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Firemanjim

Perfect Lens Alignment And Focus Dxg-125v

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OK..I will try to explain how I get the lens and the exchanger perfectly paralell to the CMOS sensor on the DXG125. Being perfectly paralell is the key to being able to focus the camera lens. If it's not perfect you will have one side or the other out of focus or possible the top and bottom of the video. I use old PCB boards as my platform. Whatever you choose to use it will need to be thin as possible and very rigid. You will need some 2 part epoxy, 3/8" drill bit, and a air compressor or a can of compressed air, a Dremel tool with a rasp bit and a cut off wheel, and a dial caliper. I am assuming everyone knows how to disassemble the camera. So you will break the camera down completely and remove the stock lens. DO NOT THROW IT AWAY YOU WILL NEED IT!!! After disassembly put the board with the CMOS sensor in a zip lock bag to protect it from the dust.

Now take your platform and cut a peice 2"x2" and drill a 3/8" hole in the center. Does not have to be exact. Take the stock lens that you removed and unscrew the small center lens from the outer holder. It has a drop of glue on it from the factory so it might need some force.

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The base of the original lens has 2 screw holes. The outer ring is exactly 3/8". Take your 2 part epoxy and mix up a little. Now glue the lens holder in the 3/8" hole.

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Now take your Security2000 lens exchanger holder and you will need to file down the ridge around the bottom till it is perfectly smooth. With your dial caliper measure all 4 sides and file till they all are EXACTLY THE SAME. A thousandeths difference can screw the focus. You do not want any ridge at all. You want the exchanger to sit as close as possible to the platform. When you epoxy the exchanger holder in place make sure you orient the slots where the exchanger runs up and down. Not side to side.

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This is what it looks like when complete.

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Now we're cooking with gas! Thanks for sharing FMJ!

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OK...Now we need to prep the front cover. You will need to take out the 3 small screws holding the small lens hole in place. Remove it and trash it. Now remove the 3 outer screws and push out the glass. Now put the red ring, chrome ring, and black plastic cover back in and replae 3 outer screws. Now you will need to dremel out most of the chrome ring to get the lens exchanger holder's lens barrel to fit thru. You will also dremel out quite a bit of the inner plastic and top screw holder. Will look like this when complete.

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Now you will need to put your cut off wheel on your dremel and carefully clip the top 2 corners on your exchanger mount so they will pass by the top 2 screws that hold the CMOS board in place.

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Now finish your hack . I route my wires out the top left corner of the camera instead of out the bottom. Reason being I GOOP my 10 position servo in place over the speaker hole and the top cross bar. Hope this helps everyone.

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As far as focusing....night time focus is best far away from the CMOS. Daytime focus is close to the CMOS so we have to find the perfect mid point. I do this in the daylight with the color filter over the CMOS. I start by slowly screwing the lens in till it is almost in focus during the daytime and I take a 15 second video aimed at a realtor sign at exactly 30 feet. If it is not in focus I screw the lens in just a tid bit and take another video. I keep doing this till I break the thresh hold where daytime focus is acceptable. I have found that when I check the night time IR focus it will also be perfect using this method. Hope this helps.

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