PXW-Z150 low light issues - help?

[Peter Barton]

Mark, it's concerning that the EX1 doesn't like LED lights, my info so far was leading me to believe that it was the single sensor cameras with issues primarily, but the EX1 is a 3 sensor camera I believe?

I used a Z1 prior to the NX5, and never had an issue with that either. The Z5 would be quite similar to both those cameras, it seems all of these have quite similar sensor systems, and they don't have an issue. Without testing cameras specifically, it's hard to come up with a rule at the moment that tells me which cameras are good for this, and which aren't. You'd basically need someone with access to the appropriate lights, and access to a variety of cameras, to go and run some tests. It sounds like even the Sony service guys here (Australia) don't have access to a setup where they can replicate this to test, to provide more info.

It seems to me like it is the newer sensor system in the Sony cameras that is having the issue, the real test I guess will be against the new NX5, depending on exactly what it has in it. Other than that, perhaps this is a Sony issue specifically, and time to look at another manufacturer?

[Mark Morreau]

Yes, the EX1 has three 1/2" sensors.
The EX1 was a troublesome camera regarding how it recorded colour towards the IR range: there was a genuine issue with the colour spectrum it recorded. Many black clothes made of synthetic fibres would record on this camera as a purple/brown, which was unfixable in post. So many of us EX1 owners were forced to invest in a IR-cut filter to fix this.

Sony resolved this issue with the EX1R.

I don't know if the EX1R also has this problem with LED lights... perhaps not.

An interesting thought about testing a range of cameras against LED lights... I might run that past the broadcast hire company I use, see if such a thing could be arranged. I certainly need to make sure it's not an issue, as I will have to look at investing in new cameras in the next couple of years.

[Dave Sperling]

Though it may seem like a good idea to test a bunch of cameras simultaneously, I think you'd need to at the same time be testing against a wide spectrum (pun intended) of LED lights as well.
I've been running into these issues ever since venues started replacing their old tungsten stage lights with LEDs and have found that there are some LED lights that can produce proper colors and others that just create bleeding and mush. This has been with a pretty wide variety of camera models - mainly Sony, but also some Panasonic and Canon.

If you've bought/used any of the higher end 1x1 LED panels, you may have noticed that aside from the fact that some brands may produce slightly pinker, bluer or greener lignt, if the camera is color balanced to them the resulting image can be excellent (no matter what camera.) I normally use some color correction gels (such as 1/4 or 1/8 minus green and 1/8 CTO) to provide a better match with normal 3200 Tungsten, and keep a number of precut gels with each LED to be able to adjust better to match available light if necessary. (I even keep 1/4 plusgreen in the kit in case I'm trying to get a match with some overly green overhead fluorescents.) Of course when buying LEDs for video lighting, I always check the specs to make sure that the CRI is at least 90+, and preferably 95+.

Unfortunately when shooting in bars that have a stage off to the side where they probably bought the absolute cheapest colored LEDs available, I sometimes run into lights that have exceptionally low color rendering qualities -- and no matter what cameras are being used my only real solution has been to turn off the offending house 'stage' lights and light the band myself.

My only suggestion when you're stuck with 'unusable' lighting is to shoot with a camera that can do Log recording for both exposure range and for color gamut (such as s-Log & s-Gamut). Then at least you may have a little more range to try to get it to work in post...

In terms of the 'no problem with the Z-1' comment -- I'm wondering if you're talking about footage shot during the last two years with the same lighting conditions? (it seems like the market has been flooded with the cheap, low-CRI 'stage' lights in the past two years, so anything shot before that might not be a proper comparison.)

[Peter Barton]

Dave, good point about the Z1 - I haven't used it a lot recently. I still use it occasionally as a secondary camera to the NX5, and it really does match it very closely when editing - I'd be quite surprised if they are in fact much different. But I can't say that I've used it at any of the venues that I know have cheap LED lighting specifically, so I can't be sure about exactly what it does there.

I did pick up the new NX5R last week, and I can tell you straight up that it does appear to have different sensors in it - it seems to need a little bit more light than the original NX5, and the image I'm seeing is a little different. I will try setting up a side by side comparison as soon as I can, and will post some images on here.

[Kenny Shem]

Hi, how's your test of NX5R? I'm considering between this cam and UX180. The only factors for me to get nx5r is its 40X clear image zoom compared to ux180 30x i.zoom. Having a narrower focal length on the wide side also means the absolute telephoto length side is much longer at a staggering 1152mm compared to 762mm for ux180. I'm referring to FHD mode as I'm doing lots of live event projection thus having a long reach is pretty important. However the sensor is smaller compared to ux180 1". Thus I'm concerned about the low light capability of it. UX180 is not out so there's no comparison at this moment.

Another con of NX5R is the lack of switchable pal and ntsc system. In this modern era, why can't Sony give us a global system?

[Paul Anderegg]

There are a few things you are not taking into account.

1: The larger sensor in the UX180 is irrelevant, because it is packed with 9 megapixels worth of 4K dots, and has f4.5 aperture at telephoto. Panasonic does spec the UX180 at f11@2000 NTSC/f12@2000PAL, the same as any newer FHD video camera.

2: The digital zoom on the NX5R would give you SD or maybe 720p resolution as it crops into the 2MP sensor. The iZoom on the Panasonic is for lossless FHD, it also has digital zoom, so you will get much better and crisper and longer zoom capability with the Panny.

Digital Zoom (2x, 5x or 10x)
The AG-UX180 is equipped with 2x, 5x and 10x digital zoom. Using
the 20x optical zoom and i.Zoom together, it gives you supertelephoto
magnification equivalent to a 300x zoom without dropping in
light intensity.

Paul

[Kenny Shem]

Hi Paul, thank you for your inputs. Do you mean both sony and panny have the same capability in low lights. Even though panny has larger sensor but because of the high pixel density, the light capturing is the same as sony?

Sony clear image zoom and panny i.zoom uses the same kind of technology isn't it? Why do you say panny is lossless whereas sony is lossy?

[Paul Anderegg]

Someone who bought an R who has the original NX5 said the R is slightly LESS sensitive.........I have never owned an NX5, so I cannot testify to the low light sensitivity of it, and Sony refuses to list fx@2000 figures for these cameras. The whole lux rating is useless.

I would not think twice to get a UX180 over the NX5R, unless I really needed live streaming, which I do.

Paul

[Kenny Shem]

I have no idea how to interpret the fx@2000 figure....

[Paul Anderegg]

Standard camera sensitivity rating...the target is illuminated with exactly 2000 lux, and the first number is the f stop (aperture) the camera must be closed down to achieve 100% video signal level at 0db. Basically, the smaller the number, the wider the camera lens must be opened up to get the same brightness. An old Betacam from 1990 would be f5.6@2000. The newer cameras like the PXW-X200 are f12@2000. So you can close the iris down to f12 on the PXW to get the same brightness of the old cameras at f5.6.

Is that a good enough explanation? If you browse big shoulder cameras on B&H, you will find that f@ rating on all of them, back to the 80's at least.

Paul

[Ron Evans]

I think the NX5R is basically an NX3 with some extra NX5 features. The original had a sensor with large sensor sites, less than 1920x1080 and interpolated to 1920x1080. The NX3 has a full raster so the sensor sites are smaller than on the NX5U and thus may not be as sensitive. However my NX5U is useless above 12db of gain but the AX100 I have ( 1" sensor with lots of 4K pixels ) is a lot quieter at 27db of gain. Side by side though the NX5U is more sensitive if somewhat unusable at times. I expect the NX5R has this characteristic meaning not as sensitive as the original but with an image with less noise. You may need more gain but the image is then usable. Until the UX180 is out and tested we will just have to wait but I am going to consider it as a replacement for my NX5U as a better option than the NX5R as I do not need streaming or to use as a HD multicam but want UHD 60P.

Ron Evans

[Kenny Shem]

Originally Posted by Paul Anderegg

Standard camera sensitivity rating...the target is illuminated with exactly 2000 lux, and the first number is the f stop (aperture) the camera must be closed down to achieve 100% video signal level at 0db. Basically, the smaller the number, the wider the camera lens must be opened up to get the same brightness. An old Betacam from 1990 would be f5.6@2000. The newer cameras like the PXW-X200 are f12@2000. So you can close the iris down to f12 on the PXW to get the same brightness of the old cameras at f5.6.

Is that a good enough explanation? If you browse big shoulder cameras on B&H, you will find that f@ rating on all of them, back to the 80's at least.

Paul

Thanks! That's a good explanation! It simply shows modern cam are a lot more light sensitive.

[Paul Anderegg]

Really old 1985 tube cameras, f4@2000
Last gen tube/first gen CCD cameras 1990, f5.6@2000
"HyperHAD" Betacams 1993, f8@2000
Sony DVCAM cameras 1996, f11@2000
Panasonic DVCPRO50 cameras 2006, f13@2000 (I love you SPX800!)
Fist gen Sony PDW XDCAM HD 2006, f9@2000
First gen DVCPROHD P2 2007, f10@2000

Recently...
PMW320 f10@2000
PMW300 f12@2000
PMW400 f12@2000
PXW-X180 f9@2000
PXW-X200 f12@2000
PXW-X400 f12@2000


Those figures, along with the signal to noise ratio, allow you to better understand how these cameras will look as you gain up. We know that every stop is 6db of gain, and that ever 6db of gain introduces 3db of noise, so it's easier to figure out how cameras perform when the manufacturer gives out these numbers. Sony gives us "1.2 lux auto iris/gain". How useful is that? They tend to give those figures when the cameras underperform in low light against the expensive cameras. Also, see drop in light sensitivity when HD hit the chips?

Paul

Figures given in NTSC, PAL default slower shutter speeds add f1 to each figure. Results typically expected top be 1/60 shutter for NTSC, for 60i. Fun note, the HPC27H DVCPROHD camera was f10@2000 in 60i, but f12@2000 in 24p due to shutter speed, they were playing with the rating, but listed both.

[Paul Anderegg]

One last note about those figures. Due to the loss of light sensitivity with increased pixel count, several manufactures have begun blatantly making up figures, FALSE FIGURES. These would be Panasonic and JVC. Both of these companies have introduced standard and "extended" modes to their line of cameras. The extended or "low light" modes add 6db of gain to the readout, so when the camera says 0db, it is actually at 6db. Because the figures are taken at 0db, they get a rating of f11@2000, when in fact their cameras are a full stop less sensitive. Remember, every 6db is a stop. The HPX370 and HM890 cameras are rated at f11@2000, but at 0db on extended mode where they receive this rating, they are noisy, and the image is identical to their standard setting at 6db of gain. Sony uses REAL image sensitivity, no games. When you see Sony say f12@20000, that is a real number, with no fake or hidden gain tricks applied.

I have owned and operated HPX and JVC camera with these modes, so this is from real world experience, not just guessed about.

Paul

[Dan Gunn]

Paul you are a great wealth of useful information!