So I finally upgraded to the R7 last month specifically for birding because of that 1.6x crop and the autofocus specs, but man, I am losing my mind with my current setup. I've been shooting wildlife for about six years now, mostly using an old EF-S setup, so I thought adapting my Sigma 150-600mm Contemporary would be a breeze. Nope. The autofocus pulsing and hunting on this R7 is absolutely driving me insane. I missed like three killer shots of a bald eagle yesterday because the focus kept jumping back and forth.
I have a trip booked for Costa Rica in five weeks and I desperately need a replacement lens that actually plays nice with the R7 autofocus system. The catch is my budget is super tight now after buying the body. I have about $700, maybe $800 max to spend.
Here is what I'm looking at:
- Canon RF 100-400mm f/5.6-8 IS USM (concerned about that f/8 aperture in the rainforest canopy)
- Adapting an older Canon EF 100-400mm L mark I (is the older AF system too slow for this body?)
Is the RF 100-400 actually usable in lower light or am I gonna regret the slow aperture? Or is there another budget option I'm completely missing here...
Honestly, grab the Canon RF 100-400mm f/5.6-8 IS USM. In my experience, the autofocus is lightning fast on the R7, way better than adapting old EF glass. Sure, f/8 is dark for the rainforest, but the R7 handles high ISO noise so well these days. The old EF mark I is just too slow to track birds anyway.
If you go with the Canon RF 100-400mm f/5.6-8 IS USM, you can easily find it used for around $500. To deal with the f/8 aperture in the canopy, use the leftover cash for software to clean up the noise. A couple of practical tips:
- Buy used to save at least $150
- Grab DxO PureRAW 3 to handle high ISO
- Keep shutter speeds fast and let the ISO climb It works surprisingly well for the price.
In my experience, avoid the EF 100-400mm Mark I. The AF motor and 2-stop stabilizer on that 90s lens just cant keep up with the R7. If you want reliability on your trip, try these options:
- Search used markets for a Canon EF 100-400mm f/4.5-5.6L IS II USM which adapts flawlessly.
- Rent a Canon RF 100-500mm f/4.5-7.1L IS USM just for the Costa Rica trip.
