How To Swing A Metal Detector For Success

Written by Dean Novosat

When swinging a metal detector, proper technique is essential. if you holdrepparttar coil too high aboverepparttar 150823 ground depth is lost. If you swingrepparttar 150824 coil to quickly, you may miss a valuable target. And if you walk too quickly, you may pass over a target.

I like to think ofrepparttar 150825 coil as a paint roller. Pretend that your coil is loaded with paint, and that you're trying to paintrepparttar 150826 ground that you're walking across. As you slowly sweeprepparttar 150827 coil back-and-forth acrossrepparttar 150828 ground imagine paint being applied. You're trying to paintrepparttar 150829 entire area you were trying to cover. If you can imaginerepparttar 150830 paint, you should be able to coverrepparttar 150831 entire area without missing a single spot.

As far asrepparttar 150832 height aboverepparttar 150833 ground goes, you want to holdrepparttar 150834 coil as close torepparttar 150835 ground as possible. Obviously, if you're working in tall grass you're maybe 3 or 4 in. aboverepparttar 150836 ground. Onrepparttar 150837 other hand, on a smooth flat beach surface, you can easily skimrepparttar 150838 coil right overrepparttar 150839 sand. Remember,repparttar 150840 higherrepparttar 150841 coil is aboverepparttar 150842 surfacerepparttar 150843 more depth you will lose. If they've got a old coin that is 6 in. belowrepparttar 150844 surface, and your detector can detect 8 in., andrepparttar 150845 coil is 3 in. aboverepparttar 150846 ground, you will miss that target. Ifrepparttar 150847 coil had been directly uponrepparttar 150848 ground you would be able to detect that target.

Taking Panoramic Landscapes - The Easy Solution

Written by Gary Nugent

I love panoramas. There's something very appealing about their shape. It's probably because we seerepparttar world more in these dimensions thanrepparttar 150707 near square format of standard film/sensor frames. It might also explainrepparttar 150708 upsurge inrepparttar 150709 popularity of widescreen TVs!

Panoramas have a reputation of being hard to take. There are dedicated panorama cameras available but unless you've got at least a thousand dollars to spare, you probably can't afford one! But you can take panoramas with any kind of camera.

All a panorama is, is a sequence of images where you turn slightly for each different frame. Inrepparttar 150710 old days, before PCs andrepparttar 150711 likes of Photoshop were around, you'd take your prints (there wasn't much point in shooting panoramas on slide film, for obvious reasons), lay them out on a table and position them over each other where they overlapped. A bit of sticky tape held them together. [As a side note, this technique was used by NASA to build up mosaic pictures ofrepparttar 150712 planets and satellites their spaceprobes visited, up tillrepparttar 150713 late '70s/early 80s when computers were introduced to makerepparttar 150714 process less laborious].

Now that PCs and image manipulation packages are easy to come by, high-quality panoramas can now be created by anyone. If you're shooting slide or negative film, you will need to have your images scanned before you do anything else.

DIY Panoramas

The idea behind taking panoramas with SLR cameras is thatrepparttar 150715 camera is rotated around its nodal point during each successive exposure. What'srepparttar 150716 Nodal Point? It'srepparttar 150717 point inside your camera whererepparttar 150718 light rays converge and flip over. It's different for different focal lengths (on zoom lenses) and for different prime lenses (fixed focal length lenses like a standard 50mm lens). It's important to rotate about this point to eliminate image mismatches due to changes in parallax. Parallax isrepparttar 150719 apparent shift of an object against a background due to a change in observer position.

Just to be clear,repparttar 150720 Nodal Point is notrepparttar 150721 same asrepparttar 150722 film/sensor plane. Generally, for most SLR cameras and lenses,repparttar 150723 Nodal Point is located somewhere towardsrepparttar 150724 center ofrepparttar 150725 lens barrel and lies in front ofrepparttar 150726 image/sensor plane.

The Problem With Parallax

Parallax is easily demonstrated by a simple experiment. Hold up your finger about 1 foot in front of your face and alternately open and close your left and right eyes. You'll notice that your finger shifts left and right with respect torepparttar 150727 background depending on which eye is open. Try another experiment: With your finger still raised, close one eye and turn your head from side to side. Notice how your finger moves with respect torepparttar 150728 background. This relative movement is due torepparttar 150729 fact that you’re not rotating your head around your eye’s nodal point, which is somewhere inrepparttar 150730 center of your eyeball. Instead, you’re rotating about your spine which is several inches torepparttar 150731 rear and off to one side. It is this relative side-to-side motion that we try to eliminate when setting up a camera for panoramas. [If you want to read up more about parallax, Wikipedia have a good explanatory article.]

Now, if you consider a camera held up to your face - it will suffer even greater parallax errors as it's farther from your spine (the point of rotation of your head) than your eye. It's surprisingly common for people to take panoramas in this fashion and then findrepparttar 150732 individual pictures don't match up.

So use a tripod and rotaterepparttar 150733 camera onrepparttar 150734 tripod. The parallax errors will be significantly smaller but there will still be some error involved. However,repparttar 150735 images will match up better than withrepparttar 150736 head rotation method.

Mechanical Contraptions

What perfectionists strive for is to haverepparttar 150737 camera rotate aboutrepparttar 150738 nodal point. There are brackets and contraptions available that will let you offset your camera fromrepparttar 150739 tripod's axis of rotation and with a little experimentation and trial and error, you can position your camera so that its nodal point is directly overrepparttar 150740 axis of rotation ofrepparttar 150741 bracket. Getting this spot-on means your images should line up perfectly.

A few months ago I bought such a bracket -repparttar 150742 Kaidan Kiwi. This comes in two halves which produce an L-shaped bracket. Its instruction manual explains how to set it up and findrepparttar 150743 nodal point for your camera and lens. However, you have to get your tripod perfectly level before using it, otherwise you end up with a curved panorama rather than a straight one.

I've had good success using this bracket, but it is large and heavy and certainly a bit too cumbersome to be carrying on long walks or while away on vacation.

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