which camera for low-altitude aerial photography (for use with PhotoScan)?

[jan]

Thanks RalfH, I made similar calculations, and I came to a similar conclusion (i.e. starting with 1ms). Didn't thought about other camera movements though. In the next days I will trial and error...

[jan]

For those interested, I made good pictures with 1/2000 shutter speed, 400 ISO and infinity focus in high light intensity outdoor areas. The speed of the kopter was 15 km/h (4.2 m/s). I used a Canon IXUS 220hs, with the following CHDK intervalometer script (which I found on http://chdk.setepontos.com/index.php?topic=8984.15), hereby shooting an image every 1.5 seconds.

this CHDK lua intervalometer script is written below

--[[
@title UAV Shooter 4
@param a Delay Start (Min)
@default a 0
@param b Delay Start (Sec)
@default b 20
@param c Number of Shots
@default c 50
@param d Interval (Sec)
@default d 2
@param e Interval (1/10 Sec)
@default e 5
@param g Endless? No=0 Yes=1
@default g 0
@param l LCD off? Yes=0 No=1
@default l 0
--]]

function restore()
    release("shoot_half")
    set_aflock(0)
    set_record(0)
    set_backlight(0)
end

interval=d*1000+e*100
wait=a*60000+b*1000
shotcount=0
set_console_layout(1,1,40,13)

print("startup delay - LCD off")
sleep(1000)
set_backlight(l)
sleep(wait)

print("running")
if( get_mode() ==false ) then
   set_record(1)
   while ( get_mode() == false ) do
      sleep(100)
   end
end
press("shoot_half")
repeat sleep(100) until get_shooting() == true   
set_aflock(1)

print("focus locked")
nextshot=get_tick_count()
starttime=nextshot
repeat
    shotcount=shotcount+1
    print ( "shot", shotcount, "at", ((get_tick_count()-starttime)/1000),"sec. Err=", (nextshot-get_tick_count()), "mSec" )
    nextshot=nextshot+interval
    ecnt=get_exp_count()
    press("shoot_full_only")
    repeat
       sleep(20)
    until(get_exp_count()~=ecnt)
    release("shoot_full_only")
    while ( nextshot > get_tick_count()) do
      set_backlight(l)
      sleep(50)
    end
until ( (g==0) and (shotcount >= c))
restore()

[pedram55]

how much is the best focal length for maximum coverage and  minimum distortion and fish-eye error ?

[Ardu]

We use Samsung NX1100, and (touch wood) only good results so far.