> > My task implies remote zooming at 50-70 meters distance with quality > enough to recognize a faces. >
Roman, we need to find out the actual required resolution that you need to recognize faces - I do not have any experience with that. There should be probably some studies on the matter, you can also look at artificially blurred photos to find out what resolution (in mm with a given contrast) you need. After that we can calculate the required parameters of the lens, knowing the pixel size is 2.2um and the best "5MPix" 1/2" lenses that do publish their specs have <=150 lp/mm (in most cases <120 lp/mm) > > I suggest it would be enough H10Z1218MS 12-120mm F1.8 10X, 3 > motors w/ spot from http://rmassa.com/manu/computar.htm > Am I right? May be where is another better solution? > There is no resolution data in the datasheet of that lens, and knowing that it does not say "5MPix", "3MPix" or even just "megapixel" it's resolution is likely good only for old analog video cameras that have 640x480 at most, so you'll be able to get same details with higher resolution lens with 3-4 times smaller focal length. It can make more sense to have a custom setup with 2 sensors and 2 fixed-focus lenses connected to the same camera using 10359 multiplexer board (the coming model 373 camera will have two sensor front end connectors on the main board) At the same time, if you plan to use zoom - you'll probably need pan/tilt platform too. Is that so? Do you have a good platform selected? > > And second question is about to control this lenses. As Elphel answered - > thereis no standard on board possibility to control such lenses from camera. > That is correct. Unfortunately there is no single standard for the motorized lenses with C/CS-mount world. Most lenses even come with unterminated wires so camera manufacturers put custom, camera-specific connector there. It is OK when you provide the cameras with a single lens, but not so convenient when you try to make something universal. Additionally, motorized lenses have generally lower resolution - and this is really a challenge to find even a good fixed-focus lens for multi-megapixel cameras. To say nothing that the C/CS-mount motorized lenses are usually much larger/heavier than the manual ones. That is why we do not provide motorized lenses with Elphel cameras But it is possible to connect lenses to camera's USB port through > controller. Can anybody suggest any model? > There are some lenses with RS-232 interface (haven't seen with USB but there are plenty ~10$ USB-to-serial adapters that are known to work nicely with the camera), but they are usually rather expensive ones ( http://www.google.com/search?q=c-mount+zoom+rs232 ). Even having 2 cameras with different focal length lenses would be less expensive. On the other hand, if you do have some lenses and pan/tilt platform it should be rather easy to connect them to the camera. Camera has php running inside, so connecting some such a device and providing basic web interface fro it can be a one day job. Or - one week if you want really nice interface. Additionally you can use many microcontroller boards (like http://www.arduino.cc/ ) that have USB device port and have outputs that can be used to control motors - directly or with small number of added components, you definitely can adapt one fro PTZ control of analog platforms and motorized lenses. Andrey
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