I'm a hobbyist photographer and want to choose a new wide angle lens and don't want to spend a lot of money (ideally less than $500 used... less then $400 would be better!). I would use the lens for:

1) group shots when I can't back up enough (this happens regularly when taking photos at my kids' school... usually I feel like I need to just back up a 3-5 feet in order to get everyone and am limited by buildings/desks/walls/etc.)

2) landscapes

I already own:

* Canon 50mm f2.5 (macro)
* Canon 28-80mm f3.5-5.6 (kit)
* Canon 75-300mm f4-5.6 (kit)

I would like a wider angle than my 28-80mm but I *really* like the blur/brokah from my 50mm lens. The kit lenses are okay, but the 50mm makes me happy in terms of quality of images and the blur/brokah.

I think I have narrowed it down (thanks to this site) to:

* Canon EF-S 18-135mm f3.5-5.6 IS - ~$300+ used
* Sigma 10-20mm f/4-5.6 EX DC HSM - ~$450+ used
* Tamron SP AF 17-50mm f2.8 XR Di-II LD Asph. IF - ~$350+ used
* Canon EF 20-35mm f2.8L - ~$325+ used

The most important factors are:

1) wide enough for my two uses
2) image quality

next would be:

3) brokah/blur for when I want the background blurry

Any advice is much appreciated!

Thanks in advance

Do you mean the Sigma 17-50/2.8 (reviewed here http://www.bobatkins.com/photography/reviews/Canon_EF-S_17-55_Sigma_17-50_review.html) or the Sigma 18-50/2.8-4.5 (reviewed here http://www.bobatkins.com/photography/reviews/sigma_18-50_28-45_review.html ? There is no 18-50/2.8 as far as I know. The 18-50/2.8-4.5 sells for $199 new, so $240 is a bad price! However it's a very good price for a Sigma 17-50mm f/2.8 EX DC OS HSM (so I suspect it isn't that lens).

Both decent lenses, though not super wide. You don't need (or want) a superwide lens for most portrait type work, but you might for landscapes, depending on the type of landscape shots you want to take.

If you want WIDE, then the best option on your list is the Sigma 10-20.

If you want fast then you haven't listed any prime lens options like the Canon 35/2, 28/2.8 or 24/2.8. The Canon EF 35/2 is an excellent lens if you just want to go a bit wider

The wider you go for portraits and group shots the more likely you are to get perspective distortion and wide angle shots won't have the "pop" of shots taken with a 50/1.8 or the 50/2.5. You won't be able to throw the background out of focus as much for example.

Maybe your best compromise out of the lenses you've listed would be the Tamron 17-50/2.8

I think that lens is the older Sigma 18-50/2.8. It's no longer made but it was a decent lens and I think $240 is a decent price. They sold for over $400 new as I recall. If it's in good shape it would be a good buy. If you didn't like it you could probably sell it for what you paid for it.

I presume you're shooting with a crop sensor digital DSLR. I presume you must be since you were considering EF-S lenses. The Sigma is also a crop sensor only lens.

The only advantage of a prime lens is that it would be faster than what you have now. Faster means better background blur. If you want wider than 28mm as well as more blur than you get at f3.5, then one of the 17/18-50/55 f2.8 zooms would be your best bet.

At the same or similar price I'd take the Tamron SP AF 17-50mm f2.8 XR Di-II LD over the Sigma 18-50mm f2.8 EX DC if I could find one. Slightly wider and I think a slightly better lens overall.

The T3 is an APS-C crop sensor DSLR. Any lens for EOS will fit including all EF-S lenses. All 3rd party lenses for EOS will also fit.

Here's a link to an article on crop sensor cameras and lenses - http://www.bobatkins.com/photography/tutorials/crop_sensor_cameras_and_lenses.html

I have used a Sigma 12-24 on my 40D and been very pleased with the results.  I also got myself a cheap 50mm lens.  For many years I have used a Pentax with a screw thread mount.  I found an adaptor that allows me to use my Pentax lenses on an EOS camera.  This not only gave me a 50mm 1.8 but also allowed me to used my old extension tubes for close-up shots.  Again I have been very pleased with the results.  OK I do not get automatic focus but I lived without that for 50 years.  For the outlay on the adaptor I can also use my old f3.5 135mm lens.
Ken

I have articles on everything! Try these two for info on background blur:

http://www.bobatkins.com/photography/tutorials/fast_primes_background_blur.html

http://www.bobatkins.com/photography/technical/bokeh.html

I read the articles and my understanding is that prime lenses tend to have wider maximum apertures when compared to "equivalent" zoom lenses (e.g. 50mm f/2.5 vs 28-80mm f/3.5-5.6). The wider aperture allows for a faster shutter speed and for more background blur.

Some other take aways:

* Some lenses may need to be "stopped down" to a smaller aperture to get a sharp image so the fact that it can take photos at the wider aperture isn't necessarily useful. You need to know the apertures the lens can take sharp images at.

* Maximum blur can be achieved with a longer/telephoto lens (though they are less practical for portrait work). The Canon EF 85mm f1.8 is a good choice (for portraits) due to the balance of good blur, sharpness, price, and reasonable working distance from subject.

* More blur can be achieved with a full format camera (vs. crop sensor) due to the focal length needed to produce an image with the same magnification. Since I only have a crop sensor camera, I don't really need to understand this one

Hopefully, I'm understanding correctly... thanks again for all the pointers. Now, I'm wanting to buy the 85mm f1.8! (I love blur!)

Kristen

Hi Kristen
I think I can answer your query about why a full frame camera can give better blur because it uses a longer focal length for a given magnification.  In an earlier posting Bob gave a link to an article that talked about the focal length for a given sensor or negative size.

The blur produced by a longer focal length lens at the same f stop is greater than that produced by a lens with a shorter focal length.  To create an image the same size on an APSC format camera requires a shorter focal length lens than that required for a full frame camera.  Thus the lens you would use on a full frame camera would give more blur.  The same lens used on an APSC camera would give the same blur. However on the APSC camera you would get less of the subject in the image (it would be cropped).  You could compensate for this by moving further away from the subject.

Enjoy your new lens.  When I used to shoot using 35mm film I used a 135mm lens for portraits and got great results.  On an APSC camera this equates to an 85mm lens, the focal length that you have selected.  I think that you will not only get more blur, you and your subjects will feel more comfortable because you are further away from them. 

Ken