Some third party lenses are excellent, some are crap. Go to www.fredmiranda.com and look at reviews for anything you're considering. While I have a lot of really expensive Canon glass, a couple of my best lenses are third party-- Sigma 105mm macro, and Tamron 28-75.

In order to get a blurry background, you need a wide aperture so that you get shallow depth of field. If you're shooting Canon, the 50mm f/1.8 will give you a very shallow depth of field and is quite reasonably-priced. Nikon probably has an equivalent.

You more or less get what you pay for in any lens. There are no particular hidden traps to bite if you use third party lenses. Check your reviews and buy what works for you.

The effect you want for portraits is achieved with a shallow depth of field. Note, for a lens of a given focal length the depth of field decreases as the lens apeture widens (a wider aperture corresponds to a lower f-stop) therefore chose a lens with a low minimum f-stop.

> Will i be sacrificing any or ALOT of image quality by going with Sigma, Tamron, Tamron (or whatever that name is...)...??

It's not quite as simple as "brand name / OEM" vs. "3rd party". For example, the "kit" lenses that sell with low-to-mid grade cameras tend to be pretty sucky, even if they DO carry the "big" names. Premium glass from the 3rd parties will slaughter most of the "kitty" lenses for quality. On the other hand, that "premium" 3rd-party glass does NOT come at the uber-cheap prices you see on some of the 3rd-party glass.

I've never heard of the big makers invalidating warranties from using 3rd-party glass. So far as I know, the 3rd parties pay license fees to the Big Boys for the privilege of using their proprietary mounts (though the 4/3 world may be different, I hear Oly kinda/sorta made it an "open" mount...?) .

Personally, I *adore* the Tamron 90mm/2.8 macro. Absolutely world-caliber glass.

I've also had a chance to use their 14/2.8 (but not extensively) and their 180/3.5 macro (also not extensively). Both are (at least) very good, but I don't know them well enough to say that they play in the Big Leagues.

As a cheap telephoto, the Sigma 400/5.6 is "OK" but not great; on my 10MP body, it's VERY soft (unacceptably so) wide open.


> Also- what kinda lens do i want to get to do portraiture that leaves JUST the subject in sharp focus,
> and blurs everything else alot...... - that's shallow depth of field, yeh...??

Yep. Get a "fast" lens with a wide aperture (low f/number: f/2.0 or preferably less); keep the aperture as open as possible, for a narrow depth-of-field.

Telephoto's also have shallower depth-of-field (at any given aperture), and being a bit closer to the subject can narrow your d-o-f too...

As Patti suggested, a good used 50/1.8 (that's a 50/1.7 for Sony) would likely be a great place to start. Many regard the 85/1.4 as the "ultimate" portrait lens, giving a wider aperture AND some telephoto. FWIW, some of my favorite portraits have been shot with (oddly enough) the 90/2.8 Tamron macro I mention above (partly, of course, it's the photographer: he's brilliant).


- Steve

<<Will i be sacrificing any or ALOT of image quality by going with Sigma, Tamron, Tamron (or whatever that name is...)...?? >>
Each lens is different, even within the major manufacturers. Check reviews for a specific lens.

<<I am seeing that across the board they are cheaper..., but is it a case of getting what u pay for....? >>
Sometimes you pay for the name "Nikon" or "Canon" as well. Third party are cheaper for all sorts of reasons, some aren't weather sealed, some have plastic construction. Then again some are built incredibly well. So, once more, check reviews for a specific lens.

<<Do the big guys invalidate anything if u use 3rd party lenses in any way >>
They support the body, but not the lens. If lens doesn't talk to the body, that's an issue with the lens company.

<<Personal experiences anyone>>
I love my Tamron 17-50 f2.8

<<Also- what kinda lens do i want to get to do portraiture that leaves JUST the subject in sharp focus , and blurs everything else alot.>>
For that you need to open up the lens - f2.8 or lower. Cheapest lens is a 50mm f1.8. Canon and Nikon both have ones around $100 that work great. For a zoom lens, get an f2.8 constant lens. Sigma, Tamron, and Tokina all make good ones (did I mention I love my Tamron?).