Should I get the RF 600mm f11 or just grab an old EF 400mm f5.6 L for my R7? Im getting so annoyed trying to figure out which prime makes sense for birds and stuff because the crop factor on the R7 is already huge and I dont want to end up with a lens thats basically impossible to use when the sun starts going down.
Ive got this trip to a marshy area in South Carolina coming up in about two weeks and I still havent pulled the trigger. The 800mm f11 is on the table too but I feel like that might be overkill? Or maybe not enough light? My budget is stuck around 800-900 bucks right now since I just bought the body and I'm honestly starting to regret not just sticking with a zoom even though everyone says primes are sharper.
The 600mm seems like the sweet spot for reach but that f11 aperture is actually terrifying me for morning shots. Then again the old EF 400mm is legendary but it doesnt have IS and I'm worried the adapter will make it feel way too bulky. If you had to pick one for hiking around all day which one actually works better for smaller birds without making me want to throw the whole setup in the lake...
I have tried many setups for birding over the years and i really think the Canon RF 600mm f/11 IS STM is your best bet for the R7. While the Canon EF 400mm f/5.6L USM is a classic, the lack of image stabilization makes it a nightmare for handheld hiking on a high-res crop sensor. In my experience, the autofocus on the native RF glass is also significantly stickier for tracking fast birds in flight. The f/11 aperture is intimidating but modern noise reduction software has basically fixed that issue. On my last trip, I found that having the extra reach of the 600mm meant fewer heavy crops in post, which keeps your image quality higher than zooming in digitally. Its light enough to carry all day without a tripod which is a massive plus for marshes, and i honestly dont think youll regret the switch.
