I'm looking for a future-proof (read: 4k) camera for my retirement days (which came earlier than expected due to my illness) - and am torn between the 2 options:

- a camera with large sensor (Sony AX100 or X70), unable of anything above 30p
- a camera with a smallish sensor (1/3.2"), less sensitive but capable of 50/60p - like the Panasonic HC-X1000

The first "teaser" clips from Panasonic on YT were not very spectacular, with a much softer and less detailed image that that coming from the little Sonys - moreover, ever since there is almost no discussion of the HC-X1000 on the fora. Does it mean that the image quality is really that bad? Please share your opinions - I'm tempted by the superb form factor, ergonomics, 3 lens rings of the Pana but of course wouldn't like to end up with a camera whose IQ is questionable! TIA

Piotr

Yes I agree with you in that the Panasonic has a soft image compared to the AX100 for example.

I heard the Panasonic crops the image smaller for HD.....you lose a lot of wide angle.

Paul

I heard the Panasonic crops the image smaller for HD.....you lose a lot of wide angle.

Paul

This is not what Panasonic people are saying (e.g. in the B&H product page video); 1080p is supposed to be obtained by "very clever" (as they put it) line addition or something to that effect...

But what matters for me is 4k IQ; I'm unable to shoot for production anymore (editing I will still be doing of course), so what I'm after is a cam for those "beauty shots" of architecture, landscape etc, edited with my own music.Something I have always been planning for retirement days...

There is another promising camera coming from Panasonic in September - the AG-DVX200 - which will ofer the best of the 2 worlds: larger sensor (4/3", though with a fixed lens), and better recording format choices (50/60p, 4k at 150 Mbps, etc.) Plus - as it's still planned as just an 8 bit, 4:2:0 camera - the price is supposed to be good (4-5k USD). But with the experience of not-quite-good IQ in the HC-X1000, I'm not sure whether it's worthwhile to wait.

BTW I have always been a Sony guy; is it normal for Panasonic that such a thoughtfully designed machine like the X1000 offers a sub-standard picture quality?!!

If you stand by the AX100, wait a little longer. The HXR-NX100 shows they're going the 1'' route for cameras. That new NXCAM has a digital doubler that doesn't lose resolution... Sounds like a 4K capable sensor straight from the AX100.

I would have no doubts we'll see a 4K 60p capable 1'' camera from Sony from IBC.

Then again, this is coming at the end of July:

https://www.blackmagicdesign.com/products/blackmagicursamini

Just. Wow. 4K, interchangeable lenses, dual CF recorders, and XLR audio for $3K. Kind of puts my X70 to shame. Could it be overrated?

EDIT: Possibly even the $3K 4K model has GLOBAL SHUTTER. Damn.

By the time you buy lens, batteries and CF cards it may be several times the cost of the X70 !!!

Ron Evans

And you'll want a EVF at ? $1500?

Mike, please elaborate your post - is it a question for me?

Piotr

Piotr,
I think for what you want to do the AX100 at the slower frame rate may not be a problem and it is not going to break the bank to buy and try. Will get you into playing with UHD and if something better comes out later in the year it will still have resale value.

Ron Evans

Yes Ron - having checked as many pros and cons as I only could (searching the Internet for reviews, sample clips etc) - I also think that the AX100 is the best way for me to go.

BTW. Someone stated in this thread the Panasonic X1000 has the same (lower than the larger sensors cameras) PQ as the 1/2.3" Sonys (AX1 and Z100). Well - I would say, based on many clips I saw from the three small sensor 4k products - that the PQ is not the same among them at all; I'd rank them in this order (starting with the best PQ):

- JVC HM200
- Sony AX1/Z100
........................

- Panasonic X1000

Something is terribly wrong with the latter - e.g. grass or foliage looks worse than SD to me (and I'm not talking about the highly compressed YT clips, but one native cliip straight from the camera that I managed to find). Strange....

Piotr

It'll be interesting to see what Canon does with their XA20 in terms of going 4k with them. I personally like their approach to these cameras and if you note what they are doing with some of their other new 4k camera sensors (larger), they might follow suite doing the same with the XA.. line, which means, a 1" or even larger sensor. Right now it's speculation. These are nice cams for portable situations. I really like their menu system and they provide some great features. But only 4:2:0 8 bit. So it all depends on what you need/want. Probably nothing until next year though.

I'm looking for a future-proof (read: 4k) camera for my retirement days (which came earlier than expected due to my illness) - and am torn between the 2 options:

- a camera with large sensor (Sony AX100 or X70), unable of anything above 30p
- a camera with a smallish sensor (1/3.2"), less sensitive but capable of 50/60p - like the Panasonic HC-X1000

The first "teaser" clips from Panasonic on YT were not very spectacular, with a much softer and less detailed image that that coming from the little Sonys - moreover, ever since there is almost no discussion of the HC-X1000 on the fora. Does it mean that the image quality is really that bad? Please share your opinions - I'm tempted by the superb form factor, ergonomics, 3 lens rings of the Pana but of course wouldn't like to end up with a camera whose IQ is questionable! TIA

Piotr

Panisonic typically only reads it's 4k cameras in a 1:1 pixel scan. They take about 8 megapixels for UHD/4k and make their image from that. So that's 4 million green, 2 million red and 2 million blue. (Roughly)

SONY's 1 inch type sensors in 16x9 for UHD use more than 16mp...so thats over 8 million green, 4 million red and 4 million blue. Sony's green channel alone is already full raster UHD.

So yeah, Sony's over sampling pays off in allot more detail.

I think that oversampling 16+ megapixels down to 8 for 4k is better than starting with just 8mp and taking the RGGB bebayer resolution loss

So yeah, Sony's over sampling pays off in allot more detail.

I think that oversampling 16+ megapixels down to 8 for 4k is better than starting with just 8mp and taking the RGGB bebayer resolution loss
I don't think that's necessarily true. It's not so much how many photosites there are in total as to how they're used. If you start with 8Mpixel (3840x2160, to be precise) it's relatively straightforward - normal deBayer, and that gives you a desired QFHD straightaway - no scaling.

But increase the number and it's not so simple to do it well - far more photosites to deBayer, and the resultant then will need downscaling to QFHD, and high quality downscaling is difficult to do well, certainly in real time with limited processing. Consequently, it's the norm to simplify - typically via some sort of binning process - to bring the workload down to manageable levels. The result is that starting with 8Mpixels will give the optimal result - don't forget that's the count as used in some very high end pro video cameras such as the F55 and the Varicam.

In the thread about the new Sony A7R II, I've speculated about what that be doing in full frame mode, as it is quoted to have 41 Mpixel. At first sight, it may be thought it will give even worse problems - even more pixels!! :-) - and need even more "binning"!

But look more closely at the numbers, and if you have EXACTLY 7680x4320, everything changes. If you take the photosites in 2x2 Bayer blocks (2 green, 1 red, 1 blue), it follows you have exactly 3840x2160 blocks. Hence each block can translate directly to a single output pixel for 4K, with the red, green, blue values being directly read. Practically, that theoretically means very high quality 4K *WITH SIMPLE PROCESSING* from a sensor which will also give very high quality stills resolution, and with no need to crop or compromise in other ways.

I have no idea if this camera is actually doing this, but with this photosite count (*) it must be seen as highly likely. Point is that it's not a case of "more is better than less" - it's a case of how they are read, and that certain exact numbers become geometrically important.

(*) - the number 7680x4320 is for a 16:9 frame. Since for stills use it will be 3:2 (vertically cropped for video) that would imply a total count for the 3:2 frame of 7680x5120 - just under 40Mpixel. The A7R II is quoted as having max resolution of 7952x5304 - so would only need a linear crop of just over 3% to get to the "magic" number.

Sony states on all their 1 inch-type sensor cameras that they don't "line skip" or pixel bin in UHD video. The A7s supposedly does not line skip or pixel bin either.

How Sony scales down a heavily over sampled image? I have no idea. In fact, I suspect only a handful of Sony engineers know that exact math on this trick. That is part of the Sony "secret sauce".

The A7s uses 10 mega pixels and samples down to 8mp for UHD so that is a "mild" over sample. The Fs7, F5/F55 and FS700 uses 13+MP. Again, not too crazy. The AX100 and other 1 inch-type models use almost 17mp to start with and scale down. So, that's close to a 2X over sample (2:1) as opposed to Panny's 1:1.

Just about everybody I have talked to agrees that Panasonic's 1:1 read out looks OK but lacks the eye popping detail that Sony's over sample gives you. Panasonic will moire less in the high frequency details (because there are less details) And,..Sony will moire more often (Because it has more high frequency detail)

I guess the proof is in the pudding. An A/B camera comparison most of the time reveals it.

The Fs7, F5/F55 and FS700 uses 13+MP. Again, not too crazy.
Not so - all those cameras (plus others like the s35 Varicam) have sensors with active pixel counts of (4096)3840x2160 - what are generally referred to as "8 Mp" sensors. If 8Mp is good enough for a F55.......??
The AX100 and other 1 inch-type models use almost 17mp to start with and scale down. So, that's close to a 2X over sample (2:1) as opposed to Panny's 1:1.
But the same oversampling can give rise to more problems than it solves. It CAN.... which is not to say it WILL....

It must involve a downsampling of the deBayered intermediate, and digital downsampling needs a lot of processing to do well.

In terms of the question posed, then I agree that 1" is far more likely to give better results than much smaller sensors - but that doesn't necessarily mean it's down to pixel count, period. For starters there are factors like diffraction softening, and don't forget more photosites means smaller photosites.... even more of a problem for smaller chip sizes.

I stand corrected. I could have sworn that I had seen a higher pixel count listed on these cameras in the past. huh?

Well? Sony's web site has these specs listed:

FS7 "11.6 MillionTTL 8.9 in 4K; 8.3 Million in UHD snd HD"

Alister wote this about it:

http://www.xdcam-user.com/2012/07/nex-fs700-pixel-count-and-sensor-size/

It's widely speculated that the FS7 uses the same sensor as the FS700.

The FS7 is cropping an 8mp scan from the middle of the sensor? What about the "unused pixels?"

Need to look into this further.

Very interesting. Thanks for pointing that out....

I stand corrected. I could have sworn that I had seen a higher pixel count listed on these cameras in the past. huh?....
What you say above has always been the case - about 8.3Mp (effective) for QFHD, and about 8.8 Mp for 4K - and it's the "effective" count that's relevant.

As Alister says in the link you gave: "It is normal to have some extra pixels that are used for setting black levels etc, but this is a massive difference between the number of actual pixels on the sensor and the number that are used to create the pictures." All very true.

Theories I heard at the time ranged from to give the ability for outside recorded image viewfinding in a future camera, to giving flexibility to compensate for dead pixels (and so decrease the number of unusable chips), to their being used as part of the stabilisation system.

Which is correct, if any? I don't know, but in the comments at the end of that link, then usage for stabilisation seems the favourite. Practically, it may be interesting to speculate, but from a usage point of view it should just be considered as 3840(4096)x2160. It's always the "effective" number that's important from a usage point of view.

Interesting discussion; even though I'm an engineer my background on this particular subject is nothing compared to yours so I can't add anything of value. But coming back to my original question, here are 2 screen grabs from an X1000 file I got a link to as being native and without any recompression. While I can understand the softness in some (well - most of) the YT/Vimeo samples (heavy compression etc) - these grabs come from what is supposed to be a native AVC, High@5.2, MP4-wrapped, 4:2:0 3840x2160 clip at 24p with some 40 Mbps data rate - straight from the Panasonic camera. BTW, for some reason I was unable to upload any of those 3840x2160 PNG pictures, so I'm just providing a link to them on another server.

What do you make of the muddiness of the distant foliage? OK - partially it's due to blur from panning or zooming present at the moments I took the grabs - but still... It looks more like SD, not even HD - not to mention Ultra HD to me! Is this really how the Panasonic X1000 records? In the same clip there some scenes with lots of details and the UHD "wow" factor - but they are in minority... Was the camera faulty (back-focus?), was it an operator error - or is the codec implementation totally screwed up?

http://www.moldcad.idsl.pl/images/x1000.png
http://www.moldcad.idsl.pl/images/x1000-2.png

The X1000 and the AX1/Z100 are effectively 1/3 " cameras so using iris above about F4.6 or so will lead to soft image. ND needs to be switched in quite early, the camera tells the user !! On my NX5U and AX1 I try to keep iris at about F4 or larger (ie F2.8 ) for a good image. So unless the files all say exactly how they were shot it is almost impossible to compare. I can make all my cameras look great or absolutely terrible just by changing the exposure parameters.. True for my NX5U, NX30U, FDR-AX1 , the AX100 has a lot more range before it goes soft. As an example above F5.6 and the NX5U starts to look like a very cheap camera and has a hard time competing with my Xperia cell phone !!! Which may have the same sensor as the AX1/Z100 and/or the X1000 !!! I am sure the HX30V still camera I have does have the same sensor but a very much smaller lens as does the cell phone.

It is useful to look at the data code from a pure automatic shot to see what the engineers say should be the correct exposure. Most of the time on the Sony's I have that iris value is around F2.8 for the 1/3" cameras when possible. For the smaller cameras without ND the shutter speed is increased before iris closes down below F4. A good indication that I have followed to get sharp images.

For cameras with full manual controls unless they are compared with the same settings under the same conditions then it is not a lot of use !!! 4K is very difficult to focus and to me both those images are out of focus.

Ron Evans

What do you make of the muddiness of the distant foliage? OK - partially it's due to blur from panning or zooming present at the moments I took the grabs - but still...
I wouldn't want to draw any conclusions either way. One just looks out of focus (or showing softness due to diffraction effects?), the other simply looks rough due to camera movement (right hand side is sharp, left very blurred, so I'd suspect zooming and panning at the same time?) They don't look good quality but whether it's anything intrinsic to the camera, or simply the way they are shot is impossible to say.

It all goes to show why the best tests use such as charts or special test scenes - they don't just give an idea of how "good" or "bad" a result is - they're specifically designed to tell why.

What you say above has always been the case - about 8.3Mp (effective) for QFHD, and about 8.8 Mp for 4K - and it's the "effective" count that's relevant.

As Alister says in the link you gave: "It is normal to have some extra pixels that are used for setting black levels etc, but this is a massive difference between the number of actual pixels on the sensor and the number that are used to create the pictures." All very true.

Theories I heard at the time ranged from to give the ability for outside recorded image viewfinding in a future camera, to giving flexibility to compensate for dead pixels (and so decrease the number of unusable chips), to their being used as part of the stabilisation system.

Which is correct, if any? I don't know, but in the comments at the end of that link, then usage for stabilisation seems the favourite. Practically, it may be interesting to speculate, but from a usage point of view it should just be considered as 3840(4096)x2160. It's always the "effective" number that's important from a usage point of view.

Yeah,...this is quite interesting. I looked at the Sony FS7 brochure and this is what is stated:

"The FS7 is equipped with a Super 35 “Exmor” CMOS Sensor
with approximately 11.6 million total pixels and 8.8
million effective pixels. The high image readout speed
of the image sensor allows the FS7 to support 4K motion-picture
shooting and Super Slow Motion. The sensor
also realizes a high sensitivity of ISO2000 and a wide
dynamic range of 14 stops. Thanks to its full-pixel readout
capability without pixel binning and sophisticated
camera processing, jaggies and moiré are minimized"

Are we 100% sure that Sony is reading only 1:1 for UHD and DCI 4K?

There are a couple of points I can see here:

11.6 total pixels and 8.8 effective...what is Sony doing with those 3+ million pixels? The FS7 does not read the full sensor width?

Sony mentions "full pixel readout and no binning" This strongly suggests the camera IS reading all the pixels and scaling. Otherwise, a standard 1:1 readout doesn't need this to be stated. And of course there would naturally not be any binning if it's 1:1 either. Sophisticated camera processing? This doesn't sound to me like a standard 1:1 readout and 8 megapixel deBayer process. It makes me think "sophisticated SCALING engine" Maybe its just suggestive marketing talk?

I'm not saying I know the answer, but this language suggests to me that it's scanning all 11.9 and using the entire sensor width and delivering a "final" 8.8mp image after it's all processed.

I know Sony likes to oversample these days. If a resolution target is "X", they generally aim for 20% (or more) over that target to compensate for the Bayer pattern loss and arrive close to the "X" resolution they want. (This commonly results in noticeably more detail but a bit more moire too).

It's very hard to make a razor sharp and detailed UHD/4K (8+MP image) if your green channel only has 4 million pixels (HALF UHD/4K raster) and your red and blue channels are only around 2 million pixels each too...(25% UHD/4K raster).

I don't know at all how Sony is doing any of this. It's cryptic to say the least.

Are we 100% sure that Sony is reading only 1:1 for UHD and DCI 4K?

There are a couple of points I can see here:

11.6 total pixels and 8.8 effective...what is Sony doing with those 3+ million pixels? The FS7 does not read the full sensor width?
In short, yes, 100% sure!! :-)

Key is the word "effective", that unequivocally means "the number in use". It's been confirmed in testing, and in answer to what it's doing with the other 3 million, then well... that's what is not known.
It's very hard to make a razor sharp and detailed UHD/4K (8+MP image) if your green channel only has 4 million pixels (HALF UHD/4K raster) and your red and blue channels are only around 2 million pixels each too...(25% UHD/4K raster).

I don't know at all how Sony is doing any of this. It's cryptic to say the least.
Using a Bayer sensor of 3840x2160 is considered the minimum that can be used and still legitimately be called "4K". But yes, a 4K Bayer sensor won't give as much resolution as the 4k system is capable of carrying, that's true.

But it's not as bad as you fear. It's basic theory that after deBayering the luminance resolution from a Bayer sensor is likely to be about 75-80% of the sensor dimensions, and the chrominance resolution about 50%. (Which is why, in a progressive system, and using such a sensor, 4:2:2 sampling is irrelevant and won't give any advantage over 4:2:0. The extra chroma resolution it could record is not there in the first place. Worse, it just means extra bandwidth - or higher compression - for no benefit.) It's a question of where you draw lines. All I'll say is that in resolution terms, even if that is less than the 4K system is capable of, it's a lot better than 1080