We have all heard of its legendary performance.  Yet somehow, until you actually own one, the 300 2.8 IS sounds too good to be true.  I know that the lens has been upgraded, and the reviewers insist that the EF 300 2.8 IS version II has improved both the Image Stabilization and Autofocus while shaving off weight.  Some even claim that the image resolution is better in the new version.  That all may be true, and if money were no object, I would own that lens today.  But for those of us who do not have unlimited resources, a used copy of the first rendition of Canon’s famous performer is a relative bargain these days at little more than the cost of a 100-400. 
 

I bought the lens used, and took it out for a test drive to basketball practice the evening that I received it.   It was mounted to a 7DII since I find the 5diii AF inadequate for basketball.  What did I learn?
 

1. My gym is small for regular use of this lens at floor level, and my usual arsenal from 24 to 200 mm works quite well for basketball.  I should plan on staying outside the arc with the 300 unless I am trying to make intimate sportraits.  It is good, however for layups from the stands, or defense on the far court, and will be a wonderful addition for volleyball in that gym.  It will also be excellent at tournament time and college gyms that have more room behind the baseline. 40451-12 Practice
    
2. Autofocus, while not instant is fast and accurate.  I did not have a 100% keeper rate, but that more than likely reflects my need for improved technique and better learning the lens.   The lens is hand-holdable, but I’ll get a good workout using it.  Proper bracing and the usual bag of tricks will be important.
    
3. Image Stabilization allowed me to capture razor sharp images without a monopod, but its use would have dramatically improved my keeper rate.  A Gimbal head will make an exceptional platform in the great outdoors. 40791-12 Practice
4. I accidentally bumped the AF & IS switches several times, and that is not a good thing.  I will tape over them for regular use, just as I have on my 70-200 and 100-400.  Alternatively, a lens coat will prevent them from being moved unintentionally.
    
5. Today was just a practice, both for the athletes and for me, and working out with them helped me to get better.  I like shooting tight, and my instincts had me shooting too tight today.  The adjustment to shooting prime rather than zoom will take more than a single practice, and even will dictate adjustments when I step out for baseball this spring.  
    
6.     43561-12 Practice
    
7. Before heading to practice, I attached the original 2x extender to this lens, and was impressed with its performance as a 600mm f5.6 lens.  Fast enough for the autofocus to be useful and with enough reach to be meaningful, especially on my 7dii.  I look forward to the bird and wildlife potential of this beauty.
    
8. (600 mm, f 5.6, 1/60 sec, ISO 400)
    
9.  
    
10. I also did a quick test to see what would happen on macro attempts with this beauty.  The following is the handle from a dresser drawer, shot at about 6 feet on the 300 with 50 mm extension at f8.  At 40 mm wide, it fills the frame.        
     
11. 
     
12. The image quality from this lens is downright stunning.  Excellent resolution in the areas that are in focus and excellent separation from busy backgrounds add to the depth of visual appeal.  Although I have known that from others’ photos, experiencing it myself is a joy.
     

45611-12 Practice

In short, this lens looks like it is going to be a dream to use.  Everything that I have heard about it is true!  I can't wait to put it to "real world" use!