JimH Loc: Western South Jersey, USA

Most DSLRs have a sensor that is some degree smaller than an old frame of 35mm film, which is used as the reference point. They are often called 'crop-sensor' or 'crop-body' cameras.

A "Full-Frame" DSLR, like the expensive Canon 5D or 1Ds, has a sensor about the same size as a piece of 35mm film.

The smaller sensor-ed cams, like the 7D, 50D, 60D, Rebel series, and the DX-model line from Nikon use a sensor that is about 60% of the size of a full-frame camera. So the image portrayed on it is a much smaller part (e.g., cropped) than that on a larger sensor.

It's not the SAME image, reduced in size. It's a REDUCED part of the SAME image.

Cappy Loc: Wildwood, NJ

For an overall general lens that has good IQ I like and use the Tameron 18-270 on my 60D. For specific purposes, and pictures that I would want for framing, I would use one of my prime "L" lenses.

jimmya Loc: Phoenix

Full Frame means the sensor is the same size as a frame
of 35mm film. Consumer level dslr cameras are smaller, or what's called a crop sensor.

mdorn Loc: Portland, OR

I recommend the 17-40mm f/4L. Best bang for your buck and you get L glass. I love mine. When you make the switch to FF, this lens will be perfect for landscapes.

heyjoe Loc: cincinnati ohio

anotherveiw do the telconverters work ,i have heard yes and no
i have the 70-200 /4 was thinking about getting 400 or 500
could save a bunch if they do thanks

02Nomad Loc: Catonsville, MD

Really well put!

RaydancePhoto

I have a friend that is a pro photographer, young guy, i'd say 25. He travels the world and mostly does fashion and personalities. Here is the kicker, he uses a Canon 30D and the 2 kit lenses that came with the camera. An 18-55 and a 55-300 I think. When I talk with him about gear, his eyes gloss over and he says he's fine with what he has.

His pics are amazing.

2 of his photos

heltonjkv96 Loc: southwest Virginia

I have the 17-40L and it's nice..I got it at B&H for 700.oo

jan457

I just purchased the Canon EF 17-40mm F/4 L last month. I love the lens. It is the REAL wide angle I've been always wanting. Depth of field stopped down is incredible. I use an original Full Frame Canon 5D (not the Mark II) and I have been using it for landscapes, and it does an amazing job.

If you set it at 17mm, and shoot wide open on F/4, on the 5D full frame sensor, I have noticed the normal vignetting (corner darkening) exhibited by ultra wide zooms on full frame. I only noticed when I shot I few indoor flash pictures against a pure white background. The vignetting practically disappears at F/8.

My understanding is that on the 50D's APS-C cropped sensor you use the center "Sweet Spot" of the lens, and vignetting is not an issue at all even at F/4. Of course, the 1.6x crop factor makes the lens perform as if it was a far less wide angle 27mm-64mm, not the "Ultra Wide" you are paying for.

The lens hood is ridiculously large, (as are a few other hoods I have) and it consumes much precious space in the camera bag, even if reverse mounted on the lens. I finally got a larger camera bag (Lowe Pro Nova 190) because I got tired of hauling all my lens hoods in a purple velvet Crown Royal draw string sack hanging on the outside of my older camera bag.

Finally, the lens uses big 77mm filters, and you'll have to get the ultra thin kind so the lens doesn't see the edge of the filter at 17mm. The B+W 77mm SLIM Circular Polarizing works great.

If it is going to be more than a year or two before you realistically move to a full frame camera, I'd buy the Canon EF-S 10-22mm F/3.5-4.5 USM, to truly enjoy the rich benefits of ultra-wide angle zooms. On the 50D, this lens will perform as if it is a 16-35mm due to the APS-C cropped sensor. Now that's Ultra-wide angle, something you just won't get with your current 50D and the EF 17-40mm F/4 L.

The EF-S 10-22mm F/3.5-4.5 USM will NOT work on a full frame camera (none of the Canon EF-S lenses do). So, you'll sell the Canon EF-S 10-22mm F/3.5-4.5 USM on ebay, and get the EF 17-40mm F/4 L when you buy the full frame camera body!

David

SteveH Loc: Putnam Valley NY & Boynton Beach, Fla

I think I can help. I had a cropped sensor Cannon and had the 17-40MM. It is very good for the cropped sensor cameras like your 50D but I didn't need it with the 50D and sold it.

I now have the 5D and love it. However, you don't get the same magnification for sports and nature shots like with the 50D. I would keep the 50D if you decide to go to a full frame sensor.

I am now using the 24-105 F4 L and love it. It is on my camera most of the time and with the 5D I can get as wide as I ever need. The F4 is great because I can always turn up the ISO and the lens is light enough to take on a trip and walk around all day. Wonderful for scenics.

I have the 70-200 F2.8 is which is a great lense and wonderful for sports, lower light situations and terrific for portraits with the 5D.

Then I use the 100-400 L for wildlife photos. It is here that I would love to have the 50D because you can get so much closer. I had a 2X Canon Extender that I sold because I was not happy with the results and the size of the F stop.

These three lenses in my opinion are a great combo. I don't think you can go wrong with this assortment and they are also perfect for your 50D.

Dria Loc: Ohio

I have the 60D and although I own a variety of lenses the:
Canon 24-105 f/4 L lives on the 60D. True love.

ThomasS Loc: Colorado

Dave,
I have an EF 17-40mm f4L and love it. Just keep in mind that on your 50D it is a 27-64mm (nothing wrong with that). I shoot a lot of low light, so I may eventually have to get a 16-35mm f/2.8L II, but at the price those are going for, I'm in no hurry. I just use a tripod, when necessary.

travlnman46 Loc: Yakima WA

Hi DaveJSchumaker: I understand that 50D isn't a full frame camera and you plan to move up to a full frame in the not to distant future. That having been said when it comes to your question about which lens to purchase may I suggest you look at this Canon website which goes into great detail about all the lenses they have to offer. Breaks them down on various uses as well as quality, it also touches on other lens mfg and the pros and cons of some of those. The best part is it's easy to understand. Here is that website. http://photonotes.org/articles/beginner-faq/lenses.html Hope this helps.

Jer Loc: Mesa, Arizona

If you are going to move up to Full Frame don't get ef-s lens. They only work on crop frame and not full frame.
If you can afford full frame get it. The lens work correctly on it. I have a FF and all L series lens. Life is great with this arrangement. Crop frame cameras don't give you better magnification... they are just showing you a smaller part of the 35mm image. If you crop a FF the same way then you have an apparent better magnification but really it's only part of the picture.

anotherview Loc: California

Wikipedia says this: "A full-frame digital SLR is a digital single-lens reflex camera (DSLR) fitted with an image sensor that is the same size as a 35 mm (36×24 mm) film frame."

[found at: http://en.wikipedia.org/wiki/Full-frame_digital_SLR]

Doctor's Office (2011)