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.