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Lens standards

garycd
Fri, 02 Dec 2016 16:53:50 GMT

Friends: I have been shooting several “test” videos (actual projects/events, but just to do a complete workflow with the iPhone and iPad), and will be shooting my first “professional” video using my iPad. I believe that one of the things that is holding back the “professional” development of the system is the absence of information about the available lenses. Those of us who have worked in film (35mm and 16mm) and in video from 3/4” to 1/4” and to digital, and in DSLR video, are used to the concept of lens descriptions — i.e. … “Normal” (eye view) focal length lenses being approximately 50mm, with a horizontal angle view of about 40 degrees; “Wide Angle” focal length lenses being approximately 35mm, with a horizontal angle view of about 55 degrees; (Anything less than 35mm being more of a “Super Wide Angel”); “Telephoto” focal length lenses being approximately 85mm, horizontal angle view of about 25 degrees; (Anything greater than 85mm being more of an “Extreme telephoto”); (All rounded numbers). But the marking of lenses in the iPhone/iPad technology do not s eem to follow that pattern, and/but it is difficult to find out exactly what the available lenses offer in terms of horizontal angle (the vertical dimension) and its relationship to the above (rough) “standards.” I believe that it is critical that lens manufacturers code the equivalent (mm) of their lenses and their technical angles (generally related to HD ratios) and their approximation to some form of a new standard. (?) And, of course, the second critical factor is the design, in the camera housing manufacturing arena, of a more solid (probably bayonet type) mounting system for the lenses. Any thoughts? Gary Davis

Tom Barrance
Mon, 05 Dec 2016 17:44:01 GMT

Hi Gary. Yes, you need to do a bit of digging to find the information. It seems that the standard iPhone lens on my 6S is 29mm when shooting stills, or with video stabilisation turned off; and around 38mm for stabilised video. So the Moment and Ztylus Z-Prime 0.63x wide angles with stabilisation off would be 18mm superwides with stabilisation off, or 24mm wides with it on; and the 2x tele lenses would be medium telephoto portrait lenses with stabilisation on. I agree on lens mounts, but I think the problem is that they don't have much depth to play with as the accessory lens needs to be close to the front element of the phone lens.