Mark1 wrote in post #8911799
I thought the Series 1 were their budget lens. I had one and was glad to get rid of it.
Vivitar Series 1 of the 70's = good stuff, Vivitar Series 1 AF stuff = garbage, Vivitar Series 1 New stuff - 7mm f/3.5, 85mm f/1.4 = good, Vivitar Series 1 Mirror lenses = mirror lenses... i.e. junk.
The Promasters (GOD, that name is a misnomer) are generally Tamron, Sigma, and Tokina (news to me) rebadges and you can pretty much tell immediately which it is, because the lens design/barrel/finish is the same as the original. The ProMaster brand is kind of a house brand of Wolf Camera/Ritz Camera. With Ritz closing down so many stores 6 months ago, I thought we'd seen the last of ProMaster, but it seems it won't die just yet.
The difference between a ProMaster 75-300 and a Canon 70-300 IS is quite a bit, if the price difference is $200 only, its a bargain to get the Canon, and that particular ProMaster is overpriced. The 70-300IS is like a $600 lens, the ProMaster should be $200.