Best Lens for Spotting at LAX: 100-400mm vs. 150-600mm?

I've been spotting at LAX (Los Angeles International Airport, LAX) quite frequently, and I'm looking to upgrade my lens. Currently, I'm using a 70-300mm on a Canon R5, but I've been considering the Canon RF 100-400mm f/5.6-8 or the Sigma 150-600mm f/5-6.3 DG OS HSM Contemporary.

Given the variety of spotting locations around LAX, including the iconic In-N-Out Burger and the Imperial Hill, I'm torn between these two lenses. The 100-400mm seems great for versatility and portability, while the 150-600mm could give me that extra reach for distant shots, especially for arrivals on the north runways.

Does anyone have experience using these lenses at LAX or similar airports? How do they perform in terms of sharpness and autofocus speed, especially in different lighting conditions? Any recommendations on which lens would be better suited for LAX spotting? I'd love to hear your thoughts or see some sample shots if you have them. Thanks!

I've used both lenses at LAX, and each has its merits. The Canon RF 100-400mm is excellent for its portability and versatility, especially when you're moving between different spotting locations like the In-N-Out Burger and Imperial Hill. It's also easier to handle for longer periods, which is great if you're out for a whole day.

However, the Sigma 150-600mm really shines when you need that extra reach, especially for arrivals on the north runways where distance can be a challenge. It offers impressive sharpness and decent autofocus, though it's a bit heavier to manage. If you're primarily shooting from further distances, the Sigma might be the better choice. Consider your primary shooting location and style to decide which trade-offs are worth it.

I've used the Sigma 150-600mm at LAX, and it definitely offers impressive reach, which is fantastic for capturing arrivals on the north runways from spots like Imperial Hill. However, it is heavier and less portable than the Canon RF 100-400mm, which could be a consideration if you plan to move around a lot. The Sigma's autofocus is quick, but in low light, both lenses might struggle a bit, which is typical in their class. Given the versatility and lighter weight of the Canon 100-400mm, it might be better suited if you're frequently changing locations. If you often find yourself needing more reach, the Sigma could be worth the extra weight. Have you considered testing both at a local camera shop before deciding?