Is 'L' Glass Still an Advantage??

[pcasper]

Greetings to everyone. This is my first post, so please go easy!

First, I want to express my appreciation to all of you that make this forum a veritable flood of helpful information. I hope some day to also be able to contribute for the benefit of other newcomers.

I have been doing birdlife digiscoping for a couple of years, and now I am ready to expand my toolkit. I have done quite a bit of post processing in Photoshop Elements, and I think I have at least the basics understood. I frequently am astounded at the improvement careful and intelligent processing can make to an image.

Given the assumed post processing that most of us do to an image from a digital camera, I am curious as to whether the advantages of superior glass (Canon 'L' series lenses) over good quality equivalent non-L glass are diminished. I have no experience with top-quality glass, but my understanding is that the key advantages are in contrast, sharpness, color and perhaps geometric distortions. All but the last are easily improved by careful and intelligent processing. It would be really interesting to hear from someone that has carefully compared processed identical images using equivalent L and non-L glass.

Your thoughts on this topic would be much appreciated, as I try to decide what lenses to buy for the 10d I expect to order soon.

Paul

[Scottes]

...the key advantages are in contrast, sharpness, color and perhaps geometric distortions. All but the last are easily improved by careful and intelligent processing.

You've got the idea, but I'd say that "easily" is too strong a word.

1) With all of the above, you can't put back what isn't there. So if contrast in the picture reduces subtle variations then you're not going to put them back in post processing.

2) Sharpness - no amount of post processing will bring an out of focus into back into focus. Sharpness is in the same vein. You can sharpen an image to a point. But soon the aberations (halos, etc) caused by sharpening outweigh the sharpening itself.

3) Color. Yes, you can adjust color. But chromatic aberations in lesser lenses are usually found in the fringes of objects, where light bounced around, and so on. So you can't just reduce the purple in an image - you have to reduce the purple only in the areas where the purple is apparent. "Easily" is too a word - you might have purple fringes in a great number of places. And then there might be a faint tint of some color. Easily correctable if you notice it.

4) Distortions. Yes, you're right, this isn't easy in post processing. However, most "inferior" lenses will produce most of the distortions on the edges. With a digital's 1.6 crop factor of the 10d this is generally lessened.

So is L necessary? Hell no. Many substantially-cheaper lenses can produce excellent images. With a bit of post processing the differences might be negligible. But remember than pics taken with L can also be put through the same post processing (which will probably be easier due to the quality of the original) so the L will beat you again.

But necessary? No, L is not necessary. It's damned nice for the pics, and murder on the wallet.

Here's an article that kinda compares digiscoping versus L: http://photography-on-the.net/forum/showthread.php?t=24739&highlight=digiscoping

[Belmondo]

Given the assumed post processing that most of us do to an image from a digital camera, I am curious as to whether the advantages of superior glass (Canon 'L' series lenses) over good quality equivalent non-L glass are diminished. I have no experience with top-quality glass, but my understanding is that the key advantages are in contrast, sharpness, color and perhaps geometric distortions. All but the last are easily improved by careful and intelligent processing. It would be really interesting to hear from someone that has carefully compared processed identical images using equivalent L and non-L glass.


Paul:
Welcome. That's a very astute question. Your premise is at least partially correct to the extent that post processing of a digital image can correct some deficiencies in an image ‘as shot.’ Some things are easier to correct than are others. Exposure, white balance, sharpness (to a degree), contrast, and a few other things fall into the ‘easy’ category. Other things like focus, color aberration, and others are ‘difficult.’

Post processing can only go so far. It can elevate a picture from bad to acceptable, from acceptable to good, and from good to great. If the quality of the original image is hampered by optics, the degree to which it can be improved by post processing will be limited.

This is not to say that a good quality ‘non-L’ lens cannot provide you with a high level of quality, and conversely, having L glass on your camera is no guarantee that you’ll get exceptional photos every time. It only suggests that your chances of getting a better picture are improved when you use the best optics available.

It is an absolute certainty that the vast majority of professional photographers use professional level equipment, and that would include L lenses. They make that choice because the quality of their work is their stock in trade. I guarantee they don’t buy those expensive lenses purely for the prestige associated with owning them.

[maderito]

When you first view a well-exposed, properly focused image taken with an L lens on your computer at full resolution, it's like someone lifted the fog and brought light and clarity to your image. You can approximate this with digitial image editing techniques, but the result is always inferior (IMO), especially when viewing full-sized images and prints.

You'll probably get a lot of feedback and opinions on your post. But ultimately you must see for yourself to understand. Borrow an L lens and experience the joy. :)

[yenoram]

Even if it is possible to perfectly correct an image, do you really want to spend all of the time that would be required correcting each image you take? No thanks. I'd rather let an L lens do its job and save me countless hours in the process. That leaves more time for me to be out shooting. :)

[CyberDyneSystems]

No photoediting software can replace or improve image info that isn't there to begin with.

Starting with a high quality lens will blow away anything a telescope can provide.

RE: You reference to "L" in particular.. all of Canon's fast telephoto primes are L so there is no non "L" Canon to compare them to.

What this roughly translates to is that any high quality fast telephoto is "really good glass" be it Canon "L", Nikon, Pentax, Minolta or yes,. even Sigma.

At this level the intro price is $1,000.00 minimum (Canon 400mm f/5.6) up about $7,000.00....

With Canon there is no "non l" alterntive except for Sigma,. but even with Sigma,. the cost of entry is about $2k for there 300mm f/2.8

[Jesper]

When you first view a well-exposed, properly focused image taken with an L lens on your computer at full resolution, it's like someone lifted the fog and brought light and clarity to your image....

Really? I don't see THAT much difference between my non-L 28-135 and 17-40L. Is that because the 28-135 is so good or the 17-40L isn't the best L lens? Ofcourse with an L lens you can be sure that you get high quality, but there are also very good non-L lenses.

But anyway Paul (welcome!), the point is that if the information isn't recorded in the image at the moment you made the photo, you're not going to create the information from nowhere in post processing. If the image is not really sharp because the lens you used isn't good, post processing isn't going to put the details in your photo that the lens didn't see. So high-quality lenses are still important in the digital world.

[Cordell]

Some here will insist that non L (or whatever Nikon's glass is called) on a digital cam is "usually" not as good. I must disagree. First read, or re-read this recent post

http://www.photography-on-the.net/forum/showthread.php?t=25510

I truely believe non-L can be very much as good if you get the good shot in the first place. When you are finished post processing you will have L glass photography. Who says you can't automate a good portion of your post processing if you took your time to evaluate what you are shooting in the first place.

This is not to say all lesser quality glass is equal. I'm only stating that the advantage can be diminished because of computer post processing. Is it a little more work? Of course, but not much and it's less expensive.

Find anyone who can tell the difference and they are a simple liar!

[Tapeman]

I think it is. You will probably keep your glass a lot longer than your bodies.

[Canuck]

No photoediting software can replace or improve image info that isn't there to begin with.

Starting with a high quality lens will blow away anything a telescope can provide.

RE: You reference to "L" in particular.. all of Canon's fast telephoto primes are L so there is no non "L" Canon to compare them to.

What this roughly translates to is that any high quality fast telephoto is "really good glass" be it Canon "L", Nikon, Pentax, Minolta or yes,. even Sigma.

At this level the intro price is $1,000.00 minimum (Canon 400mm f/5.6) up about $7,000.00....

With Canon there is no "non l" alterntive except for Sigma,. but even with Sigma,. the cost of entry is about $2k for there 300mm f/2.8

There is also the Sigma 120-300 F2.8EX...again about $1800. That's an awesome lens! You can stick a 2x TC and get to 600 at F5.6 too!

[maderito]

When you first view a well-exposed, properly focused image taken with an L lens on your computer at full resolution, it's like someone lifted the fog and brought light and clarity to your image....

Really? I don't see THAT much difference between my non-L 28-135 and 17-40L. Is that because the 28-135 is so good or the 17-40L isn't the best L lens? Ofcourse with an L lens you can be sure that you get high quality, but there are also very good non-L lenses.

Jesper,

You and I know that the 28-135 (IS) is a fine lens. No disagreement there.

I tend to use the 17-40L for situations requiring wide angle. I'm rarely disappointed with image quality.

When I was using the 28-135, I tended to use it at the long end, say > 50 mm. Tight shots with narrow depth of field have a "pop" that can make them appear sharp. However, after buying the 50/1.4, I was suprised and delighted to discover real image sharpness. I then purchased the 85/1.8 and was similarly gratified. I stopped using my 28-135.

I haven't found any lens that gives me better shots than what I get with the 17-40L. Specifically, the wide end of the 28-105 and the 28-135 is simply not as good as what you get with the 17-40L. I don't know about the wide primes.

Judging the 28-135 aginst the 17-40L is an apples/oranges comparison. In the focal length in which they overlap, the 17-40L wins. Similarly, my 70-200/4.0 L is sharper than the 28-135 where their ranges overlap. That's my subjective impression. Perhaps I look at too many full resolution versions of my images. The difference is visible, enough so that my 28-135 continues to gather dust.

[Tom W]

Here's two 100% crops made from 200 mm shots with two different lenses. If post-processing can turn this:

http://home.comcast.net/~trwilk3/Images/210C_Crop_f45.jpg

into this:

http://home.comcast.net/~trwilk3/Images/200S_Crop_f28.jpg

and add 1 1/2 stops of low-light capability, then I'll be convinced that good glass is no longer necessary.

BTW, both shots were taken wide open, with the first limited to the lenses' F/4.5 maximum aperture and the second at F/2.8.

[Scottes]

Here's two 100% crops made from 200 mm shots with two different lenses.

Great comparison Tom. Post processing could make the first shot better, but I doubt that it will come close to the second shot. And then post processing the second shot will once again blow it away.

[Cordell]

Tom, your point is "almost" headed in the right direction. HOWEVER, I don't think the issue is bad photography or bad glass. The question is all about what most consider superior glass (L and others) and the less expensive very good alternatives used by someone who knows how to photograph. My point is not to take a horrible shot in the first place or use a lens that is surely a peace of sh*t.

The first photo you have for your example looks like something someone purposely distroid in an image editor, did not take their time to setup the shot, or used the cheapest of the cheap glass. This does nothing for those who would like to learn can $600 get you a $1200 shot. This only forwards false imformation that if you don't have the professional/expensive level glass you end up with unusable photos. I think that is far from the truth. There are many other factors other than a sharp photo that give the idea of good and great glass.

[Tom W]

Tom, your point is "almost" headed in the right direction. HOWEVER, I don't think the issue is bad photography or bad glass. The question is all about what most consider superior glass (L and others) and the less expensive very good alternatives used by someone who knows how to photograph. My point is not to take a horrible shot in the first place or use a lens that is surely a peace of sh*t.

The first photo you have for your example looks like something someone purposely distroid in an image editor, did not take their time to setup the shot, or used the cheapest of the cheap glass. This does nothing for those who would like to learn can $600 get you a $1200 shot. This only forwards false imformation that if you don't have the professional/expensive level glass you end up with unusable photos. I think that is far from the truth. There are many other factors other than a sharp photo that give the idea of good and great glass.

Its a 100% crop right out of the camera from a lens that photodo.com rates at 3.3. It was not "distroid" (or perhaps you mean "destroyed") by an image editor. I take exception to your insinuation that I altered the image to prove a point, or that I don't know how to take photographs. Both were simple pictures taken of the same subject from the same vantage point for comparison purposes only.

The "bad" lens is fine at f/6.7 or so, but wide open, its not good (plus wide open at 200 mm is only f/4.5 - hardly useful in low light). If you saw the entire image at the same size, it would likely just look "a little soft", but having the advantage of being able to crop 100% images allows us to investigate our lenses further.

This is sometimes (but not always) typical of consumer glass. Fortunately, digital allows us to investigate our lenses more thoroughly. I'm not saying that there aren't good consumer-priced lenses. I'm only point out that software isn't going to make a silk purse out of a sow's ear.

BTW, I never named the lenses - the first is a mid-range Canon lens, and the second is the Sigma 70-200 EX lens. It isn't "L" glass, but it is about as close as you can get and for considerably less money.

[SWPhotoImaging]

I think this proves one thing for sure . . . .
Someone needs to clean their gutters!!

[Tom W]

I think this proves one thing for sure . . . .
Someone needs to clean their gutters!!

LOL - it sure does. Thankfully, its not my roof!

I think that it is easy to underestimate the telling properties of the 100% crop. I didn't have that advantage with my Elan, and thus considered that lens only "soft". Full 100% magnification shows unacceptable levels of fringing and softness wide open.

[mjordan]

Some here will insist that non L (or whatever Nikon's glass is called) on a digital cam is "usually" not as good. I must disagree. First read, or re-read this recent post

http://www.photography-on-the.net/forum/showthread.php?t=25510

I truely believe non-L can be very much as good if you get the good shot in the first place. When you are finished post processing you will have L glass photography. Who says you can't automate a good portion of your post processing if you took your time to evaluate what you are shooting in the first place.

This is not to say all lesser quality glass is equal. I'm only stating that the advantage can be diminished because of computer post processing. Is it a little more work? Of course, but not much and it's less expensive.

Find anyone who can tell the difference and they are a simple liar!

Since I hate being called a liar, I'll just say, find anyone who can't tell the difference and they simply need glasses, new glasses, or they are beyound glasses doing any good.

And yes, if someone uses a non-L zoom and takes the shot in the best spot of the glass, at the best possible fstop and all the other factors are perfect and you compare it with a L glass zoom that someone doesn't take the time to get the settings right, you will see a difference. Even keeping everything equal and using a tripod and shutter release you can see the difference.

So, before you start calling people liars, you might get your glasses checked. :?

Mike

[defordphoto]

Well, if anyone thinks they can 'create' L-class photographs from sub-standard glass they are only fooling themselves and I say go for it. If it makes them happy in their little world then so be it. I could care less. In the meantime I'll continue to create the incredible clarity, color rendition and dynamic range photographs that only L-glass can produce and chuckle all the way to the bank, thank you very much.

That being said (and to prevent many wads of panties), not all non L-glass lenses are crap, or sub-standard. There are many lenses out there, Canon and non-Canon that produce amazing photographs that rival L-glass. The spread between manufacturers is shrinking and that's all good for us.

Basically what I am saying is if you have a crap photograph that's as bad as that mid-line Canon shot, there's only so much you can do to attempt to save it.

You can't polish a turd.

[Belmondo]

You can't polish a turd.

Now you tell me. Wanna' buy a used buffing wheel?

[defordphoto]

You can't polish a turd.

Now you tell me. Wanna' buy a used buffing wheel?

:lol: :lol: :lol: Good grief! Did you take you comedy pills tonight or what? ;)

[Tom W]

By popular demand - OK, nobody asked for it, but I'll post it anyway - the full photos from which I gathered the crops.

First, the mid-range Canon lens picture (again, wide open):

http://home.comcast.net/~trwilk3/Images/CanonHouse.jpg

and for comparison, the Sigma lens picture (wide open):

http://home.comcast.net/~trwilk3/Images/SigmaHouse.jpg

The difference is, of course, more subtle when the full image is reduced to 750X500 pixel size, but the difference is still significant. The mid-range Canon lens is softer, and all the sharpening in the world can't save it. That is because it suffers from fringing. Now, if someone wants to go in and correct the fringing pixel by pixel for the whole scenario, they have my permission. But that's going to take a very long time.

[defordphoto]

How about some fancy-dancy L-processing on that crappy Canon shot and then do 100% crops and re-compare?

[Tom W]

How about some fancy-dancy L-processing on that crappy Canon shot and then do 100% crops and re-compare?

How the "L" does one do that? :D

[defordphoto]

How about some fancy-dancy L-processing on that crappy Canon shot and then do 100% crops and re-compare?

How the "L" does one do that? :D

Beats the crap...eerrrr L outta me. I was thinking that maybe one of the people here claiming that you don;t need L-glass to get an L-photo could show us a sample...

[Belmondo]

I think there is too much emphasis on clarity. We all get way too excited about sharpness, and tend to ignore the artistic side of this business. As long as a lens reasonably depicts the approximate shapes and colors of the subjects being photographed, then it's doing the job it was designed to do. In the case of the photos earlier in the thread, is there really any artistic difference between knowing that there are leaves in that rain gutter, or is is sufficient to acknowledge that there is a brown substance in the gutter?

POOH, I say.

[ilya]

Hmmm. I think it all depends on the Dynamic Range of the brown leafy stuff in the gutter. Until we measure that, we truly cannot declare a picture as viable form of art.

[defordphoto]

"Is it sharp enough?" Man looks at photo and eyes slice open. "My, my. That's ugly."

"Yeah. But is it sharp enough?"

Many times the downfall of today's photos is that they are too sharp and too processed.

[BDM]

Here's two 100% crops made from 200 mm shots with two different lenses. If post-processing can turn this:

http://home.comcast.net/~trwilk3/Images/210C_Crop_f45.jpg

into this:

http://home.comcast.net/~trwilk3/Images/200S_Crop_f28.jpg

and add 1 1/2 stops of low-light capability, then I'll be convinced that good glass is no longer necessary.

BTW, both shots were taken wide open, with the first limited to the lenses' F/4.5 maximum aperture and the second at F/2.8.

Yipes!! Aside from the difference in sharpness the first shot has very visible chromatic abberations - - color fringing. That is really unacceptable.

Bruce

[ilya]

The day I got the 70-200, I did a few side-by-sides with the 75-300is, just to make sure the lense worked.

Conclusion - aside from the low light advantages, optically its clearly a little bit "more pleasing", colors are truer, its a bit sharper. The more I used it, the more I leveraged the benefits.

Though for someone starting out, it could be a bit of a rude awakening, "hey this lense is not that much better etc etc".



Three points -

I can make these shots pretty identical in post. If I wasn't such a junkie, I'd be perfectly happy with the gold banded ones.

The kind of fringing you're seeing is not a normal occurrence for a decent mid-range Canon lenses

The constant search for sharper contrastier shots I believe takes the focus away from what's important.


http://images.fotopic.net/?id=2918004&outx=600&noresize=1&nostamp=1

[Tom W]

The day I got the 70-200, I did a few side-by-sides with the 75-300is, just to make sure the lense worked.

Conclusion - aside from the low light advantages, optically its clearly a little bit "more pleasing", colors are truer, its a bit sharper. The more I used it, the more I leveraged the benefits.

Though for someone starting out, it could be a bit of a rude awakening, "hey this lense is not that much better etc etc".



Three points -

I can make these shots pretty identical in post. If I wasn't such a junkie, I'd be perfectly happy with the gold banded ones.

The kind of fringing you're seeing is not a normal occurrence for a decent mid-range Canon lenses

The constant search for sharper contrastier shots I believe takes the focus away from what's important.


http://images.fotopic.net/?id=2918004&outx=600&noresize=1&nostamp=1

First off, very nice pics. I believe that he's taken a liking to the camera already. :D

Second, you're right - we sometimes forget what the point of photography is. The example I used might be a little extreme. I've had that lens for a while, and I was never satisfied with it. The purple fringing on high-contrast subjects at full aperture was often visible even on 4X6 film prints. As well, colors with that lens diverge in the bokeh, giving a somewhat unpleasant effect. It was the worst lens in my bag (which is one reason I have replaced it). Canon doesn't produce it any more.

My most commonly used lens, the 28-105 is a Canon midrange lens and it produces very sharp, brilliant images. It focuses accurately and quickly on both the 10D and the Elan. Its only weak point might be flare-related, but only under extreme conditions. The differences between it an the 17-40L are a lot more subtle that the differences between the two lenses I posted. I'm not in a hurry to replace it.

[pcasper]

Wow. What an interesting debate. Thank you all for contributing to this discussion. I certainly have more to think about when making my lens decisions.

At the risk of starting something I may wish I hadn't, I tried my hand at processing Tom's non-L 100% crop. Please note that I am far from being highly skilled at processing...I only know the basics. The image is improved and I would like to post it here, but I don't have a convenient URL to temporarily park the file. Can someone suggest a location?

I have some interesting (to me at least!) conclusions from this exercise, but I will save them until I can include the photos.

Paul

[maderito]

Three points -

I can make these shots pretty identical in post. If I wasn't such a junkie, I'd be perfectly happy with the gold banded ones.

The kind of fringing you're seeing is not a normal occurrence for a decent mid-range Canon lenses

The constant search for sharper contrastier shots I believe takes the focus away from what's important.
Excellent points, and mostly I agree.

Additional points:

Over time, I've noticed that I do less sharpening and less manipulation of saturation and contrast on images. Is this because I'm now using better lenses or because my post processing sensibilities have changed and matured. Don't know. I just know that some images from my current lenses (primes and L lenses) are stunning right out of the camera and require few adjustments other than tweaking color temperature and exposure during RAW processing.

Attention to detail is the hallmark of good work ethic - especially in artistic endeavors. When I view a painting, I don't walk up close to the canvas to check the brush work - cuz I know nothing about brushwork technique. But I may have liked the painting because some artist did care about the details of the brushwork and created his/her masterpiece by synthesizing all details of color, composition, and technique into the final work. Your point is that attention to details of sharpness/contrast can shift attention from other important details of photographic technique - and I quite agree.

In this Forum, the ratio of posts in "EOS Digital Cameras" to "Critique" + "Post Processing" + "Talk" combined is greater than 2:1. We do spend a lot of time talking about our equipment and software and less about the art of photography.

[CyberDyneSystems]

Wow. What an interesting debate. Thank you all for contributing to this discussion. I certainly have more to think about when making my lens decisions.

At the risk of starting something I may wish I hadn't, I tried my hand at processing Tom's non-L 100% crop. Please note that I am far from being highly skilled at processing...I only know the basics. The image is improved and I would like to post it here, but I don't have a convenient URL to temporarily park the file. Can someone suggest a location?

I have some interesting (to me at least!) conclusions from this exercise, but I will save them until I can include the photos.

Paul

Paul

www.fotopic.net offeres free gallery space (250 megs!) that allows hot linking and embedding :)

[randyk]

I don't have a pressing need for an L prime since Canon makes some outstanding non-L primes. But I would love one, the images from lenses like the 135L look so dreamy.

But the zooms are another story. Canon seems to have mediocre consumer level zooms, decent mid tier zooms and top (generally fast) L zooms. Canon doesn't make any fast non-L zooms. The L-zooms have removed the quality handicap from the zoom format and I think they are a must have for sports.

[pcasper]

www.fotopic.net[/url] offeres free gallery space (250 megs!) that allows hot linking and embedding :)

CDS,

Thank you for the referral. I signed up and uploaded the images for all to have a look at. If I don't foul it up, they should appear below.

The top image is Tom's non-L image, processed to look more like his L-lens image (below).

http://images.fotopic.net/?id=2925706&outx=452&oq=0

http://images.fotopic.net/?id=2925707&outx=448&oq=0

As you can easily see, the L-lens image is clearly still superior. Perhaps someone better than me at processing could do a better job, but I don't think anyone can make them substantially the same. And this is with the unrealistic advantage of having an identical L-image to refer to!

So, what have I learned from this exercise? Several things:

1) Chromatic aberations are critically important to achieving a really sharp, crisp photo. I easily removed most of the obvious color fringing, but I could not remove the more subtle effects of it all throughout the image. I think this phenomena inhibited the non-L lens from achieving better focus.

2) Contrast enhancement helps but other artifacts intrude when trying to improve the contrast to the level of the L-lens image.

3) White purity. No matter what I did, I could not process the whites to look as crisp and clean as the L-lens without blowing out much of the white detail.

4) Sharpening helps, but at the expense of noise. I could have smoothed the effects of enhanced noise, but I would have had to work on isolated areas of the photos to avoid attenuating the sharpening where I wanted it. There are other noise reduction programs that might do a better job (I used Photoshop Elements).

I could go on, but I don't want to belabor the point. Certainly, L-glass does not guarantee a good photograph, but it appears to enhance the chances of at least achieving a technically superior one. And, post-processing is no substitute for an L-quality photo, whether Canon's premium glass or another manufacturer's premium glass is used. I guess I better start saving my pennies for an L-lens or two!

Thanks to all that contributed for your knowledge and opinions.

Paul

[Jesper]

When you first view a well-exposed, properly focused image taken with an L lens on your computer at full resolution, it's like someone lifted the fog and brought light and clarity to your image....

Really? I don't see THAT much difference between my non-L 28-135 and 17-40L. Is that because the 28-135 is so good or the 17-40L isn't the best L lens? Ofcourse with an L lens you can be sure that you get high quality, but there are also very good non-L lenses.

Jesper,

You and I know that the 28-135 (IS) is a fine lens. No disagreement there.

I tend to use the 17-40L for situations requiring wide angle. I'm rarely disappointed with image quality.

When I was using the 28-135, I tended to use it at the long end, say > 50 mm. Tight shots with narrow depth of field have a "pop" that can make them appear sharp. However, after buying the 50/1.4, I was suprised and delighted to discover real image sharpness. I then purchased the 85/1.8 and was similarly gratified. I stopped using my 28-135.

I haven't found any lens that gives me better shots than what I get with the 17-40L. Specifically, the wide end of the 28-105 and the 28-135 is simply not as good as what you get with the 17-40L. I don't know about the wide primes.

Judging the 28-135 aginst the 17-40L is an apples/oranges comparison. In the focal length in which they overlap, the 17-40L wins. Similarly, my 70-200/4.0 L is sharper than the 28-135 where their ranges overlap. That's my subjective impression. Perhaps I look at too many full resolution versions of my images. The difference is visible, enough so that my 28-135 continues to gather dust.

I don't doubt that the 17-40L is better than the 28-135 in the overlapping range, but to me the difference was not like what you described in your first post (like a fog lifted from your eyes...). But you're ofcourse right when you compare a cheap kit zoom with an L lens.

Long ago I had a Minolta camera with an 28-80 kit zoom lens. I did a photography course and the teacher advised us to buy a 50mm lens. So I bought a cheap Minolta 50 f/1.7. Even on a small 4 x 6 print, the difference in sharpness was readily visible. That made me realise how important lens quality is.... :? The difference between the Canon 28-135 and 17-40L isn't as huge as that.

[Tom W]

One last note - I said that the mid-range Canon zoom got a lot better when you stopped it down a bit. Here's the same scene with the same Canon lens stopped down to (IIRC) f/6.7:

http://home.comcast.net/~trwilk3/Images/210C_Crop_f56.jpg

And again at wide open:

http://home.comcast.net/~trwilk3/Images/210C_Crop_f45.jpg

Compared to the better glass at f/2.8:

http://home.comcast.net/~trwilk3/Images/200S_Crop_f28.jpg

And at f/6.7:

http://home.comcast.net/~trwilk3/Images/200S_Crop_f56.jpg

You can see that when the mid-priced lens is stopped down a bit, it clears up rather nicely, though still not as sharp and contrasty as the better lens.

[Cordell]

Tom, thanks for the spell check :D , and please don't take acceptance to me saying you did anything to the shot or do not know how to shoot. That is not what my statement says at all.

Mike, don't worry you are not a liar.

The point is good lens or excellent lens the differences can OFTEN be minimized a great degree with digital photography (IE software). In other words, you can not tell me if I sit two printed photos on a table in front of you shot from a good lens (regardless of brand) and the "L" class you can tell me which is which! Will there be differences on a daily basis if you know how to shoot and you have GOOD glass? It varies from lens types. But aren't the difference so small that they are subjective too?

[Tom W]

Tom, thanks for the spell check :D , and please don't take acceptance to me saying you did anything to the shot or do not know how to shoot. That is not what my statement says at all.

Not to worry! The internet sometimes has a habit of making us appear to say one thing and mean something else.

Mike, don't worry you are not a liar.

The point is good lens or excellent lens the differences can OFTEN be minimized a great degree with digital photography (IE software). In other words, you can not tell me if I sit two printed photos on a table in front of you shot from a good lens (regardless of brand) and the "L" class you can tell me which is which! Will there be differences on a daily basis if you know how to shoot and you have GOOD glass? It varies from lens types. But aren't the difference so small that they are subjective too?

I think that is highly dependent on circumstances. Under good conditions, most lenses will give good results and the differences are more subtle and workable. But when you work at the extreme ends of a lenses' capability or when you make very large prints, I think the finer glass will really show its wares.

Of course, if one is a pro, subject to banging things around and getting them wet and dirty, and using them daily, then there's no question what kind of glass they should buy.

[mjordan]

Cordell, You just made a very good point in favor of all of us that say you will see a difference. :D The internet is a very big equalizer when it comes to comparing images and the equipment that created them. So much is lost during the process of getting them down to a size that will fit on a screen that it's easy for people to feel that there isn't that much of a difference between a high quality piece of glass and one that could be considered unpolised sand.

But if you did put those two prints side by side, that is where you will see a much bigger difference between the two. Especially if you use a high quality camera, either film or digital.

So not only do we have to consider the way an image was created and with what equipment... but we also have to consider the medium that it is displayed in.

Mike