Here are some shots taken in our yard on my first outing with the 150-400F4.5. This was not a test. Or, a review. I’m not qualified to test or review gear and don’t have the inclination.
I simply took off my 300F4+1.4 and replaced with the 150-400F4.5. Then walked around our yard taking shots that came along like I’ve been doing for the last 10 months. My objectives were to see how my preferred mobile birding approach might have to change and are the files comparable, or not.
I’m not going to have to change my birding approach. Although heavier, the 150-400 is very compact and balances superbly with the EM1X. The controls are very accessible and work flawlessly. It has mobility +.
My first impression specific to these files is I’m not giving up any quality compared to the 300, especially with extenders. I can keep prime quality and get the bonuses of longer reach\close-up magnification and versatility of zoom.
Just my first afternoon, but I’m feeling really good about the decision and looking forward to getting into the fields and woods with it.
Male Eastern Towhee 
Red-tailed Hawk 
Red-bellied Woodpecker 
Red-bellied Woodpecker 
Yellow-rumped Warbler 
Northern Mockingbird 
Red-winged Blackbird 
Brown Thrasher 
American Robin 
White-throated Warbler 
Female Eastern Towhee 
White-throated Sparrow 
Ruby-crowned Kinglet 
Male Eastern Towhee