Strange photo effect

[oldguy]

I didn't notice it at first but Chili talked about it at Minneapolis. while he was shooting the SX he had many shots where the tower which shows the top 5 riders would black out partially. In some of his shots the top 2 would show and not the bottom 3 others it would be mixed up and in one a whole side was dark while the other was lit. I didn't think much more about it until I saw it in one shot I took. I should have saved the shot but it was so out of focus I deleted it before I thought more about it- Chilli has many examples that are in focus.
Anyone have any ideas what would cause it?
We guessed maybe changing to show new leaders but he shot when nobody was near it. Thought maybe the LEDs fluttered but I doubt all would be in sync. Maybe shooting angle but he was on the floor shooting angled up at it while I was in the stands shooting perpendicular at it.
Come on photo gurus what could it be?

 

[Chili]

This came about as I was trying to get a shot that showed the lap time leader passing the scoring tower with his number at the top. After numerous attempts with the same results I finally shot multiple shots of just the tower and it was always the same lights showing and not showing. Here's an example.

 

[Rich Rohrich]

Doug - What is the time interval between it showing and not showing, and what is the shutter speed and frame rate?

 

[Chili]

Rich it never shows at any point. I shot an 8.5 fps burst at 1/1000 and never saw the bottom 3 laptimes at any point.

 

[Rich Rohrich]

Doug - Did you get any frames at any point where they showed up?

Did you get any shots where the Diamond vision in the background showed the lower numbers?

 

[whenfoxforks-ruled]

It worked in Indy.

 

[Chili]

Unfortunately I deleted the burst as I was concerned about storage space. Like I mentioned in the SX thread my mind was elsewhere and that included leaving 22 gigs of cards in the wrong camera bag at the hotel and only arriving with the 6 gigs in my camera.

It is obviously an angle thing based on these shots, excuse crappy photos as these are simply cropped and posted for examples.

 

[fatcat216]

I just want to thank you guys for ruining my night! I was all dressed to run and then "oh, I'll just take a little peek at the specs for LED scoreboards..." I've panaviewed univiewed daktronics mechtronics etc. and I got nothing.

Allow me to add to the mystery a bit. The lap row on all the photos: chili's, whenfoxforkruled and the daktronics pic within a pic video display screen is missing, right?

I will testify that at Minneapolis the "Lap" bay of lights was illuminated, and accurately counting laps.

'splain that mystery if you will-once you get done with the first mystery. Although that one might turn out to be easier.

 

[oldguy]

Allow me to add to the mystery a bit. The lap row on all the photos: chili's, whenfoxforkruled and the daktronics pic within a pic video display screen is missing, right?

I will testify that at Minneapolis the "Lap" bay of lights was illuminated, and accurately counting laps.

'splain that mystery if you will-once you get done with the first mystery. Although that one might turn out to be easier.

Sorry but that one is already Busted (I am watching Mythbusters right now ;) ) All the photos in the htread so far were shot during practice in the afternoon and the laps was not turned on :nod: :nener: Notice the stands are almost empty probably because people were shopping instead of watching :fft:

 

[fatcat216]

That was my guess dave. -(edit)...oh- I get the slam, too. lol.

It was so worth it though. ;)
(Remind me I said that when I grow frustrated with yet another toy and throw it off the bluff. I'm getting quite the junk pile of broken dreams out there...)

 

[fatcat216]

p.s. We have never discussed B.O.B have we?? At Aztalan? Perhaps not.

If I can sideline this Mr. Wizard thread one more time please allow me to issue a Public Apology on behalf of "Back-Out-Barbie" to Chili and Old Guy. She says she promises to do better "next time".

I return this thread to LED mystery theatre. Oh- here's a clue guys: do you know the angle view on those LED's? Is it greater or less than 140 view degrees?

 

[BigRedAF]

Perhaps they are on and off in a hertz cycle that our eyes can't see and your speed was very fast. Sometimes when I take pictures at work my instrument screens are blank in the photos and sometimes there not...

On light aircraft if you taxi under a florescent light in a parking area your prop appears to stop when you are at 600, 1200, 1800 RPM. I did this years ago as a way to check the tach accuracy.

just my .02 worth.

 

[Chili]

Perhaps they are on and off in a hertz cycle that our eyes can't see and your speed was very fast.

This was along the lines of my original thinking which was the reason why I shot a burst of about 10 photos at 8.5 frames per second. I figured they'd show in at least a few photos and they did not.

 

[IndyMX]

I'm thinking along the same lines as Fatcat here.. Angle of view.

I wonder if the angle screws with the sensor somehow... It looked like in one of those pics that the tops of some of the numbers were cut off a little..

If you get a chance again to test it out, see if the angle of the camera affects it.

Also try the camera in a portrait position, see if that has any effect on it.

 

[IndyMX]

I just noticed this one that I got at Indy..

I was sitting in the first row during practice.