GT680W lens hood & lens cap

Dashmellow

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Umpteen
One thing that always seems to me to be missing on Dash Cams are suitable lens hoods. Lens hoods (also called lens shades) are useful on all cameras but especially so in a challenging photographic environment like inside a motor vehicle near to a windshield where you have no control over the constantly changing angles of sunlight as it hits the camera. Lens shades can eliminate or at least cut down on glare and lens flare from sunlight striking the lens from an oblique angle. For a photographic image with good contrast you want the light that is coming straight through the lens onto the sensor, not the light that can bounce around inside the lens barrel and a lens hood can increase contrast by minimizing this extraneous light. Dash cams have rather wide angle lenses so there is a limit to just how deep a lens hood you can get away with but I've found that even a modest shading of the lens can make for a dramatic improvement of image quality under certain lighting conditions. A lens hood can also help reduce some of the annoying reflections of objects in your windshield.

Lens caps are another thing are often not supplied with dash cams, except for the Mobius and a few others. It is always important to protect the lens from dust, fingerprints and scratches especially when transporting or storing the camera.

On my GT300W I discovered that a standard plastic 35mm film canister is the exact diameter to make a lens shade out of. Cut the top part off at the right length and it slips over the lens barrel and makes a perfect tight fit. The remaining bottom portion of the film canister does the same and makes a perfect lens cap! Since there are quite a few dash cams on the market that use the same housing, this tip can work on a variety of cameras.

So, after my recent "stealth" paint job on my GT680W I decided it too needed a lens hood and cap so I started looking around my house and workshop for something that would work. The lens barrel on the 680W is tapered so I needed something that would fit the base of the barrel which is exactly 36mm. The first thing I found was the cap from an aerosol room freshener spray can that fit perfectly. It has tapered ribs inside which makes for a nice tight friction fit when pressed on, so I had my lens cap, ready to go with no alterations needed except for a paint job! Then, after some rummaging around I discovered I had some old plastic pipe fittings sitting in a drawer in my workshop that had an exactly 36mm inner diameter.....perfect!.....so now I had my lens hood. All I needed to do was cut the pipe fitting with a hack saw, sand it smooth and paint it flat black. Like the lens cap it fits tightly with just the friction of pressing it on.

The trick to fashioning a lens hood is to make it as absolutely deep as possible without causing any vignetting of the image. This can require some trial and error but the easiest way to determine the right length and the place to cut the pipe is to set the camera up as a web cam on your computer and use a ruler or anything you can measure with accurately against the side of the lens barrel until you just see the ruler enter into the image area on your screen. Make the cut just a "tad" too long so that you can adjust the length shorter with some sanding. You can't make the thing longer again once you cut it. ;)

This is a simple, inexpensive project that can improve the image quality of your videos and protect your lens.

hooded.jpg

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capped680.jpg

blackcap.jpg

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Nice job. Have you added extra batteries through the led light spot?
 
Interesting. .
 
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