Ok, i'll tackel this one at a time. The difference between telephoto and standard in the case you mentioned means that the 28-300 makes it a "normal" to "telephoto" wheras the fixed focal 300mm is just telephoto cuz it doesn't have the rest of that focal range. The difference between the picture taken with the 300mm fixed and the 28-300 will be absolutely the same as far as composition goes. What you see through the 28-300 all zoomed in is exactly what you'll see from the 300 fixed. Where the lenses differe is in terms of image quality. A prime is almost always sharper and of higher quality than a zoom unless you get up into the thousands of dollars professional end zoom lenses. What dude up there mentioned about it being faster means the f number is usually lower on a good quality prime than on a corresponding zoom lens. I say usually because there are some awesome zoom lenses with low fstops and some primes with higher fstops. The fstop indicates how much light is being passed through that lens... lower numbers are usually better because they give you more depth of field control as well as the ability to "open up" (drop the fnumber lower) to capture images in low light situations. So in a nutshell... depending on the quality of the lenses you picked the picture would be the exact same on the two lenses with the differences being in the quality of the picture itself in terms of sharpness, purple fringing, color and contrast and all that jazz which is all dependant on the specific lenses you pick. Oh yeah, primes are almost always cheaper than zoom lenses unless you get into really professional end stuff because they're easier to make (no crazy zoom parts.) So as a general rule prime = less expensive and better quality than a zoom and zoom = more expensive and versatile but at the cost of lower fstops and overall image quality. GENERAL rule i say because there are lenses that break this mold.
Originally Posted by Austin.Smith
Now to answer that second part about the all in one lenses. It's very difficult to manufacture a lens with a 28-300 range and as a result image quality and f numbers are sacrificed. You'll find on the 300mm end of that 28-300 the fnumber is really high, prolly in the 5 or 6 range which renders it useless for really anything indoors or less than bright sunlight. It's a convenient lens sure but at the expense of quality. On the wide end there will be a lot of distortion... it's likely to be very soft on the telephoto end and have a lot of purple fringing and all that. Yeah you've got a nice take me everywhere lens but not one of very good quality. The more you can break your focal lengths up into different lenses the better. They're easier to manufacture and you'll find the fstop range is often lower on lenses with tighter grouped focal lengths. Also it's always good to test shoot with a lens and read lots of reviews before buying one based on the specs on the side of the box. I recomend having a wide angle-normal zoom (maybe 18-50 or so) a normal prime (say 50mm) and a telephoto zoom (perhaps 70-200) to start with. It's best to buy QUALITY glass that'll last you through several body upgrades than to buy something for it's convenience then wind up hating it and replacing it because it's not a very good lens. Don't be afraid to spend more on a collection of good glass than you did your camera body. Quality glass will last you through several body upgrades in the future. I hope that helped out. Good luck.
Last edited by BonjiB; 09-20-2006 at 08:32 AM.
The name is pronounced bonn-gee-bee
Canon 1Ds Mark II
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