Telephoto lens question

[cmcm789]

I have a Mk1 55-250 IS Canon lens and occasionally enjoy photographing runners (10k races etc). I have my 60D set to AI Servo, but this is not the fastest or most accurate lens for focus. I would guess that if i fired 6 shots in rapid succession, under 50% of those would be in focus (usually alternate shots) i guess it's because the motor takes so long to readjust.

I like having the compact size of this lens, but would was getting itchy feet for a change. i also like having IS for taking photos of my kids at play.

I have searched for canon compatible telephoto lens to see if i can find a real world comparison of autofocus speed and accuracy but no luck.

The lens i have looked at are the newer 55-250 IS STM (is STM quicker than non-STM?), Canon 70-300IS and the Tamron 70-300VC which seems to get good reviews.

Does anyone have experience of these lens for sports, or any recommendations?

Thanks

(*Also posted in Amateur Photographer Forum)

 

[Mrrikki]

Tamron is the best in my opinion, that 70-300 VC lens is amazing value and quality, only downside is variable apertures are annoying but you will have that issue with all of these lenses.

On a side note for moving subjects most of the time the high shutter speed to freeze the action means you don't really need IS / VC on.