Sigma 150-600 vs Canon 100-400RF

[clint66]

Hey everyone. I’ve spent the last few days reading reviews and tests and I still don’t know which lens should I choose. I was planning to shoot planes in the sky, but I don’t know which lens should I choose. My budget is around 1000$. I’m using a canon R10. I’m talking about the C version of the 150-600. I heard that the stabilization and the AF on the 100-400 is great as well as the sharpness,but the focal length and aperture is pulling me away from this lens. I’m scared that the 150-600 will be too soft and the AF will be too slow and not good.

[ebiggs1]

"I have neither but the native mount is always going to work better.  And chances are that your crops will be better as I expect the IQ to also be better."

I tend to agree that native FL is always best and it does depend on the lens and camera used but I still say it is  generally true. Cropping or crop camera has and is and will be an ongoing debate as to which is better. Yet again it does depend on the lens and camera used plus how much knowledge you have with editing.

IMHO, if I needed 600mm I would go for the 600mm lens option over a 400mm with 1.4x tel-con 100% of the time.

[ebiggs1]

"...  due to the weight, it is best used with a tripod or a monopod for portability."

You know I hear this all the time and have for years. It is what it is and if it is too much for you, you need to find a different hobby. Of course tripods and even monopods have a place but it that's the only way you can use a big lens you are going to miss a lot of cool shots. It is no different than any endeavor we take on in life. You need to account for you own body type, strength, heath, everything, etc and choose wisely. 

I carry a 1DX with my Sigma 150-600mm f/5-6.3 DG OS HSM Sports Lens for hours and it's no big deal but that's me. It's not for everyone. Sometimes I even have my 1D Mk IV with a shorter zoom (24-70mm) at the same time.

Big tele zooms have two factors they are big and they are heavy. That's just the way it is.