2CD2387G2-LSU/LU Tear down and refocus (with pictures)

venturis

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I recently purchased a 2CD2387G2 8MP ColorVu to replace a 2386G2 monitoring the driveway and front yard of my home.

After conducting some side-by-side testing with the existing 2CD2386G2 I came to the conclusion the new 2CD2387G2 was not as well focused. Images from the 2CD2387G2 were noticeably softer and lacked the razor sharp clarity and fine details of the existing 2CD2386G2 under the exactly same conditions. Both cameras were fitted with 4mm lens. Nothing I did with bit-rate settings or compression settings made the images from the 2387G2 as crisp as the 2CD2386G2.

Faced with either sending the camera back to the supplier (which was not really an option since it was purchased from China), putting up with the loss of clarity or just fixing the focus myself, I decided on the latter.

I've disassembled and changed lenses in Hikvision cams several times before but never on a G2 ColorVu. I was concerned it was going to be difficult to disassemble and refocus but I was actually pleasantly surprised how easy the entire process. To help anyone else wanting to try I decided to take a few pictures.

STEP 1 - Disassemble the turret housing. Once the back mounting is off, three small Philips head screws need to be taken out to remove the plastic cage.

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STEP 2 - Free the camera ball from the turret housing, locate and remove the three Philips head screws which secure the two halves of the camera housing. (NOTE: Put a pen or texta alignment mark on the housing before disassembly to make sure it goes back together in the same orientation.

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STEP 3 - Carefully separate the two halves of the camera housing.

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STEP 4 - Disconnect the two multicore cables between the PCB and the pigtail. I small pair of long nose pliers will make the job easier. Gently squeeze the retaining clip against the connector body and pull away from the PCB. The rear camera housing is now free.

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STEP 5 - Locate the three black Philips head screw securing the CCD and lens assembly to the camera body and remove them.

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STEP 6 - Disconnect the ribbon cable connecting the CCD/Lens assembly to the main PCB by lifting the small brown catch located at the base of the ribbon cable. The imaging module and lens can now be lifted out.

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STEP 7 - Camera CCD/Lens assembly is now free to work on. You will note that in my case the lens focus is fixed by a resin/glue around the complete circumference of the lens. (Try not to touch the lens itself to save the trouble of having to clean it later)

Pressing the pointy tip of a knife into the resin and lifting slightly will break the adhesive. Work you way around the lens pulling gently at the adhesive as you go. In my case the adhesive came away in one piece.

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STEP 8 - Reconnect the two ribbon cables to the PCB and the cable to the CCD/Lens assembly and fire up the camera. From here you can point the lens at a suitable target and adjust the focus to your liking by rotating the end of the lens.

NOTE: In my case there was no grub screws in the two threaded holes at the base of the lens assembly but I've seen pictures of a 2087G2 which is essentially the same camera in a box format that had grub screws installed. These need to be loosened a couple of turns before attempting to rotate the lens. Failing to do so might cause damage.

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Please note that in most case fine tuning the focus requires only minute rotation of the lens. In my case the total adjustment needed to obtain the razor sharp focus I'd been chasing was only around 1-2 degrees of rotation. Before starting to refocus it's worth putting an alignment mark on each of the fixed and rotating parts of the lens to help gauge how much the lens has been moved.

Finally, fix the lens in place using either the grub screws if installed or you will need a little adhesive such as from a glue gun. Do not use acetic cure adhesives otherwise the will corrode the electronics.

Assembly is the reverse of the above.
 

wittaj

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Awesome! Thanks for documenting your lens adjustment for focus!
 

triumph202

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I've got mine apart now. That lens glue is a PITA to get off, I've only just started removing it.

One thing I have noticed is the silver metal bracket (the lens module mounts to) has adjustment screws. They are used to mount the lens square to the optical sensor. I've got the LHS of the video frame out of focus and the lens is noticeably closer on one side. I'll post pictures later.
 

triumph202

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One thing I have noticed is the silver metal bracket (the lens module mounts to) has adjustment screws. They are used to mount the lens square to the optical sensor.
I'm not so sure that's the purpose of those screws as the optical sensor appeared to be fixed in relation to the lens. But there are two screws, adjustable, with locking glue on them.

So my camera was substantially out of focus. I moved the lens probably 5 to 10 degrees. Distant objects are way sharper and the focus issues on the LHS a lot less obvious.
 

venturis

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I'm not so sure that's the purpose of those screws as the optical sensor appeared to be fixed in relation to the lens. But there are two screws, adjustable, with locking glue on them.

So my camera was substantially out of focus. I moved the lens probably 5 to 10 degrees. Distant objects are way sharper and the focus issues on the LHS a lot less obvious.
That's great you managed to refocus the cam. Shame the glue didn't come away as easily as it did in my case. It really did just peel off in one continuous piece after I broke the bond with a knife.

There was no grub screws installed in the lens barrel. Only the threaded holes were present. I suspect that some of the focus issues arise when the glue is applied which then moves the barrel slightly as it sets. How else can so many cams come from the factory out of focus?

Installing a temporary screw in the grub screw hole just before the final fixing adhesive is applied will ensure nothing moves as the adhesive cures. Then the screw can be taken out. A 3 mm metric thread screw is all that is needed.

I'll be interested to see images taken after focus correction. Rotating 5 to 10 degrees on the lens barrel is a lot although the image you posted in your other thread really did really look like it could have been much better.
 
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triumph202

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There was a small amount of glue left on the threads of the lens which made it stiff to adjust- so I didn't bother putting any glue on mine. On some older Hik cams I've done lens changes and used teflon plumbing thread tape to make the lens firm (so you can still adjust it, but it won't move accidentally. Someone posted on here about it and it works well.)

I've had other Hik "powered by dark fighter" cams with fixed lenses that have come from the factory out of focus. I don't know how they can stuff up something so basic and important to the camera's operation. I could notice with the Colorvu, when the car was parked in the driveway, that the more distant areas of it were going out of focus compared to the closest section. So I was pretty sure it was out of focus.

Those two screws are a bit strange. They basically seem to changed the angle of the lens/ optical sensor to the metal bracket that mounts to the camera chassis. On mine, it's very obvious the whole assembly is tilted compared to the bracket. I didn't adjust it, but am thinking I should have made adjusted it so it was square to the bracket. Looking at it again, there's a screw that mounts the copper part of the bracket that looks like it fouls and affects the angle.
 

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venturis

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There was a small amount of glue left on the threads of the lens which made it stiff to adjust- so I didn't bother putting any glue on mine. On some older Hik cams I've done lens changes and used teflon plumbing thread tape to make the lens firm (so you can still adjust it, but it won't move accidentally. Someone posted on here about it and it works well.)

I've had other Hik "powered by dark fighter" cams with fixed lenses that have come from the factory out of focus. I don't know how they can stuff up something so basic and important to the camera's operation. I could notice with the Colorvu, when the car was parked in the driveway, that the more distant areas of it were going out of focus compared to the closest section. So I was pretty sure it was out of focus.

Those two screws are a bit strange. They basically seem to changed the angle of the lens/ optical sensor to the metal bracket that mounts to the camera chassis. On mine, it's very obvious the whole assembly is tilted compared to the bracket. I didn't adjust it, but am thinking I should have made adjusted it so it was square to the bracket. Looking at it again, there's a screw that mounts the copper part of the bracket that looks like it fouls and affects the angle.
That image showing lens base being at an angle to the CCD bracket would definitely explain the focus shift from left to right of frame on your camera.

Seeing some of these issues such as poorly focused lenses and what I can only describe as a manufacturing fault with the lens not being exactly parallel to the CCD is a worrying sign that Hikvision has no QA control.

The screw you show that fouls with the lens is clearly not right. The photos of my camera above, the lens body appears to be in hard contact with the CCD mount bracket as you'd expect.

If you bought the cam from an Australian seller I'd be trying to make a warranty claim since there is no way that's acceptable quality. These cams sell for nearly $500 AUD which is not an insignificant amount.
 
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triumph202

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Closest pic of your camera I could find compared to mine. (Light levels played with on your pic to show more shadow detail.)

That image showing lens base being at an angle to the CCD bracket would definitely explain the focus shift from left to right of frame on your camera.

Seeing some of these issues such as poorly focused lenses and what I can only describe as a manufacturing fault with the lens not being exactly parallel to the CCD is a worrying sign that Hikvision has no QA control.

The screw you show that fouls with the lens is clearly not right. The photos of my camera above, the lens body appears to be in hard contact with the CCD mount bracket as you'd expect.
When I looked closely I wasn't so sure that the CCD/ optical sensor could move independently to the lens barrel. That copper bit seems to be more of a heatsink than a mount. There's a heatsink pad (soft) between the copper bracket and rear of the sensor. So I don't actually think that is the LHS focus problem, but could be wrong.

Comparing the two pics, I'm wondering if they fitted a screw that is too long to hold the copper bracket?
 

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venturis

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When I looked closely I wasn't so sure that the CCD/ optical sensor could move independently to the lens barrel. That copper bit seems to be more of a heatsink than a mount. There's a heatsink pad (soft) between the copper bracket and rear of the sensor. So I don't actually think that is the LHS focus problem, but could be wrong.

Comparing the two pics, I'm wondering if they fitted a screw that is too long to hold the copper bracket?
If it looks like the lens body could be rotated and fixed in a different position, is it possible that its been installed in the wrong orientation and that there is a clearance hole in the lens base that should have lined up with the screw that appears to be fouling?

I'll need to take apart my camera to check or see if I have a better photo showing the screw in question.
 

triumph202

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In the other photo it shows locator lugs on the lens assy that fit in between the suspect long screw and the glued screw. (Into the black hole which is visible on the copper section.) There's matching holes in the silver bracket. So the orientation appears okay.

Perhaps it's just happened that the screw on lhs in the photo (the tighter clearance side) was done up too tight? It looks to be fully bottomed out. Then that's thrown everything out? Yours seems to have a slight gap on the rhs, I'm guessing both sides should have a small gap?

Edit: looking again, your lhs is touching and the rhs has a slight gap. So it does appear something is physically wrong with mine. It's too late in the day to pull it apart. Maybe tomorrow.
 
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