Would you consider the EX3 and the HPX500 competitors? Are they aimed at the same users?
Both record to memory cards, both have interchangable lenses. The HPX's 2/3" chips are a big plus, but they use pixel shifting, whereas the EX's 1/2" CMOS chips are true HD. Is the SXS system better than the P2 system? Is DVCPRO HD at 100mbps superior to XDCAM's 35mbps?
I'm not bashing either camera. That's why I'm asking this in the HD "generic" forum. I'm neutral to either, but I'm wondering if they're comparable. Price-wise, they're not that far off. Perhaps the XDCAM HDs are more on the same level with the HPX?
Or, if you could afford either, which would you buy?

Same thoughts here. I'm looking at something for personal projects, so don't want to spend megabucks on HPX3000/Varicam etc. plus £30,000 or so on HD lenses, so looking at HPX500 and EX3.
I've got a shoot over the next few weeks where I'll have a Varicam kit including HD monitor, so before I head off I'm going to do some tests as I have an HPX500 and EX1 here. Will post results if I get any of use.
From what I've seen of the HPX500 so far it's picture has a nice gentle look to it, but it does seem a little soft, especially in 720 mode. Also the viewfinder is awful, impossible to follow focus pn moving subject.
Steve

Steve,

With regards to softness, do you think some thoughtful sharpening in post would improve the percieved detail?

Or help it get close to the EX-1/3 level of detail?

I use Panasonic 1/2" chip DV cameras and have learned over time the best image is when I dial back the in-camera detail and sharpen inside of Edius.

Thanks

I'm sure it'd help, but it does have the feel of something that's been blown up a bit from a small original (ie the sensor)! Will compare with the Varicam over the weekend I hope.
Steve

Is the image from the HPX that bad? I've seen a short film posted on this website shot with the Panny and it looked very impressive.

On a side note, we just ordered an HVX200 for our production company. The sales guy we talked to swore the XDCAM EX1s were nothing more than "glorified HDV" (his words) and that the Panny's 4:2:2 color sampling would produce better, more colorful images after it was broadcast. I have my doubts, comparing 1/3" CCD chips to 1/2" CMOS chips, but we'll see.

I don't think I said that the HPX500 image was "that bad", just that it looked slightly soft. Could be any number of reasons for this, but I know the Varicam is top quality so when I get the two side-by-side I'll get a better idea of how the 500 looks.
I must say that the image quality from the EX1 I tried briefly was tremendous, a really nice quality to it as well as sharp. Not sure you need to look much at chip size (1/3" vs 1/2"), more the codec, pixels on the chip and how they're processed.
Steve

"glorified HDV" (his words) and that the Panny's 4:2:2 color sampling would produce better, more colorful images after it was broadcast. I have my doubts, comparing 1/3" CCD chips to 1/2" CMOS chips

Yeah right.... Go find a dealer that KNOWS what he's talking about, that single statement is nothing more than marketing talk. The XDCAM codec is quite different to HDV and there are pro's and con's to both the DVCPRO HD codec and EX Mpeg Codec so you cannot make such a sweeping comment. Besides if that really was the case then I doubt Discovery HD would have approved the EX for 100% broadcast whilst only allowing 20% HVX200.

What makes Discovery HD the pinnacle of HD aquisition? I agree; the EX1 produces better images than the HVX. But now with the new update I believe the HVX has narrowed that gap considerably. Considering that the HVX 200A is over $1K less in price, that now makes it a hard camera to pass up.

With regards to the HPX 500, I believe the 500 looks better. But really it's apples and oranges when comparing those two cams: 2/3rd inch sensors vs 1/2 inch, shoulder mount vs handheld, DVCProHD vs MPEG 2 long GOP, global shutter vs rolling, and over $10k vs under $7K. I don't think you can call those two competitors. I believe the EX1 and 200A are in the same league and are competitors.

Because Discovery HD IS considered the pinnacle of HD acquisition. It has ben generally recognized as having the toughest standards in the industry. If you can pass muster with them, you can go anywhere with your camera. According to what I've just heard, the HPX is NOT cleared for full acquisition for D-HD, but the EX3 and EX1 are, if that matters to anyone. I know, "Deadliest Catch" is shot with the "lowly" Sony Z1, so I guess there's always exceptions.

I was asking whether the EX3 was comparable with the HPX, not the EX1. I agree, the EX1 is more aimed at the 200a.

Still can't make my mind up about the HPX500. Just had a look at some side by side shots with the Varicam and I'd say that when the HPX500 is set to 1080 then there's not a lot in it. But at 720 (ie if you want the variable frame rates which I do) it does look pretty soft.
The colour quality and overall look to the pictures is nice. The main problem is that the HPX viewfinder is dreadful, have yet to try the optional 2" one, but at about £2000 it'd add significantly to the cost.
Also did some comparisons with HD and SD lenses. I've got a Canon HJ11x4.7 and HJ18x28 and tried them against a Canon J14.5x8.5 (quite old SD lens). On the whole the HD lenses were better, but not by leaps and bounds.
Sorry I can't give a bit more by way of detailed and scientific analysis!
Steve
ps I must say that after using P2 for a bit, it felt a bit odd messing about with tapes!

I guess what we need to do is get all these different cameras side by side and do some real world tests. Paper specifications are one thing but real world tests are the only way IMHO to discover what each camera is good and bad at.

On the lens front it is much less clear cut. With some HD lenses being no better than 10 year old SD lenses you absolutely need to try before you buy. I have an ancient 14x Fujinon with a 2x extender that seems to be almost as good as my 20x HD Canon lens, it's certainly better than my 4 year old Fujinon Aspheric IF SD broadcast lens!

Once you go file based for any period of time tape just seems clunky and awkward. Can't believe that I used to spend days digitizing tapes for edits. Now I just pop in a disc or card and off I go.

I agree; the EX1 produces better images than the HVX. But now with the new update I believe the HVX has narrowed that gap considerably. Considering that the HVX 200A is over $1K less in price, that now makes it a hard camera to pass up.
Picture quality is one matter - a true manual lens another. And a lot of people would feel that in itself is worth a lot more than $1k, over a camera with servo driven controls. Add in other factors, and it becomes quite easy to pass up the HVX200A for an EX1.

The manual lens controls are worth $10,000 if your ask me! How long has it taken for Sony to hear what thousands of people have been saying for years - servo lens controls are somewhere between dreadful and unuseable!
Apart from the focus ring being a little slim, the manual lens controls on the EX1 are really good.
Steve

Picture quality is one matter - a true manual lens another. And a lot of people would feel that in itself is worth a lot more than $1k, over a camera with servo driven controls. Add in other factors, and it becomes quite easy to pass up the HVX200A for an EX1.

Yea... and a lot of people would feel that the servo lens on the HVX200A, although not perfect, is good enough.

The point that I was trying to get across is before the HVX went through its update, there wasn't any contest; the EX 1 was the only consideration between the two. But, now, those with a limited budget will take that extra look at the HVX because of the lower price and basically... it's good enough.

Now if the budget is there, the choice is easy in my opinion; it would be the EX 1 for the lens (as you brought up), the 1/2 inch sensors, and HD-SDI out.

The HPX's 2/3" chips are a big plus, but they use pixel shifting...Pixel Shift is a benefit, not a drawback. It's something you want. Most all three-chip cameras, with very rare exceptions, use Pixel Shift or some other form of pixel offset technology. It's very much a good thing, not a bad thing.

... whereas the EX's 1/2" CMOS chips are true HD.Not sure what you mean by "true" HD, but I don't think it's been conclusively stated that Sony isn't using some form of pixel offset in the EX series. They haven't said they are using it, but neither have they said they're not using it. Pretty much a non-issue relative to other major differences anyway.

Deepest respect Chris, but not sure I understand that one! It does come across there that you're saying that a camera with pixel shift is preferable to one without, so the HPX500 block is preferable to the HPX3000. Presumably you mean better to pixel shift than just stay at 950x540?
Steve

It does come across there that you're saying that a camera with pixel shift is preferable to one without...I sure hope it comes across that way, because that's exactly what I mean!

It's always better to use some form of pixel offset in a lower-cost three-chip design. It's very rare for a lower-cost three-chip camera *not* to have it -- the most notable exception is JVC's Pro HD line. Sony hasn't stated one way or the other if it's used in the EX line.

JVC's marketing spin is that because their chips are 1280x720, they don't require pixel offset. The truth is that their particular design can't use pixel offset because of the way their DSP works. Otherwise they would have used pixel offset just like every other sub-$15K three-chip design.

The only time pixel offset is controversial is when it isn't there.

Except in things like the HPX3000, which doesn't need it 'cos it's already 1920x1080?

The HPX3000 ain't no sub-$15K camera. It lists for $48,000 and that's just the body only.

But I've read nothing from Panasonic stating it doesn't use pixel offset. I wouldn't be surprised if it had, in addition to its 2.2MP native 1920x1080 chips, H-axis pixel shift as well. There's a Panasonic seminar this week at HD Expo in Chicago that covers the HPX3000, so perhaps somebody here can ask Jan or whoever the presenter is for a definitive yes-or-no answer. If they can't say no for sure, then most likely it has H-axis Pixel Shift on top of the native res.

We need to get back on track. Who cares whats magic it uses. All we are here is find out which one makes nicer pictures.

Steve I din't quite understand your post about the varicam and hpx. Where their images similar? Isn't the varicam only 720?

Basically from my understanding the EX's are sharper will the HPX has a nicer look.

I am actualy really intereted in this sence, I am also tring to decide between the two cameras

Well Chris, sub $15k sure, but that's not what it said in your original post!
Andrew, the Varicam is 720 but actually has a higher pixel count than the HPX500, even though the 500 can output 1080. Varicam is one of the defacto standards for high end broadcast (Planet Earth etc.) so I think is a good benchmark. To me the pics from the HPX500 look very pleasant (good colour, highlight handling and gentle gradation), and in 1080 mode look possibly about as sharp as the Varicam, but in 720 mode they do look quite a bit softer to me, so ruling out the use of 720/50 or 60P for slomo (main highlight of the Pana cameras for me).
Steve

Thats weird I allways heard the 500 looked better in 720 because that was closer to the pixel count.



I'm wondering if an HPX 500 would be sharper than an EX with a 35mm adaptor.

According to the Sony brochure the EX1 sensors have 1920x1080 effective picture elements. Not exactly sure what that means but implies that they use full raster imagers.

It's not even close Andrew, 1080 is a lot better than 720 on the HPX500. Strangely enough, without any prior knowledge I had the same thoughts as you though!
Steve

...the EX1 sensors have 1920x1080 effective picture elements. Not exactly sure what that means but implies that they use full raster imagers.Indeed, that was never in doubt.

Should of read your post better Chris. I did hear from one of my Sony contacts that the EX1 does not use pixel shift, but i would not take that as gospel.

"New 1/2" Exmor CMOS Sensors with 1920 x 1080 effective pixels each - no pixel interpolation necessary."

http://pro.sony.com/bbsc/ssr/cat-broadcastcameras/cat-xdcam/product-PMWEX1/

****************************************

I hate it when they use terms like that, but the no pixel interpolation wording should mean it's full raster.

(You can give me the HPX30000. I won't complain.)

I am betting that the HPX 500 in 720 varispeed would intercut just fine with 500 1080 footage. right?

No, not from what I've seen, it'd look quite obviously softer.
Steve

Getting back to the EX3 or HPX500. Considering that they're both about the same price (or seemingly will be about the same price), I would go with the HPX500 primarily because of the larger sensors. Of course, if you have to capture images in tight areas, the EX3 would probably be the best choice. I guess it all depends if you need a shoulder mount or a more compact camera.

I don't know what's up with the softer image in 720p as some have indicated on this thread. I did not notice it when I demo the unit. Of course, it has been awhile, and I didn't have any side-by-side comparisons. Maybe someone can send some screen shots of 1080i and 720p from the HPX500, so we can see the difference.

I would think it would be 1080p and 720p where the differences would show up.

Yes Tim, I tried 1080P vs 720P, don't think anyone shoots in 1080i anymore!
John, don't see myself why you'd prefer 2/3" chips over 1/2" really, unless it affected the image quality. Yes you get a bit more light gathering (though I'd guess the EX1 and HPX500 are not too disimilar), theoretically you get less noise (but again I don't think that's the case EX1 vs HPX500). You can get wide angle lenses for the EX1 so no problem there. If you want shallow dof then neither are really going to give you that so on either of them you'd want to use a Redrock/Letus etc. On the other hand if you want telephoto the 1/2" chip's a winner as you get about 50% more magnification. Plus smaller chip smaller lighter lenses, smaller lighter camera, less power draw so smaller lighter batteries.
The only concern over the EX series I have is the rolling shutter. I didn't like what I saw when I tested it, but so many people seem to think it shouldn't be an issue that I'm going to look at it again.
Steve

Pixel Shift is a benefit, not a drawback.

Not sure what you mean by "true" HD, but I don't think it's been conclusively stated that Sony isn't using some form of pixel offset in the EX series.

Could you explain further what you mean? I'm not sure I see how pixel shift is preferable over full resolution sensors. By full resolution I mean RGB sensors that are each natively the same or greater resolution compared to the luma res of the output video format. Usually pixel shift is used to make up for sensors being low resolution. Do you mean you prefer to have lower resolution sensors because bigger pixels potentially allow better light gathering and greater dynamic range? This doesnt seem to be the case with the HVX as from what I can tell it is bit noisier (less sensitive, less latitude) than most of its competitors (canon, jvc, sony).

i would imagine the less interpolation needed, the better. seems like the ideal would be a camera that has as close to the ~6million photosites used by 1080p yuv444 as possible. a single sensor full HD camera would have 2million photosites. HVX and HPX have 960x540x3= ~1.5million photosites doesnt really seem like enough to get the job done even with interpolation and shifting.

I'm guessing by "true" HD what is meant is fullHD (1920x1080) or at least natively some standard HD delivery resolution so as not to require scaling (1920x1080 or 1280x720)

Could you explain further what you mean? I'm not sure I see how pixel shift is preferable over full resolution sensors.
Resolution measurement is far more complex than simply stating a simple number, it will tend to "tail away" rather than suddenly go from perfect to nothing at a certain point.

And THEORETICALLY there is the benefit to using pixel shift with full raster 1080 sensors such as the EX uses. It should mean that the "tail off" is less than if not used, even if the maximum resolution is still limited by the system. To put it another way, to mean the contrast of fine detail is improved, even if no finer detail can be seen. I believe what Chris is trying to say is not that low-res chips with pixel shift are better than full raster res chips, but best of all is full-res chips TOGETHER WITH pixel shift - at least in theory - and I'd agree.

PRACTICALLY, I doubt it would be used (at least for a camera of this price range), since the signal processing demand then is just likely to be too high to be realistic - likely to need one working at 3840x1080 for H shift alone. Use lower than full raster chips, but full raster signal processing, and pixel shift becomes a viable proposition.

All else equal, will 960x540 chips with pixel shift be better than 1920x1080 chips without? A resounding no. Will they be better than the same chips, but pixel shift not used? A resounding yes.

Resolution measurement is far more complex than simply stating a simple number, it will tend to "tail away" rather than suddenly go from perfect to nothing at a certain point.Indeed, and thanks for stating it so well. It seems that some people tend to obsess over a single particular spec, such as the number of photosites on a chip, instead of considering the entire system. It's much easier to just focus on pixel count, but that's not at all a very accurate way to assess image "quality" or capability to any real degree.

For example, I own two vehicles that have 23hp engines. Since they're both 23 horsepower, does that mean they both have the same capability? No. Because one vehicle is a little riding mower with a 46" cutting deck and the other is a much larger farm tractor with a five-foot shredder. I can use one 23hp vehicle for working only around the yard that surrounds my house. It can't work where the other 23hp vehicle can, which is out on the rest of the property where the grass is tall and thick with huisache. Also, one of my 23hp vehicles -- the farm tractor -- can pull the the other 23hp vehicle with ease, but the riding mower would have a hard time pulling the tractor. Their 23hp engines are alike only in one specification on paper, and that spec doesn't really mean very much in a real-world comparison.

If you consider only a single spec -- such as the number of photosites on a chip -- you're not getting an accurate assessment of what the camera can do. In fact, it can be very misleading. As David smartly points out, it's much more complex than that.

Consider the idea of "full HD" or full-raster chips. The photosite count might be there, but that certainly is not the resolution you're actually getting from those chips. Remember you have to consider the *entire* chain, not just one spec. There's an optical low-pass filter on the face of the prism block (or the face of each chip) which cuts resolution -- on purpose -- in order to avoid Moire and other aliasing issues. The OLPF is easy to forget about when discussing sensor resolution, but it guarantees that a full-raster chip isn't really getting a full-resolution image. And it's made that way by intentional design.

The other factor easily forgotten is that a CCD is an *analog* device. It's outputting voltage which is then converted into a digital signal further down the chain. Because it's analog, the number of photosites doesn't have to equal the number of pixels in the recording or display formats. The bit depth and efficiency of the A/D converter, not the sensor itself, is what makes the pixels that are to be recorded. You could have three cameras each recording to the same format but with a different number of photosites on their sensors: one with less photosites than the resolution of the recording format, one with the same number as the recording format, and one with more. The actual quality of the recorded image will be determined by a number of factors, from the MTF of the lens to the efficiency of the A/D converter, and it's easy to have a situation where the camera with fewer photosites delivers a better image, because it's a complex process with many variables to consider other than pixel count.

[ Re: (http://www.dvinfo.net/conf/showpost.php?p=848070&postcount=7) The concern over sensor resolution is misplaced. Even the full 1920x1080 chips aren't receiving that much res from the glass. Remember there's an OLPF (optical low pass filter) on the face of the sensor, so even if the glass in the lens really does resolve that high, that's not what's reaching the chips -- and that's by design. What happens at the sensor does not ultimately define the image. Far too many other elements affect the process. ]

I believe what Chris is trying to say is not that low-res chips with pixel shift are better than full raster res chips, but best of all is full-res chips TOGETHER WITH pixel shift - at least in theory - and I'd agree.What I'm trying to say is that you could also have a situation where a lower-res sensor block with pixel offset might actually be better than a higher-res sensor block without. The bottom line really is that there are too many variables along a very long chain (from the differences in the glass to the differences between recording formats) for the photosite count, or the presence or lack of pixel offset, to be that much of a real-world issue.

In other words, the critical pre-purchase question should not be "does this camera use pixel shift?" but rather "how does this thing feel on my shoulder?" and "do I like the image it makes on an HDTV display?"

But yes, a very good situation would be where the sensor res plus pixel offset is greater than the native recording res. This is how the sensor block works in the Canon XH and XL line of HDV camcorders: their chips are native 1440x1080 (which is the resolution of HDV2 or, for that matter HDCAM) plus they also employ H-axis Pixel Shift for a resolution boost equaling about 1920x1080. The problems encountered when going much beyond this are primarily the limitations of processing power and cost. That's why I refer to sub-$15K or sub-$10K camcorders, because when there's such an obvious cost limitation, you run into a wall in terms of processing capability and efficiency. Pixel offset, in one form or another (whether it's H-axis, dual-axis or ClearVid), is understandably a big advantage where cost is a factor. In fact it's an advantage for all three-chip systems, but the reason why some native-res chipsets aren't using it is due either to a processing limitation (such as JVC ProHD) or a cost limitation (most likely with Sony EX), or both. Marketing spins this as "we don't need pixel shift." Well, relative to lower-res three-chip systems that do need it, that might be true. But the reality is that lower-costing native-res three-chip systems would also benefit from it as well, but they can't afford to include it.

There's an optical low-pass filter on the face of the prism block (or the face of each chip) which cuts resolution -- on purpose -- in order to avoid Moire and other aliasing issues. The OLPF is easy to forget about when discussing sensor resolution, but it guarantees that a full-raster chip isn't really getting a full-resolution image. And it's made that way by intentional design.
Chris - what you say above is true, but an optical low pass filter SHOULD be designed such that a chip doesn't receive any more resolution than it's pixel dimensions. So for 1920 H pixels, no more than 1920 lines of resolution should pass through, but for a chip with 960 H pixels, it shouldn't pass more than 960 lines. Use the 1920 LPF with a 960 chip and it will do nothing at all to limit aliasing.

Which is a problem - because if you want to make a design with (say) 960x540 chips, and you want to stop all aliasing with optical filtering, you will inevitably filter off all the detail that pixel shift techniques depend on!

So what gives? My understanding is that in practice optical lpf's only exist on the top end of the market. For sub $10,000 cameras, their use is just not viably justified for the improvement it gives. The hope is that the lens performance tails off to suit anyway, but the unfortunate truth is that the better pixel shift works within a design, the worse an aliasing problem it is likely to have.

And the most unfortunate aspects of aliasing only really come to light with motion, as aliasing artifacts move in the opposite direction to the moving object! Bad enough in itself - but made even worse if you then put it into a motion sensitive coder. And even more unpredictable if it gets recorded and edited on I-frame only codecs, then coded to a lowish bitrate long-GOP codec for transmission. The artifacts remain relatively "hidden" through the production process, but come out to bite at the last moment. Nasty.

The other factor easily forgotten is that a CCD is an *analog* device. It's outputting voltage which is then converted into a digital signal further down the chain. Because it's analog, the number of photosites doesn't have to equal the number of pixels in the recording or display formats. The bit depth and efficiency of the A/D converter, not the sensor itself, is what makes the pixels that are to be recorded.

Technically speaking, a light switch is analog. Obviously, it's not meant to be used in that manner either. The analog argument works very easily for recording media such as Hi8 vs. Digital8; it is more difficult to make for an imager with such a discrete signal. But, going back to our light switch, is the signal really so discrete? Generally, for this application, it is (not so for the light switch as the bulb and high voltage does some of the debouncing for us). The analog signal path on a modern camcorder is relatively simple, with heavy emphasis on "relatively." After a certain milestone of complexity, digital signal processing is cheaper than its analog counterpart.

The majority of the work is done to the digital signal, hence the bragging rights for 12/14/16bit DSP processing. The reason we do care about in-cam settings is because they occur prior to encoding/compressing the signal, the point of no return. Compare this to a raw output, where all you really care about is exposure, focus, and shutter.

The point: Chris is right that there is quite a bit going on between the imager and the output. Relying only on imager specs is not going to give a good comparison. How many people would argue that glass is just as important?

The EX3 will win the resolution test. But the HPX might win the subjective audience 'image quality' test because DVCPROHD is easier to grade in post and 4hr of color correction may render a 'nicer' image. With no time limit, the EX3 might win in post, I'm not sure.

These cameras should be compared in terms of their format and workflow. The rolling shutter is a huge factor as well.

there's an OLPF in front of almost every digital sensor in every camera. it's just a blur filter. sampling won't quite work right without it.

pixel shifting does the same thing that a bayer array does. in both single and 3-chip designs you have to interpolate colors from the 3 sensors. except i'd argue that you get a better fill-factor with pixel shifting.

graeme nattress makes some good comments about these things:
http://luminous-landscape.com/forum/index.php?showtopic=20367



So what gives? My understanding is that in practice optical lpf's only exist on the top end of the market. For sub $10,000 cameras, their use is just not viably justified for the improvement it gives. The hope is that the lens performance tails off to suit anyway, but the unfortunate truth is that the better pixel shift works within a design, the worse an aliasing problem it is likely to have.

And the most unfortunate aspects of aliasing only really come to light with motion, as aliasing artifacts move in the opposite direction to the moving object! Bad enough in itself - but made even worse if you then put it into a motion sensitive coder. And even more unpredictable if it gets recorded and edited on I-frame only codecs, then coded to a lowish bitrate long-GOP codec for transmission. The artifacts remain relatively "hidden" through the production process, but come out to bite at the last moment. Nasty.

Technically speaking, a light switch is analog. Obviously, it's not meant to be used in that manner either. The analog argument works very easily for recording media such as Hi8 vs. Digital8; it is more difficult to make for an imager with such a discrete signal. But, going back to our light switch, is the signal really so discrete? Generally, for this application, it is (not so for the light switch as the bulb and high voltage does some of the debouncing for us).

Sorry Jad, but I have to disagree there. A light switch is a digital device. It has two states. It passes all the current, or none at all. Two states... 1 or 0, on or off, true or false, yes or no, etc.

A rheostat (dimmer) is an analog device which passes a variable amount of current. A stylus on a turntable is an analog device. They have continuously variable output.

CCD sensors are analog devices. A photo site on the ccd is really a photo transistor. Within limits, the output current from each transistor is proportional to the light striking it. IOW a continuously variable output.

True, the signal does not stay in analog form for very long as it hits the A/D converters, but it does start out that way. And as you rightfully pointed out, the number of bits used to convert that analog signal have an impact on image fidelity as in.... how many discrete numbers are utilized to represent a given voltage level from each photosite.

But as Chris points out, these are but one part of the chain and what comes out the tail pipe is what counts.

-gb-

CCD sensors are analog devices.
Is a CCD analogue or digital? I tend to think of it in four dimensions - width, height, time and output level. Of those I'd say three are digital, and one analogue. Width and height are digital because the photosites are discrete (unlike a tube), time is digital because the chip gets sampled every frame or field, but the output is inherently analogue, only subsequently becoming digital via an A-D convertor.

Compared to a tube camera, it's the digital nature of width and height (discrete pixels) that makes it prone to aliasing.

Sorry David, CCD and CMOS image sensors are strictly analog.

In fact most of the signal processing chain is analog. It doesn't become digital until the A/D output.

Edit: Upon re-reading your post I can sort of see what you're getting at, but we really don't want to confuse people here. I've run into a lot of folks who have a hard time believing that these image sensors are not only analog, but monochrome as well.

Well, I couldn't put off the $2k rebate Panasonic was offering. The 500 ended up being $7999 after rebate...thats incredible. Also found a sweet HD Angenieux wide angle HD lens. The combo is amazing.

I love you :')

by the way was that lens over 10k?

by the way was that lens over 10k?

If I bought it new, it was, but I didn't buy it new. And quite honestly, I think it blows away any of the "kit" lenses.

most definatly.

I have been looking for an economic wide angle for sometime now. I think that's still a little out of my range though. Maybe end up with an SD wide. or a converter on the front of a standard.

I actually tried a nice broadcast SD lens on the HPX, and it looked DARN good!

Yeah I'm not comfortable paying more than half the camera price for a lens. So maybe 4k should get a nice used wide SD lens.

If not could always go with a canon standard zoom for 2k. I mean they put those on brand new D55ws.

there's an OLPF in front of almost every digital sensor in every camera. it's just a blur filter. sampling won't quite work right without it.
I'll agree with the third statement, but not the other two. A true OLPF is NOT in every camera, only in the more expensive ones - and that's why (as you say) the sampling for cameras in the low/mid price range doesn't work quite right! (At least compared to the more expensive cameras.)

It's not "just a blur filter", but rather a birefringent filter. (See http://en.wikipedia.org/wiki/Birefringence .) A simple blurring filter would not be able to reject alias frequencies sufficiently without severely affecting wanted resolution - the response of the birefringent filter rolls off far more sharply, and can be controlled (to match the sensor) by getting the thickness right. Hence they are expensive, hence only used on higher end cameras.

All this is far from academic when you compare two cameras with 960x540 pixels - the HPX500 has an OLPF, the HVX200 doesn't. Hence the HPX500 may actually seem slightly softer than the latter - but has far less aliasing than the HVX200, and is better overall. You get what you pay for. As Chris reminds us many times, there's more to cameras than simple pixel counts, and here we're dealing with two cameras with identical pixel counts!

The advantage of 1920x1080 chips is that as well as naturally improving the resolution, they ease the aliasing problem by doubling the spatial sampling frequency. The downside (compared to 960x540 chips) is each photosite being smaller, all else equal. Which is why the EX1/EX3 moving to 1/2" chips, in a form factor more normally reserved for 1/3" cameras, is very clever indeed.