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.

Replacement Lenses for SJ5000+ and GoPro

Some of the high prices being asked for "special" lenses compatible with GoPro or SJ5000 models seem hard to justify given that these optics are manufactured in huge quantities for security cameras using the same M12 screw thread mounting.


A quick Google found this page at Surveilzone who list a selection starting at $2.99. I've not yet tried any but most are cheap enough to take a chance. (Caveat: the specs show sensors size smaller than 1/2.3" so may not cover the full sensor?) If buying for daytime use then a model with an Infra -red filter are advised.

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

 

 

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.

 

 

SJCAM SJ5000+ Firmware Wishlist

There is no doubt that the SJ5000+ is a work in progress and SJCAM may now be regretting their rush to get to market before the 2014 holiday season as the bad feedback from early adopters must be harming their reputation. Unfortunately much of far eastern culture and business relationships is about saving face and it would be a shame if this got in the way of squaring up to any shortcomings which have come to light.

May I suggest that SJCAM need to first address some existing issues:

1. Crashes and freezes.
2. Power management.
3. WiFi stability. (If this is hardware related then offer a rebate or recall)
4. Waterproof case obstructing corners of still images in 4x3 aspect ratio.

When these problems are solved SJCAM could retrieve some kudos from retrospectively adding some new features to the camera.

1. Control over sharpening. Offer a zero sharpening option especially in stills.
2. Auto Shooting. more interval options to allow production of 4K Super High Definition time lapse, 1/2sec, 1sec, possibly some longer than 60sec.
3. Zoom option which crops video image "on chip". That is uses a reduced area of the image sensor and real pixels rather than cropping the video output and uprezzing which exaggerates noise and sharpening artefacts and smears detail.

Finally a suggestion for a model option, (SJ5050?), with a narrower field of view and less fisheye distortion.

SJCAM SJ5000+ and 4K Video

SJ5000+ owners who can't (or won't) afford a GoPro Hero4 and want to experience the joys of Ultra High Definition 4K Video can take advantage of the Auto Shooting function to assemble time lapse videos in 4k. This is not to be confused with the built in time lapse facility which processes in camera to output standard High Definition video. The individual 16 Megapixel frames must be imported into the video editor of your choice and assembled into footage. Not difficult, I use Photoshop, any version after PS6 will do it. There are advantages in using this method to create time lapses at lower definitions also. Provided that intervals of 3secs or greater are OK, (built in time lapse goes down to 1sec), having 16 Megapixels to play with gives you the opportunity to do zooms and pans to liven up otherwise static scenes without losing detail, likewise a fair level of de-fishing can be achieved keeping full HD resolution.HERE >
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SJ5000+ Still Image Quality

On paper the new SJ5000 models promise a big jump in quality over the previous SJCAM model, the SJ4000, which boasted of 12 MP still images but in reality only produce massively upsized files from its native 2MP imaging sensor. By contrast the two base models SJ5000 and SJ5000wifi have new 14MP Panasonic sensors and the SJ5000+ bumps up to 16MP. The number of pixels doesn't tell the whole story though and a I'll start with aquick resume of the type of requirements which govern Action Cam optical design. Small overall size and light weight is one of the factors. The GoPro aesthetic is of wide angle view with fish eye distortion. This type of lens has a deep field of focus so it is possible to have a fixed lens, (no autofocus) and have everything sharp from a couple of feet away to infinity. Fisheye lenses for large sensor cameras such as DSLRs are heavy and expensive. GoPro style cameras use a small and cheap vesion with correspondingly small sized imaging sensor, in the case of the SJ5000+ a 1/2.33" Panasonic MN34120PA CMOS type. It's dimensions are a tiny 5.8x4.3mm, close to those of the sensor of an iphone 5 and considerably smaller than that of a DSLR which has sensor dimensions 36x24mm.

With that in mind any assessment of image quality needs to be realistic and take the physical limitations of the camera into consideration. Small sensors invariably exhibit more noise especially in High ISO low light situations and dynamic range is limited.

I have seen some impressive images shot with mobile phones and the potential for decent stills quality (if only under ideal conditions), piqued my interest in buying and trying an SJ|5000+.

First off, the fisheye look is not one for all subjects the ultra wide angle makes even middle distance subjects appear to be a long way away and don't even think of photographing your nearest and dearest close up unless they can tolerate being portrayed with a huge nose.

The following images of Exeter Customs House on the Quay show what can be achieved with a little massaging in Photoshop. Remember all these images are my copyright and may not be copied and published elsewhere. If you wish to refer to them please link to this blog.


First the original image sized down to 1200 pixels wide:

The first impression is that it is drastically oversharpened making it look very gritty and accentuating noise.

This is demonstrated with the two examples below both 100% crops. The "Befores" are as shot, the "Afters have had a slight blur and some smart sharpening and noise reduction in Photoshop,

Before

 

After

 

 



 Before

After

 

Despite this there are still visible sharpening haloes and artefacts. A shame as it would have been possible to include a choice of sharpening strengths in the image menu so that it could be applied at the proper stage in post processing.

 

 



I was pleasantly surprised by the performance of the lens which is essentially a $2.99 item sold on Alibaba. Detail is held to the edge of the frame and the aggressive sharpening that the camera applies really isn't necessary. What isn't a surprise is the high level of chromatic aberration exhibited. This is of the blue-yellow variety and can be seen in the 100% crop sample from the right hand edge.

 



Before

 

The "After" crop below has had B-Y chromatic aberration correction carried out in Photoshop at a level of +66.6 which reduces it somewhat, however there is purple fringing visible at high contrast boundaries which is more stubborn to fix.

 

After

The final image is a 1200 pixel version of the final image  which has additionally been brightened using curves, straightened cropped and had  bit of de-fishing applied.

The conclusion is that with some light post-processing quite usable still images can be produced provided care is taken not to overexpose. Unfortunately for use in professional publication the aggressive sharpening applied in camera limits the size at which they can be reproduced, however quality is adequate for display at full size on a 4K ultra high definition TV screen.

There has been some debate over the accuracy of the SJCAM SJ5000+ AWB (automatic white balance). This interior shot was taken in a glass roofed conservatory lit indirectly room on the north side. Sunny day blue sky and clouds outside. I can only say that colours look absolutely spot on to me. Exposure set to -0.3EV and image brightened slightly in post processing.

SJCAM SJ5000+ a bargain GoPro?

Occasionally a brand becomes so pre-eminent that it comes to signify a whole genre. In the case of Hoover it mutated into a verb and even Dyson households still hoover their carpets. Thus has the GoPro brand become pre-eminent in the field of tiny video cameras in clear plastic waterproof boxes which can be attached to vehicle or person. Otherwise known as Action Cams these little protuberances have sprouted from every type of moving object, motorcycle, skier, quadcopter or can be seen waving about at the end of every 20-something tourist's selfie pole. The GoPro itself is now a mature product having evolved through several generations but its premium price left a hole on the market for copycat versions. The inside of a GoPro is essentially a beefed up version of the simple board camera used in countless surveillance cameras mated to a fixed focus fisheye lens. All of these components are available off the shelf needing only tooling up for a plastic case to produce a "knockoff" known in the vernacular of Action Cams as a "NoPro". Formerly these anonymous copies from Chinese factories were of inferior performance but one manufacturer, SJCAM has been attempting to raise its profile as a brand with its new SJ5000 models with specifications pitched towards the middle of the GoPro range but selling for a third of the price. The flagship model is the  SJ5000+, (SK5000 plus), priced at $169, and when the specification was announced the inclusion of an Ambarella A7LS75 processor related to that in the GoPro Hero3 Black and a true 16 Megapixel Panasonic imaging chip set up a ripple of anticipation late in 2014.

There is considerable irony in SJCAM's situation as GoPro competitor as whilst the wealth of the GoPro brand has protected it from any significant counterfeiting by sale of "clone" cameras, SJCAM has been plagued by various backstreet manufacturers of fakes which are indistinguishable from the genuine article. These may even perform similarly but have no guarantee that there will be technical backup or updated firmware. This has led to SJCAM taking steps to protect their brand by putting a scratch and check sticker on product boxes and having a system of certification for approved resellers. However it is a jungle out their and buyers are advised to avoid incredible offers and buy from sources with robust refund policies. My own SJ5000+ was bought from HERE through AliExpress and communications with them have been swift and efficient.

Whilst SJCAM are trying to build their reputation as a trusted brand name the launch of the SJ5000+ has been in danger of undoing their good work. Early models shipped in late 2014 were plagued with problems with buggy firmware and a hardware issue with the shielding of the wireless antenna. Thanks to a dialogue between the manufacturer and members of the Radio Control community these have been addressed to some extent.

At the moment though the SJ5000+ is something of a work in progress. For example I am still attempting to get the wifi feature on mine to work reliably and other users report some quality control issues which have required units to be returned which is inconvenient for those trading directly with sellers in China. My initial trials though have shown that video and stills can be very good and I believe that the camera has real potential to compete with GoPro in terms of the quality of videos produced. The potential for high quality 16Megapixel stills puts it a big jump above the earlier SJ4000 which had only a 2Megapixel sensor.

If SJCAM have aspirations to rise above the other "me too" manufacturers of NoPros then how they deal with the development of the SJ5000+ is crucial. It is important that they continue to listen to their buyers and address any hardware problems which come to light by offering exchange units and by developing firmware especially to release extra features as a reward to early adopters.

My SJ5000+ arrived from China yesterday and I'm just checking it out. First impressions of video and stills are satisfactory.