Advice between two lenses

I'm a new Rebel XT owner and I'm looking to get a good all-purpose walkabout lens. I'm looking at a couple of used 28-135IS lenses. One is listed as F-3.5-5.6 and the other as F4-4.5. I'm assuming it's a trade-off between one being faster wide-angle and the other is faster at the longer focal length? Both are the same price so which is the better choice?

Thanks,
Rick

You don't say what brand but based on the limited info you gave I would think the f/4-4.5 would be the better choice. A more constant f stop.

There is only one 28-135 IS lens and it's 3.5-5.6. It's Ok but an average optical performer compared to the likes of Sigma 24-70 2.8 and Tamron 28-75 2.8. Having owned one I found it overpriced v's the competition. It's still popular tho'. Depends on your priorities.

Sorry. Canon.

Well that confused me as well. They only list one model in the new section, but these two in the used. I thought there might be an older version.

As far as my uses, being new to the hobby I want a reasonably decent quality lens with a bit of range. My plan was to get the 28-135 IS and then add the 100-400L for the far end hoping that would satisfy most of my needs then add a prime for portraits.

Thanks for the advice.

Probably a typo!

It's a reasonably decent quality lens with a bit of range. If you have a fast prime too then you may be Ok. The 100-400 IS L is a great lens.

A 17-85 would fit the bill.