Magic Lantern Forum

Developing Magic Lantern => Scripting Corner => Topic started by: garry23 on July 07, 2016, 09:00:59 AM

Title: Latest Landscape Focus Bracketing Script
Post by: garry23 on July 07, 2016, 09:00:59 AM
For ML colleagues who wish to explore landscape focus bracketing here is my latest Lua script: https://gist.github.com/pigeonhill/6620121ebe1548eb1bdaa6bea8598fac (https://gist.github.com/pigeonhill/6620121ebe1548eb1bdaa6bea8598fac)

This script is now pretty robust (I think  ;)) but has only been tried out on my 5D3.

This version allows you to auto bracket in the following ways:
1. Focus bracket from FP to Inf stop
2. Focus bracket from FP to macro stop
3. Focus bracket from FP to HFD
4. Exposure bracket - you set the shadow exposure, the script sets the ETTR value from which the number of brackets is calculated
5. 4 above with 1, 2 or 3
6. LE simulation
7. Number of frames

In addition I have added in some feedback to help you get the optimum focus bracket set. If you are in FP2HFD mode you will get feedback in the menu as to the estimated number of brackets the script will take - add 1 extra bracket for the other modes. This is a good sanity check to do if you are NOT using a WA lens, as 'long' lenses (24mm and up) can generate lots of focus brackets. I stay below 10 brackets for sensible post processing, especially if I convolve focus bracketing with exposure bracketing!

You can see the impact on changing aperture by selecting that feature in the script's menu (with FP2HFD selected) and in real time see the number of brackets you will create. At the moment this moves the aperture in 1/3 stop increments (you can change to other increments by changing the value in the script, eg 1/2 stops). For optimum script performance, ensure diffraction aware is on in the ML menu.

In addition, the number of brackets will change dramatically by moving the starting FP away from the macro end.

As I say, with the script's menu on FP2HFD,  play around with the FL, FP and aperture to see the impact these have on the number of focus brackets that will be taken.

As usual, I welcome feedback of any kind, and, as I always say: I wrote the script for my 5D3 and my work flow  :)

Cheers

Garry
Title: Re: Latest Landscape Focus Bracketing Script
Post by: garry23 on January 23, 2017, 11:09:49 PM
Just to say I've released the latest version of this photography script, which does auto bracketing for exposures and focus, and more:

https://gist.github.com/pigeonhill/e008f051681885bc6ff84de637cb1d8e
Title: Re: Latest Landscape Focus Bracketing Script
Post by: garry23 on August 06, 2017, 01:39:42 PM
The current ML depth of field equations are sound, but the ML integer math 'engine', means the DoFs are not reporting correctly.

As I used the ML calculated DoF in my auto landscape bracketing script, I decided to decouple myself from the ML numbers.

Lua doesn't use integer math :-)

This version of the script is standalone: https://gist.github.com/pigeonhill/97a511da5a1e4d54ceffe40c8d02b24f

As usual I welcome any feedback or questions on the script.
Title: Re: Latest Landscape Focus Bracketing Script
Post by: xorpi on August 08, 2017, 05:34:10 AM
It looks very good. Additional software recommendations for focus brackets? I recommend affordable Affinity Photo software for merging and editing in MacPhun Luminar / AuroraHDR to maximize dynamic range.

Does this script work together with Dual-ISO, HDR and AutoETTR?
Title: Re: Latest Landscape Focus Bracketing Script
Post by: garry23 on August 08, 2017, 07:36:47 AM
@xorpi

I use Helicon Focus and Zerene Stacker as my focus stacking tools.

The script is pretty much embracing and is designed to do 'all' the multi-image things a landscape photographer may need to do, other than super-res multi-image taken: I have a separate script for this ;-)

There are three focus stacking options, all work from a near focus point (FP) you set:
- FP to HFD (the script alerts you to how many brackets it will take)
- FP - INF (for max focus Q I recommend this, as HFD is only just acceptable focus quality at infinity)
- QHFD (two focus brackets, one at HFD/2 and one at HFD x 2 or 3, which you can set)

As for exposure bracketing there are four options:
- Using the set exposure (ie exposed for the shadows, the script will work out all the other exposures for the scene, in 1 or 2 Ev steps)
- Fully Auto in 1 or 2 EV steps, ie it does ETTR and ETTL calculations, slightly different to the ML Auto bracketing option.

The two above bracketing schema can be combined, ie focus and exposure bracketing, together.

The script allows you to add in a dark image bookend, to help identify the bracket set in LR, say.

For Long Exposure simulation, ie taking multiple images (based on LE time or simply x images, the script allows you to also add in a single Dual-ISO at the end of the LE simulation, or a take an Auto exposure bracket set.

Cheers

Garry