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Actual lines of resolution
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  • @bwhitz - If the XF300 is so similar in resolved detail, that means the 7D can resolve 1000 TVL? fascinating.

  • @RRRR - I think we're discussing video resolution and not stills resolution from the GH2. The two modes give very different results. I've yet to see a resolution chart for the GH2's 1080p video output, so definitive statements on lines of resolution are just guesses until someone does an accurate test. I did get a chance to do my own fine-detail comparison between my GH2 and XF300. Results were posted here in the thread you linked to above, and show the XF300 clearly resolves more detail, but I don't make any claims on the actual lines of resolution that the GH2 is capable of. My guess is 800-850, but that's just a guess. The EX3, like many cameras, softens as gain is applied. I don't understand what you're trying to say with "ever heard of sharpening?" and "true resolution indeed."

  • FACT: some fancy fringing and over-sharpened images.

  • Interestingly enough, just found this on dpreview - GH2 1080p AVCHD frame grab of a resolution chart. You can clearly see aliasing begin between 600-700 lines of resolution:

    1267851.jpg
    1920 x 1080 - 1015K
  • cowpunk: it's is far less different than you think. It is the same sensor, albeit downscaled. Downscaling is done intelligently - not by skipping lines. Hence anyone can make a calculation of what the video mode SHOULD be capable of, with the right settings. (factory gh2 video compresses the video stream a lot, for instance)

    The main difference to a full scan of the sensor is that pixel-level information is averaged - which in turn reduces noise and creates a lot of fine (but false) detail that exceeds the nyquist limit without causing a lot of obvious moiré or aliasing.

    The EX3, and many other cameras - apply sharpening and decrease it in low light to avoid additional noise. Therefore, any such difference has only to do with perceived sharpness, and not to actual resolving power of the sensor.

  • GH2 doesn't match an ideal image of what you can get out of 1080p luminance wise, it's got a fair way to go when it comes to that, but leagues better than other 'dSLR' video cameras, and it's basically trash when it comes to colour resolution, worse than what 4:2:0 should be from examination.

    But it's more satisfying than any other camera I've shot motion picture with so far (I haven't shot higher end digital equipment, just things like HVX varicam and others), apart from Aaton XTRprod (Super16) @ 2K scan which wiped the floor with anything I've seen digital.

    That said there is nothing wrong with a single chip sensor, in fact, they do excellent, and demosaicing works (not total decimation like chroma sub sampling) even @ 100% off a still with a sharp lens it is excellent.

    If it was sampled down perferctly, that huge amount of oversampling would provide tremendous image quality, and it would provide the maximum possible resolution/information you could store in a 1920x1080 size image if output in full RGB or 4:4:4. Single sensor wouldn't come into the equation since the huge amount of oversampling done, the effective down-sampled pixel size would be bigger than a cluster of RGB it came from, so essentially it would be "3 chip".

    The downscaling used isn't ideal though (though much better than line skipping by a long way), so there is resolution loss, then comes compression.

  • @RRRR - actually, cameras actively apply noise reduction at high gain which smooths over detail. They don't merely stop "sharpening." Anyway, as I stated a while ago, when I submitted my comparison results, the XF300 was set to -4 sharpness and the GH2 was at 0. If you can't see the difference in actual detail, then it's because you want the GH2 to be better at resolving than it really is.

    We can talk all day long about how the GH2 may downscale it's sensor to reach an HD image, but you're just guessing. Panasonic hasn't released that information. You don't know how intelligently it's actually working, so any calculation about how it SHOULD work is completely moot. It's nothing more than a wish.

    Take a look at the chart right above. How does that documented performance of the GH2 in video mode factor into your calculation of how it "should" be working?

  • I think @Anthril is on the right path here. Look, these are all just numbers and measurements and techno-babble whatever. It's ok if the what's on paper comes up short. What matters is picture - and the feel it is able to impart. And the GH2 is able to satisfy that need in spades. So if you want to know the numbers, that's fine. Just don't be surprised if the numbers don't live up to the emotional impact that the GH2's picture can give - because ultimately, that's all that matters.

  • @cowpunk52 "If the XF300 is so similar in resolved detail, that means the 7D can resolve 1000 TVL? fascinating."

    Well, the 7D was measured at about 700-800 in that last Zacuto test, so no, I don't think it can hit 1000lines... but the XF doesn't look like it can either. And I'm actually editing some XF stuff right now... it's pretty soft, and the detail really doesn't look that great... it looks electronic. Probably because the sensor is native, and doesn't benefit from the organic look of oversampling. A GH2 still image extraction looks photographic... and really could pass as a photo in most viewing situations. Where as a still extraction from the XF screams "video freeze frame". They just don't stack up.

  • @bwhitz - the opinion that the XF300 image looks very video-like vs the GH2 is very valid. I'm sure that a lot of people might share that opinion, and it's not a bad thing either way. And, while I can't comment on why the XF footage you're working on right now looks soft, the fact of what the XF300/305 series is capable of in regards to resolution isn't really up to debate. Just look up any review or white-paper test of the camera.

  • I've compared some down sampled to 1080p from full RAW images of the GH2 of the same subject to 1080p AVCHD and MJPEG.

    Luminance was pretty good in AVCHD, but is not a match for being downsampled properly from the full size image (meaning there is loss in Panasonic's down sampling and compression, though I think you'll find the same with uncompressed HDMI out), MJPEG was a little worse in luminance resolution, but significantly better than AVCHD in U and V resolution, but MJPEG still looks much worse than what 4:2:0 is.. so yeah.

    I'm not sure what I'd like improved in the next generation. I honestly do not like cameras in the XF300's class. That 'handicam' form factor is the worst imho. People point to dSLR video's form factor as a weakness and then point to handicam style form factor as being a 'proper' video camera, when they area poor low end design, extremely bad ergonomics.

    @bwhitz is probably comparing real luma resolution (an actual scene), ie: low contrast resolution, not high contrast resolution (test chart/silhouettes), high spatial frequencies in the real world are mostly low contrast, that is to say most detail and resolution people are interested in making films and taking photographs occur across low contrast changes.

  • @anthril - possibly, but even in low-contrast environs the xf300 outresolves fine detail when compared to the GH2's video output. Case in point are the 1:1 center crops i posted in the other thread on this subject. My guess would be simple user error, but without seeing footage for a framegrab it's impossible to know.

  • As has already been pointed out, resolution numbers (for whatever they're worth) aren't absolute, but Alan Roberts (of the BBC), who uses a uniform methodology, puts the xf300 at about 900 lines of useable (clean) vertical resolution. The HM151 somebody referenced earlier (as being inferior to the GH2) comes in about 680 lines in Roberts' testing. The EX1/3 produces at or near the full 1080 lines in his testing.

    Draw your own conclusions.....

  • cowpunk: the chart above shows only that the user is possibly using factory firmware, shooting 50i because it is nowhere near the normal output.

  • What I don't understand is that when compared directly with other cameras in the admittedly flawed tests that Phillip Bloom did, it was visually obvious that the GH2 was more than up to the task of being usable for making films for the theater. I saw nothing that wold suggest that the image would fall apart or be a distraction for movie goers. It's not to say it would be the best thing you'd ever see, but it could pass in a low budget film just fine.

    I don't film charts! Who cares about how good a chart looks in the end? If you have a detailed scene of actual moving life, that's the best test IMO. Does it look like a film or not?

  • @Aria As I see it, you're right. The GH2 isn't the limiting factor in most types of productions. As far as I'm concerned, to get a camera significantly better (as opposed to incrementally better), you need to spend 10-15,000 USD. Bloom's test is garbage. Charts are garbage. The GH2 is a very good video camera, too bad it looks so stupid. Panasonic did everything but paint it pink.

  • What we actually learn from this is: the only thing that counts is a chart. Sony f3, canon c300, Scarlet and Sony fs100 obviously resolve less in a 1080 frame than xf300 and any real world experience is obsolete.

    My next feature film will have a chart as it's main actor. That way I will know whenever I cock up the shot.

  • I think it's important, and I think it's irrelevent .. shoot your chart .. get your 700 (or whatever) lpi .. then swap your lens and measure again :)

  • @RRRR - that chart was shot at 1080p on the GH2. Vitaly, I'm sorry about the link to another forum, but it's just satisfy naysayers who want to try to hang on to dogma despite all evidence. RRRR, you can see the chart, as well as a 1080i chart, MJPEG chart and 720p chart and more here: http://forums.dpreview.com/forums/readflat.asp?forum=1041&message=38912742

    Not enough? Check out how these tests have the exact same results here:

    And also at the 8:45 mark here:

    But I'm sure you'll find a way to justify a reason why none of that is accurate. I'm sure some here could be presented with the a number of meticulous tests and charts and would still believe the GH2 can resolve exactly 1080 lines of resolution, even if you saw a test done right in front of your own eyes or if, god forbid, you did one yourself. The dogma runs deep.

    Look, I'm the first one here to say that charts are irrelevant, except as a curiosity. What I can't stand, though, is untrue information being presented as fact just to further this idea that the GH2 is the greatest digital cine camera ever made (it's not). I feel sorry for people coming here to try to find honest information about their camera, and instead they just get a healthy dose of 'fanboyism.' The camera is just a tool, it's got limitations - all of them do. It's ok to understand what those limitations are. No one will think your d**k is smaller.

  • I see no need to refer to @mpgxsvcd tests on dpreview, as he is active member here.

    All I see here, is almost exactly same topic. with same arguments as closed similar topic. Special to mentally challenged guys who think that "GH2 is best camera in the world", it is not.
    It is not best, it is not worst, it is just camera owned by many of our members, but many have professional large sensor cameras, Canon DSLRs instead or Sony NEX cameras.

  • Just to put in a good word for charts - the attached jpeg (sorry, a bit low rez) is from a camera which has lots of passionate defenders and has been used to shoot features, commercials, etc. And good for the shooters, who got results with it. But, based on the the chart, most folks probably wouldn't choose to use it for a nature documentary, shots of building facades or men's tweed suits.

    Which is why it can be useful to have charts -- to get a better idea of what your limits are on the screen, big or small. That was all the original poster wanted to know, and asking it wouldn't seem to be all that unreasonable.

    3.JPG
    640 x 512 - 48K
  • Thing is, that I saw very big amount of topics about shooting charts, debating charts, calculating resolution according to different techniques. Almost all of them are big waste of time of all viewers. Absolutely without any relation to cameras used.

  • I'm sorry cowpunk but you have taken the "evidence" you present out of context. Some high iso shots comparing high iso resolution differences between 3 cameras. Second you present a test that is only good for the shooter himself.. (it is lacking in terms of information). It is no better than other test footage that has been referred to or presented as evidence of what the gh2 is capable of. Let's stop wasting time with this nonsensical debate and get to work. Each to his own agenda.

    Personally, I have no qualms over using the gh2 for shooting nature scenery whatsoever.. which was what the original question was referring to.

  • Dunno about GH2, but I did bunch of tests between my old GH1 and my Canon 550D "back in the days". Aliasing or not, GHx looked "a tad" more detailed than Canon. Maybe both cameras have same Nyqvist limit but pictures tell a tale. For example, both cameras show very thin fence lines, being around 1 pixel wide. But if you look at the grass, you can tell which one is "pixel binned" and which is "pixel skipped". Canon has detail, but it's a lot of noise and stuff that wasn't there in the first place.

    GH1: http://i1024.photobucket.com/albums/y306/grunf12/gh13s.jpg

    Canon 550D: http://i1024.photobucket.com/albums/y306/grunf12/550ds.jpg

    Canon had 24-70 f2.8 Sigma and GH used stock 14-140 lens.

  • ^ are those actual video stills? That's quite a dramatic difference. I didn't realize it was that much.