Lens change on DS-2CD2335-I ?

[gth]

Two questions:

1. Does anyone sell the genuine Hikvision 2.8mm lens for this camera?

2. Has anyone done a lens change? Is it very complicated?

I saw some tear-downs that look like I could accomplish - I've wired my house with cat6 and done hardware changes on servers, PCs and laptops in the past, so I'm willing to have a go. Just interested in any hard lessons folks have learned from previous attempts...

PS: Anyone wanting an 8mm lens, I'll probably have a few spare soon.

 

[zero-degrees]

You might have better luck trying to trade an 8mm turret with someone who has a 2.8mm turret.

 

[gth]

That doesn't sound promising...

 

[gth]

If anyone else is interested, the procedure to do a lens swap for this model camera is as follows:

1. Have the camera on a clean, even surface, unplugged.

2. Unscrew the locking tab screw and remove the turret shroud, and metal base

3. Unscrew the three screws holding the two hemispheres of the ball unit together. Careful when unscrewing the last screw, as the two hemispheres have wires and a ribbon cable running between them, internally. I'll call one the cable hemisphere and the other the lens hemisphere...

4. Using a permanent marker, mark the end of the ribbon cable and the ribbon slot that goes into the lens hemisphere so you can tell which end (and which side) goes into the ribbon cable slot later on. Then gently lift the two tabs holding the ribbon cable in place and disconnect it.

5. Same again on the wires this time, use the marker to mark which way it connects to the socket on the cable hemisphere, then disconnect. The two hemispheres are now separate.

6. Unscrew the two screws holding the lens assembly plate. Once removed, you can see the hot glue that holds the lens in place. You'll need to carefully remove this glue (I find it easiest to apply some heat, then use a small jeweller's screwdriver to pry it off, working my way around the lens).

7. With the glue removed, you can then unscrew the old lens (normal thread direction) and then carefully screw in the new lens about 3/4 of the way in.

8. Reassemble the wires and ribbon cable using the markings made earlier (steps 4 & 5 above) but leave the lens plate disassembled for now.

9. Being careful with exposed components, plug the camera in and view the resulting image (laptop, phone, etc) - it will be rather out of focus. Use the image to assist in screwing the lens to the correct position for the image to be in focus. Avoid screwing the lens all the way in, as you may damage the sensor. If the image is black and white, the IR has kicked into night mode: adjust the position of the other hemisphere so the light sensor gets some light and it will return to normal.

10. Once you're done with the focus, disconnected the network and power and then reassemble the camera lens plate, hemispheres, and the turret shroud and base - the reverse of the steps above. You're done!

(Images to follow when I'm back online, along with a link to the lens I used).

 

[alastairstevenson]

Interesting.
A couple of questions -
Did you find there was a need to choose a distance for best focus, or is the depth of focus good enough that it doesn't matter?
I take it the lens rotation was stiff enough that there was no need to glue the best focus position in place?

 

[mlapaglia]

If you're moving to a 2.8mm lens the field of view is going to be huge.

 

[gth]

Although there were a few positions that would focus close objects, once an object at a reasonable distance was in focus it was fine for the whole scene.

More than enough friction to hold my new lens. A mount position with lots of vibration might need some glue I guess?

Large field of view is the plan. Pondering an even larger FoV lens if I can. Probably a limit of the confined space.

 

[mlapaglia]

What's your goal of having such a wide field of view?

 

[gth]

Having been to court a few times, my experience has been that any time the target is not on camera, their legal representative will paint a totally innocent reason / behaviour / activity is going on than what actually happens.

So by way of example, instead of just seeing the letterbox (and perhaps a semi-decent picture of the target at that location), I can now see them approaching the property, looking down the side of the house, passing the letterbox, entering the property, removing the flyscreen on a window, etc. and so on.

 

[alastairstevenson]

So by way of example, instead of just seeing the letterbox (and perhaps a semi-decent picture of the target at that location), I can now see them approaching the property, looking down the side of the house, passing the letterbox, entering the property, removing the flyscreen on a window, etc. and so on.

Possibly at the expense of enough resolution that facial identification of the target is not possible?
Or do you have another camera for that close-up shot?

 

[gth]

Multiple cameras. Some not as obvious as the Hikvision turrets.