Sony unveils the EX3 successor: PMW-300

[Brent Kaplan]

can anyone explain what is meant as a place in the camera to hold sony wireless receiver?

[Joachim Hoge]

Only let down seems to me that its the same old sensor, just tweaking of firmware. I thought they would have come up with a new one by now?

Otherwise nice upgrade, but it took a bit too long I think.
But as always, one have to wait until o e can see some footage coming from this new baby.

My EX-3 was the best camera buy I did financially as it has paid it self many times over, but I don't think I will get the new one as I'm in a different place in life from where I was when I bought my EX-3

[Gints Klimanis]

The only let down? A MAJOR let down. Sensor or overall image quality improvement would be noted in the press release.

Since the EX1 in 2008, I've been waiting for an image quality upgrade EX1/EX3 upgrade to 1080p60 with a corresponding doubling of the recorded data rate. If delivering that quality requires a new lens, 2x/3x zoom or fixed focal length, bring that on as well. I'll buy.

[David Heath]

Originally Posted by Gints Klimanis

.............. I've been waiting for an image quality upgrade EX1/EX3 upgrade to 1080p60 with a corresponding doubling of the recorded data rate.

I thought the expectation was that the PMW300 WILL do 1080p/60.......... with the XAVC upgrade? [EDIT - Looking back on this thread, I see Alister Chapman says to expect more information about XAVC at IBC, so hopefully the 50/60p issue may get clarified there. Currently, the expectation seems to be we may expect the higher framerates, but we'll see.)

(And doubling the frame rate does not necessarily mean doubling recorded data rate - IF it's using a long-GOP codec. Principle is that the time interval between I-frames is kept the same, it's the number of difference frames that gets bigger.)

As for quality improvements, I'd considered that a year or so back it was the codec that was seen as the limitation of such as the EX1/3, the 1/3" front end that was seen as the limitation of the corresponding Canon and Panasonic cameras. What people were asking for was either a better codec (such as XDCAM422) in the Sony cameras, or a better (1/2") front end in the others. Surely that's now been answered?

[Jack Zhang]

We could face the possibility that 4K in 1/2'' may be next in line. Remember the NX5 4K prototype?

Sony would be fools not include the Exmor R (BSI) tech in a 1/2'' or 1/3'' 4K sensor. Throw in Global Shutter and that's a winner.

In the very least, BSI has to make it into the next iteration of cameras.

[Gints Klimanis]

Originally Posted by David Heath

(And doubling the frame rate does not necessarily mean doubling recorded data rate - IF it's using a long-GOP codec. Principle is that the time interval between I-frames is kept the same, it's the number of difference frames that gets bigger.)

I argue from the increase in image dimensions : 720p60 to 1080p60 entails a doubling of the number of pixels.

[David Heath]

Originally Posted by Gints Klimanis

I argue from the increase in image dimensions : 720p60 to 1080p60 entails a doubling of the number of pixels.

Doesn't really relate directly - that's why if you compress to JPEG in (say) Photoshop, then for a given quality the file sizes don't scale in proportion to the size of the image. (Try it -save a high res image as JPEG, then try downrezzing to half the size - so a quarter the pixels - then save as JPEG with the same quality setting.)

For 1080p/60, you really have to refer to 1080p/30 for equivalence. For the same per frame compression you need to double the bitrate if it's an Intra frame codec, but not for inter frame. In the latter case you need a lot less than double for equivalence for the reasons I gave above. This is why it's possible to code 50/60p in AVC-HD using about 28Mbs - far less than double 24Mbs.

[Jack Zhang]

I argue AVCHD 2.0's choice of bitrate. In the very least, Canon's XA20 and XA25's MP4 recording has 35Mbps, and the GH3 has 50Mbps Long-GOP (which is optimal)

AVCHD 2.0 handles low motion well, but once it comes to complex stuff like crashing waves, it falls apart.

[David Heath]

Originally Posted by Jack Zhang

I argue AVCHD 2.0's choice of bitrate. In the very least, Canon's XA20 and XA25's MP4 recording has 35Mbps, and the GH3 has 50Mbps Long-GOP (which is optimal)

I won't disagree with you about the bitrate of AVCHD 2.0 in absolute terms, it was only meant as an example of the principle - that with an interframe codec, you don't need to double the bitrate when you double the framerate. In this case, it's nowhere near double and it may well be argued that it needs to be more. (Same point could be made for normal AVCHD!)

It's also worth saying again that specifying the codec and bitrate doesn't definitively specify the quality level. All coders are not equal, and with all else equal it's possible to get better quality with a lower bitrate if a better design of coder is used. That's why broadcast coders for transmission are able to get away with such low bitrates and preserve quality. they're able to use more of the possibilities built into the spec. (Of course, you pay for it - a broadcast H264 transmission encoder will cost probably as much as a complete decent pro video camcorder!)

Taking your example of the GH3, then it's worth asking why the 50Mbs? Since it's primarily a stills camera, then at the price it's unrealistic to expect a very sophisticated encoder. That's no problem from a design point of view. Make up for it by upping the bitrate.

[David Heath]

Originally Posted by Jack Zhang

We could face the possibility that 4K in 1/2'' may be next in line. Remember the NX5 4K prototype?

I wonder...... I wouldn't underestimate the engineering challenges involved. Currently, all decent 1/2" and 1/3" cameras are 3 chip. Move to 4k and how possible will it be to align 3 1/2" chips? (Even 3 2/3" chips for that matter, let alone 1/3"?)

The alternative is obviously to go to single chip designs - but that brings other issues. Smaller photosites will impact on sensitivity, and going single chip must knock down basic sensitivity by over a stop in it's own right. Never say never, and maybe we will get 4K in 1/2" eventually. Whether the inevitable compromises will outweigh the "it's 4K!" appeal remains to be seen.

There are good technical reasons why the first 4K designs to be seen are all via a large sensor.

[Alister Chapman]

Back illuminated sensors only bring a useful advantage when the pixel,size is extremely small. That's why you only see them used on small sized single sensor cameras that have a high pixel density on a small chip. It's to do with the ratio of the size of the light gathering pixel to the rest of the electronics. On bigger chips there is no appreciable sensitivity improvement.

[Jack Zhang]

Originally Posted by Alister Chapman

Back illuminated sensors only bring a useful advantage when the pixel,size is extremely small. That's why you only see them used on small sized single sensor cameras that have a high pixel density on a small chip. It's to do with the ratio of the size of the light gathering pixel to the rest of the electronics. On bigger chips there is no appreciable sensitivity improvement.

Which makes it perfect for 1/3'' or 1/2'' 4K. I agree it would be pointless for BSI to be implemented on a Super35 or Full Frame camera, but if we want to go 4K while maintaining decent sensitivity on a smaller sensor, BSI is a no brainer. Current sensitivity figures would still require a 3-chip system to get decent sensitivity.

The JVC currently out there only has one part of the equation correct: the BSI sensor. The rest with poor optics completely nullifies the sensor resolving power. Even the 4 SDHC cards is a nightmare for redundancy/reliability.

Edit: Actually, there is a reason why BSI would be useful on a Super35 or Full Frame sensor: Better sensitivity for a Global Shutter sensor.

[Brent Kaplan]

can anyone explain what is meant as a place in the camera to hold sony wireless receiver?

[David Heath]

Originally Posted by Brent Kaplan

can anyone explain what is meant as a place in the camera to hold sony wireless receiver?

On most current shouldermount cameras there's a slot towards the rear of the camera where you can slot in a compatible wireless mic receiver. It makes for a neat arrangement, since the connector it slots into powers the receiver and connects the audio output to the camera - no having a receiver attached to the outside of the camera with trailing power/audio cables.

Slightly surprised to see the feature on a camera such as this for reasons of size etc.......

[Brent Kaplan]

I agree but I wish there was more info on this, like will sony offer a dual channel receiver that fits in this slot and doesnt use the external xlrs, Im familiar with this set up on pmw-800