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07/04/2006 04:35:44 PM · #1 |
| I am totally clueless on lenses zoom,macro is all foregin to me. Can anyone recommend a good book that will explain it all |
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07/04/2006 04:41:08 PM · #2 |
Can't really recomend a book, but i really suggest going into your local photography store and asking any questions you have! I find that the smaller stores are more than happy to answer any questions you have about lenses, and most are more than happy to let you try them out. It's much easier to learn when you have it infront of you rather than learning out of a book :-)
Edit: damn English
Message edited by author 2006-07-04 16:42:05. |
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07/04/2006 04:53:28 PM · #3 |
lens basics:
Two types of lenses:
1. Prime/fixed lenses are those which cannot zoom in and out. They are generally faster, sharper, and cheaper than most zoom type lenses.
2. Zoom lenses are those which can zoom in and out on a scene.
(pretty easy so far right?)
mm's and what they mean:
- The lower the mm number the wider a lens is and the higher it is the longer the lens is. Not the physical length mind you but how close or far away things seem in the viewfinder. On digital I'd say 28 and under is considered wide around 35-50 is normal (similar to one of your eyes) 85+ is telephoto or super telephoto.
What does the F3.5-5.6 etc mean?
-the F number listed on the lens is the maximum size of the aperture of the lens. If you have a lens that's say 15-30mm and the F stop value is 3.5-5.6 at 15mm the maximum will be 3.5 and at 30mm the maximum will be 5.6. Notice that it changes, we call this a variable aperture zoom lens. A constant aperture lens (including all primes) would be for example if the lens said 16-35mm F2.8, then lens can open to F2.8 at any focal length the lens has.
Note that sometimes this can be figured as a ratio such as 1:2.8-4.0. This means the same as it saying F2.8-4.0. A variable aperture zoom lens.
Magnificiation/macro:
Here is where it can get tricky. If a lens has a decently close to macro (1:1 ratio (the size of the subject is the same as the image of the subject cast on the sensor)) it may have a ratio listed on the lens. For example a lens that can get pretty close to macro but not all the way might say 1:2 on it. The reason this is confusing is because the F stop can be also listed as a ratio. Luckily this is usually only put on the lens if it's a macro lens. If you start getting past true macro, you may start seeing ratios such as 2:1 or 5:1 meaning 2 or 5 times larger on the sensor than the actual object is. |
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07/04/2006 04:58:34 PM · #4 |
| let me know if you have any other questions or that didn't make sense. |
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07/04/2006 05:07:44 PM · #5 |
i have a question...I know IS means image stabilization, VR=vibration reduction, what does USM mean (for a camera lens, not for PP).
Thanks
Eric
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07/04/2006 05:10:12 PM · #6 |
Originally posted by anmldoc:
what does USM mean |
Ultrasonic Motor - Basically it can focus faster and quieter than the older type. This is the Canon word but other makers have a similar term - I think HSM is sigma's version of the same thing, not sure about the others.
Message edited by author 2006-07-04 17:10:53. |
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07/04/2006 05:18:19 PM · #7 |
Originally posted by robs:
Originally posted by anmldoc:
what does USM mean |
Ultrasonic Motor - Basically it can focus faster and quieter than the older type. This is the Canon word but other makers have a similar term - I think HSM is sigma's version of the same thing, not sure about the others. |
And it makes a bigger difference then you think it would.
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