Defender Pro Cameras - changing lenses?

[johnmh 0]

I expect this post is similar to one not much farther down on Wider Angle Lenses http://www.cctvforum.com/viewtopic.php?f=5&t=35614

Got a 'Defender Pro' system from a friend for next to nothing (so please don't bust on me for the choice of systems). Playing around with it I'm finding that the 60 degree field of view is inadequate for certain locations. After doing some research and taking apart one of the cameras that had a broken mount, it seems that it should be possible to change the lens and replace it with a wider one. The camera uses a 1/3" sensor with a 5mm lens. It seems that I can replace this lens with a standard M12 lens to get a wider field.

 

http://www.m12lenses.com/Board-Lenses-s/12.htm offers a number of choices.

 

Seems as if the only possible issues are:

 

1) the depth of the lens holder fitting (to allow for proper focus) although the current 5mm lens uses a good couple of mm worth of threads so I expect at least one other lens will work.

2) the overall length of the new lens/board compared to the original - if too long it may not fit in the existing housing without modification (again, there seems to be some slack so I think it will be manageable)

 

The Defender system uses IR at night so I presume I'm better off without IR filters in place. Seems as if the motion detection is software driven off the image (you use a grid on the monitor to set the zone) and things like day/night are hardware controlled in the camera so I can't see a lens making much of a difference.

 

I'm thinking a simple lens switch and refocusing should given me a wider angle view on these cameras.

 

Any thoughts, warnings or other advice?

 

or am I totally wrong about this?

 

It doesn't seem as if there are other cameras with a wider field of view that are an exact match for the specs on these cameras.

 

http://www.defender-usa.com/product/Vandal_Resistant_Ultra_High_Resolution_Outdoor_Security_Camera.eng-102.html

 

The few wide angle lenses I found are not much wider (75 degrees vs 60) and are not 600 lines or draw more power or have different connectors. As a side note, seems like the housings for these cameras waste a heck of a lot of space - they could be a LOT smaller.

 

Since this is a second hand system, no issues about voiding warranties so I figure what do I have to lose trying.......

[johnmh 0]

Got a standard lens assortment. Going wider, the only one that works (and barely gets in focus) was the 4mm one.

 

Others can't get to the focus point in the camera mount Defender uses. oh well.... looks like the best bet for wider lenses is changing the whole camera.

 

 

Kind of a dumb move having a limited view angle and no way to go wider - not even a choice of cameras from the maker. Would make the system more attractive.