Werid video highlights burnout artifacts !?!

typo on... weird* my bad

anywhoo, ive been shooting a fairly big night project for an important client. Ive been starting to noticing allot of weird burnout highlights or bright flickering artifacts on sharp edges that are in focus. They also kinda flicker and pop out during movement. I dont really know how to explain them.

All the clients footage is properly exposed. We used nikon lens with adapters and LED dimmers to constantly maintain 1/50 shutter and 2500 iso for every shot.

I cant post the actual footage due to NDA papers but i have found a shot from something else that shows the problem... Im going to post more a few more shot as i have to recreate the scene to explain this issue better.


heres a raw still frame example from a mov file.
http://www.ozan.ca/mk2/frame_1a.tif

anyone?

[Jon Fairhurst]

Ozan,

That's almost certainly aliasing. On the stills, it's hard to tell, since I don't know what the scene looked like. However, the clue is that it happened on horizontal lines.

The 5D MkII only captures every third line. If there is fine detail - especially on horizontal lines and fine patterns - then it might be captured on one frame and missed in the next. That's why they flicker and pop in and out.

The only solutions are to 1) use a softening filter, or 2) avoid sharp detail in fine patterns and horizontal lines. I've got a Tiffen Soft #1 and Diffusion #3. I need to do some tests to find exactly what we need. I just got the camera back from my son, who filmed our recent short at his place. Hopefully, I'll get a chance to do some tests this week...

[Ozan Biron]

hmmm, aliasing...? The footage doesnt really show those rolling waves in certain areas.

In this case It pops out in areas that are in focus and are kinda burnout out or read as hot in camera in sharp edges.

Blahhhh, This is it hard explaining without being able to show any of the footage. And that frame still i posted is a bad example. Im going to look for something better that shows the issue or if i can find an image from the footage that i can have permission to post.

Originally Posted by Jon Fairhurst

Ozan,

That's almost certainly aliasing. On the stills, it's hard to tell, since I don't know what the scene looked like. However, the clue is that it happened on horizontal lines.

The 5D MkII only captures every third line. If there is fine detail - especially on horizontal lines and fine patterns - then it might be captured on one frame and missed in the next. That's why they flicker and pop in and out.

The only solutions are to 1) use a softening filter, or 2) avoid sharp detail in fine patterns and horizontal lines. I've got a Tiffen Soft #1 and Diffusion #3. I need to do some tests to find exactly what we need. I just got the camera back from my son, who filmed our recent short at his place. Hopefully, I'll get a chance to do some tests this week...

[Mark Hahn]

Originally Posted by Ozan Biron

hmmm, aliasing...? The footage doesnt really show those rolling waves in certain areas.

In this case It pops out in areas that are in focus and are kinda burnout out or read as hot in camera in sharp edges.

Blahhhh, This is it hard explaining without being able to show any of the footage. And that frame still i posted is a bad example. Im going to look for something better that shows the issue or if i can find an image from the footage that i can have permission to post.

Rolling shutter has nothing to do with aliasing.

Aliasing will pop in and out if the camera moves, even tiny amounts. Also aliasing happens in sharp edges and not in dull ones.

[Dave Blackhurst]

Not sure if you're referring to those odd blue/white colorations, but I presume those are the artifacts you're referring to...

I'd guess that they are some sort of aberration in the compression scheme... Seen this sort of thing in stills from the HF-S10/100, my SR11 has some odd artifacts in stills too...

[Daniel Browning]

I concur with Jon that they are aliasing artifacts. Most cameras have at least a little aliasing, but the 5D2 has it very bad. Fortunately, many photographers and viewers really like aliasing artifacts (they call it "sharpness", "crunchiness", etc., just ask anyone who likes Foveon). Even the $250,000+ Panavision Genesis has aliasing artifacts (more than RED ONE, but much less than the 5D2).

Personally, I don't like them, and it sounds like you don't either, Ozan.

[Cody Dulock]

Have you tried shooting with a lower ISO? I know for a fact that anything above ISO6xx starts getting noisy and weird things start happening...

Is the sharpness turned all the way down in your picture style settings?

[Ozan Biron]

Originally Posted by Cody Dulock

Have you tried shooting with a lower ISO? I know for a fact that anything above ISO6xx starts getting noisy and weird things start happening...

Is the sharpness turned all the way down in your picture style settings?

In the settings... evrything is set to zero... I think... Should i try bringing the sharpness all the way down? Under picture style right?

update:

Camera is set to "neutral" and ive noticed that with "faithful" the sharpness is all the way down. Maybe faithful preset will help me outs.

im going to post a better example soon tonight. Jst waiting for it to get dark. Eh daylight savings.

[Ozan Biron]

ight,

here a another bad example. I didnt have time to go and properly shot somthing. But i did a quick capture at one of the same locations we filmed at.

Here is the raw mov file directly from camera. If u play it back in slow-mo u can see BLue lights on the cars and background and on various objects.

http://www.ozan.ca/mk2/MVI_0243.MOV

i guess this is an aliasing problem?

[Daniel Browning]

Originally Posted by Ozan Biron

If u play it back in slow-mo u can see BLue lights on the cars and background and on various objects.

I see some lens flare, but I don't think that's what you're talking about. Can you point out a specific part of one of the frames?

[Ozan Biron]

Originally Posted by Daniel Browning

I see some lens flare, but I don't think that's what you're talking about. Can you point out a specific part of one of the frames?

Like it said u have to play back in slow-mo to see it.

Look at the back where the ground road lines curve around the bend and the above pillers. You will see blue lines. Or even when the bus apporaches you can see it allover the vehicle... like the front grill.


Im jst analysis the other "forbidden footage"... and i think its aliasing the more i look at it. eh

[Mark Hahn]

Originally Posted by Ozan Biron

Like it said u have to play back in slow-mo to see it.

Look at the back where the ground road lines curve around the bend and the above pillers. You will see blue lines. Or even when the bus apporaches you can see it allover the vehicle... like the front grill.


Im jst analysis the other "forbidden footage"... and i think its aliasing the more i look at it. eh

I behaves exactly like reflections of something off to the left, like fluorescent lights. As the glass in a window curves, so does the reflection.

[Ozan Biron]

Originally Posted by Mark Hahn

I behaves exactly like reflections of something off to the left, like fluorescent lights. As the glass in a window curves, so does the reflection.

ah what?


let me slow it down and comp in arrows to show what im looking at...

[Mark Hahn]

Originally Posted by Ozan Biron

ah what?


let me slow it down and comp in arrows to show what im looking at...

I see the blue stripes all over the left side of cars. For example the third to last car is covered with them. That is what I'm talking about.

[Daniel Browning]

Originally Posted by Ozan Biron

Or even when the bus apporaches you can see it allover the vehicle... like the front grill.

Those are aliasing artifacts.