CHDK Landscape Bracketing

lbs.lua

--[[
@title Landscape Bracketing
'Perfect' focus brackets from near to blur defined 'infinity': overlap defined at a fraction of camera's CoC
Plus option of two additional exposure brackets at each focus step, at 1Ev, 2Ev or 3Ev using -/+ or -/-- or +/++ logic
More info at https://chdk.wikia.com/wiki/Landscape_Focus_Bracketing_:_perfect_near_to_far_focus_brackets
Camera should be in manual focus mode and M mode
Release 1.9985
Tested on a G7X & G1X
(c) Garry George
@chdk_version 1.5
@param u Focus stack mode?
    @default u 0
    @values  u X2Inf Mac2Inf Mac2X X2delX
@param g Overlap at?
    @default g 3
    @values  g CoC 2CoC/3 CoC/2 diff
@param p Exposure bracket delta?
    @default p 0
    @values  p None 1Ev 2Ev 3Ev 800 1600 ZN
@param j Exposure bracket logic?
    @default j 0
    @values  j 0/-/+ 0/-/-- 0/+/++ 
@param m Delta from X (mm)
    @default m 25
    @range   m 1 200
@param n Max number of focus brackets?
    @default n 0
    @values  n Inf <10 <20 <30
@param c Script Delay (s)
    @default c 3
    @range   c 0 5
@param b Bookends?
    @default b 1
    @values  b No Yes
@param q Infinity focus quality?
    @default q 1
    @values  q CoC/2 CoC/3 CoC/4
@param v Show bracket pos?
    @default v 1
    @values  v No Yes
@param k Log?
    @default k 0
    @values  k No Yes
@param e Delete Log File?
    @default e 0
    @values  e No Yes
--]]

capmode = require("capmode")
if (capmode.get_name() ~= "M") then
    print("Switch to M mode")
    return -- exit script
end

if get_focus_mode() ~= 1 then
    print("Switch to MF mode")
    return -- exit script
end

if e == 1 then
    local fp = io.open("A/CHDK/DATA/LBS.CFG")
    local str = fp:read("*all")
    fp:close()
    temp = string.sub(str, 1, 1)
    temp = "A/CHDK/DATA/LBS."..temp
    fp = io.open (temp,"r")
    if fp == nil then
        print("No ConFig file found")
        return 
    else
        str = fp:read("*all")
        fp:close()
        if string.find(str,"e=0") == nil then
            str = string.gsub(str,"#e=1","#e=0")
            fp = io.open (temp,"w")
            fp:write(str)
            fp:close()
            os.remove("A/CHDK/LOGS/LOG_2306.TXT")
            print("Log File Deleted")
            return -- exit script
        end
    end
end

if (get_focus() == -1) then
    print("@ Infinity")
    return -- exit script
end

press("shoot_half") -- get current exposure
t = get_tick_count()
repeat 
    sleep(50)
    if get_tick_count() - t > 5000 then
        print("Unknown Error")
        release("shoot_half")
        return
    end
until (get_shooting() == true)
release("shoot_half")
s = get_tv96()
av = get_av96()

dof = get_dofinfo()
x = dof.focus
x_start = x
last_x = x
base_h = dof.hyp_dist
temp = 0
temp1 = 0
temp2 = 0
ok = true
fl = dof.focal_length/100
log = {}
count = 0
ecnt = get_exp_count()

if u == 1 or u == 2 then -- change focus to min focus
    set_focus((4*fl)/10)
    press("shoot_half") 
    repeat
        x = get_focus()
        sleep(100) -- seems to work on G7X & G1X, may need changing on other cams
    until x == get_focus()
    release("shoot_half")
end

-- A few Functions

function myshoot()
    ecnt = get_exp_count()
    shoot()
end

function bookend()
    if b == 1 then
        set_tv96(960)
        set_av96(640)
        myshoot()
        set_tv96_direct(s)
        set_av96_direct(av)
        repeat sleep(20) until(get_exp_count()~=ecnt)
    end
end

function refocus(xx)
    local dis = 0
    set_focus(xx)
    press("shoot_half") 
    repeat
        dis = get_focus()
        sleep(200) -- seems to work on G7X & G1X, may need changing on other cams
    until dis == get_focus()
    release("shoot_half")
end

function X_bracket()
    set_tv96_direct(s)
    count = count + 1
    if p == 0 then 
        myshoot()
    elseif p < 4 and j == 0 then
        myshoot()
        set_tv96_direct(s-96*p)
        myshoot()
        set_tv96_direct(s+96*p)
        myshoot()
    elseif p < 4 and j == 1 then
        myshoot()
        set_tv96_direct(s+96*p)
        myshoot()
        set_tv96_direct(s+2*96*p)
        myshoot()
    elseif p < 4 and j == 2 then
        myshoot()
        set_tv96_direct(s-96*p)
        myshoot()
        set_tv96_direct(s-2*96*p)
        myshoot()
    elseif p == 4 then
        local iso = get_sv96()
        set_sv96(sv96_market_to_real(iso_to_sv96(100)))
        myshoot()
        set_sv96(sv96_market_to_real(iso_to_sv96(800)))
        myshoot()
        set_sv96(iso)
    elseif p == 5 then
        local iso = get_sv96()
        set_sv96(sv96_market_to_real(iso_to_sv96(100)))
        myshoot()
        set_sv96(sv96_market_to_real(iso_to_sv96(1600)))
        myshoot()
        set_sv96(iso)
    elseif p == 6 then
        myshoot()
        set_tv96_direct(s-96*4)
        myshoot()
    end
    set_tv96_direct(s)
end

h = base_h -- no overlap case: brackets 'touch' at CHDK CoC

if g == 1 then -- adjust h to achieve the requested overlap, ie 'touching' at 2*CoC/3 or CoC/2 or at the diffraction aware defocus blur
    h = (h*3)/2
elseif g == 2 then
    h = 2*h
elseif g == 3 then -- use diffraction aware overlap: Assume CHDK CoC is total blur, formed in quadrature from defocus and diffraction blurs
    temp1 = 1000*dof.coc -- total blur set up for imath
    temp2 = (1342*dof.aperture)/1000 -- set up for imath. From diff_blur = 2.44*0.55*N (um)
    if temp1 > temp2 then -- can use diffraction aware overlap
        temp = imath.sqrt(imath.mul(temp1,temp1) - imath.mul(temp2,temp2)) -- diffraction aware defocus blur
        temp2 = imath.div(temp1,temp)
        if temp2 > 3000 then 
            h = 3*h
            print("Warning: High Diff: using CoC/3")
        else
            h = (h*temp2)/1000
        end
    else -- diff blur > total blur
        h = 3*h
        print("Warning: Diff>Defocus: using CoC/3")
    end
end

if (x > base_h or x == -1) then
    print("@/beyond H")
    sleep(c*1000)
    bookend()
    X_bracket()
    temp = get_exp_count().." @ "..x_start.."mm"
    if v == 1 then print(temp) end
    bookend()
    return -- exit script
else
    num = ((10*(h + x))/(2*x) + 5)/10
end

if u == 2 or u == 3 then
    dof = get_dofinfo()
    x = dof.focus -- register actual x
    last_x = x
    sleep(c*1000)
    bookend()
    if u == 3 then x_start = x_start+m end
    repeat -- to capture focus brackets from min focus up to x
        X_bracket()
        temp = get_exp_count().." @ "..x.."mm"
        if v == 1 then print(temp) end
        x = (x*(h*10 - 2*fl))/(h*10 - 2*x*10) -- position of next focus bracket
        if (x - last_x) == 0 then x = last_x + 1 end
        if x < last_x or x <= 0 then 
            print("Unknown Error")   
            refocus(x_start)
            return
        end   
        refocus(x) -- request move to x
        dof = get_dofinfo()
        x = dof.focus -- register actual x moved by cam
        last_x = x
    until (x > x_start)
    refocus(x_start)
    dof = get_dofinfo()
    x = dof.focus -- register actual x moved by cam
    X_bracket()
    bookend()
    temp = get_exp_count().." @ "..x.."mm"
    if v == 1 then print(temp) end
    return -- exit script
end

if (n ~= 0 and num > (n*10)-1) then -- accounting for last bracket at infinity focus
    print("Warning")
    temp2 = num + 1
    print("Focus Steps = "..temp2)
    return -- exit script
end

sleep(c*1000)
bookend()

-- else look after u == 0 or 1 cases
refocus(x) -- explicitly refocus to start
dof = get_dofinfo()
x = dof.focus
last_x = x
if k == 1 then log[#log + 1] = "\n"..os.date() end
X_bracket()
temp = get_exp_count().." @ "..x.."mm"
if v == 1 then print(temp) end
if k == 1 then log[#log + 1] = temp end

repeat -- to capture focus brackets up to just past h/3
    x = (x*(h*10 - 2*fl))/(h*10 - 2*x*10) -- position of next focus bracket
    if x <= last_x or x <= 0 then 
        print("Unknown Error")   
        refocus(x_start)
        return
    end   
    refocus(x) -- request move to x
    dof = get_dofinfo()
    x = dof.focus -- register actual x moved by cam
    last_x = x
    X_bracket()
    temp = get_exp_count().." @ "..x.."mm"
    if v == 1 then print(temp) end
    if k == 1 then log[#log + 1] = temp end
until (x > h/3)

temp1 = h
temp2 = base_h*(q+2)

refocus(temp1) -- take shot at h
X_bracket()
temp = get_exp_count().." @ "..temp1.."mm"
if v == 1 then print(temp) end
if k == 1 then log[#log + 1] = temp end

if temp2 > temp1 then -- take additional infinity focus shot
    refocus(temp2)
    X_bracket()     
    temp = get_exp_count().." @ "..temp2.."mm"
    if v == 1 then print(temp) end
    if k == 1 then log[#log + 1] = temp end
end

bookend()

temp = count.." focus brackets"
print(temp)
if k == 1 then log[#log + 1] = temp end
temp1 = ((10*dof.coc*base_h)/temp2 + 5)/10
temp = "Infinity blur "..temp1.."um"
if k == 1 then log[#log + 1] = temp end
if p ~= 0 and k == 1 then log[#log + 1] = "Exposure offset = "..p.."Ev" end

refocus(x_start)

if k == 1 then
    print_screen(-2306)
    for i = 1, #log do
        print(log[i].."\n")
    end
end