Zoom comparison today! These are roughly equivalent field of views, given that the Olympus is a little bit tighter at the widest end with 40mm being roughly an 80mm FOV to start. I picked these lenses because I think that when people decide to buy lenses like these, they are looking more at the equivalence in field of view, not the actual focal lengths. Yes, there are going to be differences in depth of field and compression, but they are very similar in reach and how you will be able to compose with them. While these might not be award winning images, they are more than enough to give you the idea of the sharpness and real world usage of these lenses. The kit used: Olympus OM-D E-M5 Olympus 40-150/4-5.6R bought used at $100 Nikon Df Tamron 70-300/4-5.6 VC bought new $350 I went out to my local park and walked around and just started shooting. Exposure wise, the Nikon and Olympus were pretty much dead on for every shot. In the wider focal lengths, the IQ from the 2 lenses were pretty close, with only a slight end going to the Nikon/Tamron combination. Where there is a larger disparity is when you get to the 300mm FOV. The Olympus really started losing some clarity and sharpness once we got out beyond the 100mm focal length setting on the lens. That is when we are pixel peeping at 100%. How this equates into real world is a different matter as you'll see from some head to head examples. Subscribe to see EXIF info for this image (if available) Nikon Df/Tamron Image Subscribe to see EXIF info for this image (if available) Olympus OMD EM5/Oly Lens Combo I almost never show images without putting my post processing stamp on them. Once that is done, the gap between the 2 kits are narrowed. I will say this, though....possibly in defense of the Olympus optic...I think the lightness of the kit is a bit of a detriment for shooting these longer lenses. Without the weight for resistance, I think that I am having some issues adjusting to shooting this lens hand held out beyond the 100mm focal length. Even with the IBIS, I am going to need more time to get used to shooting this lens at the long end. I'm also wondering if the added weight of the HDL-6 Olympus grip might help add just that little bit of extra weight to give it a better feedback. The Tamron was not without its issues either, at least in reference to my usage of it. There were some test shots that the shutter speed was 1/1250 at 300mm at I forgot to turn the VC off. There was some visible blurring of the fine details because the VC got confused. For those unfamiliar, if you leave the VC on and put the camera on a tripod, the VC can actually introduce blurring because it compensates for camera movement when there is none. I believe this same phenomenon occurred here. So, just know that I am not claiming this test to be scientific....it is definitely more real world usage. On the IBIS/VC note - they both worked very well and when needed, kicked in and worked great. Subscribe to see EXIF info for this image (if available) Subscribe to see EXIF info for this image (if available) Olympus on the top, Nikon/Tamron on the bottom. At the end of the day, and for the price, the 40-150 optic is very good. It is also noticeably smaller than the Tamron/Nikon equivalent lenses in the range. Using the same Maxpedition "Mongo" shoulder bag, I can fit the Nikon Df with the Nikon 24-85 zoom attached and the Tamron 70-300mm and that pretty much takes up the main compartment. With the Olympus kit, I can fit the EM5, and all 4 of the Olympus lenses(17/1.8,45/1.8, 12-50,40-150) I own in the bag and still have room left over. So, take that for what you will...all of you who are looking for a smaller kit. Subscribe to see EXIF info for this image (if available) Subscribe to see EXIF info for this image (if available) Nikon on the top/Olympus on the bottom When you look at a lot of the head to head shots, after the post processing is complete - only but the most picky of pixel peepers are going to be able to know/tell which lens/camera was used for these shots.