So I recently upgraded to the Canon R7 for birding and hiking here in the rainy Pacific Northwest, but I am stuck on which telephoto lens to pair with it. I have been researching options for weeks now and my head is spinning.
I keep seeing people recommend the RF 100-400mm f5.6-8 because it is super light and cheap. But I worry that f8 on the long end is going to be way too dark under the thick forest canopy we get up here. The other option I looked at is the adapted Sigma 150-600mm Contemporary. The extra reach sounds amazing for small birds, but I read some forum posts about autofocus pulsing issues on the R7 sensor, and it also looks like an absolute beast to carry around all day.
Here is what I am working with:
- Budget: around $800 max, totally fine buying used
- Use case: local songbirds and deer during morning hikes
- Portability: needs to fit in a standard daypack without breaking my back
Is the RF 100-400 actually usable in lower light if I push the ISO, or should I brave the weight of the Sigma? Or maybe there is another EF lens I am overlooking?
Get the Canon RF 100-400mm f/5.6-8 IS USM and dont look back! Seriously, I shoot with this exact setup for hiking and it is an amazing combo. The adapted Sigma 150-600mm f/5-6.3 DG OS HSM Contemporary is way too heavy for a daypack and the AF pulsing on the R7 is incredibly frustrating. Here is why the RF is the way to go:
- Weight: It weighs next to nothing. You can carry it all day without even noticing.
- Autofocus: The native RF autofocus is blazing fast and locks onto bird eyes instantly.
- Low light: Just push your ISO! The R7 handles noise well, and running software like DxO PureRAW makes f8 shots look pristine anyway. Grab a used RF 100-400 for under $500 and you will love it!
I spent years shooting in the damp Oregon woods and faced this exact speed vs weight dilemma. In my experience, you have to compromise.
- Canon RF 100-400mm f5.6-8 IS USM: Extremely light and has great IS, but that f/8 aperture really forces you to push the ISO under dark branches.
- Canon EF 400mm f5.6L USM: You get a constant f/5.6 and legendary sharpness, but you lose image stabilization. Personally, I chose the RF for hiking.
Honestly, shooting birds under the PNW canopy is a constant exercise in frustration. You either carry a heavy brick and destroy your back, or you end up with noisy, unusable shots because of the dark f/8 aperture. I've spent years trying to find a cheap, light, fast lens for these damp woods, and it just doesn't exist. If you want my advice, look for a used Canon EF 400mm f5.6L USM. It goes for around $600 used now. Yes, it lacks image stabilization, which is incredibly annoying in low light, but the autofocus is blisteringly fast on the R7 and the image quality destroys the cheap zooms. Just pack a lightweight monopod to help steady your shots in the dark. It is the best budget compromise I've found.
