Hints and tips for a tilt & shift lens

[swag72]

Will be out and about next week with the 24mm TSE. I haven't really had a play yet, but have read loats of links with loads of technical stuff!!

So my question to you owners out there - Looking at Ed Bray, Canon Bob and Duncan Disorderly - To name a few, do you have any hints and tips for me?

I won't be using a tripod as that will be going via the Packers and I only have limited camera equipment space.

Hope there are a few of you who can chip in and offer some tips

 

[Canon Bob]

Sara,

You may have already been to this site but I considered it to be the TS Bible
http://hame.ca/tiltshift.htm links and info galore.

Here's a tip though....a hotshoe level would be a useful extra to carry with you.

Bob

 

[swag72]

Thanks for that Bob - There's certainly loads in that link - Will read that on a rainy day in Spain!!

 

[EdBray]

I agree with the hotshoe level, pm your address and I will send you a three way one, I bought two the same (god knows why).

I have found the best way to use TSE lenses is with live view on a tripod, (as you have already said a tripod is not an option) I would take a small bean-bag and fill it with dried lentils or split beans and rest it on a suitable object.

Also, you do not need as much shift as you would expect to get front to back sharpness as the table from www.davidsummerhayes.com shows:

24mm lens Degree of tilt against Focus Plane

1 ° 1.3m
1.5 ° 900mm
2 ° 690mm
2.5 ° 550mm
3 ° 460mm
3.5 ° 390mm
4 ° 345mm
5 ° 275mm
6 ° 230mm
7 ° 197mm
8 ° 172mm

The first number is the degree of tilt the second the height of the lens above the ground.

Hope this helps.

 

[swag72]

Thanks for that Ed - PM'd.

 

[HoppyUK]

I think you'll need the tripod really.

For getting the camera dead level, working out your Scheimpflug angles, doing all the manual lens stuff, in live view etc. All quite tricky hand-held and getting the most out of that kind of lens is all a matter of precision.

 

[swag72]

Mmm. May have to work on that at another time then if I really do need a tripod.

I'm a little bemused now by the figures Eddie posted above.

Say I have my camera on the tripod and it's at 1.70m above the ground - Where does that fit in with the degree of tilt required?

Also, initally, my plan was to use it primarily to sort out some converging verticals on buildings. How will I have to work that out?

 

[EdBray]

Sara,

The lens has two seperate and distinctly different modes (tilt & shift), although they can be used together if required.

The main characteristics of this type of lens is that the degree of coverage at the film/sensor plane is very large (compared to a non tilt shift lens of the same focal length) which allow the movement of the lens laterally (across up or down parallel) or tilted/swung (twisted) to the sensor/film plane. The option to move in either orientation is usually acomplished by some mechanical means.

Shift gives you the option to move the image around the sensor, this is particularly useful for correcting verticals as you can use the amount of shift required to 'move' the image across the sensor to get the subject fully in the frame whilst keeping the sensor/film plane parallel to the subject. With extreme shift you will experience a degree of vignetting due to light loss as the light rays at the edge have further to travel to reach the sensor.

Tilt/Swing gives you the opportunity of maximising or limiting the depth of field by twisting the lens (moving the plane of focus) relative to the film sensor.

This is where the table is used when you want to maximise the DOF. By having the camera on a tripod and tilting the camera slightly, then using 1 degree of tilt on the lens should give you everything acceptably sharp from the closest focus point to infinity at a relatively wide aperture. As depth of field increases in 3 dimensions for a landscape you can usually cover everything from near to far with a little tilt and a maximum aperture of f8 or even wider.

This is a good site with some good diagrams.

 

[HoppyUK]

I think you'll have a lot of fun with this lens Sara While the converging verticals thing can be done in post processing (and arguably better, certainly to a greater degree) the DoF control is unique to the lens' tilt feature.

To which I would say two things. You can make DoF as complicated as you like with calculations, but at the end of the day the whole thing is based on a raft of subjective assumptions about what is sharp and what is not. And ultimately what matters is what you see in the finished picture, and that is so easy to do and check with digital by zooming in to the LCD and simply seeing for yourself.

And Scheimpflug can sound a bit difficult but it's simply about bisecting the subject plane (the bit you want sharp) and the sensor plane (which is obviously fixed) with the lens plane (which you then move). I just tilt the lens and adjust the angle by eye, by standing back a bit and looking at the camera from the side. Easy.

The more difficult bit is deciding where to focus and what f/number to use. There's no subsitute for a bit of experience there but it's only normal DoF principles on the squint! I would just use normal DoF tables and hyperfocal distance settings as a starting point, focus a third in, that kind of stuff - but you should get the DoF you want at several f/stops lower than usual. Check it out on the LCD.

If you do any table-top still life or product photography it is brilliant for that, as you can get everything sharp and squared in camera, in seconds, with no PP required.