Bubbles and Grinding

[Justin Kirchhoff]

Shot this last weekend. Excuse the edges of the Grind footage. I didn't reexport it to fix the REDAlert problem. And of course the bubbles are lit by home depot lights, so don't give your hopes up.

Both shot 2k 2:1 120fps. Bubbles shot with RED 18-50mm zoom at T5.6 (I think). Converted to h264.

Grind footage shot with 300mm, wide open about 11 ft back, downrezzed to 1k h264

Right click and save as please:

www.digitalshakedown.com/REEL/MillerBubble.mov

www.digitalshakedown.com/REEL/GRINDCU-H.264.mov

 

[jbeale]

flying sparks

flying sparks

Thanks for posting this, flying sparks are always a fun subject. I'm curious about the colors in the "GRIND" clip, it looks to me like there are purple halos around some of the orange sparks, and green around the edges of others (eg. long diagonal streak in background near center). Do you have a feeling for whether these colors are something to do with the lens, or the sensor? I'm sure sparks have plenty of IR, which may be a factor.

 

[Justin Kirchhoff]

The colors have to do with the sensor, after all, they are molten hot pieces of iron! Just like the pink sun, this is the same effect.

When I was playing with the image I brought down the ISO to check it myself, and the colors shifted dramatically in the sparks. The lens did a great job on color representation. I love the 300.

 

[I Bloom]

Awesome stuff.

Awesome stuff.

I love the colors in the spark image. The 300mm lense is lookin' great!

 

[garydxd]

Nice shots. What is causing the flickering in the bubble shot?

 

[Justin K Phillips]

The colors have to do with the sensor, after all, they are molten hot pieces of iron! Just like the pink sun, this is the same effect.

Wrong! The purple and green halos jbeale is referring to are caused by chromatic aberration. That is to say, caused by the lens, not the sensor.

 

[sparkhope]

Wrong! The purple and green halos jbeale is referring to are caused by chromatic aberration. That is to say, caused by the lens, not the sensor.

maybe it's a little of both? the purple fringing certainly looks of CA but the dark center appears to point to the cmos. I wouldn't expect CA in the center of the spark...

Then again I recall reading that lens flare can also create the purple fringing.

 

[Justin Kirchhoff]

Easy there um3k, I was referring to the center hot spots of the sparks, which caused a similar effect to that of the pink sun.

The flickering in the bubble shot is due to some crappy fluorescent lights in combination with quartz lights. The fluorescents flicker occurs because the high frame rate catches the phase of the flickering. We tried a few things to reduce the flicker, which helped, but still had what you see there.

 

[Justin K Phillips]

Well, I didn't notice the dark centers. I was talking about only the fringes, which I believe is what jbeale was referring to.

 

[Petr Dvorak]

... What is causing the flickering in the bubble shot?

Ditto
I wonder too

 

[Kenn Christenson]

Were you able to see the flickering on set?

 

[Justin Kirchhoff]

Ditto
I wonder too........

The flickering in the bubble shot is due to some crappy fluorescent lights in combination with quartz lights. The fluorescents flicker occurs because the high frame rate catches the phase of the flickering. We tried a few things to reduce the flicker, which helped, but still had what you see there.

I posted above. And during playback you can see the flicker, like I said, Home Depot lights, so don't expect the rembrandt of lighting.