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Old Jan 4, 2004, 11:27 PM   #11
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Unfortunately, I donít believe itís as easy as "something 300 ft. looks like its 75 ft".

Here are some broad generalizations and then some facts.
The human eye sees roughly the same as a 50mm lens on a film camera.
The larger the focal length of the lens (> 50mm), the larger something looks in the picture compared to the human eye at that same location.
The smaller the focal length of the lens (< 50mm), the smaller something looks in the picture compared to the human eye at that same location.

Now for the facts. Here is the reason the ďxĒ factor that is used in fixed lens cameras is basically meaningless on an SLR. The max focal length divided by the min focal length gives you the ďxĒ factor.

A 100-300mm zoom lens is a 3x lens.
A 16.6-50mm zoom lens (if one existed) is a 3x lens.

That first lens would have roughly 6 times more magnification than the human eye. The second lens a wide-angle lens that would actually make things smaller (by 1/3) and can record a wider field of view than the first lens. Both are ď3xĒ lenses, but they are completely different lenses, for completely different purposes.

Does that make sense?

As to what the numbers mean. What you need is the definition of ďfocal lengthĒ. Instead of rewriting one, here is one already written:
http://www.dpreview.com/learn/Glossa..._length_01.htm

Itís a rather technical definition. The first sentence is really the definition and the other info is useful but not actually necessary (but in your case you might find it helpful, assuming you understand it.)

I completely agree with lg. You had a 38-380mm f2.8-3.5 lens on your previous camera. To be happy, you at least need to match the 380mm on the long end to get the same telephoto reach with your DRebel. Since that camera has a 1.6x field-of-view crop, you really need a lens that is 240mm lens (or larger.) The trouble is going to be that the maximum aperture is f3.5 on the long end. That is fairly large (which is good.) Matching that in a 300mm lens will be expensive. Your best choice is probably the Sigma 100-300 f4 APO EX lens (found here, for example:
http://www.bhphotovideo.com/bnh/cont...722&is=REG
) The problem is that it will cost you as much as the entire Drebel at $839USD. A lot of money, but a very good lens. It might not be as good as a similar Canon, but itís cheaper and itís still very good. If you donít need F4 (which is close, but still not as good as what you had) then things get cheaper when f5.6 is available. This lens:
http://www.bhphotovideo.com/bnh/cont...059&is=USA
a 100-300 f3.5-5.6 lens from Canon is much cheaper ($280) but optically it isnít nearly as good as the SigmaÖ. And the price reflects that.

I could go on. I donít want to drown you in info (I probably already have.) Iíll end with this. A SLR/DSLR is a system. Youíll end up spending more money on lenses than the camera body. The nice thing is that when you replace that camera body in X years, youíll keep using those lenses. So they are an investment in future photography.

If Iíve confused you, please feel free to ask. Weíre a friendly bunch. If I donít answer I bet others will.

Eric
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Old Jan 5, 2004, 1:18 PM   #12
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Eric, thanks for the info. Every little bit helps. OK, I've just got a couple of questions for you.

1. How is the Sigma Zoom Telephoto 100-300mm F/4.0 EX IF HSM w/ a 1.4 or 2.0 TC? Is a tripod a must? Also is a tripod necessary for just that lens without the TC?

2. How does the Sigma Zoom Telephoto 70-200mm f/2.8 EX APO IF HSM w/ a TC compare to the 100-300? Do any of the Canon EF IS USM lenses compare? The Canon 75-300 USM/IS reviews have been mixed. Some say it's very poor for sports action photos.

I'll mainly be doing action sports shots from college football stadiums (D1) and some basketball pics. I'm beginning to understand the lenses, but the more I read, the more unsure I am about which one(s) to get. $1,000 is my threshhold. Thanks for everyones replies. Your posts are very valuable in trying to understand my Dreb and lenses.
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Old Jan 7, 2004, 3:10 AM   #13
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Thanks for all the replies, it helps alot.
It will take a while til i will understand it.
Ill have to talk to a friend of mine, he just got that big pro. kodak with the i think 14 pix. a 6000.00 set up , he has many lenses .
He works for the sheriff dept. So he really didnt buy it with his money,lol.
Anyway i hope i can pick this up.
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Old Jan 7, 2004, 8:16 PM   #14
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Just got a bunch of my pics posted. Only the BB pics were taken with my DigiReb. All the football ones were taken w/ an F717.

http://www.pbase.com/aaltenburger/irish_pics&page=all
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Old Jan 8, 2004, 4:23 AM   #15
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When you took the bball pictures did you use a different lens, or just the one that comes on it?
Were you down on the floor or up high with a zoom?
Inside gym shots i really cant do well with , ive had some luck in some well lite white lighted gyms.
I..............cant ...........wait ...............to ............get ................the
....................REBEL......................... .................................................. .................................................. .................. :shock: :shock: :shock:
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Old Jan 8, 2004, 7:55 AM   #16
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I was actually in the 1st row on the baseline for the game. The lens I used was a Canon EF 70-200mm, not that good of a lens. I wish I would have had more time to experiment before going to the game. Lost some good shots. Next time I'll be better prepared.
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