mwsilvers Loc: Central New Jersey

I indicated some of the reasons for premium prices of pro lenses in my earlier post which I believe you read. In addition there is the glass and coatings used and the optical designs that make these lenses special. Words will not change your opinion. If you've developed the photographers eye, when you actually use one or more of these lenses on a top notch body over an extended period of time, you will begin to appreciate what makes them superior.

f8lee Loc: New Mexico

I believe my earlier post did answer your question as to the price differences between otherwise similar-seeming lenses - there can be substantial mechanical differences for longevity, etc.

Also, the car analogy falls apart because most components of various lenses are not interchangeable (they say that 70% of the parts in a Porsche and a VW are the same) - the individual optical components, the glued-together groups, etc. Also, on the more expensive lenses more costly coatings may be applied, adding further to the cost. And the glass from which the individual elements are made differs as well - all of these factor in to the cost, as does the sheer number that will be manufactured based on expected demand.

Largobob

You say, "I know the answer is a difficult one or else I wouldn't be asking." No, the answer is not difficult. Several members have provided ample reason for differences in prices/values of lenses. Perhaps, your not understanding, or wanting to understand, is the difficulty here?

waegwan Loc: Mae Won Li

I have several L series lenses. I offered to loan one to a friend and he turned it down because he heard that if you ever use one you won't go back to standard and he said he can't afford one. :b

camerapapi Loc: Miami, Fl.

I guess you have enough information by now to know why a lens is more expensive than others. As far as I know and I do not use Canon gear, L lenses have very good quality.
I am sure you know that there are in U-tube and in independent articles many types of "reviewers." You find reviewers that do not have lots of experience in photography to those bias to the product they are reviewing.
If I need a lens I test it first and let me tell you right now that the majority of the lenses made today are excellent at around f8 and I do not mean that is the rule. If you need the lens for landscape photography you need to know that you will be around f8-16 most of the time and at those apertures all lenses do very well. If you need the lens for portraits then you need to know how well the lens will do out of focus backgrounds when while open IF you are going to shoot portraits outdoors. In the studio you do not need to go so wide with the aperture. These are only examples.
Buy a lens and test it at the apertures you know you will be using more often. If you see flows you know the lens is not for you.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

No matter what the product, some folks wouldn't be happy if they could walk on water. Others will give it high marks regardless. The old saying is, 20% of the folks are against you no matter what, 20% are for you no matter what, it's the 60% in the middle you must be aware of. So, read all reviews carefully. I am not a Canon guy but my friends who are all speak highly of the L lenses. Another old saying, buy the best glass you can, it will stay with you no matter what body you use.

hj Loc: Florida

If I want to absorb a review for my own personal purchase, I want to know if the review is from a professional or a hobbyist. The professional will often be highly critical of a lens which is wonderful for the hobbyist. I would want to know the opinions of those whose photography experience mirrors my own. As an example of what I NEED, I recently sold my Canon 70-200mm lens after I purchased a Canon 70-300mm IS II USM lens and found the latter was more than enough for my purposes. A pro would have downgraded the 70-300 and it is perfect for me at only $500.

zug55 Loc: Naivasha, Kenya, and Austin, Texas

Many posters already explained what the quality indicators of a lens are. There is no perfect lens. Different lenses behave differently under different circumstances. This is the reason why you can see different reviews on the same lens as reviewers prioritize different properties. If you are looking for low-light qualities or a great bokeh in a lens, then a f/4 maximum aperture is not acceptable. If the sensor of your camera has good low-light qualities then f/4 is not an issue.

Then there is the issue of amateur ratings on Amazon or B&H. As others pointed out eloquently, lenses lose stars for reasons that have nothing to do with the lens. So take that with a grain of salt. But if you have 100+ reviews, the numeric information might be useful.

So my advice to you. Read a lot of professional reviews, or see their Youtube videos, or both. Learn what professionals look for in a lens and how they define quality. Decide what matters to you. If you want to buy a specific lens, read all the professional reviews on the lens. I recently bought a SONY a7 III as a novice to SONY (after doing a lot of research on SONY and Nikon FF cameras). I wanted to buy an ultra-wide lens. So I did an inventory of the lenses available, read up on all of them to understand their strengths and weaknesses, decided what qualities are important to me and my style of photography, and then I bought the Zeiss Batis 18mm f/2.8 (which I love so far). One factor was that at 330g it weighs less than the other lenses I considered. This has nothing to do with the quality of the lens, but to me as a travel photographer that was important. Another factor was that I want to move away from zoom lenses and work more with prime lenses. This is a personal decision as well that only partly has to do with the quality of the lens.

My point is that a good lens is the lens that does what you want it to do, regardless of reviews. There is only so much we can do for you here, as others have stressed as well. So roll up your sleeves, do your homework and decide for yourself.

rmalarz Loc: Tempe, Arizona

Nikkor lenses are superior to lenses of the same focal length(s) made by other companies. Quite simply, it's the composition of the glass. If one looks at just the front element of different Nikkor lenses, one will note a difference from lens to lens. That isn't lack of quality control. On the contrary, it's chemical composition of the glass that works best for a particular lens.
--Bob

As for reviews, I guess everyone has their own ax to grind. In this day of youtube and twitter anyone will publish anything to get noticed and their 15 minutes of fame.
--Bob

SteveR Loc: Michigan

All L's are not equal.

chrisg-optical Loc: New York, NY

When evaluating a lens I take reviews somewhat lightly (especially consumer reviews on - B&H, Amazon)...my eye is the ultimate judge. I think some are overly critical or expecting the results of a $12,000 lens from a $1,500 or $700 lens. Some may be using the wrong AF mode, too low a shutter speed, or other basic issues (especially when a lens has 40x5stars, 15x4stars, 4x3stars and 1x1 star.) That one critic may have a lemon in the bunch, or doing something wrong.

Go to youtube and see what the experts are saying.

Go to flickr and pixelpeeper, etc. and see what the images look like - sample a 100 or so full res images.

Lab tests are one thing but actual in the field results are what matters to me.

Finally, go to a local store and see how the lens handles on your particular body.

Don, the 2nd son Loc: Crowded Florida

Spirit Vision Photography Loc: Behind a Camera.

Keep in mind that there are many shooters that have poor technique. Given a high quality lens, their results would still be mediocre at best. By the best glass that you can afford. Then spend the time to hone your vision and skill. “L” lenses will not improve you photographic endeavors.

DanielB Loc: San Diego, Ca

Canon photographer here and I wouldn't shoot anything without my "L" lenses. I'm not going to get into semantics here but in a word - quality. In build, materials and image. Here is an article that does a good job explaining the differences. https://photographylife.com/why-are-some-lenses-so-expensive

waegwan Loc: Mae Won Li

Very true