If it is the same focal length then generally that seems true. I don't think there is a physics reason behind it. I think it is the same as camera lenses. Faster (brighter) lenses are usually part of camera companies premium lines and are better engineered. Anyway why don't you try Kodak's Ektapro Select line of lenses. I own one and it's really nice. Those things were really expensive back in the day but can be had for less than $50 if you are patient. I have not done any scientific head to head lens comparisons. I just bought Ektapro Select and stopped worrying about it. I actually have a few other lenses in different focal lengths from other manufactures. I researched them at the time and they seemed to get good reviews too. Can't remember the names of them.
Originally Posted by Normo