I've been reading some of the previous suggestions, including re-reading my own, and I think we have gotten somewhat off-base. First, you state you are brand new to photography and want to do astrophotography, landscapes, portraits and close-up photography. You also plan to hike with your gear.
ļ¼Œåå€å·®ä»· ä½³čƒ½rf24-105 2.8 vs ä½³čƒ½ef24-105 f4 č…¾é¾™28-105 f2.8ļ¼Œå“Ŗę”Ærfå„—ęœŗé•œå¤“ę›“é€‚åˆä½ ļ¼Ÿ RF 24-105mm f/4L IS USM åƹęƔ RF 24-105mm f/4-7.1 IS STMļ¼ 首锵
The new RF 24-70 f/2.8L IS lens, as the last two letĀ­ters of the modĀ­el name reveal, has a built-in optiĀ­cal image staĀ­biĀ­lizĀ­er, as does the RF 24-105 f/4L IS I testĀ­ed here. On the othĀ­er hand, the EF verĀ­sion of the 24-70 f/2.8L II that I testĀ­ed here does not feaĀ­ture a built-in optiĀ­cal image staĀ­biĀ­lizĀ­er.
The Comparison: Canon vs Tamron. Canonā€™s EF 24-70 f/2.8L II USM has been hailed as the sharpest lens of its type, but it has no image-stabilization, and it carries a hefty price tag at $2049. On the other hand, Tamronā€™s new 24-70 f/2.8 VC USD does have image stabilization, but the companyā€™s optics only occasionally match the standards yYvs.