# Wide Angle Architecture Perspective Correction in PS



## cgipson1 (Aug 23, 2011)

My girlfriend recently made me take her to downtown Denver.. to shoot some buildings, a type of photography I have never been enamored of. I love doing interiors... but shooting tall buildings with normal lenses never seemed like fun. I did enjoy it.. and now am in the process of trying to learn to correct the perspective on the buildings. These were shot with a D7000 and and the 10-24 DX lens. 

I am looking for suggestions on how I can do this more accurately...  basically the correct way to do it, rather than the way I did it, lol! I  have never attempted perspective correction on this scale before... and  find it very interesting.

This first image is the original direct from camera image.

The second image is what I have been able to do, using my old version 6 of Photoshop. 

Uncorrected






Corrected... but how can I improve it? I pulled the car out of the shot, and "painted" the curb and wall to cover the hole from the car.


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## cgipson1 (Aug 23, 2011)

Thanks.. but I really had only a minimal idea of what I was supposed to be doing. I know there are people here who can help me to do it right!


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## Helen B (Aug 23, 2011)

The 'accurate' way to do it is to hold the width of the correct part of the building constant while narrowing the building below that line and expanding above. You could simply hold the width of the centre of the image constant. The accurate location of the constant width line can be estimated by imagining the level of the camera (ie imagine a horizontal plane at the level of the camera) and placing a guide, then placing a horizontal guide at the mid-point of the uncropped image (ie on the lens axis). Then you place a third guide exactly between those two. The third guide is the line that should be constant width.

In the case of your image the first line would go about half way up the ground ("first" in USA) floor of the Chase building, if the ground is roughly level.

Having got the 'line of constant width' you then expand the canvas so that that line becomes the new centre line of the image, allowing the use of the perspective correction tool (Lens Correction filter in PS6?).

This method keeps the ratio of horizontal and vertical proportions fairly accurate. Whether you want to do that or not is up to you - you can use the simpler method of keeping the centre line of the original image constant.

Best,
Helen


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## analog.universe (Aug 23, 2011)

I use vertical guides to ensure that I get a constant width..  put one basically right on top of each edge of the building, so when you're adjusting you know exactly when you've hit vertical.  This also makes obvious any barrel/pincushion that may need correcting as well.


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## cgipson1 (Aug 23, 2011)

Helen B said:


> The 'accurate' way to do it is to hold the width of the correct part of the building constant while narrowing the building below that line and expanding above. You could simply hold the width of the centre of the image constant. The accurate location of the constant width line can be estimated by imagining the level of the camera (ie imagine a horizontal plane at the level of the camera) and placing a guide, then placing a horizontal guide at the mid-point of the uncropped image (ie on the lens axis). Then you place a third guide exactly between those two. The third guide is the line that should be constant width.
> 
> In the case of your image the first line would go about half way up the ground ("first" in USA) floor of the Chase building, if the ground is roughly level.
> 
> ...



Thank you, Helen! That makes sense... I used the bottom width of the building as the constant, and it just didn't look quite right. I will have to play with that...  having fun learning! 



analog.universe said:


> I use vertical guides to ensure that I get a constant width..  put one basically right on top of each edge of the building, so when you're adjusting you know exactly when you've hit vertical.  This also makes obvious any barrel/pincushion that may need correcting as well.



Ok... I guess I need to learn to use the guides also... lol! I think if I combine this with what Helen mentioned.. it will give me a much better image. Thanks... I appreciate it!


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