75-300 usm II vs. 100-300 usm

Hi, I have an EOS 50e (elan IIe) with 28-105 usm and 380ex

 

flash (battery pack BP-50). I would like to add to these a telephoto

 

and currently deciding a purchase between a 75-300 f4.0-5.6 USM Series

 

II for $170 (introduced year 1995) or a 100-300 f4.5-5.6 USM for $210

 

(introduced year 1990). I wonder why the 100-300 is more expensive

 

when it is an older model lens and the 75-300 covers a little more

 

range than the 100-300, also both are practically the same speed. Can

 

anybody justify the difference in price and/or performance. By the way

 

my budget is limited to these price range only and Im no pro so please

 

dont convince me to buy the model with Image Stabilizer although I

 

know their better but it does not justify to me the cost which is

 

double. Thanks in advance to those who can help me decide. JOHN.

 

(Manila, Philippines)

Bob Atkins has a write up about the various Canon XX-300 zooms on his nature photography page on photo.net. The 100-300 has an actual ring USM, and a non-rotating front element, and is a little sharper at 300mm. You can check his artical for more details. Personally, if you have the money, I think the 75-300 IS is the best bet, considering how slow these zooms are.