Canon L series lenses

[Dylan Couper]

Hey guys
Is there anywhere I can find some examples of how much sharper Canon L series lenses are over their regular lenses?

Like a photo taken with both an L lens and a regular one?

[Jeff Donald]

Yes, go to the Canon web site and look at the sample shots and the MTF charts. You can go here to learn how to read MTF charts.

[Ken Tanaka]

Two additional suggestions.

1. Get a copy of Canon's book EF Lens Work III, generally only available through Canon dealers. It's an inexpensive but outstanding reference to Canon's line of lenses (at least through 2003) as well as to lens technology and issues in general.

2. Don't necessarily turn your nose up at non-"L" lenses, particularly at shorter focal lengths. While most of my lenses are L's, the non-"L"s I own are each excellent lenses and values. As a good example, I recently picked up an 85mm f/1.8 (non-L) lens. It has an excellent build and weighs-in at around 1lb. It's "L" counterpart is an 85mm f/1.2L...slightly faster. But it weighs in at almost 4 lbs! (The 85mm's are mainly used as portrait lenses.) But I'm here to tell you that my non-L 85mm is simply superb and instantly became one of my favorite lenses. As another example, the 100mm f/2.8 Macro lens is one of Canon's finest lenses. Sharp, faithful contrast, relatively light, excellent build. (Jeff actually recommended it to me when I began climbing back into still photography in 2003.)

[Dylan Couper]

Thanks Jeff and Ken
After reading the Luminous Landscapes aritcle, I mostly figured out the MTF charts, at least enough to make some sense of them.

ANother question:
If you put a lens on a D-SLR with the 1.6 crop, it doesn't change any characteristics of the lens, it just gives you a bigger picture, right? For example, if I put a 50mm on a 10d, it wouldn't exhibit the same properties as a 80mm lens, it would just be a crop from a 50mm. I'm thinking for portrait photography, you'd still want a telephoto lens, you'd just have to deal with standing farther back to get the same shot. Right?

[Ken Tanaka]

Crop factors with respect to lenses are really just that. Lenses produce their imaging in a circle. The circle is designed to encompass an area the size of a 35mm frame. The sensors in cameras like the 10D occupy a smaller area in the center of that circle. Hence the amount of the image circle that they can record is "cropped". But the other characteristics of the lens remain the same (i.e. minimum focus distance, apertures, etc.).

[John Locke]

Dylan,

That 1:6 crop had me pulling my hair out...I found myself constantly backing up to be able to fit something into frame. Not long ago, I got a Sigma lens that's designed especially for digital SLRs.

The Sigma 18-125mm f/3.5-5.6 DC lens was exclusively designed for digital SLR cameras. The image circle (rear of lens) is made to match the smaller dimensions used for the image sensor on digital cameras. As a result these lenses are also more compact and lightweight, and are better matched to digital SLR cameras.

[Dylan Couper]

John, I just found that lens too. Looks pretty good, except I have reservations about Sigma. I know some of their telephoto lenses are very good, but have heard a lot of bad things about the sharpness of their cheaper lenses. Any reviews or MTF charts on this one?

[Jeff Donald]

The only two companies that have the "guts" to publish MTF charts are Canon and Carl Zeiss.

[John Locke]

I wouldn't dare to compare a Sigma lens with a Canon for optical quality. But I've loved it since I got so tired of stepping back to fit the subject in the frame, and then guessing what's going to be cut off from the view in the viewfinder. This lens has made shooting with a 10D much more enjoyable.

Of course, we could solve the whole problem by just getting a Mach III...

[Jeff Donald]

My solution to the crop/magnification factor was to buy the 15mm fisheye and defishing software.

[John Locke]

Defishing software?! Hmmm...sounds interesting. Is it a PS plug-in by chance?

[Jeff Donald]

The Imaging Factory plug-in, Debarrelizer is my favorite and it's cheap $40. Sigma has a very highly regarded fisheye also. It's the only Sigma lens I would consider, after all, how hard is it to make a lens with 100% distortion?

[Jeff Toogood]

I had the Sigma 18-125 and although it isn't a bad lens, I found that at full wide angle there was some obvious vignetting. And it tended to be soft at 18mm and 125mm, but that could have just been my copy.
I loved the range, but in the end I sold it for a Tamron 28-75 F2.8 and so far have not regretted it one bit.
I love the constant aperture, and it's 'almost' L quality images.

[Dylan Couper]

<<<-- Originally posted by Jeff Donald : The only two companies that have the "guts" to publish MTF charts are Canon and Carl Zeiss. -->>>

Heh.... That explains why I couldn't find any for the Sigma 50-500mm lens. Spent about an hour and a half looking for it a couple days ago. Doh. :)