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Old Jan 18, 2007, 9:40 PM   #1
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My cousin bought the CA6, and my co-worker just came back from Taiwan with his new CG6 (costs about US$370 over there). Ibeg and beg and finally get my hands on all 3 modelsat the same time,only for one evening - mainly tocompare theirlow light video performance.

Here they are:

http://s2.quicksharing.com/v/693404/C6_400.MP4.html

http://s2.quicksharing.com/v/5122579/CA6_400.MP4.html

http://s2.quicksharing.com/v/9914324/CG6_400.MP4.html

http://s2.quicksharing.com/v/4907128/CG6_800.MP4.html

http://s2.quicksharing.com/v/1056918/CG6_1600.MP4.html

(Each file is about 17-18 MB, about 45 seconds long)

The video clips have the highest quality (TV-SHQ) setting, manually set ISO (in my C6, "400" = ISO 3600 in video mode; CA6 also has a max. setting of 400; CG6 has a max. setting of 1600 - I don't have the manualsso I don't knowwhat they represent in video mode), manually set WB ("incandescent"), and no anti-shake.

My roomis dark and illuminated bya 60W bulb (with lampshade, which makes it darker). The figurineis about 6-7 ft away.

I unintentionally tested two more things: (1) auto-focus (performance in dim light) (2) mechanical noise from the autofocus/ zoom.

Conclusion:

(1) There is definite improvement of the low light performance in the CG6. I assume the CA6 has the same internal components as the C6, but the CA6 video seems a tad brighter than the C6 (the lighting condition is exactly the same in all videos). There is not much difference in the CG6 videos at ISO 400, 800 and 1600 settings - maybe brightness is limited by the optics (max. aperture)?

(2) I find the C6 video smoother than the CA6 and CG6 - in the CA6/CG6 there seems to be more mosaic pattern in the background, especially noticeable when I pan. The edges of objects are also rougher. The image of C6 seems softer but has less digital noise by comparison. The video filesize turns out to be similar. Maybe a new compression algorithym is used in the CA6 and CG6?

(3) There is definitely less mechanical noise in the CA6 and CG6. The C6 sounds very grindy by comparison. You can hardly hear any noisefrom the CG6.

(4) There also appears to be improvement in the low light autofocus in the CA6 and CG6 - there seems to be faster acquisition and less hunting.

(5) Zoom speed: CG6 first, CA6 second, and C6 very slow by comparison.

Other things:

The CA6 and CG6 have a rocker switch for zooming, which I find too firm to operate smoothly. I like the silky smoothslider of the C6 much better.

The CA6 and CG6's larger LCD screens are nice!

It is true, there is no lens cap for the CA6!

The CA6 feelsa bitplasticky, but I guess it is for weatherproving. The CG6 is lighter and more plasticky than the C6.
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Old Jan 18, 2007, 11:48 PM   #2
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Wow, nice, really interesting, thanks for the tests! !

By the way, I looked at the ISO in the file's MP4 tags and they are all marked as having an ISO of 3600. I can't really see any difference between the three CG6 ones either.

Ouch, that lens mechanism noise is indeed much louder on the C6, faster and nicely quiet on the others.

I did a gamma correction test to bring the C6 image mean/median brightness levels up to that of the CG6. It's close, but the full range is not there. But I find the CG6 image too yellow, unlike the C6 consideringthe whitebalance is set to incandescent for both?


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Old Jan 19, 2007, 9:03 AM   #3
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I am quite sure I set the CG6's WB to "incandescent", because I remember the WB setting is right below the ISO setting in the menu (in fact the menus on all three cams are identical). Anyway I have returned the cams so I can't retest (at least for some time), sorry!

If the videos from all cameras have ISO 3600 setting, there must be higher electronic gain in the CG6 to boost the brightness - maybe this also boosts the amonut of digital noise (the mosaic pattern I described). When I say "new compression algorithym" I don't mean a new codec, I should say a "new 9 pixel mix algorithym to create the video from the CCD".

By the way, how do you read the ISO value on digital videos? I guess this is the equivalence of EXIF in JPEG still pictures, right? Both AVICodec and GSpot only give the codec information of the video.


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Old Jan 19, 2007, 10:03 AM   #4
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I'm actually manually reading, using a hexeditor,the ISO from the MP4 header tags. I found thetags & offsetsdocumented on anExifTool page, so perhaps that software can read them, I haven't tried it.

I also wonder howloosely the ISO ratings are applied, perhaps the guidelines, if any,are very general. Perhaps they are not a good measure of actual lux sensitivity? I don't know.
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Old Jan 19, 2007, 1:28 PM   #5
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Interesting test Blindsight. One thing though, the reason you don't see any difference between 400, 800 and 1600 ISO is that they all equals 3600 in video mode.

Here:

Ofcourse there is the lamp mode at 7200 ISO, but I don't find it useful as it adds to much noise.

Edit: image didn't work.
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Old Feb 15, 2007, 9:41 AM   #6
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Congratulations on the new CG6 blindsight , so now you can retest the WB. :lol:
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Old Feb 15, 2007, 2:54 PM   #7
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Thanks much for posting these videos!! :-)
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Old Feb 17, 2007, 10:53 PM   #8
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I repeated the color test with auto WB and incandescent settings. I don't think I made a mistake previously.

I think the reason there is so little autofocus/ zoom noise is because the microphone is now placed at the back of the LCD screen, which is far away from the body of the camera.

I think the CG6 is brighter than the C6 in similar low light, but at the expense of more noise.

P.S.

I also wonder what the "gyro sensor" stuff is all about. There is no mention about this in the user manual. Maybe it is something mis-translated from Japanese.

In "Specifications" under "Image Stabilization" - "Electronic (video clip recoding mode or still image playback mode only)".

When I read the "Shooting" section, there is no mention of any "still image stabilization" mechanism.

When I read the "Playback" section, there is a topic on "Correcting Camera Shake and Red-eye Reduction" - there is a "Blur Correction" function, which is processing of blurred pictures already taken and stored in the camera. I don't think this counts as "image stabilization" which works in real time.
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Old Feb 18, 2007, 11:06 PM   #9
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Thanks for the follow up, I'm very interested in your comparisons/tests/info. That is strange that "Blur correction with gyro sensor" in the specs.

About the microphones,they appear to basically be in the samelocation they were for the C6:
CG6:


C6:

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Old Feb 18, 2007, 11:55 PM   #10
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Thanks Caelum - I never looked at where the mic was placed on the C6, but now that I have sold it, I didn't realize it was also on the back of the LCD, :lol:. So it seems that they did reduce the mechanical noise or they somehow mask the audio pickup of this noise.

I do remember Steve's "Breaking News" mentioned about Sanyo using a new InvenSense Gyroscope as mechanical image stabilization for their new cameras (posted 11/9/2006). Quote:

Sanyo stated, "Image stabilization is becoming one of the most sought-after features by consumers when purchasing a camera. InvenSense's integrated dual-axis gyroscope is a key enabler of this feature and is already used within our current models. We have also chosen InvenSense to be the supplier of the gyroscope for many of our camera models next year."

I certainly did not find any IS mode for still images in the CG6 - in the manual under "Motion Compensation (Image Stabiization)", it clearly states that this is "compensating for unintentional hand motion (video clips only).





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