![]() The most striking difference is the colour. While not very scientific I think the clips highlight some interesting differences between the two cameras. This is typical of the dilemma you get when trying to expose a scene with a greater range than the camera can deal with, do you overexpose the sky to preserve the mid range or underexpose the mid range to keep the sky. If this shot included a person or face then I would have been forced to either over expose the sky still further or use some fill lighting or a reflector to bring up the foreground. ![]() I would normally aim to put middle grey around 45-48% for Sony’s REC-709 compliant gammas. ![]() The result is that the standard gamma shots are under exposed by around 1.5 stops, mid grey is only 33% on the F3 and 30% on the FS700. Exposure for the standard 709 gamma was established with the histograms trying to get a reasonable balance between clipped highlights and a reasonable mid range. In fact the mid grey patch on the DSC S-Log chart is around 38-40% on both cameras which is just a touch low for the cinegammas (I normally aim for 42%-45% with cinegammas). For the Cinegamma 4 tests I used the histogram to keep peak white at about 95% with similar mid range exposure. The HDSDi out from the cameras was recorded using ProRes 4:2:2 on an Atomos Samurai.įor the S-Log sample I exposed using the DSC Labs S-Log exposure reference chart (which you can see in all the frames) by placing the cameras centre spot meter over the middle grey and aiming for 38%, however my waveform monitors are telling me the mid grey exposure was actually 35% so I’m about a 1/4 stop under (and need to check why I didn’t get 38%). Frame rate was 25fps with a 180 degree – 1/50th shutter. The cameras were set to 800 ISO for all the clips, so the FS700 had +6db gain applied for all clips while the F3 had +6db applied for the Cinegamma and standard gamma clips and no additional gain in S-Log. I wasn’t looking to actually measure anything here, just get a feel for the differences between the cameras. If you take the S-Log clip as the reference the clouds are at about +5.5 stops over nominal middle grey and the darkest part of the image, the black stand holding the chart, is about 6 stops under. The scene has about an 11 to 12 stop range if you include the specular highlights and reflections off the silver car bonnet and the brightest clouds. So I just did a very simple side by side test to look at noise and dynamic range. It is very good, of that there is no doubt, but my benchmark right now is the F3. I’m still exploring the image quality of the FS700. OK, not really very scientific, but I’m busy on some paying projects at the moment and the weather is very changeable so I only had a short window to do this. So… why 11.6 MP and what else was this sensor designed for? Another thought is that the FS700 does read the full height and width of the sensor but then uses some pixel skipping only actually reading 8.3MP, but why do that? In stills mode the camera only uses 8.4MP yet with so many extra pixels you could get higher resolution stills. If (and this is just random speculation) the FS700 is taking an 8.3MP window out of the middle of the sensor, that makes it a pretty big chip. What would you put a near full frame 35mm 11.6 MP sensor in these days? That’s a low pixel count for a modern large sensor DSLR or stills camera, even the compact NEX7 stills camera has 24MP. Where are all the un-used pixels? Given that this is a Super 35mm sensor, the active area used for video is APS-C ish sized, so it’s quite a big sensor already. Why create a sensor with 11.6 million pixels and then use only 8.3M? It is normal to have some extra pixels that are used for setting black levels etc, but this is a massive difference between the number of actual pixels on the sensor and the number that are used to create the pictures. 8.3MĮffective pixels in still picture shooting (16:9) approx. There is something a little curious about the specs for the sensor in the FS700: ImagerĮffective pixels in movie shooting (16:9) approx.
0 Comments
Leave a Reply. |