this. It is a fact of photography. The only way it could be remedied would be to shoot from a MUCH higher altitude... probably close to a mile, and use a telephoto lens instead of a wide angle.

Photoshop will not be able to change this either. It is simply the geometry of things and not distortion at all.

 

[sshephard]

Actually, Photoshop has some pretty powerful tools for distortions introduced by lenses, especially the wide angle one on the P4P. Check out this tutorial:

Perspective Correction In Photoshop - Repairing Keystoning

 

[Jim Roof]

Actually, Photoshop has some pretty powerful tools for distortions introduced by lenses, especially the wide angle one on the P4P. Check out this tutorial:

Perspective Correction In Photoshop - Repairing Keystoning

What this person is describing is NOT distortion. It is a function of the focal length and the angle of view. Photoshop cannot help with this.

 

[KevMo Photog]

Lets see an example of exactly what OP is talking about Jim. If it's just on edges then using lens correction won't help in PS. But you can alter the distortion that is caused by wide angle focal lengths when things are not square. You can help it I should say. Of course it bends everything to a point to achieve a wanted result where you want it. But if this is just on the very edges of his image I would think that aperture selection might help a tad. And to slightly shoot a little looser so he can crop out this fringing distortion maybe.

 

[Meta4]

For a client I realize a mission of photographic shots from a P4 Pro over a river, the camera pointing at -90 °.
The customer is generally satisfied with the result, however the edges of the photos seem distorted (the tree trunks on the edges of the photos do not appear vertical but a little oblique: are these distortions what is called "flash eye"?) .
Is it possible to affect the camera settings (ISO, exposure, shutter speed, ...) to reduce distortions?
Or can we reduce these distortions by resuming the photos under PhotoShop, PaintShop or other application?

Like Jim says in post #2, this is not distortion and nothing you do in Photoshop will "fix" it.
This shows the effect you are seeing:

You are looking straight down on the trees you are above.
But you get a different view of the trees further away.
The camera is accurately showing the view from that point.
The further away from the centre point, the greater the effect.
Flying higher will reduce this but produce less detail.

Or .. if it's a large area, you could shoot a series of overlapping images as you fly overthe site and stitch them to produce an orthophoto like this: created from 24 (6x4) individual images

 

[Bucho]

What you are seeing is not a distortion. ... You cannot fix this. It is a fact of photography. The only way it could be remedied would be to shoot from a MUCH higher altitude... probably close to a mile, and use a telephoto lens instead of a wide angle. Photoshop will not be able to change this either. It is simply the geometry of things and not distortion at all.

Thank you for your very useful explanations, I appreciated.

 

[richardhurst]

Bucho message me one of the images and let me see what can be done with it

 

[Bucho]

Actually, Photoshop has some pretty powerful tools for distortions introduced by lenses, especially the wide angle one on the P4P. Check out this tutorial:
Perspective Correction In Photoshop - Repairing Keystoning

Thanks, very helpful!
I attached an example of a photo, below.

 

[Bucho]

Like Jim says in post #2, this is not distortion and nothing you do in Photoshop will "fix" it ... Or .. if it's a large area, you could shoot a series of overlapping images as you fly overthe site and stitch them to produce an orthophoto

Thank you very much, I understand much better what happens.
How to produce an orthophoto? Needs what software?

 

[Bucho]

Bucho message me one of the images and let me see what can be done with it

The red arrows show what is disturbing, on the edges.

 

[AyeYo]

That looks perfectly normal. If those lines were vertical, THAT would be distorted.

 

[KevMo Photog]

The red arrows show what is disturbing, on the edges.

Ok Meta4 and Jim were def right. Wasn't sure what kind of issue you were having here. You'll have to do it with multiple images like Meta and Jim mentioned. No way to fix this much bending and not effect the rest of the photo. I might add that this totally normal to most of us. So they must have a reason to want everything to look like its directly over it's head no matter what.

 

[Jim Roof]

Lets see an example of exactly what OP is talking about Jim. If it's just on edges then using lens correction won't help in PS. But you can alter the distortion that is caused by wide angle focal lengths when things are not square. You can help it I should say. Of course it bends everything to a point to achieve a wanted result where you want it. But if this is just on the very edges of his image I would think that aperture selection might help a tad. And to slightly shoot a little looser so he can crop out this fringing distortion maybe.

I think one of the problems with this kind of topic is the way we sort of use the term 'distortion' very loosely. I have shot with wide angle lenses for 40 years now and have owned some of the best wide angle lenses ever made (Schneider and Rodenstock lenses for large format and now some very fine Canon glass). Clients will often look at a round table that is near the edge of an interior shot and ask me why it is 'distorted' and I very kindly tell them that it is NOT distorted, but rather, our brains are being challenged by seeing an image that represents a 75 degree angle of view that is only taking up about TWENTY percent of our viewing angle. Ie., if we held an 8x10 print taken with a 75 degree angle lens CLOSE enough to our eyes that the print ALSO took up a 75 degree angle of our view - it would look just right.

The problem is, our brains default to something that makes things LOOK distorted even though the image may have been taken with a perfect lens.

Barrel distortion and pincushion distortion are the only REAL distortion that exist. OK, there is also the 'mustache' that some wide angle lenses make. As long as there are straight lines in the photo where straight lines exist in the real world... there is no distortion. But, there are many problems of perception that most people will instinctively call 'distortion'.