Perspective distortion..

Admiral Huddy

Admiral Huddy

Admiral Huddy

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Is there anything I can do to correct the vertical distortion at the rear tower?

23132320089_41a8da3d54_z.jpg




I've used the distortion and correction tools in LR but this then puts the front tower out.

thanks
 
Three are 2 ways.
The best, but most expensive so least used approach, is to buy a perspective correcting lens. Nikon sells these as PC lenses, canon as TS. This way you make the correction in the lens and so the sensor records the maximum detail.

The most commonly used approach is just to,use the perspective correction and distortion controls in light room or photoshop. It works well but does mean your image is stretched a little reducing detail and enlarging image defects like chromatic aberration. I suggest you use this but if architecture (or landscapes) is really something you get into then look at buying a PC lens.
 
Jono said:
Something in Photoshop? I forget what it's called. I'm sure there's something like free transform that gives you a grid to manipulate how you'd need to.
Click to expand...

Thanks I found this after what you suggested http://www.photoshopessentials.com/basics/free-transform/

D.P. said:
Three are 2 ways.
The best, but most expensive so least used approach, is to buy a perspective correcting lens. Nikon sells these as PC lenses, canon as TS. This way you make the correction in the lens and so the sensor records the maximum detail.

The most commonly used approach is just to,use the perspective correction and distortion controls in light room or photoshop. It works well but does mean your image is stretched a little reducing detail and enlarging image defects like chromatic aberration. I suggest you use this but if architecture (or landscapes) is really something you get into then look at buying a PC lens.
Click to expand...

I will do. Thanks :)
 
Admiral Huddy said:
Certainly a lot cheaper. On a cropped sensor, that going to pan out 38mm :/
Click to expand...

Something you can do with a PC/TS lens is accurate stitching by shifting the lens to the left and right capture 3 exposure which you can stitch together easily in photoshop. Doesn't work for subject motion.


The other cool thing you can do with a PC lens is tilt the focus plan. Normally when you capture an image the focal plane is parallel with the image sensor, so is typically vertical when taking a photograph. With a PC lens you can tilt the lens left-right or up-down (the lens can rotate 90* to allow either or), doing so tilts the focal plane. This can be useful because a lot of the things you photograph are on a horizontal plane, e.g. the ground in front of you, while a vertical focal plane just captures a slice of your intended subject, with the depth that is in focus (DoF) related to the focus distance and aperture. Tilting the focal plane can allow more of the foreground to be in focus while using a larger aperture so you don;t have to stop down so much.

Here is a non-technical overview of PC lens capabilities
http://www.digitalcameraworld.com/2...hy-how-to-use-1-lens-for-6-different-effects/



The good thing about the samyang TS lens is that autofous is irrelevant because no PC/TS lens can autofocus.
 
You could try the DXO Viewpoint software.
It is specifically for perspective issues. I've used it once or twice and it does seem to have more control than LR tools.

There is a demo version.
 
I found the DXO software is better for correction like this but you then often run into issues like you've found there with losing some of the image. This changes the composition of the shot so ideally you need to account for that when you take the original shot (or use different lenses with less distortion and stitch etc).

In this case it's not a massive issue as you've only got dark sky to try to fill but if it was buildings/people etc then it would be a bit more difficult :)
 
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