Are primes really better?

[zemlin]

Being a stickler for words, my first thought is "Define better".

And as a design engineer, even through I'm not involved with optics, the answer is obvious - at least to me.

A zoom is "better" when you need the flexibility of adjusting your focal length to create the image. A prime is "better" when you are trying to achieve the ultimate in sharpness, etc.

From an optical design standpoint, a zoom has to be a compromise throughout the focal length range. I am certain if you were to take top of the line 24-70mm zoom (pick your range) and set it to 35mm - ask the engineer who designed it if the optics are ideal at this focal length. The response would be a resounding "No". There might be one focal length where a zoom is optimal, but I doubt it. If an engineer has the option of the creating the ultimate 35mm lens, without question it's going to be where each element and its placement is optimized for that particular focal length - and that same level of design could not be achieved in a zoom.

Today's good zooms are very good, but by definition, the designs are compromises.

That said, a zoom is going to be "better" if your primes are not the optimal focal length for the image you want.

[scootermcq]

Very well said Zemlin

[jerryph]

Are primes better than zooms... another global question that has no one 100% absolutely single answer.

Also, in the sense of photography, let's ASSume that they define "better" as the lens with the superior specifications and ability to produce the superior photo between 2 lenses. Convenience I do not categorize as "better"... it is more convenient.

In general, yes. Most (but not all) primes are better than zoom lenses. Primes are generally faster than zooms and the quality needed to accomplish these goals is more stringent. In other words, it costs less and is technically less demanding to make a variable aperture zoom than a fast prime.

That then begs another question... so does that mean that zooms that are NOT variable aperture are worse, as good as or are better than zooms? Again, generally speaking, no, even fixed aperture zoom lenses, IN GENERAL, will not be as good as primes.

My math teacher used to say "for every rule claimed as an absolute, if you can find even ONE exception, then that rule is false and no longer an absolute".

Photography is FILLED with absolutes that are false... lol

In my variation of this rule, you cannot say with absolute conviction that ALL primes are better than ALL zooms. There are some pretty poor primes out there, and there are some absolutely incredible zoom lenses out there... so good in fact, that they compare very well with even the very best primes on the market today.

So the answer is... whatever. lol

Perhaps a wiser and more pertinent question would be "Is this one particular specific zoom lens worse, equal or better than this one particular specific prime?".

Case in point, my Nikkor 135mm F/2 is absolutely incredible, I have not yet tested or seen it's equal. Every time I use it, I am surprised at how sharp the images are, even at F/2... but I can also say that the Nikkor 24-70 F/2.8 is known as being world class and has tested as having specifications equal to, and in some cases, superior to, many top of the line primes on the market today.

Generally primes will give you better photos than zooms, but there are quite a few really nice zooms out there in various configurations that can do as well or better. Normally these zooms have a 4-digit price to match their abilities.

What a top of the line zoom will never be able to do that a top of the line prime can do is be the "fastest". You will never see a 24-70 F/1.4, because the lens would be super expensive and weigh about 500 pounds (lol)... and the cost of the technology to create it is just not viable. No one would sell enough of them if they cost $15,000 or more each.

Years ago primes ruled over zooms, but that definitely cannot be said now... but again, NOT globally, this is only true if you compare a specific lens to another specific lens.

Anything less is pretty much meaningless.

[patterfr]

I'd love to see the high end zoom and prime comparison same exact settings, lighting, etc, etc. I'm not talking pixel peeping I'm talking print or high resolution screen image, hand held in actual shooting conditions.....I wonder if I really could tell the difference...I mean I swear I like diet pepsi more than diet coke, but if you put them both in a cup not sure I could reliably tell the difference either....

[Douglas]

Lets say you are a portrait photographer (or model/glamor/etc. Camera on a tripod with controlled action or inaction).

And you have the ability to use 2.8 zoom glass (2x to 70 2.8 and 70-200 2. or a 35 1.8, 50 1.x, 85 1.x, 105 1.x (on up). Which would be the preferred method for crisp sharp images.

And lets say both wide open and F8.

[jerryph]

Fran, again, the best vs the best at the same focal lengths and apertures under identical lighting conditions, yeah, it would be tough today. In the end it would come down to personal preference to characteristics like colour casts, contrast, etc.

However, those 2 lenses each have one clear advantage over the other... the prime in it's ability to just open up way wider than the zoom, and that zoom has the advantage of convenience, so which ever are more important to you, thats the lens you would choose in the end.

[jerryph]

Originally Posted by Douglas

Lets say you are a portrait photographer (or model/glamor/etc. Camera on a tripod with controlled action or inaction).

Would a 24 (or 2-70 2.8 + 70-200 2.8 or a 35 1.8, 50 1.x, 85 1.x, 105 1.x (on up) be the preferred method for crisp sharp images. And lets say wide open and F8.

That setup favors the zoom lens. Change venues into a dark location or in situations where motion (and hence maximum shutter speeds) is a factor, and that prime becomes the favored tool.

There is no one answer, because there is no one fixed way to photograph anything.

Oh, there is also one characteristic that I did not take into account... again, generally speaking, NO lens is at it's sharpest wide open. If I take a zoom to F/2.8 the shot will not be as sharp as if taken from a F/1.4 lens set to F/2.8, another factor to consider.

Another factor... the more crap you put between your camera and your lens, the lower the quality becomes. filters, teleconverters, etc... all detract from ultimate image quality.

[Douglas]

Originally Posted by jerryph

That setup favors the zoom lens. Change venues into a dark location or in situations where motion (and hence maximum shutter speeds) is a factor, and that prime becomes the favored tool.

There is no one answer, because there is no one fixed way to photograph anything.

I worded this badly, originally. Edited my previous post for a little more ease of reading my mind

[patterfr]

Originally Posted by jerryph

Fran, again, the best vs the best at the same focal lengths and apertures under identical lighting conditions, yeah, it would be tough today. In the end it would come down to personal preference to characteristics like colour casts, contrast, etc.

However, those 2 lenses each have one clear advantage over the other... the prime in it's ability to just open up way wider than the zoom, and that zoom has the advantage of convenience, so which ever are more important to you, thats the lens you would choose in the end.

Yup I agree, in the end, though I have both and use both, I prefer to zoom with my hands and not my feet..... And it's hard to quantify that. Especially when shooting from a place you can't move very easily from.

If I had $1500 to buy a lens, I'd go for the 2.8 70-200 every time over the beautiful 85mm 1.4G.

[jerryph]

Originally Posted by Douglas

I worded this badly, originally. Edited my previous post for a little more ease of reading my mind

Cripes, he's making me work today? LOL!!

In your setup, you are missing very important info... focal lengths are important when talking portraiture, but again, just as an example, Canon makes 4 variations of the 70-200... some absolute crap, some totally awesome.

So, again speaking generally, and ASSuming (lol) you are talking either external light sources or bright conditions, I would take the longest and/or the most expensive lens for sharpest portrait shots. I also would not place anything between the camera/lens nor any filters on that lens.

This discussion also has not even mentioned "style" desired. Is that blurred background completely undesireable or is the maximum blur look the only answer? Of the 5 factors that control DOF, 2 are controlled by the lens, one by camera body and 2 by physical positioning.