Half term and a sunny afternoon brought out the bird feeders. Taken using the time lapse function. One second interval, 100 ISO, AWB, (slightly cooled in processing), centre metering, -1.0EV. Assembled using Photoshop CC.
quay from Anthony Collins on Vimeo.
Showing posts with label review. Show all posts
Showing posts with label review. Show all posts
Tuesday, 17 February 2015
Sunday, 15 February 2015
Sj5000+ Post Processing to Improve Video Quality
As a photographer, one thing I can't abide is a washed out sky. Much action cam footage you see shot using default settings has horrible blown out patches of cloud or strange colour casts to what should be blue sky. This is because the small sensor can't handle the high dynamic range in many scenes so defaults to, (hopefully), exposing the main subject correctly whilst the sky takes its chances. If you want to achieve good exposure for the whole scene then a technique to try is to set exposure to the maximum that doesn't blow out the sky then bring up mid tones and shadows in post processing. In the clips below the original clip was shot with exposure set to -1.0EV and AWB at ISO 100. As you can see the sky looks fine, detail visible in the clouds and realistic blue sky patches. Shadows and mids took too dark though, and in the second video the original clip has had a curves adjustment made to brighten mid tones and shadows, with a little tweaking of saturation and colour balance. Unfortunately pushing adjustment of the 8 bit video files too far will result in banding and/or excessive noise but I was very pleasantly surprised that the adjustments I made for this demonstration have not caused any such problems and the SJ5000+ video files are more robust than I gave them credit for.
One downside of post production adjustments is the resulting slow down in rendering video on my low spec PC. Today's trial was the first action footage I've shot using the SJ5000+ . Pausing allows examination of individual frames and the image is sharp from edge to edge (I won't bang on about the excessive in camera sharpening). Colour is natural looking and there is enough headroom in files to make some adjustments to brightness without images falling apart. Even if the WiFi problems aren't solved I'm inclined to keep the camera. It would be great if SJCAM could add a camera setting to mimic GoPro's Protune setting for the benefit of those of us wanting to squeeze out the last drops of image quality. I would definitely buy again based on the quality of video which can be obtained.
You can watch these samples together with a bit of pausing to synchronise.
The compression Youtube uses degrades video quality terribly so a couple of full 720 video stills:
Tuesday, 10 February 2015
SJ5000+ Battery life
Early adopters of the SJCAM SJ5000+ reported poor battery life. Mine arrived with firmware 1.7 loaded and after running batteries through several charge/discharge cycles videoed my watch (indoors at about 17 degrees C). Settings were 1080 60p screen, LEDs and wifi turned off. The battery ran out after 59 minutes. When I've really nothing better to do I'll run some tests on time lapse and on my other two batteries to see if there is any variation. Please feel free to add your own battery test results in comments
Time Lapse SJ5000+
A bit of fun in the lab. 1 sec interval, heavily cropped to conceal people walking by. lab. Real time over an hour so connected to external battery just in case.
Monday, 9 February 2015
SJ5000+ More Exposure Trials
Seagulls plus bread equals some videogenic content so a test of the SJ5000+ with -2.0 EV of underexposure dialled in. The resulting clips show that that still isn't enough to completely tame hotspots making me wonder if the right base setting for exposure has been chosen in the firmware. I was using multipoint metering and ISO 100 so I will have a look at other options.
On the question of optimum ISO it is possible that the base ISO is something other than 100 in which case it is possible that another setting will yield wider dynamic range. A certain amount of blown highlights is acceptable for video where there are dynamic changes in light but a nono for stills. The range of exposure latitude is not enough to assemble multiple exposures to get the benefit of HDR without some tactic to fool the metering. Anyway a couple more clips for your delectation.
The second is also on Vimeo and looks a bit better https://vimeo.com/119166796
On the question of optimum ISO it is possible that the base ISO is something other than 100 in which case it is possible that another setting will yield wider dynamic range. A certain amount of blown highlights is acceptable for video where there are dynamic changes in light but a nono for stills. The range of exposure latitude is not enough to assemble multiple exposures to get the benefit of HDR without some tactic to fool the metering. Anyway a couple more clips for your delectation.
The second is also on Vimeo and looks a bit better https://vimeo.com/119166796
SJ5000+ Optimum Exposure Setting
Like all small sensor cameras the SJ5000+ has limited dynamic range. Out of the box it tends to blow out highlights resulting in white skies and strange colour casts. I shot some test dashcam video with exposure set to -1.0EV The sky looks pretty good but bright buildings are still blowing out. Other settings were 1080 60P and AWB, no post production adjustments were made. Even underexposed the level of shadow detail looks pretty good and could be boosted in post. I will test at -2.0EV and see if that improves things though I expect some Photoshop work will be required to bring up mid tones and shadows.
Summing up, video is pretty good here and I reckon that better is possible yet.
The Youtube link posted below doesn't do justice to the original which looks much better.
Summing up, video is pretty good here and I reckon that better is possible yet.
The Youtube link posted below doesn't do justice to the original which looks much better.
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