Fixing distortion

[ziggy©]

I am trying to learn how to fix a distorted picture in CS4 but cant seem to get it right.

The main problem i think i have is im not sure exactly how to fix the distortion. I usually use one of two options in CS4. Either rotating the picture or using the "Distortion" options under the "Filter" menu.

The problem with rotating the image is that it messes up other areas of the image which are perfectly straight. Take this image for example, if i rotate it, the taller structure does straighten but the ground becomes tilted and the other structure on the left also becomes tilted.

The option in the "Filter>Distort" menu looks quite usefull but i cant really work out how to use it correctly. I usually use the first option which is for distortion. When i try it, can never get it to straighten the image. Here is another example,

The minarets are not straight at all. If i try the distort option in photoshop i find that anything above +3 make the image look slightly weird. The problem is that at +3 the minarets are nowhere near straight.

So how can i fix distortion in my images? I have tried my best to keep the horizontal straight when i take the picture but they always appear distorted. This seems to be worse when i use a wide focal length i.e. 17mm to 20mm.

 

[mipevo6]

What type of camera do you have? I have a Canon which comes with DPP which allows me to correct lens distortions... I am not sure how you do lens correction in CS4 but I would guess you can.....

 

[ziggy©]

The above were taken using a 400D and 17-85mm. I havent tried the lens distortion option in DPP but does it not use the same engine as that of the one in in CS4.

 

[Rocket58]

I use. Edit> Transform> Perspective.

Then drag the corners untill it looks right.

Ron

 

[trencheel303]

Perspective distortion and barrel distortion are two different things. DPP fixes barrel distortion on some lenses, but won't fix perspective distortion. These images are suffering from slight perspective distortion only.

 

[ziggy©]

Perspective distortion and barrel distortion are two different things. DPP fixes barrel distortion on some lenses, but won't fix perspective distortion. These images are suffering from slight perspective distortion only.

I've looked up "perspective distortion". It looks like i would have avoided it if i moved back and zoomed in on the subject.

 

[Mike54]

Hi. I think you are trying to change perspective rather than distort.
If you go to Edit - Transform - Perspective, you can pull the corner out horizontally and create a Key stone effect which will straighten the verticals, there will be some foreshortening which can be corrected and some cropping but as quick go :-

 

[ziggy©]

I wasnt aware that the "Edit/Transform" option could also be used for this purpose. I will try this later today and see how it goes.

I think you are trying to change perspective rather than distort.

What exactly is the difference between perspective and distort?

Here is the option that i am currently using.

http://www.gilsmethod.com/images/how-to-correct-lens-distortion-with-photoshop.png

It brings up the following window. I use the "remove distortion" option shown at top right. The slider shrinks or expands the image depending on which side you move it to (see the small icons next to the right and the left of the slider). I think this option is very ineffective unless maybe i am using it incorrectly.

 

[Edsport]

In cs4 i used the rectangular marquee tool to quickly highlight the pylon then went to edit, transform, rotate and rotated the pylon, then go to select and deslect. Click on the history brush tool and clean up the space around it. Use a small brush...

 

[cargo]

Great stuff just tried this on the above image.Works a treat. Never used the history brush before.

Thanks

In cs4 i used the rectangular marquee tool to quickly highlight the pylon then went to edit, transform, rotate and rotated the pylon, then go to select and deslect. Click on the history brush tool and clean up the space around it. Use a small brush...

 

[Chaz Photos]

this is easy to do with freetransform tool
Here is one I done