Panasonic GF1 official

[Ben Syverson]

Panasonic unveils DMC-GF1 Micro four-thirds camera: Digital Photography Review

I'm not thrilled with AVCHD Lite... We'll see about the MJPEG.

[Chris Hurd]

Wow, very interesting. Thanks for posting this, Ben! I'll probably change the GH1 board to include this camera.

[Graham Hickling]

Does AVCHD "Lite" mean it will be restricted to 30P ... or could it possibly support 60P as well?

[Ben Syverson]

It's not totally clear... Here's what the DPReview spec sheet says:

AVCHD lite (three quality levels)
• Motion JPEG
• Mono sound
• AVCDHD: 1280 x 720, 60p (sensor output is 30fps) 9-17 Mbps
• MJPEG: 320x240, 640x480, 848x480, 1280x720 (all at 30fps)

60p, but sensor output is 30fps? Weird.

The MJPEG samples in DPReview's preview look pretty good though. Look at the pinwheel sample. Looking at it frame for frame, it doesn't seem to have any rolling shutter artifacts at all...

[Graham Hickling]

There was an earlier post, in the AVCHD forum, about another camera (I forget which) that was outputting "60P", but on closer inspection was generating identical pairs of frames ... so I guess that's what "30P at the sensor" produces.

Which is a pity, because my Samsung HMX-104 outputs genuine 60P ... so it is possible within the spec it seems.

[Paulo Teixeira]

You must be talking about the ZS3.



It’s still a good camera regardless but it’s disturbing that Panasonic decided to do that to this camera. Its almost as bad as Canon’s decision to put 1080 20p in the T1i. If it’s a technical issue than at least tell people why for example it appears to have the G1's sensor so maybe it‘s not really made for true 60p. Unless Panasonic wants to separate as much features from the GH1 as possible. I mean the GH1 has an articulating screen and a bundled 10x lens for crying out load. They don’t really need to do that if that was the case.

I still predict that theirs a good chance that the HD modes of the GF1 will look better than Nikon’s D300s HD video mode.


I just wonder how much the f1.7 lens is going to be separately because my GH1 will fall in love with it if they were to ever meet.

[Ben Syverson]

The f/1.7 is $399 and available for pre-order on Amazon.

[Wacharapong Chiowanich]

Originally Posted by Ben Syverson

60p, but sensor output is 30fps? Weird....

Whatever Panasonic says, 30fps output is 30fps output. The extra frames that follow the genuine ones do not help improve the actual image quality one bit. It, nevertheless, could confuse your NLEs as actual 60fps and make them recognize the footage as such. I can say this much since I have the Panasonic FT1 (the PAL-framerate version of the US. TS1) and TZ7 (ZS3), both of which have this peculiarity in their AVCHD Lite recording mode (50fps from actual 25fps).

The MJPEG mode is straight 30fps and this also looks to be the case for the GF1. Aside from a lack of the AVCHD Lite support from most major NLEs, this doubling-of-the-frame annoyance has made me shoot only in the MJPEG mode.

[Barry Green]

Originally Posted by Graham Hickling

Does AVCHD "Lite" mean it will be restricted to 30P ... or could it possibly support 60P as well?

My understanding of "AVCHD Lite" is that it's 720p-only, no 1080.

I believe AVCHD Lite includes 720/60p.

Sounds like the GF1 records 720/60p but that the sensor can only supply 720/30p, so therefore your recording would look exactly like 720/30p. You'd just have duplicate frames.

[Brian Standing]

Very, very interesting indeed. Here are my criteria for a second camera to complement my JVC GY-HD100:

- Be capable of shooting B-Roll for a 720 24p timeline;
- Small, light and portable;
- Allow for creative control of DOF;
- Allow for ambient light indoor shooting;
- Potential for an angle of view equal to or wider than 74 degrees;
- HD video record time limited only by size of media;
- Cineform Neo Scene compatible video format;
- Manual aperture, shutter speed and ISO control;
- (Optional) allow me to reuse my Pentax and Nikon SLR lenses;
- Cheap as possible.

I don't care so much about 1920x1080 or 60p, since I'm shooting 720 24p anyway.

This looks like it might fit the bill very nicely -- and at a better price (and hopefully better availability) than the GH-1.

[Steve Mullen]

Originally Posted by Wacharapong Chiowanich

Whatever Panasonic says, 30fps output is 30fps output. It, nevertheless, could confuse your NLEs as actual 60fps and make them recognize the footage as such.

The MJPEG mode is straight 30fps and this also looks to be the case for the GF1.

1) If you use OS X-based NLE's, you should have no problem with M-JPEG. In fact, even iMovie 09 can edit it natively. This is a huge advantage as there is no forced conversion from AVCHD to AIC.

2) I've found M-JPEG to look cleaner than AVCHD.

3) iMovie has been updated to support AVCHD Lite. It simply drops the duplicate frames.

4) It looks like Panasonic plans the future to be 720p60, but can't deliver the sensors yet at a reasonable price. Or, doesn't want to.

5) According to the Voltaic AVCHD software site -- the GH1 uses the AVCHD Lite codec. This makes perfect sense to me, as it explains the odd behavior of 1080p24. As I have posted before, the motion quality problem with 1920x1080 seems to me be an issue with the SIZE of the frame -- not the lack of B-frames or the bit-rate. I suspect Panasonic has used the Lite codec in the GH1 without any mention of doing so.

6) So the GH1 gives us a preview of what 720p60 will look like. Looks another year to wait -- or buy the GH1.

[Wacharapong Chiowanich]

Steve, do you mean the GH1 actually records 720/60p to the AVCHD Lite format (as opposed to AVCHD) and then the IP resizes and applies a pulldown to this 720/60p footage to output it as 1080/24p?

[Noah Yuan-Vogel]

i wonder what effect duplicate frames has on image quality at those low bitrates. if it were i-frame encoding, youd be wasting half your bitrate encoding redundant copies of the same frames (meaning 17Mbps would look like 8.5Mbps once the duplicate frames are removed). avchd im sure is smarter than this and doesnt have to record too much extra data to store the extra frames, but im sure something is lost, and 9-17Mbps is pretty low as it is...

[Steve Mullen]

Originally Posted by Wacharapong Chiowanich

Steve, do you mean the GH1 actually records 720/60p to the AVCHD Lite format (as opposed to AVCHD) and then the IP resizes and applies a pulldown to this 720/60p footage to output it as 1080/24p?

No!

I suspect that Pana has used the AVCHD Lite codec, but has found a way to feed it 1920x1080 frames rather than 1280x720 frames. If you understand how MPEG-2 gets encoded, the 2X more pixels requires 4 times more 8x8 macroblock search operations.

Since the codec can't do this -- Pana may have had to change to a 16x16 macroblock. This would cut the number of comparisons by 4 so the codec would do the same number of operations per second.

Of course, the use of 16x16 macroblock would cause the predictions to be far less accurate and so under rapid motion, video quality would drop -- even though the data rate was the same as for 720p60.

Obviously, Pana isn't going to reveal this modification. So they will suffer negative reviews of 1080p24 until they can get a new low-power FullHD codec into a camera.

IF I'm correct, the future holds a far better GH1 with both 1080p24 and 1080p30 as well as cheap AVCHD Lite cameras using 720p60. They need cheap CMOS chips that run at 60Hz and new FullHD codecs.

I'd bet on both by next year.

PS: Voltic makes AVCHD conversion software. Perhaps they discovered this when they added GH1 support.

[Graham Hickling]

QUOTE: "...the future holds ... cheap AVCHD Lite cameras using 720p60. They need cheap CMOS chips that run at 60Hz and new FullHD codecs. I'd bet on both by next year."

As I mentioned earlier, the Samsung HMX-100 series produces excellent 720p60 video for under $500. The Samsungs have other limitations (poor manual exposure control through a menu system, no external mic input, poor in low light, etc). But they can fix shutter speed at 1/60, and the video resolution beats my Canon HF10. They are underrated cameras, IMHO.