How wide is wide ?... Your Lens

Lester Wareham wrote in post #2158192
I may be wrong but as far as I can make out most Canon lenses including the smaller L's seem to be mostly plastic.

You are partly wrong. There is plastic on a L lens but the body of the lens is made out of a alloy and the glass is glass. That usually is the standard in L lenses. The 17-40 L is made out of metal, the 70-200's are made out of metal, and so on. The 17-40 L is built like a tank yet is relitively light weight.

cjm wrote in post #2158487
You are partly wrong. There is plastic on a L lens but the body of the lens is made out of a alloy and the glass is glass. That usually is the standard in L lenses. The 17-40 L is made out of metal, the 70-200's are made out of metal, and so on. The 17-40 L is built like a tank yet is relitively light weight.

OK you surprise me, I assumed it had a metal frame inside but the barrel does seem to be plastic. Its solid enough as modern lenses go but I would not say built like a tank (I am not nocking it - I have and use it) but it is not built as well as the old FD lenses IMHO. You also notice the solidity difference if you compare to the MP-E 65mm which feels like metal.

According to photonotes the 17-40:

Mount material Metal
Barrel colour Black
Barrel material Type 2 plastic

cjm wrote in post #2158472
I went from the Tokina 12-24 lens to the Canon 17-40L lens and I have to say the little less wideness of the 17mm over the 12mm is not that great. Basically if I stepped back about a foot I would have the same frame with one good exception, no distortion like the Ultra Wide lenses do.

And, depending upon what and where you are shooting, you simply do not have 1-2 ft to back up and take your shot! I remember about 20 years ago trying to shoot in Europe with a 28mm lens on a 35mm SLR. It was not wide enough for me, so I immediately sold it and bought a 24mm lens. While I eventually bought a 20mm lens, I rarely use it because 24mm would be all I needed on the many trips I have been to Europe and elsewhere.

That translates to:
28mm on film is a 17mm lens on APS-C, and that was not good enough to shoot building interiors in Europe
24mm on film is a 15mm lens on APS-C, and that is entirely satisfactory for 98% of the shooting needs I have for wide angle
20mm on film is a 12mm lens on APS-C, and that is rarely needed by me. (Having 10-12mm available opens the more creative and artistic photographic opportunities for me.)

cjm wrote in post #2158472
A UW lens will sort of distort lines and stuff not making it appear exactly the same. Not that big of a difference but enough for me to notice.!

Not always. It depends on lens design and how well it has designed out the barrel distortion. Fisheye is not the same as a rectilinear lens of same focal length...the fisheye distorts much more noticeable any straight line that does not pass thru the center point of the lens.

Extreme wide angle lenses *will* cause 'perspective distortion' when close objects loom so much larger in the photo than objects a short distance away....makes noses look big (or worse, makes butts look even bigger!)

Lester you are right about that comparing them to a FD mount they are not even close the same build as todays. My dad has old lenses from Canon to Kinon to Praktica and they are all build like steel baseball bat. These new lenses are made out a alloy so they are strong but not too heavy.

Sometimes messing around I will lift my dads 200mm zoom lens. Well good grief it makes the 70-200mm IS L feel like a kit lens, those old lenses they didnt skimp on anything, they weighed the same as a brick of gold, which is what some of them cost I suspect.

The 17-40 is very solidly built though, pretty much the same build as the 16-35 L lens. They are a huge improvement over the plastic feeling 17-35 f2.8 L lens and probably the 20-35 L also. They are rugged built, have a good paint job and are built like a tank in modern lens ways. They do give you the feeling like "Gee this is a really strong lens" which is good because after optically, you're paying for the L build which is exceptional.

The only plastic feeling recent L lens I have tried out at a store is the 24-105 IS lens, but that is because its a walk about all purpose L lens so I guess that is why. The EFS 10-22 from Canon is also a very similar build to a L lens except it is a EFS lens which is a big factor why it isnt a L lens even though the optics and build are similar (And it costs more then two L lenses!).

Plastic is used on a Lens now to replace things that used to be made out of metal. The bayonet is connected to the Alloy of the lens making it very strong. If you've ever held old lenses, you'd see instantly how good of a thing this is.

Wilt wrote in post #2158540
Not always. It depends on lens design and how well it has designed out the barrel distortion. Fisheye is not the same as a rectilinear lens of same focal length...the fisheye distorts much more noticeable any straight line that does not pass thru the center point of the lens.

Extreme wide angle lenses *will* cause 'perspective distortion' when close objects loom so much larger in the photo than objects a short distance away....makes noses look big (or worse, makes butts look even bigger!)

Here is a good example of how a UW lens distorts. Tokina 12-24 sample. It is not bad, but if you want lines to be straight then dont be using a UW lens made for APS-C sensors. See the soccer goal posts.

cjm wrote in post #2158587
Here is a good example of how a UW lens distorts. Tokina 12-24 sample. It is not bad, but if you want lines to be straight then dont be using a UW lens made for APS-C sensors. See the soccer goal posts.

The distortion there could well be 'perspective distortion'! The camera lens is aimed upward to capture less of the foreground and more of the sky. The goal posts converge as they go upward. SAME effect if you aimed a 50mm upward at a skyscraper!!!

Here is a 10mm shot on my 20D, where I employed the SAME upward angle on the lens to capture some of the upper detailing in this interior. Notice the columns at the sides converging.

cjm wrote in post #2158576
Lester you are right about that comparing them to a FD mount they are not even close the same build as todays. My dad has old lenses from Canon to Kinon to Praktica and they are all build like steel baseball bat. These new lenses are made out a alloy so they are strong but not too heavy.

Sometimes messing around I will lift my dads 200mm zoom lens. Well good grief it makes the 70-200mm IS L feel like a kit lens, those old lenses they didnt skimp on anything, they weighed the same as a brick of gold, which is what some of them cost I suspect.

The 17-40 is very solidly built though, pretty much the same build as the 16-35 L lens. They are a huge improvement over the plastic feeling 17-35 f2.8 L lens and probably the 20-35 L also. They are rugged built, have a good paint job and are built like a tank in modern lens ways. They do give you the feeling like "Gee this is a really strong lens" which is good because after optically, you're paying for the L build which is exceptional.

The only plastic feeling recent L lens I have tried out at a store is the 24-105 IS lens, but that is because its a walk about all purpose L lens so I guess that is why. The EFS 10-22 from Canon is also a very similar build to a L lens except it is a EFS lens which is a big factor why it isnt a L lens even though the optics and build are similar (And it costs more then two L lenses!).

Plastic is used on a Lens now to replace things that used to be made out of metal. The bayonet is connected to the Alloy of the lens making it very strong. If you've ever held old lenses, you'd see instantly how good of a thing this is.

Yes this essentially what I am saying. Plastic is not necesserily cheap or bad - ie its used in L lenses.

mjgravina wrote in post #2156127
Thanks for the comments. Here are the three choices I have for architectural photography:

- Canon EF-S 10-22mm (Expensive, non L lens) but they say it takes good photos. (To me it looks like the 18-55 kit lens, hence my fear of dropping $600-$800 for a plastiquy looking thing)

- Sigma 12-24mm EX (I am a big fan of Sigma, but I am reading tons of reports of soft pictures with these lenses). Almost $1k.

- Canon 17-40mm L (Not really a wide angle, but from 28mm I have now, I might be enough of a difference, if the IQ is spectacular, and the build quality worthy of the L designation).

Which ones do you own/use/prefer ?

Dropping a 17-40L is a BAD idea - it's heavy enough to build up quite a bit of momentum. Good build quality is meant to absorb knocks and blows from hard professional use, but not to insulate you from ill fortune or carelessness.

Having said that, I totally agree, I'd hate to watch a 10-22 get dropped

mjgravina wrote in post #2157929
Thanks to all for all the comments.

I have now narrowed it down to the Canon 10-22, or the Sigma 10-20.

My Worry about canon is an almost all plastic lens for a lot of money. Other than that, it looks to be the appropriate lens. (EF-S is a worry, but no FF Cameras on my plans for at least 6-8 months, and ironically enough, the wide angle lens would have to help pay for it, before hand).

Sigma, of course, is what I am used to shooting with. And I am pleased with the Build Quality of the EX Series, these lenses will chip but keep on shooting through almost anything. My worry with this one, is the mixed reviews.

Seems to be a toss up. At this point I must go with whatever lens makes me the happiest. And that may be the one that feels right on my camera, and in Photoshop once the photo was taken.

Thanks again to all, and if anyone has any other comments and suggestions, post away !!... (And another Thanks for the Samples posted).

You've already pretty much said it. Flip a coin, either lens will make you happy. The EF-S 10-22 has perhaps a slight advantage however is it worth the cost and would the advantage be visible?
I'm more than happy with my Sigma 10-20!

steved110 wrote in post #2159147
Dropping a 17-40L is a BAD idea - it's heavy enough to build up quite a bit of momentum. Good build quality is meant to absorb knocks and blows from hard professional use, but not to insulate you from ill fortune or carelessness.

Having said that, I totally agree, I'd hate to watch a 10-22 get dropped

In fact the 10-22 might fare better, its 20% lighter presumably due to the smaller glass.

Dropping any lens is not a good idea, even if they apear OK something may be nocked out of alignment.

cjm wrote in post #2158472
Basically if I stepped back about a foot I would have the same frame with one good exception

This won't apply to outdoor shots, especially landscapes.

cjm wrote in post #2158472
If you buy the 17-40 L you will find it is pretty wide. Someday when you buy a FF camera you can use this lens on it perfectly and then discover how wide 17mm really is! It is a win-win lens!

As an owner of both, the 10-22 and 17-40L, I will say that they feel similar, each taking 77mm filters. I recently purchased the 17-40L to go with my 5D.

Did I regret not getting it in the first place? No. I wouldn't have gotten all those shots in the Canadian Rockies without my 10-22 on my XT. The majority of my keepers were at 10mm.

Sig 10-20...I love mine and I'm a complete believer in this lens...Great IQ from the shots I have taken....maybe it's just how a wide angle compacts the light/colors that come in that gives it such charm, what ever,,I'm charmed!

On a 1.6x body, the 10-22mm makes a lot of sense. Even the 16-35mm, while wide - isn't that wide on such bodies. Just keep in mind that the distortion increases the more you zoom out... An effect you might not like in architectural shots. It'll certainly get in a good bit of the room though. There are some great Sigma lenses available also.

There's also the Tilt/Shift lenses... They'll ensure you get straight lines - but they're more espensive and more complicated to operate and unfortunately not the widest angles.

I find my 17-40 just right on my 1.3 crop camera.