Auto Hand Held Focus Stacking

HHFS.lua

--HHFS Script Release 0.8

--[[
********************************************************************************************
This script creates a two image focus stack via aperture bracketing.
The script attempts to maintain the same exposure of the closed down aperture as the base exposure, between two limits: the minimum handheld shutter and the maximum ISO.
The script 'remembers' menu settings at camera close, so you will only need to set them once: only change things as required.
The base exposure should be taken at a wide aperture.

Garry George
March 2018
www.photography.grayheron.net
********************************************************************************************
--]]

require("config")

max_iso = 0 -- Set in menu
max_iso_apex = 0
base_shutter_apex = 0
base_iso_apex = 0
base_aperture_apex = 0
options0 = {"ON", "OFF"}
options1 = {"Auto", "Manual"}
options2 = {"0 delay", "2s delay", "5s delay"}
options3 = {"FF Sensor", "Crop Sensor"}
options4 = {"1600", "3200","6400"}
options5 = {"Auto","1/30","1/60"}
options6 = {"None", "Audio","Led", "Both"}
options8 = {"F/16", "F/22"}

min_shutter_value =0
min_shutter_apex = 0
timer_running = false
time_pressed = 0
run_HHFS = false
beeped = false
good_to_go = false

function HHFS_bracket(arg) -- note this function is called regularly by the shoot_task event handler and does all the main work
    
    if HHFS_menu.submenu["Turn Script on and off"].value == "ON" then good_to_go = true else good_to_go = false end -- track the script's on/off state 

    if good_to_go and timer_running and (not beeped) and (dryos.ms_clock - time_pressed > 3000) then -- give user feedback if requested
        if HHFS_menu.submenu["User feedback"].value == "Audio" or HHFS_menu.submenu["User feedback"].value == "Both" then beep() end
        if HHFS_menu.submenu["User feedback"].value == "Led" or HHFS_menu.submenu["User feedback"].value == "Both" then led_blink() end
        beeped = true -- so don't beep again
    end

    if good_to_go and not run_HHFS then -- keep track of min shutter speed in auto mode
        if lens.focal_length == 0 then menu.set("Hand Held Bracketing", "Min Shutter options", "Manual") end -- handle lenses that don't report FL, but ensure ETTR min shutter set correctly
        if HHFS_menu.submenu["Min Shutter options"].value == "Auto" then -- set ETTR automatically based on focal length and min hand holding shutter set in script's menu
             local x = lens.focal_length
             if HHFS_menu.submenu["Sensor Type"].value == "Crop Sensor" then x = x*1.6 end -- account for crop sensor
             x = 8*(7+math.ceil(math.log(x)/math.log(2)))
                 if x < 96 and HHFS_menu.submenu["Your min hand holding limit"].value == "1/30" then
                    x = 96
                 elseif x < 104 and HHFS_menu.submenu["Your min hand holding limit"].value == "1/60" then
                    x = 104
                 end
             menu.set("Auto ETTR","Slowest shutter", x) -- set slowest ETTR shutter to FL-informed value, ie 1/FL guidance + your min hand holding limit (1/30 or 1/60)
        end
             min_shutter_value = menu.get("Auto ETTR","Slowest shutter",1)
             min_shutter_value = 1/(2^(min_shutter_value/8 - 7)) -- set min shutter in seconds based on ETTR setting
    end

    if good_to_go and run_HHFS then -- capture brackets
            if HHFS_menu.submenu["Delay?"].value == "2s delay" then
                msleep(2000) -- inject a 2 sec delay
            elseif HHFS_menu.submenu["Delay?"].value == "5s delay" then
                msleep(5000) -- inject a 5 sec delay
            end -- else no delay
            base_shutter_apex = camera.shutter.apex
            base_iso_apex = camera.iso.apex
            base_aperture_apex = camera.aperture.apex
            max_iso = tonumber(HHFS_menu.submenu["Max ISO"].value)
            camera.iso.value = max_iso
            max_iso_apex = camera.iso.apex
            camera.iso.apex = base_iso_apex
            camera.shoot() -- take base image
            camera.shutter.value = min_shutter_value -- set to slowest shutter
            min_shutter_apex = camera.shutter.apex
            local min_aperture_apex = 0
            if HHFS_menu.submenu["Min aperture"].value == "F/16" then min_aperture_apex = 8 else min_aperture_apex = 9 end
            camera.aperture.apex = min_aperture_apex
            local delta_ev = min_aperture_apex - base_aperture_apex
            local delta_tv = base_shutter_apex - min_shutter_apex
            if base_shutter_apex == min_shutter_apex then -- can only use ISO
                camera.iso.apex = camera.iso.apex + delta_ev
                if camera.iso.apex > max_iso_apex then camera.iso.apex = max_iso_apex end
            else -- can use shutter and ISO
                camera.shutter.apex =  min_shutter_apex
                camera.iso.apex = camera.iso.apex + (delta_ev - delta_tv)
                if camera.iso.apex > max_iso_apex then camera.iso.apex = max_iso_apex end
            end
            camera.shoot() -- take the closed down aperture image
            camera.shutter.apex = base_shutter_apex -- reset settings to initial state
            camera.iso.apex = base_iso_apex 
            camera.aperture.apex = base_aperture_apex
            if timer_running and (not beeped) then -- give user feedback if requested
                if HHFS_menu.submenu["User feedback"].value == "Audio" or HHFS_menu.submenu["User feedback"].value == "Both" then beep() end
                if HHFS_menu.submenu["User feedback"].value == "Led" or HHFS_menu.submenu["User feedback"].value == "Both" then led_blink() end
            end
            run_HHFS = false
    end
    return true -- no reason not to
end

function test4key(key)
    if key == KEY.HALFSHUTTER and good_to_go and (not timer_running) and (not run_HHFS) then -- note assumes the shoot_task runs at least once following camera start
        timer_running = true -- start looking for half shutter long press
	time_pressed = dryos.ms_clock
        beeped = false
        return false -- steal key press
    elseif key == KEY.UNPRESS_HALFSHUTTER and good_to_go and timer_running and (not run_HHFS) then
        if dryos.ms_clock - time_pressed > 3000 then -- 3 sec plus half shutter press, so start HH bracketing
           run_HHFS = true -- OK to run the main script
           timer_running = false -- stop looking for a long press
           return false -- steal key press
        else -- less than 3 seconds so handle as a normal half shutter unpress
           timer_running = false
           return true
        end
    else -- must be a normal key press
        return true
    end
end

event.keypress = test4key
event.shoot_task = HHFS_bracket

HHFS_menu = menu.new
{
    parent = "Shoot",
    name = "Hand Held Focus Stacking",
    help = "Start at max aperture",
    submenu =
    {
        {
            name = "Turn Script on and off",
            help = "Does what it says",
            choices = options0,
        },
        {
            name = "Min Shutter options",
            help = "Auto means script sets ETTR min, manual means you do",
            help2 = "For manual, set min in ETTR menu",
            choices = options1,
        },
        {
            name = "Sensor Type",
            help = "Full Frame or Crop 1.6?",
            choices = options3,
        },
        {
            name = "Delay?",
            help = "Injects the requested delay before bracketing",
            help2 = "Switch off Canon delays",
            choices = options2,
        },
        {
            name = "Max ISO",
            help = "Don't over push it!'",
            choices = options4,
        },
        {
            name = "Min aperture",
            help = "Smallest aperture",
            choices = options8,
        },
        {
            name = "Your min hand holding limit",
            help = "Your hand holding shutter speed limit",
            help2 = "Useful when in Auto mode to override 1/FL for WA lenses",
            choices = options5,
        },
        {
            name = "User feedback",
            help = "To help with 3s half shutter and indicate bracket end",
            choices = options6,
        }
    }
}

config.create_from_menu(HHFS_menu) -- keep a track of the script's menu state at camera close