View Full Version : 720p e-t-c
Martyn Hull March 1st, 2011, 03:39 AM Its a shame the GH2s E-T-C loses quality in recording in 720P unlike the other two frame rates
YouTube - E-T-C TEST.mp4 (http://www.youtube.com/watch?v=c7tecfq_830) a test i did showing E-T-C in 720P with it on and off,there are only a few clips with E-T-C off.
Gediminas Sulcas March 1st, 2011, 08:54 AM y it is, with e-t-c mode u loose quality, but i see same at 1080 24p. i think everyone who has gh2 or even t3i, can say the same. Still there is some situation its nice to have this mode.
Martyn Hull March 1st, 2011, 10:36 AM Do you meen you see the same yourself using E-T-C in all the frame rates on the GH2 ?, i only notice E-T-C degradation in 720P frame rate myself.
Gediminas Sulcas March 2nd, 2011, 03:45 AM i didnt test it on 720p, i only tryed at 1080 24p. U can try test like, take some close up picture with etc. Then move camre closer to object, to fit same frame without etc. And u definitely will see different. I didnt look after converting footage, but i guess it still will be same. with etc i dont like that "blinking pixels" at non focus area.
Martyn Hull March 2nd, 2011, 03:54 AM Interesting i will do tests in other frame rates, I think you are the first to see problems with E-T-C exept in 720P, interested what others find.
Waldi Krasowski March 3rd, 2011, 01:25 AM I think it is only an impression of degradation in ETC mode. Except of ETC mode the image is taken from the whole 18Mp sensor and then downscaled, so pixels become tight/dense. But in ETC you get an image 1:1 as it really is - without downscaling therefore you may think the image quality is degraded.
Martyn Hull March 4th, 2011, 10:34 AM Your right even in 24P there is more noise on the picture at the same angle of view using E-T-C i dont know about resolution though.
Martyn Hull March 7th, 2011, 02:18 AM Here is a 24P E-T-C test set at around the same zoom,there is deffinately more noise and slightly less resolution in E-T-C IMO YouTube - TESTING GH2s E-T-C MODE AT 24P FRAME RATE.mp4 (http://www.youtube.com/watch?v=rje_9Dzta-k)
Waldi Krasowski March 8th, 2011, 02:14 PM I must disagree. The resolution of the sensor is fixed! And the real resolution you see in ETC mode, as it is 1:1 pixel to pixel. Without ETC you get downscaled pictures/frames, what makes them only LOOK better, but does not provide higher resolution. In downscaled pictures pixels are packed tightly, therefore seems to have higher resolution.
Kin Lau March 8th, 2011, 07:26 PM We know that noise/grain, aliasing and moire gives you false resolution/detail, and that ETC removes much of the last two.
So ETC may seem to be getting less resolution/detail, but it's actually real detail. Perhaps a different profile, with contrast and sharpness dialed up a notch or two might help.
On the 1st 720p clip tho, it looks like a bit of camera shake and thermals are also robbing you of resolution.
Gaetano Capolino March 9th, 2011, 03:28 AM From the DVXuser's member mpgxsvcd:
-- I need to break this down into Horizontal and vertical resolution because the ranking is different for each one.
Horizontal Resolution:
1. 1080p - about 900 lines
2. 1080i and 720p - 800 to 850 lines
I think horizontal resolution is limited much more by the scaling than by final output resolution.
Vertical Resolution:
1. 1080p - 800-850 lines
2. 1080i(Not deinterlaced - Static scene) - 750 lines
2. 1080i(deinterlaced with Yadif deinterlace in VLC) and 720p - 650 lines
Please note that 1080i not deinterlaced is not a realistic scenario because it would have serious interlaced artifacts. It was included to show that 1080i does not contain as much resolution as 1080p period!
Horizontal Resolution:
1. 1080p ETC and 1080i ETC - 750 lines
2. 720p ETC - 600 lines
Vertical Resolution:
1. 1080p ETC - 800 lines
2. 1080i ETC and 720p ETC - 600 lines
As you can see the 720p mode is not desirable for resolution in the ETC mode. That is understandable since it starts with so much less resolution. --
Stand to his findings, in ETC mode, resolution is somewhat lower than in standard mode.
Waldi Krasowski March 9th, 2011, 03:37 AM First of all - how these horizontal and vertical resolution has been measured? With what tools and technique? How it could differ if ETC is just an output of image taken from a center part of the the same sensor? Physically same sensor having the same number of pixels per raw and column all the time, no matter if ETC is used or not.
Better resolution in downscaled image is just an impression. Take any picture of the size about 18Mp and downscale it to about 2Mp and you will see how the resolution is "improved"...
Martyn Hull March 9th, 2011, 11:40 AM Its a job to judge any loss of resolution with 24P and E-T-C but it puts extra noise without doubt on the picture.
Jim Snow March 9th, 2011, 01:15 PM Here is a 24P E-T-C test set at around the same zoom,there is deffinately more noise and slightly less resolution in E-T-C IMO YouTube - TESTING GH2s E-T-C MODE AT 24P FRAME RATE.mp4 (http://www.youtube.com/watch?v=rje_9Dzta-k)
Thanks for posting this clip. Unfortunately after Youtube finishes mangling it, the comparison is totally obliterated. Youtube's compression artifacts are orders of magnitude greater than the sample clips. A good way to show clips like this that will be used for critical comparisons is a service like Dropbox where actual clips may be made available for people to download and view with a player on their own computer.
Martyn Hull March 11th, 2011, 02:01 AM Mine plays clear with youtube and i plyed it on a friends pc its as clear as the file plays, a bit slow to buffer qith my broadband though.
Waldi Krasowski March 13th, 2011, 03:34 PM Golden eye on Vimeo
here is a sample of 720p e-t-c, I can't see any image or resolution degradation.
Martyn Hull March 14th, 2011, 01:25 AM To be fair it would be hard to spot on shots like that,but i and many others i have heard from find more noise on E-T-C with 720P E-T-C the worst,but for getting close in on things like wildlife it can be a godsend.
|
|