There are several people i encountered that firmly believe that if the lens on your camera is not a "true brand" name (i.e. Nikon or Canon only) or a "fast" lens which we know it comes with a price, it is not worth it. I have a Nikon D50 with a 28-90mm Sigma f/3.5-5.6 lens and personaly I think it works realy good and was looking into upgrading my inventory and get a 50-200mm (VR) from Nikon, but also see that Sigma has something similar. Is there really a big difference between a Nikon (or Canon) vs a Sigma or Tamron?

sigma and tamron both produce lenses that can match the big two on quality - at least on their regular brand lenses. there are, however, some downsides. I like my Tamron lenses but compared to the Canon's I have they are very slow, noisy and a bit industrial. image and build quality are both perfectly fine though.

Thank you very much for your reply.

I really think that the difference between Sigma (don't know about Tamron but it must be the same) and the 'big two' decreases constantly.
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I would say you also have to go lens by lens. Some of the third party stuff is good, and some of it isn't as good. (same goes for the canon/nikon stuff). My sigma 10-20 is very good, and im very happy i bought it. One thing that bugs me about sigma is there lens caps. The caps on both ends are horrible compared to the ones nikon ships with there stuff. I almost want to replace it with a nikon one, but they are too expensive.

edit: I should mention that the caps do work even though i don't like them. I just find the rear one harder to get on, which is annoying, and the front one never seems to be on as tightly. You kinda have to put it on and then twist it a bit into the filter thread so it stays. The nikon ones you just squeeze and stick on. Much better:P.

While I haven't had any experience with Canon's L-Series lenses, I have found Sigma's to be quite comparable to Canon's regular line. Although, I haven't had the same problem with the lens caps as Milo.

To add in my own opinion lol. I personally just gained my new ally (Canon Rebel XTI) as a birthday present. getting this badboy instead of a car was something I actually enjoyed. Of course it came with the 18-55mm lens and all was happy. I love the camera and love the lens, my issue came in when of course we all need new lenses, after purchasing a Canon EF 75-300mm f/4-5.6 III I had found a closer image and the joy of being farther back and still getting that crisp image. I love the camera and lenses but my TRUE joy is taking photos of birds... SADLY I cant capture much from the ground as the birds enjoy the rooftops, I have looked into some lenses and found an attachment that is to triple the distance of your lens (unsure how well) and also looked into some 650-1300 lenses... My question is now formed... Does anyone have any suggestions on what a 16 year old should save up for and what you think will be the best to achieve his long distance goals?

Personally I think a 16-year old should be saving up for women. They can be damned expensive you know.

I would try to make do with what you've got at the moment. But if you've got have more magnification you could try extension tubes but they're not going to give as much as you want.

I second that zorro, and mr. Hippie, save up the money for a really good lens and then decide, you'll get your answer quick when you have the ability to make the choice rather than dreaming about the possibilities. It also lets you keep working with what you got and you may realize you don't need it. Think you can avoid women for that long?

LOL! Women can never be avoided... Me and my girlfriend have currently been dating for 10 months now and man does money fly. Earning a Hundred through cleaning my house and mowing lawns and then in one night my pocket is filled with 4 receipts and $2.35 lol... I appreciate the replies and Will of course continue to work with what I have in hopes to capture the perfect photos...

Also remember you don't necessarily need more than 300mm to take a good bird shot. There is a picture floating around my house that my grandpa took of two birds. They are feeding each other or something. I would say its quite a good shot. Unfortunately he is not around anymore to ask how he took it, but my mom says he never had a lens longer than his 50mm. I'm not sure i believe her entirely, but she is probably right. Try some bird seed to attract the birds. Then sit still and wait for them to come. It wont always work, but you can probably get some good shots.

Thanks to all for your input, very much appreciated.

you could also coat the branches with asphalt to slow the little blighters down and negate the need for any sort of long lens :-)

LOL I guess that would work lol... I catch a few birds flying around the houses but never near mine... Im going down to Colorado on Sunday where my grandparents own some land so hopefully I will get some good shots of many things...

I have 2 Sigma lenses that I love, a 170-500mm and a 105mm Macro. I am currently looking into getting rid of my Canon 75-300mm f4-5.6 IS AF USM and get a Canon 70-200mm f4 L.