4K camera suggestions for LED lighting / theatre work?

[Peter Barton]

I've been looking at replacing my older HXR-NX5P, preferably with something 4K. I've been following various discussions here and elsewhere, and can't seem to find any clear winner for want I'm wanting to do.

I purchased a Z150 back when they were new, and that was a bit of a horror story under various LED lights (https://www.dvinfo.net/forum/sony-4k...sues-help.html), I returned that, and purchased an HXR-NX5R. That wasn't without issues either (https://www.dvinfo.net/forum/sony-nx...up-issues.html), but those issues were able to be worked around, and I've since bought a second HXR-NX5R camera.

The HXR-NX5P doesn't get much use, but when it does I'm feeling it is getting a little old - the HXR-NX5R images look better, particularly going to 1080p, with the older camera only going to 720p. I was thinking of just going with another HXR-NX5R, although it doesn't seem right to invest that much in another HD camera, and not try to go for 4K at this point.

The specs on the Z190 looked like it might be a winner, but the reviews on that camera under low light aren't good. The reviews on B&H tell a pretty poor story in low light, and also in theatre/LED light.

Is anyone else out there filming a lot of theatre / LED lighting material, and having success with any other cameras? I'm not locked into Sony in particular, I've found their cameras to do what I need in the past, and I'm more familiar with their range, but I'm not opposed to switching manufacturers if Sony no longer has something useable. I'd also be prepared to step up in price range a little (with Sony or other), again, so long as the camera can work well with the lighting I'm subjected to. Or maybe even step down, I've seen others using the Z90 for theatre work, I would have assumed it would have issues also, but I've not been able to find any examples.

Any input appreciated - if there's nothing out there, I can always stick with what I have and wait a little longer, I just figured there should be something that can do what I need, without all the issues, in the 4K format by now.

[Pete Cofrancesco]

I assume you must be referring to banding and washed out details when they use a single color. Let’s first be clear the problem is the Led lights not the camera and any modern camera with a cmos sensor (they all use that type of sensor) are susceptible. Not all led lights are bad I just think some theaters will either have low quality or old led that have this problem and there’s not much you can do about it.

I saw this video which had a good explanation.

YouTube (Short URL)

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[Paul R Johnson]

I totally disagree here. I'm lucky enough to have a job that has me in theatre's with all kinds of LED gear, and the blame for poor images from LED lighting is down to camera manufacturers simply not making sure their kit matches LED. The facts are that LED, like discharge lighting is a light source that has particular characteristics, and the sensors dont like them. In the same way different cameras had issues with old crt tubes. It wasn't the computer monitors that were poor, it was simply that they have a way of working the cameras find a problem.

ALL LEDs flicker when dimmed. PWM dimming means a proportion of the time they are off, and if the camera frame rates are not compatible, then banding results. A 20,000 Robe fixture can be just as bad as a 50 Chinese fixture when they are dimmed. Most problems can be minimised by lighting and video people working together, but in theatre events, vision is pretty well a last minute addition and the lighting people will have been working on their contribution for days when video kicks off, perhaps mere minutes after arriving and setting up.

That's a a logistics and hierarchical issue, not an LED issue.

Once light levels and dimming cycles are sorted, the colour issue remains and this is my biggest complaint. No matter if we are talking about broadcast, or not, the sensors react to LED very differently. Some, do a reasonable job but have issues with some colours. Red sensor performance seem variable. Pink, red, purple, magenta can be resolved by some cameras (video or still) as pretty much the same colour. No idea why, but my older DSLR I use for stills has good colour rendition between blue and red but it's newer brother is horrible. I've pretty much bought JVC video kit for years now since the 100 series because the colour response is pretty good, and I will keep buying JVC until they change. At venues when we are doing lights and sound, my worst fear is the video guy walking in with certain cameras I know will generate requests for less red or less blue. When we know the shows are going to be videoed NOt by us, I always ask the client which is more important, the audience, or the video. The one worked on las week was three days rehearsal and two shows, and video was their income generator, not the audience in the venue, so even without the video people present, the lighting designer used one of our cheaper cameras into a monitor when he was programming. The video crew turned up 90 minutes before showtime and even with their problematic sensors were happy.

The show next week in repeal yesterday are making money from the show, not the video which is more for archive. They will hate it. We have saturated blue stages, with high UV content to make some costumes glow and we have lots of shadows. Looks great to the eye, and I've told the lighting designer to resist last minute reques for change.

Frankly, Cheap LED lights are how it is. They offer extremely good performance for the price, and I'd rather buy 20 cheap ones than two expensive ones, because lighting now is to do with the look totally, and quantity is paramount. For the hire price of just one mega light, I can get at least 10 beams or washes, so it applies to hire too.

The camera manufacturers need to sort their problem, not the cause, because in my world, one in ten has video, so they cannot expect venues to equip for them, that's crazy.

If I take a Robe Esprite and light a person on stage with it, or I do the same thing with a Chinese 90w beam, then on full the Robe is brighter. If I dim them to the last step before off, they BOTH flicker on my JVC. If I bring them to full in red, and gradually cross fade to blue, BOTH have the same gentle response on my JVC. Blaming the flicker on the lights is silly, because pulsed solutions to brightness are just unfriendly to cameras of all kinds with short effective sensor 'open' periods. That's physics not a fault.

I really hate the idea that lights are to blame. I suspect it's simply the manufactures and the users. I don't see camera people complaining about propellers with rolling shutter any more. Did we just get used to bent blades being normal, or did everyone stop complaining . Nobody blamed Robinson for making cheap helicopters that made their rotor blade look horrible. Next time you are in the market for a video camera for theatre work. Hire yourself a moving light, and take it to the dealer and try the damn things out before you buy a camera and the discover Mr Sony or whoever didn't make their cameras compatible or just friendly to LED.

It is NOT about cheap LED. It's about quantity of equipment. If you have lots of lights, then you probably dim them, and THAT is the problem. If you don't have lots of lights you run them brighter.

Odd that nobody complains about LED lights in their strobe modes. Now that really makes a mess of video with random timing!

[Peter Barton]

Thanks Pete & Paul, I probably wasn't totally clear, the LED lighting issue I'm mainly trying to avoid is with over saturated images / lost detail, i.e. This:
http://www.dvnonstop.com/hxr-nx5r/Si...tainFrame1.jpg

versus this:
http://www.dvnonstop.com/hxr-nx5r/Si...tainFrame5.jpg

There are other examples in threads linked in the first post, but it's basically the complete loss of detail you see in the second pic, when the scene was lit with "purple" LED lighting (the colours were strobing in that item, so some registered fine, and when the purple/blue was used, the detail was lost). I'm aware of the other issues with dimmed (flickering) LEDs, rolling shutter, strobes, etc - I don't consider any of those particularly fixable on a live show (where I can't control the lighting), and I'm happy enough with the results the camera gets there. Usually any impact of these effects is minimal - losing all the detail because a particular colour light is used in an item is a much bigger issue.

Paul has hit the nail on the head with respect to live shows, most of mine and children's dance schools, and I'm just making a recording of the event for them. Pretty much no camera consideration is ever given in the lighting design, I'm never asked for any input, and I've even been told outright by one client "not to complain about the lighting like the last guy did!" (Their show was at least 50% pink/purple/red LED lighting, it was horrible to film).

The thing that most gets me here, is that the older cameras handled this better. The Sony Z1 (CCD sensor) captures the colours fine, the HXR-NX5P (CMOS) was quite similar. The HXR-NX5R was where I first experienced the over saturation issue, but so long as you change the colour mode on that camera to anything other than ITU709, you're fine, only that colour mode over saturates and loses the detail. Every newer camera / 4K camera I've looked at seems to now have the issue (with no work around), or is a mess of noise or other issues when trying to film under this sort of lighting.

It almost seems like the manufacturers have just accepted this issue at this point, even though it affects more than just theatre situations. As an example, taking a look at the video posted here:
https://www.dvinfo.net/forum/sony-xd...t-footage.html

The light bars on the emergency vehicles are all LED, and all suffer the same over-saturation / loss of detail issue. There are quite a few scenes in that video where the vision is primarily lit by those LED lights, and to me it all looks awful (wrong colours, loss of detail, etc). Maybe I'm just being too fussy about all of this, and no one else really cares (maybe my clients won't care if I hand them something looking washed out like that). To me, I'm just trying to capture the scene as best as I see it with my own eye, and when I see the camera losing details and misrepresenting colours that badly, I'm not a fan.

[Pete Cofrancesco]

The over saturated loss of detail again is due to RGB led lights. This new technology allows color changes without adding a gel to a white light. While it might look ok to our eyes, it causes problems with the camera sensor. This isn’t about assigning blame but describing the reality of the situation. Today’s camera sensors can film daylight or tungsten well and even good led white light but not led rgb. Today’s theater lights are increasing using led rgb lights instead of gels, as long as it looks good to the human eye of the audience that’s all that matters to a theater production.

The answer to your original question, there are no cameras that I know of today that will avoid the problems you describe because they use the same sensor technology. The best you can do is explain to the client why it looks that way. But in truth there has always been limitations with how video cameras capture color. For example the lack of an ability to capture details in saturated red has been a problem and continues to this day (look at the dancers red dress in the still you posted). Since the primary purpose of events like dance recitals is for the audience and not the video you have to resign yourself to the realities of the situation.

In the samples you posted you were lucky they only used rgb led to color the background. I’ve filmed productions where they’ve used that blue light on the entire stage and everything including the dancers are washed out with no details.

This video touches on how color is effected by different types of light and it’s impact on video.

YouTube (Short URL)

[Ron Evans]

The other thing to note is that most video cameras in the range we are taking about record 4:2:0. So immediately that colour resolution is 1/4 of the luminance. If the scene is all one colour, no white light, then what was a HD image is now like a poor VHS SD image. Of course if you use a very expensive global shutter camera shooting 4:4:4 then it may very well look just like the audience sees. Whatever the lighting.

[Paul R Johnson]

In suppose the problem is that we're used to a white light world. The problem now is that white is rare. In theatre, for as long as I've done it, lighting designers wanted saturated colours, but couldn't have it! Dark blue is not primary blue, that's got red and green in it. Congo - however is a very deep blue. Queen and Pink Floyd loved it, BUT it converts 98% of the light passing through it to heat - leaving 2% as the light output. The heat burns the colour out, leaving it steaming and whiter and whiter in the middle. It means a recolour every show! With 1KW par cans the norm, designers often went lighter blue. Theatre was often shades of a colour for light level reasons. Now, for the first time, you can have beams of heavily saturated colour 100% red, blue, green, amber and even UV if you want - although UV is blue tinged far more than discharge UV.

The cameras can actually cope better than we think because if you deliberately under expose, red gets much less sparkly and the blue less bland. I think the camera chips are just over exposed by the camera making the problem worse. Nobody has given any satisfactory reasons why some cameras handle colour badly, but I wonder if they just still calibrate everything with assumptions of gentle colour temp and spectral balance? Sony seem to be worse than others, and I don't know why they cannot address it. Dance in theatres is all about costume, movement and colour. It seems odd vivid costume choices and saturated colour cannot be handled by some very expensive bits of kit! We did have sparky red issues years ago when shooting in dark rooms, with developing lights. This was handled badly too - so not a new problem really. Post box and telephone box red could also be trouble. We were just lucky that very saturated colours were usually reds, not blue.

If lighting designers have better tools for their profession, we really cannot blame them for using them. Don't forget the Samoiloff effect from the 1920s - if they had had our cameras back then the problem would have been even worse - saturated but very dim! Worst combination. If you google this, you'll find it a rather magical way to make costumes or sets change colour or reveal things not seen. Shine blue light on red and nothing reflects, giving black, so you can make red spots suddenly stand out by going from blue light to red, or you can make snow appear - clever stuff like that, but our modern cameras would be pretty rubbish, even though this trick has quite wide colour bandwidth and not tight spikes like LED.

I really love LED colour, I just wish all the manufacturers did a bit of R&D on how their products react to it!

[Peter Barton]

Don't worry Pete - I've had those purple/blue LEDs used across the entire stage, and lost the detail on costumes & people as well (look at the skirt on the girl in the lower left, compared to those standing in white light at the top of frame):
http://www.dvnonstop.com/hxr-nx5r/BalletSkirts.jpg

What gets me with the NX5R, is that the over saturation only occurs when using the ITU709 colour profile:
http://www.dvnonstop.com/hxr-nx5r/ColorITU709.jpg

The other colour profiles on the NX5R just don't over saturate the blue channel to the point of losing detail like that:
http://www.dvnonstop.com/hxr-nx5r/ColorCinematone2.jpg

The older NX5P doesn't have the issue at all (on any colour profile). To me it seems like it isn't just a function of the sensor alone, but other components or software in the camera as well. The fact that changing the colour mode on the NX5R can basically remove the saturation problem says to me that the problem is solvable, but none of the current Sony cameras are implemented in a way to make that possible for whatever reason. Note that with the work around on the NX5R, the colours still need some adjusting in post (the camera still prefers blue over red under LED), but at least with all the detail retained, those adjustments are possible. Usually for my work, I just add a bit of red back in, and pull some blue out, and that's all that's needed.

I also note your point Ron, that possibly the higher end cameras may be able to better represent the colour resolution. That's part of the intention of this thread, if someone pointed me to a more expensive model as a definite 100% solution to this problem, then I would at least be open to looking at that.

It seems to me like the cameras just need a "LED lighting" button, that effectively just pulls back the saturation levels, similar to what changing the colour mode on the NX5R does. The video Pete posted provides a great explanation on why the issues exist (thanks so much for posting that), but I'm eternally confused that the NX5R seems to have a work around to some of these issues somewhere in its internals, that nothing else currently seems to have. Perhaps I need to try writing to Sony and asking more directly.

[Oren Arieli]

If you have a camera with adjustable picture profiles (especially in the RGB matrix), you MIGHT be able to minimize the oversaturation effect of pure RGB lighting. It's all theoretical, as I haven't tried it yet. But perhaps you can attend a rehearsal and tweak the camera during the shoot. It helps if you have access to a monitor with RGB parade scopes, as it will likely be much less objective than what your eye sees.
I've seen Sony sensors suffer more than Canon sensors in these scenarios, but that could be more a function of the color science than the actual silicon.
FWIW, I'm shooting 4:2:2 with a Sony FS5 and in post, you can dial down the Hue vs. Saturation to tone down the colors slightly, but you'll never get rid of them completely without strange artifacts.
If someone who shoots RAW could chime in with their experience, that would be great.

[Oren Arieli]

If you have a camera with adjustable picture profiles (especially in the RGB matrix), you MIGHT be able to minimize the oversaturation effect of pure RGB lighting. It's all theoretical, as I haven't tried it yet. But perhaps you can attend a rehearsal and tweak the camera during the shoot. It helps if you have access to a monitor with RGB parade scopes, as it will likely be much less objective than what your eye sees.
I've seen Sony sensors suffer more than Canon sensors in these scenarios, but that could be more a function of the color science than the actual silicon.
FWIW, I'm shooting 4:2:2 with a Sony FS5 and in post, you can dial down the Hue vs. Saturation to tone down the colors slightly, but you'll never get rid of them completely without strange artifacts.
If someone who shoots RAW could chime in with their experience, that would be great.

[Doug Jensen]

Originally Posted by Peter Barton

I've been looking at replacing my older HXR-NX5P, preferably with something 4K.

The Z280 would suit your needs perfectly. And it has a function called "Adaptive Matrix" that helps control oversaturated LED stage lights without affecting other areas of the picture. I leave it turned on all the time on my Z280 even though I don't do concerts or events. It helps with police lights and other odd lighting situations. I don't see any negative side effects from just leaving it turned on all the time.

[Oren Arieli]

That sounds like a fantastic feature, Doug. Would you have any examples of how it looks with the feature turned on and off with a super-saturated LED/RGB source?
Is this something Sony could change in firmware for my FS5. I'd rather pay for that feature than RAW capture, which I don't currently need.

[Doug Jensen]

I've seen it in action at NAB, and it worked great, but I don't have any examples I could show you. Unfortunately it is not a feature that could be added in firmware. And I've only seen it on the ENG cameras, such as the Z450, Z750 and Z280. Even my FS7 and F55 don't have it.

[Peter Barton]

Thanks Doug - that's a feature I wasn't aware of, and certainly something for me to look into. I probably can't afford a Z280 right now (they're worth about double what my existing cameras are worth), but if the feature works to resolve this issue, I would definitely look towards upgrading into that range.

[Doug Jensen]

Peter, when you start comparing the features and specifications of your NX5 to the Z280 you'll find that this one feature is just the tip of the iceberg of the ways the Z280 blows away anything else in this class of camcorder. Yes, it costs more, but the capabilities are well worth the difference, in my opinion. And you'll get a lot of that difference in price back out of it when you got to sell it someday as the Z280 is going to be worth more than the NX5. The Z280 is basically a FS7mark2 with smaller sensors and a f17x lens.