Southern Lady Loc: Statesville,NC

I am using a Canon Rebel XTi with a 28-200 tamron lens. When I was shooting 35 mm film I used a 24 mm wide angle lens for weddings and group shots with great results. Now that I am shooting digital I am confused about what lens to get. I assumed that the Canon 18-55 mm lens would be even better as far as giving me the wide view I need in close quarters with large groups of people. But from what I have read here and on reviews it appears that a lens such as a 17-35 is actually only giving me the same width as a 27-45 mm equilivant to film lens. Is that correct? If so what do I really need to get the same results as a 24mm film lens? I hope all of this makes sense. I have a tight budget so I need to find something for between $150-$200 range. Thanks for any help you guys can give me.

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

You would need a 14mm lens on that body . It would give you the 35mm equivalent of a 23mm lens. I'm sure that would be kinda pricey... I shoot Nikon (1.5x rop factor vs your 1.6x) & I use a Sigma 10-20mm zoom for my ultra wide shots (15-30mm FX equivalent on my camera)

skooters Loc: Flagstaff, Arizona

I believe it would be around 15mm. Due to the sensor being 1.6

Some one correct me if I am wrong.

St3v3M Loc: 35,000 feet

Canon EOS Rebel XTi
http://www.usa.canon.com/cusa/support/consumer/eos_slr_camera_systems/eos_digital_slr_cameras/digital_rebel_xti#Overview

Specifications
http://www.usa.canon.com/cusa/support/consumer/eos_slr_camera_systems/eos_digital_slr_cameras/digital_rebel_xti#Specifications

Features
http://www.usa.canon.com/cusa/support/consumer/eos_slr_camera_systems/eos_digital_slr_cameras/digital_rebel_xti#Features
"This APS-C size sensor (22.2 x 14.8mm) has the same 3:2 ratio as film cameras, enabling an effective angle of view that is 1.6x the normal EF Lens focal length."

With a 1.6 multiplier, you will need a 15 mm lens to achieve the 24 mm focal length you desire.

EF Lens Lineup
http://www.usa.canon.com/cusa/consumer/products/cameras/ef_lens_lineup

There are third party lens offerings of course.

Shellback Loc: North of Cheyenne Bottoms Wetlands - Kansas

The lenses that I found that will provide that coverage that are close to your price range are:

Canon EF-S 10-18mm f/4.5-5.6 IS STM Lens
B&H $249 (used)

Bower 14mm f/2.8 Ultra Wide Angle Manual Focus Lens for Canon EOS Digital SLR Cameras
$259

with a 1.6 factor - you are looking at:
Lens Equivalent
10......16
11......17.6
12......19.2
13......20.8
14......22.4
15......24
16......25.6
17......27.2
18......28.8
19......30.4
20......32

robertjerl Loc: Corona, California

Canon EF-S 10-18 mm @ 299.99 list is the closest to your budget that will get you as wide or wider than the 24 mm you used before. You might find a refurb or used closer to your budget. At the Canon On Line store the refurb is 269.99 when they have any, you just have to keep checking since stock comes and goes.

big-guy Loc: Peterborough Ontario Canada

Your camera has a crop factor of 1.6 which means that for any given lens focal length you need to multiply that number by 1.6 to get the equivalent 35mm focal length. So your 18-55 would have the field of view of a 29-88.
18x1.6=28.8
55x1.6=88

If you had a full frame camera then there would be no crop factor. Your camera's sensor is smaller (22.2 x 14.8 mm) than full frame (36 x 24 mm) so basically, the outer limits are not capture-able. Also, if you had a Nikon (23.6 x 15.7 mm) your crop factor would be 1.5 as that sensor is ever so slightly larger than Canon.

Linda From Maine Loc: Yakima, Washington

Just wanted to chime in about the 10-18 mm ultra-wide angle that robertjerl mentioned: you might call Canon or read reviews on it. I love it but have only used for landscapes. The edges of the frame do distort near the 10 mm end; in other words, you could stand just a few feet in front of a large group of people, get them all in the shot, but the ones at the edges will look like they're leaning inwards.

The 18-55 is likely your best bet; you'll just need to stand further back and crop if you can't fit everyone in.

Check B&H for used lenses. I have purchased two from them. Here is an 18-55 for $130. Free shipping, no tax.

http://www.bhphotovideo.com/c/product/801153949-USE/canon_2042b002_ef_s_18_55mm_f_3_5_5_6_is.html

Refurbished 10-18 mm for $250:
http://www.bhphotovideo.com/c/product/1109628-REF/canon_9519b008aa_ef_s_10_18mm_f_4_5_5_6_is.html

Blurryeyed Loc: NC Mountains.

You are going to have a hard time on that budget, your best bet may be the new Canon 10-18mm. It is actually a superior lens optically and is considered to be an ultrawide on your camera, equivalent to a 16-28mm on your old film camera. It costs $299 new and is a recent lens so finding used is probably pretty tough. I had the Canon 10-22 and it was one of my best lenses, the 10-18 is supposed to be better optically which I find very surprising as I happily paid $800 for my 10-22 and was very happy with it.

Mr PC Loc: Austin, TX

Most lens distortion can be corrected for using standard presets in Lightroom for many lenses. Still, I think I'd back up and crop the picture using a little longer focal length. Kelby's books talk about getting too close with a wide angle lens and the people don't look as good as standing back with maybe a 70-120mm focal length because it tends to flatten out big noses, ears and such.

Barbara E Loc: Long Island, NY

Just bought this lens Canon 10-18mm few months ago...love it!

CHG_CANON Loc: the Windy City

I have 28mm and 35mm primes so I do know how much wider the difference can be in the small focal lengths. That said, you might also consider the EF-S 24mm f/2.8 STM that will shoot like a 38mm lens. You might have to take a step or two back, if space is needed, but at $149 new tonight for this brand new lens from Canon, you should think about this idea too. Look to at KEH.com for used lenses. They're a bit cheaper than B&H-used and they back up their lenses with a 6-month warranty.

ralphc4176 Loc: Conyers, GA

I see that others have given you the specs on a lens that would work for you. In addition to B&H, I highly recommend KEH Camera (www.keh.com) for used equipment. Everything I have ever bought from them has been at least as good as described on their Web site, and their prices are quite reasonable.

lowkick Loc: Connecticut

When you were shooting 35mm film, you were getting the full effect of whatever lens you were using. If you had a full frame digital camera, you would be getting the full effect of your lenses since the full frame sensor is the size of a 35mm negative. But your camera is a crop sensor camera, meaning the sensor is smaller than than full frame sensor. Canon crop sensors have a multiplication factor if 1.6 times, so your Tamron 18-200mm is really giving you the effect of a 18.8-320mm lens on the crop sensor. And your 18-55mm is really giving you the view of an 28.8-88mm. If you want to get the effect you used to get from a 24mm lens, you will need a 16-35mm lens, which will give you the equivalent of 25.6-56mm on your crop sensor camera.

amfoto1 Loc: San Jose, Calif. USA

Optical distortions are hard to correct in ultrawide lenses. A 15mm lens is what you need, to equal the angle of view of your 24mm on full frame.

However, 15mm is 15mm and that's pretty extreme. It will have some distortions that can especially be a problem with portraiture. Too close to your subjects, you'll get perspective distortions where peoples' noses look big while their ears look small. Also there is exaggerated anamorphic distortion that occurs near the edges of the image area, with extremely with lenses. The result are "Hellboy arms" (the arm nearest the edge looks much larger than the other arm) and "elephant legs" (the person's leg near the bottom edge of the image is heavily distorted and looks massive).

Both these types of distortion are very difficult to correct in post-processing. It's not like slight pin cushion or barrel distortion, or moderate vignetting that can be pretty easily fixed via software. These are heavy distortions that can especially be problematic with portraits.

Zoom lenses are hardest for manufacturers to correct... especially inexpensive ones. Prime lenses are easier, but there are few that are truly ultrawide on crop sensor cameras.

Best solution: Back up and don't even try to use such an extreme lens. On your camera - with its crop factor - a 28-200mm acts as a "standard to strong telephoto" and is a "safer" focal length range to use for portraiture. A 28mm or 24mm prime lens likely would have fewer distortion effects.

If you do get an ultrawide, be sure to shoot some tests with it in advance. You'll likely find a limit in focal length you want to use, and can avoid some of the distortions by not getting too close to your subject and/or being careful to keep them well away from the edge of the image (crop the image later instead, if an off-center composition is wanted).