Hikvision bullet M12 lens focussing

[bob bear]

I have about a couple of dozen Hikvision fixed-focus bullet cameras in service, mainly DS-2CD2032s and DS-2CD2042s and generally speaking they offer great performance for the money, but occasionally I get one that is not focussed too well and in the past I've opened them up, removed the blob of hot-melt glue tacking the lens into position and optimised the focussing. I've just got a DS-2CD2035 which is not focussed as well as the others and on opening it up I find that this lens appears to be locked in place with a liquid glue that has gone down into the M12 threads and cannot be removed with a pair of tweezers like the old hot-melt blob could - Aaaargh - don't you just love Hikvision.. I'm reluctant to apply too much force to the lens to try and turn it. Has anyone got any suggestions or experience of this latest lens locking technique?

 

[Phil]

We haven't.
Possibly something at YouTube?

 

[bob bear]

Thanks for the reply, Phil. I originally found the info. for the old hot melt glue blob method of lens locking on You Tube but not this latest liquid glue method. I could just apply force and hope the glue shear strength is less than the sensor pcb strength, but it's a bit iffy. I was hoping someone had done it before me..

 

[bob bear]

Well, I took the bull by the horns, cut some 2mm thick by 6mm wide rubber strips for protection and by clamping the two halves of the lens in pipe grips, (remove the lens assembly completely from the aluminium chassis), with the rubber strips as buffers and by using gentle pressure & torque I managed to unscrew it relatively easy and once freed it would screw up and down quite freely, so now to re-assemble it and focus it. Fortunately the thread-lock compound that Hikvision has used is fairly soft with not too much shear strength, just right to stabilise the lens position once set but not enough to prevent it being moved if necessary. Phew..
I noticed that this unit didn't have a little bag of silica dessicant in it like they usually do. Fortunately I seem to accumulate them so I'll have one somewhere. Always useful to help prevent fogging.