Tilt-Shift Example

[TCampbell]

I thought I posted this, but apparently not...

Here's a quick tilt-shift example I created to show what the lens can do. The two images show off what the tilt-shift can do. Not the best pictures... if I had it to do over there's a number of things I'd change. I mostly posted these to demonstrate one feature of the lens.

First, here's what you get without any correction:


Riverhouse (uncorrected) by Tim Campbell1, on Flickr

And here's what you get WITH just "shift" correction (no tilt):


Riverhouse by Tim Campbell1, on Flickr

This is one of my first few times out with this new lens -- so I've got a lot of learning to do with it.

As I analyze the image, I probably "over-corrected" the perspective on the building by trying to make it perfect. It turns out the human eye & brain want to see just a little narrowing of a building. If you don't see it, you get the idea that the building gets wider as it goes up (when it's really perfectly aligned.) So they usually recommend you back-off the shift correction by just a couple of degrees.

I wish I would have had a strong ND filter to smooth out the river, but as the lens was less than I week old, I haven't picked up the filters for it's 82mm diameter yet (all my filters are 77mm.)

These are shot with my Canon 5D mk II & the TS-E 24mm f/3.5L II tilt-shift lens.

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[stonehorse]

Very interesting. Can you use the tilt/shift to get nearly unlimited depth of field like view cameras can do?

[TCampbell]

Very interesting. Can you use the tilt/shift to get nearly unlimited depth of field like view cameras can do?

Yes.

The lens can rack sideways (shift) along one axis. It can "tilt" along another. But the lens mount allows it to rotate 360º on the camera body (so the axis of tilt or shift can be in any direction you want). Also there's a control that allows you to change the tilt & shift axes so that they either align or are orthogonal to each other.

When "shifted" it produces the perspective control that you see here (nice when shooting tall subjects).

When "tilted" it swings the plane of focus so that it's no longer simply parallel to the image plane. You can "lay" the plane of focus onto an angle in any direction you want.

[bert]

Uhh...did you have to re-mortgage the house to buy the lens ?

It's interesting that you refer to human perception, the ancient Greeks deliberately built huge stone columns that were significantly wider at the top, so as to enhance them perspectually.

Anyway, useful post, thanks, sir, you are alway posting really useful, helpful things

The first pic looks like one of mine, hahaha... I'd like to fix my pics up better, but I think I want to find some software that might do it,

cos a perspective-correction lens is currently way beyond the capabilities of my pocket

Do you know of any plug-ins that might do it ?

[TCampbell]

Photoshop and Photoshop Elements have the feature built-in. They move it around in the menu system from version to version, but look for a filter called "Lens distortion" or "Lens correction". I used the feature in Photoshop for years before getting the lens. The downside of software is that you lose some of the image in order to do the correction, so depending on how you framed up the original shot, it might end up cropping out something you really wanted to keep in the image. And of course... software can't do the "tilt", which is what allows control over the angle of the DoF.

I wouldn't necessarily advise someone to buy a tilt-shift lens just to have "in the collection". There are a lot of caveats involved... they are all essentially completely manual lenses (The only thing the camera controls is the aperture. Everything is else is up to you.) They take some work to understand how to control them, and I still don't think I do that great of a job controlling it. BUT... when I do get everything worked out, I sure do love the results.

[KevinH]

OK, the tilt shift is a pretty cool gadget. I have use the lens corrections features in PSE and CS5, they definitely help the image. But one thing I notice is the exposure appears less exposed at the top of the shifted image. Is this from the lens tilt shift? A result of stretching the light over the sensor?
Kevin

[bert]

Thanks for the tips, TCampbell, you are a tremendous asset to this forum - you're always very generous with the fruits of your knowledge and experience.

A proper gent !

I'll look for lens correction stuff in my Photoshop. Thanks again

[TCampbell]

Thank you for the compliments Bert.

When you use Photoshop to do the perspective correction you'll want to have some extra room in the original image.

Essentially the image is going to go from a rectangle shape to a trapezoid shape (to correct the perspective distortion). Since you don't want to frame a trapezoid shaped image, Photoshop then crops the image back to it's original rectangular aspect ratio. This means you crop out two triangle shaped "wings" on the sides of your image. You don't want any of your intended subject in the parts of the photo that end up being cropped out.

If you practice with a few images, you'll get the feel for how much padding you need to leave no the sides of your subject (or if your adjusting horizontal perspective then you'd be cropping the top/bottom - but usually people are fixing vertical perspective.)

[TCampbell]

Kevin, I forgot to answer the question... yes you do lose light as you fix the perspective in a "shift".

Essentially the lens is producing a focused image circle into the camera body that's much larger than it needs to be -- even for a full frame sensor. This gives you room to move the lens around and still make sure there's a focused image landing on the sensor. If you could see the entire image being projected into the camera body (instead of just the image that happens to land on the sensor area) you'd see that it does "dim" as it approaches the edges of the image circle.

For anyone who's ever used an old "view" camera (where you stick your head under the black drape to look at the image on the frosted glass plate to focus prior to sliding in the film), the image is always projected into the camera body upside-down. When fixing perspective, I have to rack the shift upward. That means the "bottom" of the image inside the camera is vignetting a bit darker. Since the image is really upside-down inside the camera, that means the top of the image you see is actually vignetted a bit.

I didn't correct the vignetting in this image -- but then it's normal for a sky to go a little bluer toward the zenith as you can see from the uncorrected image (where the lens is using no correction and it's working like an ordinary prime lens.) When you compare it to the corrected image, you can see the sky is slightly darker, and that is the vignetting as the light "falls off" approaching the edge of it's image circle.

Very acute of you to notice that difference!

[bert]

I'm hugely impressed by both of you, but now I need some aspirin...