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Lightning

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Offline Roger

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Lightning
« on: 23 / May / 2008, 02:03:26 »
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I thought I'd share my first MD lightning experience. Last Saturday, around 1:00am,  I noticed "heat lightning" towards the west. I pulled up the NWS radar and sure enough, there was a line of thunder storms headed my way. Initially, I set my camera up on the toolbox of my truck. I got one decent shot of the sky and grounds lighted, literally like daylight. The actual bolt was to the left, blocked by my truck (first photo). ISO 800, f/3.2, 1/8 sec.

The second photo was taken from inside, out the front door, straight at the clouds. (It began to rain, so I setup on a tripod, just inside the front door.) When I first viewed this shot, I almost deleted it because it was washed out. I decided to keep it and run it through Photo Shop. I figured I had to have something there, as I witnessed the bolt , and the camera take the shot. I had to lower the brightness by 75, and bump the contrast by 30. It's not pretty, but definitely shows proof of concept. ISO 800, f/2.8, 1/15 sec.

I had my A650is set to manual mode, and used several different scripts. I missed some great shots while fiddling with the camera. And one of the scripts would just stop working - even waving my hand in front of the lens wouldn't trigger a shot after a while. All in all, it was a good hands-on, real-life learning experience. I know which scripts work, and those that don't. I've also learned that I can probably stay out of the higher ISO range - lightning is bright! Also, I've augmented my research by setting my camera up in front of a monitor displaying lightning videos from You Tube. - (no timing test programs to mess with; just the "real" thing).
« Last Edit: 23 / May / 2008, 02:08:24 by Roger »
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Offline brainwash

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Re: Lightning
« Reply #1 on: 26 / May / 2008, 08:22:06 »
Take a look at the Fast MD script (it's here somewhere). I tried it over the previous MD scripts and the improvement is HUGE. With the previous script I could wave my hand twice before it triggered, now it catches my hand just as it enters the viewport.
The shots seem overexposed, I suggest you manually set the focus to infinity, ISO 200 and perhaps 1/500 or 1/250.

The pictures below however were shot with a 15 sec exposure, ISO 50, manually triggered.
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Offline A630Lover

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Re: Lightning
« Reply #2 on: 26 / May / 2008, 09:14:18 »
There is a strange flying object in your first picture!! It doesn't seem like a plane nor a bird... :s
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Offline fe50

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Re: Lightning
« Reply #3 on: 26 / May / 2008, 09:32:41 »
Hi brainwash, very nice pics !

With those kind of pictures you notice your sensors hot pixels - have you tried the "badpixel" feature yet (i will do so the next days) ?
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Offline brainwash

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Re: Lightning
« Reply #4 on: 26 / May / 2008, 10:34:59 »
There are about 3 birds visible, the largest one has the wingspan facing the camera. :)
Some dead pixels are also rearing their ugly face :(
Thanks fe50. I think these pictures were taken pre-CHDK and since I got the new Fast MD script I never got around to photographing lightning strikes.
I was bored when I took the pictures so I just left the camera do its 15sec exposure with a 2 sec delay for shooting, placed it on a rock then started again after the shot and NR were performed. With scripts one could probably could have taken dozens of usable pictures instead of just about 5.
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Offline sumoetx

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Re: Lightning
« Reply #5 on: 27 / May / 2008, 02:23:18 »
Roger, Nice shots! good to see that MD works. Those bolts looked close! Any way you could tell us which script worked best for you?

I'd agree with you that the upper ISO's are more than you need, 200 should be more than enough for lightning. With my old OM-1 SLR at night I'd use ISO 50 and leave it open until I got a bolt- easy to do with a bulb setting and locking shutter cable.
 When you test using Youtube vids what settings are you using?

Thanks for sharing!! :D

@brainwash, that bird looks alot like a big bat!  :-X lol, very nice shots!! thanks for sharing those. I love lightning shots, we had storms all weekend but almost no strikes, just rain. :(

sumoetx
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Offline Roger

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Re: Lightning
« Reply #6 on: 27 / May / 2008, 12:33:20 »
The script I used is composed of bits and pieces of other scripts that have been posted here. Mainly though, it uses the get property 206, and I elected to have md_detect_motion take the shot. Grid is 3x2, Block size is 24, Threshold is 10.

Code: [Select]
@title MD_A650
@param a Cols
@default a 3
@param b Rows
@default b 2
rem Treshold: 10=Lightning, 12=Sunshine, 24=Cloudy, 36=Dawn/Dusk
@param c Threshold (0-255)
@default c 10
@param d Interval (mSec)
@default d 1
rem Delay: 0=Ultrafast(Lightning), 16=Normal, 32=Slow
@param e Delay (.1 Sec)(0=UltraFast)
@default e 0
@param f BlockSize
@default f 24
@param g Mode(U=0,Y=1,V=2)
@default g 1

if a<1 then a=1
if b<1 then b=1
if c<0 then c=0
if e<0 then e=0
if f<1 then f=1
if g<0 then g=0
if g>5 then g=5

rem time in msecs md will detect
x=30000

while 1
  press "shoot_half"
  do
    get_prop 206 p
  until p=1
  t=0
  md_detect_motion a, b, g, x, d, c, 0, t, 0, 1, 1, a, b, 1, f, e
  do
    get_prop 206 p
  until p<>1
wend
For testing, I used videos from www.extremestorms.com. Here's a picture taken from one of their videos (QuickTime) using MD. The camera was set up about 4" from the screen. Manual focus, ISO100, f/3.2, 1/10 sec. Pause the video right before the lightning strike (use the slider to get it just right). Start the script, then click the video play button.
« Last Edit: 28 / May / 2008, 01:11:06 by Roger »
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Offline Roger

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Re: Lightning
« Reply #7 on: 28 / May / 2008, 01:24:40 »
Quote from: brainwash on 26 / May / 2008, 10:34:59
There are about 3 birds visible, the largest one has the wingspan facing the camera. :)...
Actually, they may be bats. Seriously; look closely at the large one.
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Offline PhyrePhoX

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Re: Lightning
« Reply #8 on: 28 / May / 2008, 04:02:22 »
yeah, thought so too. cool pics
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Offline A630Lover

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Re: Lightning
« Reply #9 on: 28 / May / 2008, 04:24:42 »
...or maybe an UFO! Yeah, you picture is maybe worth millions of bucks ^^
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