Can't decide: PXW-Z190 versus PXW-Z280

[Paul Anderegg]

Agreed Doug, but then again, look at what Sony does. Sony lists the Z190 at f11@2000...in high sensitivity mode at 0db (really 12db!). It seems that any new camera that comes out must at least meet a fictional f11@2000 (NTSC) spec. JCV does the "high sensitivity" mode, call it extended, but it's only 6db. Same with Panasonic, it's a solid 6db. HPX2000/3000 had a button called "line level", did the same thing.

Would you join me Doug, in calling for a ban on the "high sensitivity" ratings and specifications, and a return to "0db means no gain!". :-D

Paul

[Doug Jensen]

Sure, I'll join you in that, but I'll go one better . . .

The manufacturers should just publish honest ISO figures. That's all you need to know about a camera if the manufacturer reports the numbers honestly. Don't get me wrong, I am totally against displaying ISO numbers in the viewfinder because gain is much more informative. But in the camera's specifications they should tell us the true ISO of the camera instead of LUX, or f11@2000 or some crap like that. I don't even know what that means!! On the other hand, if you tell me _____ camera is rated at _____ ISO with the default paint menus, I know exactly what that means and can easily compare it with other cameras.

How the camera looks with additional gain added (whether it is regular gain or High Sensitivity gain) is a totally different matter and must be evaluated by actually looking at the picture quality and making judgement calls. You cannot compare one camera's gain against another simply by the numbers. One camera at 12dB gain might look way better than another camera at 12db gain even if the exposure is the same.

[Paul Anderegg]

I don't understand ISO ratings at all!

f@ figures make a lot of sense to me, especially when comparing B4 cameras, simply because aperture is always roughly the same, and if you see an f@ number increase one stop, you know the camera will do a 0db what it's predecessor did at 6db...speaking from an exposure level, not noise level.

I still have no clue WTF 1.5 lux in low light mode is on my Z90...and despise Sony's use of rating the big Sony's with a lux at 42db or with 64 frame accumulation! 0.000002 lux at 48db + 64 frame accumulation...go to hell Sony :-P

Paul

[Doug Jensen]

Wow, you really take this stuff personally. :-)

I just evaluate what the camera can actually do and move on. It only takes a few minutes to figure out the true sensitivity of the camera and how much gain I find acceptable. Once I know the limitations, I can get down to work making money with it.

BTW, you really should understand ISO. It's the same as ASA and has been around for a hundred years. All still photographers, cinematographers, etc. use the numbers as an international standard for exposure sensitivity. Even if you don't use it, you should understand it.

[Cliff Totten]

The thing with "0db" versus what we often call "native ISO" rating (and dual-gain/ISO settings) is that these two values are completely set from the camera maker.

Every sensor has a pre-amp amount that is added after its voltage collection. The sensor needs to be amplified to reach what the company wants to be a "respectable" 0db. So,..."0db" already has tons of preamp in it that we have no access too. If Sony wants their "0db" to equal 100 ISO or 400 ISO, they simply preamp the sensor to get the "ISO" they want for "0db".

Now....here is the trick! The more preamp they use to make a brighter "0db",...the LESS overhead WE have to go over 0db for ourselves. In other words,...if our 0db looks ok but our 12db is noisy as hell, that means Sony "used up" some of the signal to noise ratio overhead with higher preamp to give us the 0db brightness they thought was good.

I hope that makes sense. This is why the A7S sensor has sooooo much gain overhead. Because the collection voltages are already so high, that Sony doesnt need high preamp values. That "0db" is already very bright on its own....so to speak. Therefore, when we start cranking 12, 18, 24db....it STILL looks phenominal. The sensor's signal to noise ratio is NOT being "used up" on high amounts of sensor collection pre amp.

Tiny image sensors cannot do this, therefore camera companies need to crank that preamp to make a reasonably bright "0db"

With small image sensors, a camera maker's last option is to add more and more and more and more noise reduction processing to recover some of that signal to compensate for a dim sensor, high gain output. Noise reduction is the last line of denfense. However, that truck itself also brings it own problems to the table.

I have no idea how good or bad the Z190 and Z280 performs yet. However, I cant wait to get some original files to look at first hand.

CT

[Vincent Del Vecchio]

But Doug...

...I bought the Z-190 and I'm enjoying it and don't think the low light is all that bad. But now you've said some horrible things that are making me regret not buying the Z-280... and I had the chance to do it but now my 30 day return policy is up from Adorama...

[Doug Jensen]

The Z190 is a nice camera, especially for the price. But it's not very good in low light. I'm sorry to break the news but it's not just my opinion it is a fact that is easy to see when it is side by side with the Z280. If you don't shoot in low light situations very often then you're good to go. When there is enough light it is hard to tell the camera's apart.

[Kenny Shem]

I have to say that Z190 low light is pretty bad. Comparing with my NX5R, both wide open and the same setting, NX5R is just so much brighter. I have to up the gain of Z190 to around 6-9db to match it. The only saving grace is the Z190 gain does not add much noise. Given that Z190 is on a higher class compared to NX5R, I am rather disappointed in this low light aspect. I do lots of events and often have to zoom up to 90-99% and lose a lot of light on the way. I'm shocked that I often have to shoot at 18db unless I do 25p instead of 50i in order to bring down the shutter speed to allow more light in. I love the constant aperture of Z280 but I need the 25x zoom of Z190.

[Cliff Totten]

Yeah, those Z190 sensors seem to have a pretty dim voltage output. I'm sure if there was a way to access the raw pre-processed data off them we could see how heavily the Z190 leans of massive amounts of noise reductuon.

The Z280 has a sweet constant aperture lens that is just as fast on the long as it is on the wide. So, zooming in with that one doesnt kill your low light. So you might want to look at the Z280 instead.

Im thinking about the Z280 for next year's budget but I'll hang on to another Z150 untill the spring and see what comes out at NAB 2019. I already spent allot this year. I bought a 2018 RAM work van and I'm about to drop $11k on a DJI Inspire 2 drone and with 6k raw/ProRes liscense...so Im out of spending money for a while!!!

The Z150 is still has beautiful image for the price. That 1inch-type sensor output is gorgeous if you can deal with the loss of some pro functions.

CT

[Paul Anderegg]

Cliff, the Z280 does not have a constant aperture zoom lens. The lens has a mechanical iris ring, and like all cameras with a mechanical iris, the iris position sensor determine the physical location of the teeth of the ring when displaying the iris value in the viewfinder. It's a common misconception with lenses of this type. On my B4 and 1/2" cameras, when you zoom to full telephoto, it gets a stop darker, and you can rotate the iris from f1.4-f2.0 without any changes in exposure level...once you "catch up to the ramp", you start actually irising down.

Doug, I guess I am showing my age. Back when I started camera evaluating, cameras had three settings, 0, 9, and 18db. You got an fX@2000 figure for 0db, all cameras were 1/60 shutter locked (NTSC, and they gave you a signal to noise ratio. Other than that, the only other variable to consider is if you wanted to pay $10,000 extra for the model with FIT chips, or live with intense vertical smear! As an experienced user, you should agree that even with ISO ratings and all the specs int he world, you really cannot determine the cameras capability until you put it side by side with another cameras image!

Originally Posted by Doug Jensen

Wow, you really take this stuff personally. :-)

I just evaluate what the camera can actually do and move on. It only takes a few minutes to figure out the true sensitivity of the camera and how much gain I find acceptable. Once I know the limitations, I can get down to work making money with it.

BTW, you really should understand ISO. It's the same as ASA and has been around for a hundred years. All still photographers, cinematographers, etc. use the numbers as an international standard for exposure sensitivity. Even if you don't use it, you should understand it.

[Cliff Totten]

You mean the Z190 doesn't have a constant aperture? If so, this is true.

The Z280 is F1.9 all through it's zoom range. From wide to it's longest end.

CT

[Doug Jensen]

Incorrect. The Z280 also ramps at max. aperture, even though the display in the viewfinder stays constant. According to my measurements it drops about 1-stop from f/1.9 to f/2.8.

But the Z190's ramping is much worse. The Z190 ramps at ALL f-stops, not just maximum aperture.

All settings being equal, the Z280 is four stops faster than the Z190.

[Cliff Totten]

Thanks for that clarification Paul and Doug, I thought it was a constant f1,9....Wow! dang it,...my bad!

CT.

[Paul Anderegg]

The only big ENG lenses I know of that are constant are ones like the Fujinon HAs18x4.2 BERM for the JVC and Panasonic 1/3" cameras. The only reason they maintain f1.4 at full telephoto is that they are basically 2/3" B4 lenses modified for the smaller sensor, so the glass through the pipe is super big.

Paul