 BetterPhoto Member |
wide-angled lenses i am totally new to this, and I need to know...if a wide-angled lens has a higher X, is it better or worse? I am looking to buy a 0.7, but have been told to buy a 0.45! can someone help please???
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Alan N. Marcus |
Hi David, Cameras marketed now days are generally equipped with a zoom lens. My guess is your camera is equipped with a zoom. Now as you zoom “in” (makes images appear larger) this region or zone of the zoom is known as “telephoto”. Telephoto lenses give a narrow field of view because they act like a telescope giving an enlarged view. As you zoom your lens “out” the images get smaller. As you reach about the middle of the zoom range, you achieve a “normal” view. Now as you continue to zoom “out” more, your lens enters into the zone we call “wide angle”. This makes images appear tiny like looking through binoculars backwards. This is the region we call “wide angle” because the view is very wide. You can always achieve a wide angle view by just stepping back, this is increased camera-to-subject distance. As an example, suppose you are photographing a group of friends. You line them up shoulder-to-shoulder and compose in the viewfinder / view screen. If the guys on ends are cropped out (missing), you can step back, this increased distance yields a wider angle of view. Or you can accomplish the same thing staying put and zooming “out”. As you zoom “out”, from the cameras prospective, it’s the same as stepping back i.e. you bring about a wider field of view. Either way you accomplish your goal of shooting a group with no one omitted. Sometimes its impossible to step back. That’s when we want to zoom “out” (simulates stepping back). When we run out of room to back step we start using the zoom “out” feature. When this trick runs out we need to do something optically. Most cameras used by professionals allow the camera lens to be dismounted and replaced by another. The replacement can be a zoom or a fixed lens. With regard to your question, you are asking about wide angle lens. So the answer is, if possible replace the camera lens with one that gives a wider view. Sometime replacement(your case I think) it's not possible because yoy camera design will not allow lens mounting and dismounting. Sometimes it’s a matter of cost. A super wide lens might be too expensive. What to do? You can buy a supplemental lens that mounts over your existing camera lens. Supplemental lens are reasonable as to cost but they are not as good as a complete lens replacement. The X factor you are asking about is a measure of power or strength of a supplemental lens. A .5 means you multiply your current lens by .5 (same as dividing by 2) to figure out what will happen. A .4 is weaker than a .5 so it won’t give as wide a view. Which should you buy? The weaker (smallest number) is best as to overall sharpness. The larger the number the more effect you will realize. I think, in your case, this is a matter of effect rather than overall sharpness. I say go for the stronger. Good luck,
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Jon Close |
You usually give great, detailed answers, Alan, but I think you're off on a couple of points here. First, "You can always achieve a wide angle view by just stepping back" is incorrect. Backing up does not give a wider angle, the lens's angle of view does not change. Backing up only allows more to be included in the view by changing perspective and magnification. Re the supplemental lens factors, With wide-angle converter the smaller the number, the greater the effect. .4x will give wider angle than will .5x. But with lower numbered factors (wider angle) the greater the optical compromises/distortions introduced. Typical digital compact cameras have lenses that are equivalent to 35mm-xxx. A .7x wide angle converter will give the equivalent to 24.5mm, which is plenty wide for most people. A .45x converter would give the equivalent of 15.75mm, but is apt to be less sharp and introduce more barrel distortion. Composition at such ultra-wide angle becomes more difficult, and objects near the border of the image will be unnaturally stretched.
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Alan N. Marcus |
Jon, A tip of the hat to you.
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