Are all 35mm zoom lens change f-stop?

[MitchLewis]

Yes, that's a perfect lens to replace the lenses you describe......except that it's "only" 2.8. You can buy an inexpensive 50mm that is 1.4. That's a significant difference especially if you're shooting indoors with natural light. I'd keep the 50mm f/1.4 and buy the 28-70mm. I've been saving my pennies to do exactly that.

 

[Lor]

Thanks! Yes, I already own the 50mm f1.4. I'm trying to carry as little as I can with me when traveling. So, swapping between multiple lenses isn't convenience to. That's why. I'm also thinking of dumping my 130mm f2.8 and 180mm f2.8 once I got the 80-200mm f2.8 lens. It would be nice to carry the 17-30mm, 28-70mm, 80-200mm f2.8, and 50mm f1.4 if need to.