SJ5000+ WiFi light at the end of the tunnel?

The Android LinkinEyes App has been updated and I have been getting passable results testing wifi on my Motorola Moto G 2nd gen which previously refused to play.

Basic taking of video and stills and switching modes worked ok but a couple of times changing camera settings caused a glitch. I'm running firmware version 1.7.

Apparently good news for iOS also with the discovery of another Ambarella wireless app called INTOVA Edge X which has been reported to work better than Linkineyes.

SJ5000+ to Infinity and Beyond, some thoughts on fixed focus.

Some buyers have reported being able to close focus but are out of focus for distant objects, not what they want, especially for aerial photography. The SJ5000 and many other similar cameras like the GoPro are fixed focus, i.e. have no autofocus facility and the lens is adjusted in the factory by screwing into its mount then fixed with glue to stop vibration putting it out of focus. As this process is done by hand then there is always the possibility of human error or carelessness. For most uses the optimum focus setting is to the Hyperfocal distance which is the distance from the lens which gives acceptable focus over the maximum distance from infinity towards the camera. A quick Google will turn up the formula for calculating this distance, which is a function of lens focal length, aperture value and sensor size but will also throw up a good deal of internet bickering. In reality even if armed with the hyperfocal distance there are extreme difficulties in setting that as the focus point. Due to the wide angle of the lens  it becomes very hard to see fine detail and judge sharpness once the subject is more than a couple of feet (600mm) in front of the camera. SJ5000+ jpegs don't help as image artefacts visible at 100% add to the confusion. By the time you are looking at distant objects, detail like twigs or wires are too small to see and often atmospheric haze reduces sharpness. I carried out some quick and dirty minimum focus distance tests on my SJ5000+ by laying out a tape measure with Zero in line with the front of the camera body offset about 300mm to make numbers visible and parallel to the line of sight.

Difficult to judge the first point in focus because of the dreaded sharpening artefacts but I'd say about 10 inches is around the mark. A better test would be with tape oriented along the line of sight and a vertical target moved progressively as my offset tape test is susceptible to any field curvature inherent in the lens.

 I'm happy with the focus of images overall but am curious whether closer focus could be achieved without visibly softening distant objects.

In practice the best way to set focus is to hook up to a large TV and live focus on a scene covering a range from close up to the horizon and come up with the most pleasing setting.

Likewise those with a macro interest can adjust focus as they require, though this will require moving the lens forward and may interfere with fitting the waterproof case.

If you do need to adjust focus look for the YouTube tutorials on lens changing but proceed with caution and at your own risk. Ideally I would like the camera to have adjustable focus as a feature with an unglued mount and a clamping mount tread to hold the lens in place.

I'd be interested to have feedback from others' tests of minimum focus distance and whether far-focus is acceptable.
 
 

SJ5000+ Timelapse Video of Exeter Quay

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.

Here

quay from Anthony Collins on Vimeo.

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.

 

 

 

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:

 

 

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.

SJ5000+ on Exeter Canal

https://vimeo.com/119708086

Some higher quality footage on Vimeo for your delectation :-)

SJ5000+ wifi woes continue

 

 

Just posted a couple of Youtube Videos showing either lack of connection or dropout of SJ5000+wifi with two Android devices.

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.

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