Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

I don't really mean to inject myself into this debate, but I will point out that signal processing and output are necessarily different things; an 8 bit signal processing would output at best 6 bits, if my high school maths are remembered, it would take at least 11 bits to output 8.

Years ago there was a DV camcorder that had signal processing of 10 bits, and the resulting output had noticeable banding as it was something below 8 bits of output.

Just to make the point that output and processing are different things, and can't possibly share the same value ...

Cheers,
GB

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Cheers GB

Well that's what is mentioned the camera has 8 Bit signal processing so therefore if what you're saying is right it only outputs 6 bits?

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Thanks GB.

Mark, I was talking about recording the cameras output, not about the DSP.

The FS100's HDMI output is 8 bit and the F3's and EX1's is 10 bit.

I have been led to believe by those that should know that the internal processing of the FS100 is 12 bit, not as sophisticated as the F3's and using a simpler DSP.

There seems to be an assumption being made that the DSP and the output bit depths are the same, which certainly in the case of the F3 they are not and in the case of the FS100, I can't see how it's possible to use an 8 bit DSP to get a decent 8 bit output.
To get the kind of dynamic range being seen from the FS100 or F3 hints at the sensor output being at least 12 bit, if not 14 bit. You cannot simply ignore 4 bits of data without having a significant impact on the systems dynamic range. As there is little difference in DR between the FS100 and F3 it is my opinion that at the very least the FS100 DSP must do some processing on all 12 bits of sensor data.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Test Test Test

Would be nice to walk into a store take the camera outside and test maybe spend a few hours hook the camera up to a monitor film in low light test the highlights do some colour correction try some gamma curves Hook up to a recorder etc The likliehood though is it will be plonked on the counter shown where the buttons are and sweet talked by a salesman who shows you the glossy brochure and tell explains why it is better than the competition.

Objective Information can be gleaned from the internet where real users can upload clips give opinions and where you can judge those opinions by their honesty and integrity from past reviews like Alan Roberts for example. Please don't tell me Alan Roberts hasn't tested the FS100.. It was just an example.

Hiring a camera I agree would be a much better idea.

I have downloaded footage for these cameras looked at pics of what they can do seen the specs tried to uncover how they do what they do which is often hidden in some cases to deflect bad publicity and criticism. The next best thing to hiring one.

Just as an aside. With the EX1 I knew almost straight away from reviews this camera was the real deal and fairly rapidly had one on order.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

It has been a long time since my maths been tested -- but with certainty I can say that if the processing takes place at 8 bits the output must be lower. Conversely, if the output is 8 bits ... the processing must have been higher. Someone that paid closer attention in school can doubtless give the precise relationship between process and output -- best I can recall is that a couple of bits of headroom is required.

(Hope all is well in Herts; been a few years since I lived in Hitchin but fond memories of springtime)

Cheers,
GB

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Okay Alister so you don't know what the camera processor does only that someone led you believe it was 12bit.

QUOTE
There seems to be an assumption being made that the DSP and the output bit depths are the same
---------------------------------------------
No Not at all. The assumption is that WHERE information is provided the Sony FS100 is said to have 8 Bit signal processing and you said it has 12 bit. Now you say you were led to believe this and not the statement of fact you originally made.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

I'd go to one of the professional dealers, they usually have demo cameras and you can get good price deals from a number of them. Unless the dealer knows you, they mightn't let you take it away, but you can arrange to shoot some tests on their premises and take them away

Not all cameras are as simple to pick as the EX series, they've been around for a numbers of years and still regarded as a good bank for buck camera.

The only other place I recall seeing 8 bit mentioned is Philip Blooms blog, but it was rather loosely used rather than referring to the sensor DSP as such. I'd be surprised if that particular section is 8 bit.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Personally I don't know what the DSP is but it looks as if it could be 8 bit Phillip Bloom probably got his info from Kanta Yamamoto from Sony Europe. However I could be wrong Hopefully we will find out.

Sony NEX-FS100
The FS100 shares its sensor with the F3, however the similarity ends there because its signal processing is 8-bit

Sony FS100?just my first impressions | Bengske.com - Photography: How TO Tutorials, Tips, Tricks and Techniques.
t has the same Super 35mm sized sensor as the F3 but different processing. It has no SDI out, just HDMI and it is only 8 bit 422 even though HDMI can do 10 bit 422 because the processor is only 8 bit. Compromises have had to be made to slash the price down from the F3.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Well if the processing is 8 bit then the output is necessarily less than that -- which would show up very quickly as banding in areas of solid colour/varying brightness. Blue sky, for instance, would rapidly pick up banding if the output was only 6 bit. There is no way around it.

So I think someone misspoke. Just my 2 cents.

Cheers,
GB

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

In that case, I would take the 8bit to be the back end processing rather than front end at the sensor. They usually would define it as being the sensor (eg 12 bit A/D conversion) rather than just in general terms. You can have different rates, eg the F900 was 10bit and then processed at 8bit

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Mark, even if Sony wrote it in the manual, it would still be VERY unlikely that the signal processing was 8 bit. Unless it is some new process being used, I would presume the DSP is at least 12 bit.

The chances of it being a miscommunication are FAR higher.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

My source is a Sony engineer, I don't wish to say any more as that engineer may have revealed more than he should and I am under NDA. With the greatest of respect to Phil Bloom, he is not an engineer and technical stuff is not his forte. In addition knowing Kanta and his less than perfect english, it is very possible that there could have been a miss-understanding.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Exactly some new process could be the answer and partly the reason why power consumption is so low.

Time will tell.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

I am curious to what everyone thinks gives the best film look, seeing that these camers have now been compared.

To my eyes the 5d2 looks the most filmic with the AF100 looking the most video-ish, or as some have coined it *the reality look"

To place things into perspective I think the Panavision Genesis also looks video-ish.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Early days yet, I suspect the widest range of options are with the F3 shooting S-log and you'll get a closer film look possibilities with that once you get into post.

Most film looking camera, the Arri Alexa. Unfortunately, Kodak have rather bland stocks these days, which are tending to look more and more like HD.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Alister, I think you are spot on about the F3 and FS100. Why?

I have a decade old math model that I use to predict measured resolution based upon published sensor specs. So I updated it for the RED ONE. It predicts 3193 LW/ph and the consensus is 3200LW/ph.

So I input your F3 and FS100 measures plus Sony's 3.37MP (2456x1372) frame. We do not use any row or column skipping. We simply downscale H and V by 64% for the F3 and 55% for the FS100 which is the "over-sampling Juan talks about. During the down-scale, all pixels are de-bayered.

An HD progressive Kell factor of 0.97 is used.

The estimated F3 resolution will be 858 LW/ph by 852 LW.

The estimated FS100 resolution will be 737 LW/ph by 732 LW.

So the photosites are 4X larger. And, the estimates seem to match your numbers quite well.

There remains one issue -- why if Sony has told us the chip is 3.37MP (2456x1372) frame, why does Juan say he can't tell us the sensor's specs? What's left that we don't know?

PS1: My math model also estimates EX1 1080p at 1048 LW/ph and 1048 LW.

PS2: I suspect the VG10 may work differently. Need to do more work.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Steve, couple of questions.

What is TW/PH and where do the downscale numbers come from?

Could the bayer matrix be twisted somehow?

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Now I am confused!!

In my understanding a picture pixel is a picture element consisting of 3 elements R+G+B.

Are you now telling me that Sony has pulled the same old gimmick they used to use to with the flat screens, using the combined numbers of RGB elements to lead me as a costumer to believe that the product has higher specifications that it actually has.

I have actually preordered a FS100 in the believe, that I got a genuine HD2 camera!!
If it for some reasons only resolves 750 lines horizontally I can live whit that, but if Sony is twisting the specifications to lead me to believe the camera is something it isn’t. I feel betrayed.
If the sensor is only 1.1 mp coming from 1.1mpR+1.1mpG+1.1mpB.
Then the specification should say sensor pixels used 1.1mp!!!

Does any of you actually knows the provided specks from Sony is the combined numbers of R+G+B on the sensor, putting the camera in the HD1 category, or is it something you assume from the resolution you can see from the camera?

Now you probably says it doesn’t matter if the sensor is HD1 or HD2 if the resolution is only HD1. Maybe it is so in theory, but my experience in real life is that a sensor with a high native pixel count is going to produce an optically nicer image than a sensor with lesser pixels. Giving they is mounted in a camera with the same optical resolution. What I am trying to say is, opsampling is bad, downsampling is fine.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

I would take it that the sensor has a standard Bayer arrangement, same as the RED and the Arri Alexa, which has 2880 x 1620 Pixels for the image area.

Bayer filter - Wikipedia, the free encyclopedia

I'd assume that the Alexa has a lot more processing going on for its higher resolution figures.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Sorry Alister, my typo. Should be LW although I prefer TVL.

And yes, the secret may not be -- as I have been assuming -- the photosite count of the F3 sensor, but the arrangement of the photosites on the silicon die.

1) Some think the chip could be a Super 35 version of the ClearVid design we both know.

2) Some think the chip could be a Super 35 version of the Q67 design. Here is an edited comment on it.

"After complaining about Bayer Pattern sensors in digital cinema cameras, Sony magically think that rotating a Bayer Pattern 45degrees somehow makes it better. When you look at Sony's "Simulation" image, their Q67 is using 17.7mp compared to their Bayer example of 8.8mp. The Q67 is basically using twice as many pixels."

3) Some think the chip could be a Super 35 version of the "RGB Stripe" design. Here is an edited comment on it.

"About Sony's "Full RGB" solution they use in the F35. At high levels of detail, the RGB Stripe pattern produces rainbow patterns due to the lack of alignment between the three channels. This is plainly visible."

==========

The difference between the 64% value for the F3 verses the 55% for the FS100 may come from a pure marketing decision, or given there are many ways to debayer and some ways yield both higher resolution and lower artifacting -- I'm inclined to guess the F3 uses a more powerful algorithm. This likely requires a more powerful DSP. Conversely, the FS100 (and VG10?) use a simpler algorithm that requires a less powerful DSP.

I have a question for you about resolution measures for the VG10. Did you obtain any?

And, does anyone have from Panasonic the AF100's actual sensor row by column numbers?

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

A few important notes Brian.

No one outside of Sony truly knows how the pixels on the F3/FS100 sensor are arranged. We have been told Bayer, but that may mean quite a few things. Normally bayer is a pattern of groups of 4 pixels arranged like this:

R G
G B

Normally from this arrangement you can accurately extrapolate useable resolutions around 70 to 80% of the horizontal pixel count, which for the F3 sensor is calculated to be 2456x1372, this gives a ball park theoretical resolution of around 1840 pixels or around 920 LW/PH. Nyquist for 1920x1080 is 960 LW/PH, Any resolution beyond this will contain aliasing aterfacts which are undesireable, so a perfect camera would have a resolution of 960 LW/PH, but there are many issues which mean that we cannot create the perfect camera so compromises will be made.

My MTF50 results are not the finite resolution of the cameras as above.

MTF50 is where the contrast between a black and a white line becomes 50%, or mid grey. This is important because this is the point where the viewer normally stops seeing any fine details as the contrast between the details is so low that they cannot be perceived, even through they may still be there. It is quite normal to have the finite resolution around 25-35 percent higher than the MTF50, but this will vary from camera to camera, system to system. MTF is also a measure of the system, i.e. camera plus lens plus processing. As a guide if you see an MTF50 figure of 750 LW/PH then the finite resolution may well be around 900 - 1000 LW/PH which does tie in quite well with what has been measured from the F3 and FS100 and the pixel numbers supplied by Sony. In addition it's not a bad result.

MTF50 also tells you about contrast in the mid range and how sharp the image will look with less fine image details. This is important as even with a substandard display this difference will still be seen.

So both the F3 and FS100 are definitely at the good end of 1920 x1080 camcorders in terms of resolution. The F3 has a higher MTF50 than the FS100 and this will likely lead to slightly better mid range contrast and perceived sharpness.

Sorry Steve no VG10 resolution tests. I'm prepping for a big shoot at the moment and the PC is in the my other office, not sure I will get a chance to do it this week.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Allister;

I have been following this debate from the beginning, not understanding half or more of the technical arguments. Thanks for posting this last explanation. Really interesting crystalization of what you guys are talking about in terms of technical aspects of our mysterious machines.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Thanks for the notes Alistair

I can see the FS 100 being used on larger productions as a B camera, where space is tight or its light weight could be an advantage for rigging a camera,

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Steve, David: Don't know if you know the definitive answer to this, but I have been looking more at interpreting the very subtle clues that zone plates give about sensors, in particular bayer. One thing I had thought is that when you see red/blue colored rings i.e. colored aliases (not to be confused with the rainbow green, red, blue moire rings caused by lack of luma resolution) on the horizontal and vertical axis that are typically out of step with the luma aliases it is a measure of the difference in resolution between the G and the R/B samples typical of a bayer sensor. Can anyone confirm this or have I got this wrong?

Looking at both mine and Alan Roberts zone plates that explore beyond Nyquist you can see these strongly coloured aliases, to me this suggests a conventional bayer sensor, assuming that I have the above correct.

Looking at a Q67 sensor with the bayer matrix basically rotated through 45 degrees these blue/red aliases shift through 45 degrees and now appear on the diagonal axis, so that rules out Q67 for the F3/FS100.

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

Hello Alister,

Looking at Alans zone plate ( http://thebrownings.name/WHP034/pdf/...ony_PMW-F3.pdf ) then what I find most revealing is what you can see in figure 2 - the centre monochrome pattern, not the big red/green zone plates. That gives the out of band response, and here we basically see the lower examples of eight alias centres, all in a square, with four at the the corners, four in the centres of the sides. The corner ones are green/magenta, the vert/hor ones are more orange/blue.

It's my belief that the dimensions of this square is fundamental with the sensor dimensions, and backs up the figures given by Sony as being of the order of 3.5 million photosites.

Compare it with the diagrams here - ProVideo Coalition.com: Camera Log by Adam Wilt | Founder | Pro Cameras, HDV Camera, HD Camera, Sony, Panasonic, JVC, RED, Video Camera Reviews and for the BAYER sensor note that the colours of the alias rings are exactly as for the zone plates for Alans F3 tests. This suggests very strongly that the sensor not only does have the photosite count stated by Sony, but is also (as they say) Bayer, not Q67.

As I understand it, the beauty of Q67 should be that it doesn't offer a magical resolution increase over Bayer for a given photosite count - but for a video usage should mean high quality with far easier processing. It relies on being implemented with twice as many photosites as system resolution - so 2x1920x1080 photosites for a 1920x1080 system. See ProVideo Coalition.com: SONY Livewire | Vendor Chanel - each output pixel (bounded by white line) is formed from one unique green photosite, and two blue quarters and two red quarters. That seems far easier than Bayer processing, and will mean a direct 1080 output - no need for downconversion.

I also think it's important to realise that the subtle clues from zone plates aren't just generated by the sensor dimensions and layout - but by the way the photosites are read and processed. This becomes particularly true for DSLR video - zone plate patterns from something like a 5D are far from what the basic sensor layout would suggest!

Re: Upcoming hands-on comparison of F3, FS100 and AF100 from Philip Bloom
 

I too doubt the use of Q67 or Striped Filter.

But, if the sensor has about 4 million photosites and it is Bayer -- then what are the "specifications" that Juan says he cannot reveal?

One clue from Roberts' is that he notes is the MISSING extra strength of the Green signal which he says traditionally comes from the Bayer having twice the number of green photosites as either Red or Blue. This is why I assumed 8x8 Bayer photosites (with the extra Green sample) were combined into RGB pixels where all three signals had the same strength. The combining was, I assumed, also the way sensor sensitivity was increased.


There is a version of the Bayer filter that replaces one of the extra green filters with a translucent filter. This type of filter would show equal RGB signal strength AND, of course, the point of the translucent photosite is to increase sensitivity.

"The panchromatic pixels have no filter so they are at least a stop faster than the color pixels. Half the pixels are panchromatic so they provide the backbone of the image (a stand-in for the luma channel). First, interpolate the missing panchromatic values at colored pixelsites. Second, the RGB signals are treated like chrominance channels: R-P, G-P, B-P. Once they are interpolated and cleaned, they are added back to the panchromatic values and the result is hi-res RGB. There is a combined hardware / software paradigm shift. The panchromatic pixels provide the photographic speed and record the scene detail. Once the colors have been interpolated using the panchromatic values as a guide, the panchromatic record is cancelled out and the colors remain and the color errors are no worse than for the Bayer pattern."

Perhaps the sensor's extra sensitivity is a function of both the 4X larger photosites AND the translucent photosites.