[Laser] (OT) Uses for a 35-60 zoom lens

n5gui at cox.net n5gui at cox.net
Tue Dec 28 20:34:10 EST 2010


I am not sure of a value for that particular camera lens for optical communication experimentation.  I think from the description that you gave that the lens diameter ( clear aperture ) is less than 10 mm.

Your inquiry did remind me of a lens that I have on a back shelf.  I cannot recall where I got it, probably from a garage sale.  It is a 12.5 mm to 75 mm zoom and is about 42 mm diameter.  Since it has a 6:1 zoom ratio, I thought that if used with a photo sensor, it should have a 6:1 field of view range.  In the wide field mode, if could be used to detect a station, although there is a large potential of picking up a lot of noise as well.  Then you could "swing" the optics to find where the limits of the field of view are, return to that approximate center.  Then by zooming in on the desired signal, you can reduce the likelyhood of noise sources in the restricted field of view.

You could repeat the swinging of the optics, this time in smaller steps, and slower, to re-center, and zoom in further.  The idea is to have a broad field of view for detecting the desired station, then narrow the field of view to limit noise sources.  The parallel activity on radio is to tune the frequency with a broad filter, then use narrow filters to improve the signal to noise ratio.

I am not sure that it has much of an application.  Perhaps if you are trying to set up a temporary link among a lot of city lights.  It certainly does not sound cost effective to me to try to obtain a zoom lens for this purpose.  But I already have the unused lens, like you have the camera from which to get the parts.


Best wishes to all for the new year.


James
 n5gui


---- Paolo Cravero <pcravero at as2594.net> wrote: 
> Sirs,
> I couldn't find any idea through a search engine, so I ask to the 
> largest community of "optical builders" I know of. Please reply directly 
> since my request is off-topic. Thank you for you patience.
> 
> 
> After few days in the hands of my daughter, a point and shoot 35mm 
> camera plastic has started to break apart... time to put it aside and 
> start opening it up.
> 
> The viewfinder lens is good for a macro addition to my cameraphone 
> (instead of a much smaller DVD laser head lens!). Then there are 
> electronics, motors, flashes, and ... the motorized 35-60 mm (f/4,3 to 
> f/6,3) zoom.
> 
> Is there any useful re-use of that piece of optics? Not necessarily in 
> front of my never-finished light receiver... I know the focus area is 
> pretty wide, 35mm in fact :-), way larger than any photosensor, so an 
> opto-RX might not find that zoom too useful.
> 
> Any idea is welcome, also for reusing other parts I will find inside the 
> camera.
> 
> 
> I wish you all a Bright 2011,
> Paolo IK1ZYW
> 
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