Script for Tilt-Shift Lens

[garry23]

This thread is superseded by https://www.magiclantern.fm/forum/index.php?topic=25286.msg230159#msg230159

If you are lucky enough to own a tilt-shift lens, in my case a 24mm TS-EL II, you may be interested in my latest script.

Full details can be read here: http://photography.grayheron.net/2019/11/in-camera-ts-e-lens-simulation.html

The script can also be downloaded from the above link.

I'll update this post as I write more about the script.

As usual I welcome feedback.

[garry23]

BTW you don't need a TS-E lens to use the script 

So if you wish to explore what a TS-E could do, play with the script.

The only requirement is that the lens should report focus.

[garry23]

Slight tweak to some maths to correct a silly mistake 

[DeafEyeJedi]

I'll definitely borrow a TS-E lens from work to try the script out.

I still feel silly for not keeping up with your work @garry23! 

[garry23]

@DeafEyeJedi

It would be great to get another user's perspective.

If you are not using a 24mm L II, make sure you change the lens min focus and max mag at the beginning of the script, i.e. use the Canon quoted values, or measure your own.

I was thinking of adding other focusing info, eg FoV, but I need to work out a way of doing this without cluttering the screen with too many more lines.

Cheers

Garry

[garry23]

Added some comments to the code to help those who wish to use Lua, better understand what I've coded.

Also made the focus stacking feedback more robust: after taking an image the focus overlap feedback (centre dot) now shows Green, until you lose the overlap. Thus to focus stack with the the Tilter, all you need to do is focus your TS-E for the first image, using whatever means you like, and then focus stack using the Tilter until you have covered your required angle.

Thus, if you are shooting at a low hinge height, you can get the floor tack sharp, near to front, by placing the plane of maximum focus on the ground, and focus stack for elevation until you have reached the required upper (near) DoF angle.

As I said, I be writing a tutorial on TS-E focus stacking soon.

More to come 

[garry23]

Added some comments to the code to help those who wish to use Lua, better understand what I've coded.

Also made the focus stacking feedback more robust: after taking an image the focus overlap feedback (centre dot) now shows Green, until you lose the overlap. Thus to focus stack with the the Tilter, all you need to do is focus your TS-E for the first image, using whatever means you like, and then focus stack using the Tilter until you have covered your required angle.

Thus, if you are shooting at a low hinge height, you can get the floor tack sharp, near to front, by placing the plane of maximum focus on the ground, ie zero blur on the ground plane, and focus stack for elevation until you have reached the required upper (near) DoF angle.

As I said, I be writing a tutorial on TS-E focus stacking soon.

More to come 

Didn't intend to post this one: finger trouble 

[garry23]

As promised, here is the first tutorial on using my new Tilter script, that is designed to help you focus your TS-E lens and, uniquely, I believe, carry out tilted focus stacking; which is illustrated in this post: http://photography.grayheron.net/2019/11/using-tilter.html

The Tilter screen, with the lens FoV switched on looks like this:

Here we see I'm at f/12 and focused at 1.51m. I set the FoV (orange lines) in Tilter to non-shifted landscape mode.

The tilted FoV (yellow) is centred, ie the plane of sharp focus, at 41 deg, and the upper/near and lower/far DoF angles are at 55 and 18 deg respectively. I set a 20 micron blur in ML, and Tilter tells me that my diffraction blur is 17 microns, giving a convolved blur of 26 microns at the DoF envelope edges.

The red dot at the centre tells me that either I haven't taken a shot yet or that this focus doesn't overlap the last one.

The focus dot is yellow, indicating that I'm focused short of the hyperfocal (the vertical white line).

Finally, as I was on a tripod, Tilter tells me I'm at 1.25m above the ground.

As usual I welcome any feedback or suggestions to make Tilter better.

[garry23]

The Tilter script remains in 'development mode' and thus I will keep alerting prospective users on updates.

The latest rev adds in the functionality to disable the ML overlays and the Tilter display, so that you can see a clean screen, ie for composing.

As I use a gearhead, I find this an essential feature to ensure my capture is aligned the way I wish it to be.

The script allows you to specify a toggle key, that still allows normal functionality.

On my 5D3 I use the MENU key, ie top left on the camera.

To use the latest feature, once you have coded your toggle key into the script, all you need to do is press the key twice in quick succession for normal key use, and press it once, followed by a 2+ seconds, then a second time to toggle the ML screen on and off.

As usual the latest version is always here: https://gist.github.com/pigeonhill/2c799711e1a774b4ebe1ef09d2d95749

[garry23]

As promised, here is further info on Tilter: http://photography.grayheron.net/2019/11/more-on-tilted-focus-stacking-with.html

In the latest post I discuss why you would wish to do tilted focus stacking.

In addition, Tilter now provides feedback on the number of tilted focus brackets required to cover from the current position to the ground plane, ie where the hinge is positioned.

The Tilter screen now looks like this: