OK, I've had this lens for a couple of weeks now and here are my initial impressions. 1. The build quality is great. Pretty durable, "beatable" lens that has earned a place in my bag. 2. The Image quality is OK but you've got to be really, really careful with this beast. First of all, it's heavier than it seems. Without the HLD-2, this lens would be almost impossible to handhold. It's extremely front heavy and having a battery grip counterbalances the lens. Having said that, you've got to be aware of your SS at all times. I've shot hundreds of thousands of exposures through the years and I've hand-held the Oly 14-54 @ 1/8 and gotten sharp images. This lens really accentuates any camera shake or movement to the max. I've found that shooting at anything less than 1/250 is a waste of harddisk space. Additionally, it's not the sharpest wide open or at 400mm. Stopping it down a couple of stops to f 8 or 11 is wise. Went out and bought a monopod and that helps big time. But I don't expect to be blowing anything up larger than an 8x10 with this lens. On a scale of 1-10, I'd give this lens a 7. Dat be my thoughts on da Sigma 135-400.
:thumbsup:
Mark