Tilt shift (TS-E 24) panarama hints

[DebT]

Hi,
I have just acquired a 24m Tilt shift lens with the intent of stiching shots together - anyone enjoy playing with the same who cares to share hints etc ?
Deb T

[DaveB]

I don't have one of these, but I do have access to one and have played with it a bit.

Be aware that out towards the edge of the image circle (which you approach when you start shifting) this lens has fairly severe chromatic aberrations (colour fringing). The newer (Mk.II) lens improves this, but even it's not perfect.

Usually when I have CA in a shot I just tweak the adjustments in ACR/Lightroom. However as soon as you shift or tilt, the CA corrections available in RAW processors are no use. They assume that the lens is centred on the sensor.
What you need to do is stitch the images together with no CA correction, THEN use Photoshop's Lens Corrections filter to reduce the CA. On normal shots it doesn't do as a good a job as the corrections in ACR, but in this case it will do a better job.

I usually use Photoshop's inbuilt PhotoMerge function to merge multiple images (typically 3-5 shots, depending on whether the camera is horizontal/vertical, full-frame/1.6x, etc). Or you could make a large canvas, put each image on a layer, and move them around by hand. PhotoMerge is quicker and easier.
Then flatten, then correct CA, then correct any distortion/tilt issues, then crop back to a rectangle in your desired aspect ratio.


For "shift panoramas" to work properly, you really need the lens to remain in the same place and the camera body to move behind it. That way you get no parallax/etc issues between the photos.
However this is slightly awkward with the TS-E lenses. Some other shift adapters actually have a tripod mount under the lens which makes this easy, but what you'll have to do is shift the lens in one direction, then shift the camera back the same amount in the opposite direction so the lens is back where it started.

On my gear (which uses Arca-Swiss style QR plates) I just loosen the clamp, slide the camera, and retighten the clamp. It's not too hard, but depending on your gear this might be very awkward. You might be interested in reading this article at Digital Outback Photo.


One other thing: the Mk.I lens by default has the tilt and shift functions acting at 90 degrees to each other. It is possible to reconfigure the lens so that they're in the same axis. It just takes a screwdriver (although you need to be careful to not damage the internal cables when putting the rear plate back on the lens). There are several tutorials on the web showing how to do this.

[DebT]

Thanks Dave, comments appreciated.
I haven taken a shot as yet but am doing a lot of web research and hunting down as many tutorials I can find . I understand they are tricky to get the hang of but have seen some excellent work which has inspired me to give it a go so I'm taking this on as a bit of a technical exercise and it will be interesting where it may lead. Once I get going I'll post the odd shot so would appreciate any comments you may have. The good thing is I got a great 2nd hand deal and am confident it should retain it's market value if I am a dismal failure
Have you posted any TS images in the past I can look at ?
Deb T

[DaveB]

Here's a quick stitch I did as a test last year. This is the result of 3 horizontal frames on a 40D. One on the left, one on the right, and one in the middle. As I described in my previous post I moved the body side-to-side between the frames.
It isn't a great photo: it was only at f/8 and while the parking meter is in focus, not enough else is.



The resulting image is 7362x2569 pixels (18 Mp from 3 merged 10 Mp originals) and as you can see is a very wide view.

What I should have done is had the camera in vertical and taken about 5 shots for a much larger file. Also, if you look at the picture here you can see the camera was pointing down slightly, resulting in slight perspective distortion (vertical lines leaning in a bit). Once you get images this wide these little details become more obvious.


You've got me enthused now - I might borrow this lens again and have a play with the 5DmkII...

[DaveB]

This is of course just shifting the lens. Tilting has its place also, but not so much for panoramas.
With tilting you get to play with the Schiempflug effect!

[gstark]

This is of course just shifting the lens. Tilting has its place also, but not so much for panoramas.
With tilting you get to play with the Schiempflug effect!

[surenj]

Just in case someone didn't know what the Scheimpflug principle is all about, here is an interesting link.

http://en.wikipedia.org/wiki/Scheimpflug_principle

Looks very easy to understand!

[DaveB]

http://en.wikipedia.org/wiki/Scheimpflug_principle

Looks very easy to understand!

Actually it's not a complete mind-bender. If you understand Figure 2 on that page you should understand the basics.

[DebT]

Well I now have it in my hot little hands and can't wait to try it out ...so thanks for the links and hints ...looks like tonight I'll be busy trying to understand exactly what I have and how to use it ...
Deb T

[big pix]

...... use as a manual lens. Get the centre image exposure correct and the one to the right and left expose the same, even if your camera says different...... trust me

[DebT]

Even though my mother warned me to beware of the nice 'trust me' guys I'll make an exception in this case - you have probably saved me heaps of aggrivation
Thanks
Deb

[DaveB]

How are you getting on with this lens Deb?

I just got hold of this lens again tonight (borrowed from its owner): hopefully later in the week I'll have a chance to take it out into the big wide world.