Yes, it still front focuses near the minimum focusing distance (on the 30D, it was fine on the 1D), but I can live with it. This lens may be sharper than I once thought. Here are three full size crops shot at f4. I would recommend this lens to anybody looking for a good way to get to 300mm @f4 for less than the cost of the Canon 300mm f4 prime. Processed in RAW. Sharpening set to 4 in DPP Calvin Johnson James Johnson Both of them. You'll also notice all of these were taken under 150mm. I would not have been able to get these with the 300 prime. Kudos to Sigma for making both a 100-300 f4 and a 120-300 2.8. Hopefully Canon will catch up in the fast telephoto zoom area. Obviously their telephoto primes can't be beat.