Canon EF 28-135mm f/3.5-5.6 IS USM or Canon EF 85mm f/1.8 USM?

Question

I'm looking to purchase a new lens. The types of photos I take are:

1. Portraits
2. Candids
3. Street
4. Random objects here and there
5. Architecture
6. Occasional landscape when on vacation

They are ordered in descending order of preference and frequency. I know that the 85mm would be an ideal choice seeing that I love taking portraits, but the 28-135 seems to have pretty good review and it's definitely good for street, or any general walkaround when I don't want to change from prime to prime all the time. Of course I plan to get a 85mm eventually if I were to buy the 28-135, thing is which one of them would be a better investment for now given a budget constraint. (ie if I buy one I'll need to at least wait another year or so before I buy another)

Note that I already have a 50mm f/1.8 and am only a hobbyist photographer.

Answer

Well, a prime lens is usually much better optically than a zoom and usually has much better light gathering ability, which in this case is pretty clear. Having said that, the flexibility of a zoom is hard to ignore, especially if it is a good one, and your interests are spread about a bit.

I think, if you're not looking to sell your results professionally, then the zoom will give you more ability to cover the range of interests you have and do it quite well. Ideally, if money were no object, then a series of high quality of primes would be better option for professional work, but you'll be lens swapping more. So, given the circumstance, I would probably recommend the zoom and then recommend that you start to acquire some different prime lenses as the opportunity arises (either new or used, don't ignore the used market) and you find focal lengths from the zoom that start to interest you most.

By the way, all that isn't to say you can't get professional grade output from the zoom. You certainly can, but the conditions under which you can do it are more limited.

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