Shooting High Visibility Jackets

[Geoff Addis]

A recent shoot on a building site on which workers were waring yellow, high visibilty safety vests resulted in very high out of range chrominence although luminance was held within range. It was a very bright day and I was using Doug Jensens suggested picture profile. Using the broadcast/colour safe settings in either FCP, PP CS5 or Edius do not appear to fully resolve this issue as seen on the software scopes although the image appears fine on the monitor. I am able to de-sature the yellow of the vests to get within range, but this can effect other areas of the image. Has anyone else had experience of this and have suggestions as to how to approach such scenarios in the future?

Geoff

[Andy Wilkinson]

Yes, I've had several shoots where this has been a problem.

Most recently, this week in Cambridge I was shooting a lot of bright yellow cranes (one a 100 ton one), people in hi-viz jackets and helmets whilst we filmed a big piece of machinery being taken off a low loader (eventually - when the high winds had died down enough allowed the lift to be done safely). The light was also highly problematic as over the 2-3 days I was there we had rapidly changing bright sun/cloud/sun/cloud (no doubt due to the wind) and the loading area where the work was being filmed was up against the often sun bathed, highly reflective corrugated aluminum walls of the factory buildings - on 2 sides - good job I like challenges!

Man, getting the exposure correct so I did not blow out the yellows was really tricky! Sure, I screwed up on a few shots but with the aid of the tools on the EX3 (especially the histogram and zebras) I got there most of the time by deliberately under-exposing (compared to what I would have ordinarily set my manual exposure at). I certainly don't trust auto exposure in such scenarios, ever!

Fixing it in post is not something I can help you with though - but maybe someone has some suggestions..

[Marcus Durham]

Originally Posted by Geoff Addis

Has anyone else had experience of this and have suggestions as to how to approach such scenarios in the future?

Geoff

I often shoot people in high viz. You have to make the call when shooting what you are going to do. Underexposing can end up with some darker parts of the image ending up noisy.

Personally I expose the jackets so they are at no more than 100IRE (which is where my second zebra is set) as they are liable to be the brightest thing in the image by far, then fix in post with Colorista and the broadcast safe filter (if you are aiming for web only forget the broadcast safe filter).

It is very hard to get right and you may find you have to sacrifice the high-viz slightly in order to get the best overall image as the jackets can be by far and away the brightest thing in the image. But don't get obsessed by the jackets. Set the image up for what you want and then tweak to take account of the high viz.

[Geoff Addis]

I was filming under the same conditions as Andy and it wasn't made any easier by the dynamic range necessary to include both the workers and the subject, a very old water mill. The histogram wasn't clipped and the Zebra was just begining to show at the 100 IRE. In Post, the best results have been achieved using Edius 3 way colour corrector, probably due to my greater familiarity with that NLE.

[Dave Sperling]

Just wondering,
Did you try different gamma settings at all? I'll sometimes move into Cinegam2 and increase the level a bit for more highlight compression.
Or was this a chroma overload issue?
One other thing to watch out for (though this didn't seem to be the issue here) is the ScotchLite-style reflective strips on many of these jackets. If you use any kind of on-camera light they can quickly go way out of range, so having a not-on-camera lighting option becomes a necessity in such cases. (...or, if you like the bright stripes, using an on-camera light with a full range dimmer to separately adjust the brightness of the reflective areas.)

[Don Parrish]

Just a suggestion, perhaps a polarizing filter (or other) would help ?

[Geoff Addis]

Thanks Dave and John.

It was an example of Chroma Overload.

I didn't have a polarising filter with me, but I will give it a try next time.

Geoff.

[Alister Chapman]

Dial down the matrix level or use the cinema matrix in the picture profiles to prevent the chroma from exceeding the cameras gamut range and clipping. Then selectively bring the levels back up in post.

[Chuck Fishbein]

Also, as an aside, if you are working at a construction site, be aware of the lasers used by the architects to measure depth. They usually appear as spinning discs sitting on a tripod. If you accidentally shoot directly into one, it can cause damage to the camera's sensor. (As I have twice learned)

[Will Salley]

That's interesting Chuck. I haven't heard that before. What kind of damage was done to the sensor and was it permanent? What wavelength (color) of laser did this?

I ask because I shoot a lot of live music and studio work that often use lasers. There would be no way NOT to get the lens hit by these. They are visual effect lasers and are usually 515nm Argon, which shouldn't be harmful.

[Chuck Fishbein]

I too, have shot under concert lighting with lasers without issue. This was different. These were red lasers, not sure what type or strength. The damage to the sensor was instant and it caused the image to have a contrasty orange glow, as if you had an orange peaking on maximum in your viewfinder.

The first camera was a Z1 and then an EX1. I didn't realize just what caused the first issue, but the second time I was standing next to the guy that holds the stick that reads the laser when similar damage occurred.

The possibility/probability of the damage being caused by this type of laser was confirmed by a tech up at Sony.

[Geoff Addis]

Thanks for the head up on the laser issue, Chuck. I have a lot more shooting at the site over the next 5-6 months so that could ell save me.

I've manage to tame the yellow using the Chrominence selection filter in Edius and then dialling down the saturation, it seems to work well.

Alister, thanks too for your suggestion, I'll give that a try too.

Geoff

[Patrick McLoad]

Yes, these high-viz jackets have been a constant problem for me as well. I do try to iris down just a bit, but too much and the picture looks like crap. And, I don't often have the luxury of manipulating the iris as I run and gun just for the sake of the jackets.

Although we have not gone to final edit on a show, I do supply the client with shot samplers to show what we got. In some of these situations, I use the selective color filtering capability in FCP color corrector tomute down the chroma on those jackets. It's not great, but better than nothing. I may take these clips to a production house for color-correcting to see if they can do any better with their software.

May look at other options listed on this thread too.

Patrick McLoad

[Gabor Heeres]

Geoff,

I do use Alister's picture profiles for a while now and it helps me a lot. This video was shot with the PMW-350K in default mode:

YouTube - ‪Zwaargewonden bij ongeval knooppunt Batadorp‬‏

And these items were shot with Alister's Neut1 picture profile:

YouTube - ‪Auto van talud Berenkuil Eindhoven‬‏

YouTube - ‪Grote brand bij Hurks beton Veldhoven‬‏

YouTube - ‪Gewonden bij overval op restaurant Maarheeze‬‏

YouTube - ‪Uitslaande brand bij Albert Heijn‬‏

Gabor

[Patrick McLoad]

Thank you Gabor for posting those clips. Indeed, Alistair's setting do much to improve the blooming of that hiviz lime color. I have some of Alistairs settings, but have not installed any. Will give it a shot soon...I have not messed with settings at all and I'm not quite sure how to go about it. I'll just have to dive in.
Thanks again; good work.

Patrick