How to correct vertical line

[Linhof]

By using Photoshop CS5 lens correction, I still failed to correct vertical and horizontal lines. Just wonder if you can advise a better way to do the job.

Thanks

[Preston]

I use "Skew" when needed. Sorry, I'm not at the computer with CS5, and I can't remember how to access the tool. (Gettin' old, you know. :-) )

I find it helpful to display the grid when using the 'skew' tool. Or, you can use vertical and horizontal guidelines.

You might want to look in PS Help--F1 is your friend.

--P

[Jim Noel]

DO it in the camera as you mak the photograph. That is what the movements are for.

[Preston]

I agree with you Jim, but if correction after the fact is needed, PS tools may be of help.

As an aside, one thing that really helps me when I'm doing architectural shots is having a ground glass with a grid. I don't rely on bubble levels, because buildings/ windows/ doors may not be plumb or level. Using the grid with tilt and/or swing of the back makes things much easier in the long run

--P

[brian mcweeney]

In CS5 I would first place a guide line to see what vertical should be, select the whole image say with the rectangular marquee, then go to edit/transform/perspective and drag the corner until your vertical in the image is parallel with the vertical guide you placed over the image. Hit apply when it looks good. Use skew if one side needs more adjusting than the other for vertical.

[Linhof]

Hi,

Totally agree that camera movement is perfect solution. But just a short trip to shanghai without my view camera. Thanks for all advice here.

[polyglot]

You have a curved horizon, which implies a fisheye lens or bad stitching effort. That's not something correctable with camera movements!

To straighten it in post, look for "defish" software/plugins. There's plenty out there.

[Fourtoes]

PS has a lens correction filter that will help a little with the fisheye etc. Sometimes it works great and sometimes it doesnt.

[Paul H]

Apart from the previously mentioned de-fish programs, you could try a panorama tool like Hugin.

I'm not sure whether this is the result of a multi-frame panorama or not, but Hugin can not only do a really good job of stitching it properly in the first place, it can also be used to fix the verticals and make your horizontals straight.

[Greg Miller]

Using the ruler function you can set reference lines. Then using Free Transform (Ctrl (or command) + T), and a combination of perspective, skew and warp you can get pretty close.