What does 'better glass' actually mean?

[Hair Bear]

I still dont htink I know what to look for in order to get better glass.


Simply stating get 'better glass' or they are sharper and faster doesn't cut it with me.

Better than what, sharper and faster than what?

Name lenses and makes so I can compair and learn

 

[Digital Matt]

A 70-300 vs a 70-200. Don't ask me why, but 70-200's are always made better. Canon and Nikon both make a cheap consumer 70-300, and a much better 70-200. The 70-300's are usually 3.5-5.6, and the 70-200's are 2.8 with VR or IS. Sigma and Tamron also make 70-300s, and while I don't know about Tamron, Sigma makes a 70-200 2.8 which is very good.

Read lens reviews. You start to hear about the "usual suspects" ie. the lenses that are good in every manufacturer's lineup.

In general, if you see two lenses, and one costs $180, and the other is $1800, you know which one is "better" glass.

 

[LWW]

"BETTER" needs a definition if it is to have meaning, I think that may be what is confusing you Hair Bear.

As an example...if you want a lightweight lens for shooting relatively slow objects in sunlight/flash, such as family picnics, then the 18-135 kit lens actually is better than many expensive alternatives.

Now, OTOH if you are shooting sporting events, planes, auto racing and such then the 18-135 will come up short to other choices. It won't have the reach of an 80-200 F2.8 to get you up close. You will also lose 2 stops of light. This means that under the exact same conditions I can shoot the same moving object at 4 times as fast a shutter speed as the 18-135. IOW I can shoot at 1/1000 under the same light that you shoot at 1/250. The shallower depth of field from 2 stops more aperture will also give my photos more pop. As a trade off the "BETTER" lens will cost more and by nature weigh more, largely because the front element has to be much larger.

At the same time if you were wanting to take wide angle panorama views your 18-135 would again be "BETTER" than the 80-200. An even "BETTER" choice would be a 12-24 F4.

As to brands, I don't believe that anyone makes "BETTER" glass than Nikon...but all glass is not equal. Here are some things to look for, and why.

WIDE APERTURE: If everything else is equal then a lens with a larger aperture (smaller F number) will be the "BETTER" lens. Why? It can work at faster shutter speeds in the same light. It can work in lower light. It gives your photos more pop from shallow DOF.

APOCHROMATIC GLASS: This is the big one. Apochromatic glass is known under several names. Canon calls it L glass. Sigma calls it APO. Nikon calls it ED (Extra low dispersion). This type of glass is much harder than regular glass which makes it more abuse resistant and heavier. The mfring process requires that impurities and bubbles are as absent as modern tech allows. It also solves a huge problem in photography. Not all colors of light focus at the exact same point on the film/CCD plane. This leads to color fringing. The longer the telephoto the more obvious it becomes. Apochromatic glass is pure and it focuses all the colors of the spectrum at the same point on the film/CCD plane.

My main lenses and their use:

Nikon 300MM F4 ED. Great lens for wildlife, planes, etcetera. 5%.
Nikon 80-200 F2.8 ED. Great for sporting events. 20%.
Nikon 50MM F1.8. Dazzling performance and extremely fast. 10%.
Nikon 28-105. Great walking around all purpose lens. 35%.
Nikon 18-55 ED. Same as above but a little wider and shorter. 30%.

I hope this has helped instead of confused the issue.

LWW

 

[fmw]

The reason a 70-200 would be optically superior to a 70-300 is simply that the longer the zoom range, the more compromises required in the lens design. It's harder to correct mountains than molehills. Zooms with modest zoom ranges are always optically superior to zooms with wide zoom ranges. Every time. Single focal length lenses are always superior to zooms. Every time. View camera lenses are always superior to lenses that have to focus themselves. Every time. Laws of physics.

LWW makes a good point about your application. My wife and I shoot together from time to time. She has a tiny, credit card sized Sony digicam and I carry about 25 lbs. of stuff or more. We have different requirements of our equipment. Also, as an example, I usually carry my 12-24 zoom on my Nikon as a "normal" lens because I really like working with wide angles. I shoot up close and personal most of the time and enjoy the wide angle perspective. LWW doesn't even have anything other than a modest wide angle so our shooting styles are obviously quite different. A 12-24 isn't important to him but, for me, it is the most used lens I have. My 300 f4 rarely leaves the house and my 80-200 f2.8 usually stays in the car unless I need it specifically for some purpose but my 12-24 is with me all the time. So what is better for one photographer may not be better for another.

 

[Tiberius]

fmw - Not really true. I doubt you'll find anyone saying the 70-300 has better optics than the Nikon 80-400VR, which has a bigger zoom range. You'll find plenty of people who consider the 17-55f/2.8 and 28-70f/2.8 every bit as good as a 50f/1.8 at 50mm. Etc.

 

[fmw]

fmw - Not really true. I doubt you'll find anyone saying the 70-300 has better optics than the Nikon 80-400VR, which has a bigger zoom range. You'll find plenty of people who consider the 17-55f/2.8 and 28-70f/2.8 every bit as good as a 50f/1.8 at 50mm. Etc.

I'd be interested in seeing some lens tests. I would simply not believe the zooms can stay with primes otherwise. People have a tendency to love what they bought and I take those opinions with a grain of salt. I have the 17-55 f2.8 DX lens and, while I think it is a fine lens, I'm pretty sure the primes that the range covers would outperform it. I'd test them myself except I sold all my 35mm primes. My 18mm f2.8 is still at the camera store on consignment. If it doesn't sell, I'll run some lens tests and I'm virtually certain it will outperform the zoom at the 18mm setting. It has to really, since the 18 has a 35mm image circle and you would only use the sweet spot on a digital. I think it would be a blowout but it would be an unfair comparison.

It just isn't possible to make a zoom lens with fewer compromises than a fixed focal length lens. Any lens designer would tell you that. They make some great ones, no doubt, and I buy them and use them personally. But you would be kidding yourself to think a fixed focal length lens won't give you more contrast, less distortion and less softness in the corners. Not a lot less, but less.

I'm not familiar with the longer zooms you mention above but there is no doubt you can design a lens to sell cheaply that will underperform others with a wider or same zoom range. My D50 kit lens is an example. It is the same zoom range as the 17-55 but noticeably inferior optically. That wasn't my point. My point was intended to compare lenses of comparable quality.

 

[mysteryscribe]

it has always been a lens maxuim or whatever the word is... More air to glass surfaces equal less sharpness.. Ie zoom will always be less sharp than fixed lens. Not sure if it is still true but its what I grew up with.

 

[Hair Bear]

So what is really been said here is better glass means a lens thats pecific to your needs.

If you do long shots all the time buy a 300mm fixed as a 70-300mm will not have the same qualities.

If you buy a specific to your needs lens then make sure its from a good manufacture.

If you cant afford specific lenses then a kit lens will do fine and is a compromise until you have confirmed your exact needs and or had a go with other lense to see the quality.

 

[KevinR]

Yes, it's all relative to what you see. If you are taking images that are pleasing to you and your friends/family, then what's wrong? When your taste changes so does the needs of what you are using as equipment. Think about some of the most famous images in the world. What where they using and was it good enough.

I think it used to be easier to find the better lenses:
Canon still has their L lenses, which are their pro-line lenses and uses their UD glass. But there are always exceptions the rules, because their 85mm is not a L lens and is really great.
Nikon used to have their ED-IS line which was their pro line. They don't use that label anymore, and the line is blurred between consumer/pro. Money is the factor it seems now.

Just a few of my thoughts on a Sat morning