I am happy to announce the fifth week of our photo photography theme challenge and Raw editing challenge. It’s hard to believe it’s been a month since we’ve started these!

One of the most popular types of telephoto lenses is the humble 70-300mm variable-aperture zoom. They’re small, light, and cheap – and many of them still manage good image quality. It’s anyone’s guess why Nikon has taken so long to introduce one to their Z system. Instead, photographers who want a lightweight telephoto have been adapting the F-mount Nikon AF-P 70-300mm f/4.5-5.6E for years. However, now that Tamron’s 70-300mm f/4.5-6.3 is also available with a native Nikon Z mount, I wanted to compare the two lenses in detail. Which one is better?

Partly for fun – and partly to see if you get what you pay for – I wanted to compare two rather different telephoto zooms today. One of them is among Nikon’s most coveted professional lenses, the Z 100-400mm f/4.5-5.6 S; the other is a third-party optic that costs about 1/3 as much, the Tamron 70-300mm f/4.5-6.3. Which lens wins? Well, that’s not going to be a surprise, it’s the Nikon. But by how much? That’s what I’ll cover below!

I’ve just published my full-length review of the Tamron 70-300mm f/4.5-6.3 Di III RXD, which is Tamron’s first official lens for the Nikon Z system! The lens is also available for Sony E mount. You may have already seen my comparison articles between this Tamron lens and some of Nikon’s alternatives over the past couple of days. In total, I’ve written five articles of coverage on the Tamron 70-300mm f/4.5-6.3 so far: