Prime or Zoom, which is better?

[Designer]

Hi, all. My question is; which has better optics, a prime (fixed focus) or a zoom lens? I understand that camera optics have improved over the years, and many zoom lenses now have the optical quality of yesteryear's prime lenses, but has anyone experienced a noticable difference in picture quality in the two types of lens using modern lenses?

[arith]

Yes; todays zooms outperform yesterdays primes. But we haven't got any modern primes as far as I know.

[Momo]

Yes; todays zooms outperform yesterdays primes. But we haven't got any modern primes as far as I know.

@arith
I'm curious, what exactly is a "modern prime"? I own both a 35mm and 50mm Nikkor prime. They're relatively new, so... are they an archaic design? Even if so, it seems to be they would be built using the latest and best technology. My 50mm prime is sharper than a chipped piece of obsidian. I should actually run a test between my 50mm prime and my kit 15-55mm lens dialed in at 50mm. Hmmm...

@Designer
If you want to compare primes vs zooms, check out this application on dpreview.com -- pretty slick.

[Colin Southern]

If the question is really "If I want the best image quality, should I use a prime or a quality zoom?" then - in real-world shooting - the zoom normally wins by a HUGE margin. Why? Because the image quality will be indistinguishable in a real-world print and in an online display; in fact the only time you'll see ANY difference is when examining the image at 100% in Photoshop - and that's NOT how we view images in the real world.

The downside of a prime is that it can SEVERELY limit the type of shot that you can take; if all you have is a 50mm lens and I have a 24-105 then I can shoot wide-angle - telephoto - or ANYTHING inbetween - you're stuck with 50mm. In my opinion, primes are specialist lenses eg my 14mm is useful for extreme wide-angle when my 16-35mm isn't wide enough (and I only use the 14mm occasionally) or my TS-E 90mm for when I need tilt & shift functionality.

For day to day shooting it's zoom zoom zoom - and I've get to take a single image that would have been improved by using a prime in the same situation.

[Designer]

Er...thanks, "arith". No modern primes, then?

[Designer]

Thanks for the link! I will spend more time with it later. There is a tutorial here that goes into detail with quite a lot of numbers and graphs, etc, but the best I can gather from all that is that the differences are probably to slight as to be noticible with the naked eye.

The test comparison between lenses on our own is an excellent idea. If we can't see the difference, why pay the difference?

[Designer]

Colin, thanks for the reply. It all makes perfect sense.

BTW: son #2 is wearing his "All Blacks" fan jersey as I write.

[Andrew76]

I think you're trying to compare two different tools. And you'll never get an answer doing that. I think what Colin has said is right. He uses different lenses for different jobs. But comparing a zoom to a prime, directly, like Momo suggests will render very noticeable results. I'm pretty sure that kit lens will not open up to 1.4, or even 1.2 for that matter at 50mm. That may be the reason for the cost difference. So what exactly are you trying to accomplish?

[Designer]

Andrew, thanks for the reply. As I am new to digital, I was hoping to (eventually) replace my two kit lenses with a zoom covering more "range". As I also am aware that most zooms do not open up to 1.4, I was trying to understand if there is any point in persuing a zoom lens that covers focal lengths from about 18 to 200 or 300.

More to the point; I was hoping there would be a way to avoid changing lenses every half hour when touring some point of interest.

[rpcrowe]

I totally agree with what Colin says.

Let me throw one more consideration into this ever ranging debate...

If I want to frame a scene in a certain fashion, I need to serendipitiously be standing in exactly the right spot or be able to quickly move to that spot. This is not always possible, in fact it is probably seldom possible. My recourse would be to slap on the next widest lens that I have with me and then crop to the compoition that I desire. That ends up with me only using a portion of the information collected by my sensor.

Using zoom lenses, I can almost always crop to very close (often exactly) to the composition I desire. That way, I am able to use all the information collected by my sensor.

Carrying a pair of cameras with 17-55mm and 70-200mm focal length lenses; I have a wide focal range at my finger tips. I really seldom do much cropping at all.

BTW: In response to Steve's post about no new primes available:

Canon has some modern primes:

100mm f/2.8L IS Macro , and the two brand spanking new new IS primes: 24mm and 28mm f/2.8...

However, I have none of these new lenses and I don't have any plans to acquire one.

If Canon had come out with a 24 or 28mm f/1.4 IS lens, I might have been tempted. That would have been a super low light lens. As is, my 17-55mm f/2.8 IS lens works great for me since I use the 1.6x format.

As for the Macro L lens; my Tamron 90mm f.2.8 AF SP Macro suits me just fine. Maybe it's not quite a good as the L but it cost me only $100 (USD) used on eBay and it is fine for the amount of macro that I do!

[Momo]

Well, I enjoy my two prime lenses because (1) they're fast and (2) I can do some amazing stuff when shooting wide open. None of my other lenses even come close to the f/1.8 of my primes. Although, if you're looking for versatility as suggested above, then definitely go with a zoom lens. Today's zoom lenses are top notch. My 55-300 shoots an amazing photo even at 300mm. To answer your question with the new info you provided, a zoom lens is "better" only because it will give you more versatility.

[arith]

Er...thanks, "arith". No modern primes, then?

I didn't think there was many new or modern primes; in fact I read that most design effort is spent designing better zooms and I find resolution and dispersion to be handled better in a modern zoom than say the ef 28mm f2.8, or the ef 50mm f1.4.

But of course there are some very expensive specialist primes with very wide aperture even f0.8 I think, I had some primes but got fed up with changing lenses and dust.

I don't know about Nikon though.

As a matter of interest; is there a sharpest or highest resolution to a camera? Because I constantly hear that the better the lens the better the image but Nyquist on my camera is 2250LW/PH which is less than is achievable at all focal lengths and all apertures with any of the L type zooms as far as I can see.
Also dispersion is virtually zero and with rounded aperture and a fairly fast speed with IS, can you really tell the difference.

My Tamron is cheap and nasty but at f5.6 or above it has a resolution exceeding that of the camera for most focal lengths and with VC I can get 9 stops under hand held sharp, it is advertised as four stops, and even at 17mm where the edges might be suspect I can't tell even at f2.8.

So, erm I didn't think about Nikon but have not heard of many modern or launched in the last year or so primes, and even if there was I cannot think of a reason to buy one.

[inkista]

... I was trying to understand if there is any point in persuing a zoom lens that covers focal lengths from about 18 to 200 or 300.

That's a different question.

Superzooms are amazing, given the focal length ranges they can cover, but the general wisdom is that they're slow, and often will have some type of image quality compromise to cover the huge zoom range. Hypercritical folks often consider zooms with zoom factors larger than 3x or 4x to be compromised in this way. The most common flaw I see is "wave" distortion at the wide end of the lens, which cannot easily be fixed in post without specialized software. But there are also a large number of folks who find the quality delivered to be more than acceptable. But understand that you are trading off some performance for the huge zoom range. Most superzooms I've seen deliver roughly the same quality as an 18-55/55-200ish twin lens kit, and if an OEM lens, for a much higher price.

But whether it's worth it is up to you. "Worth it" depends on how much cash you've got to throw around, and how much you hate changing lenses. Many folks find a superzoom to be an ideal travel lens, and a good compromise.

More to the point; I was hoping there would be a way to avoid changing lenses every half hour when touring some point of interest.

Run around. A LOT.

I'm so sedentary that shooting with primes is practically the only exercise I get.

Myself, I really like primes. But I'm a hobbyist and my income doesn't depend on framing precision. I like lenses that are faster than f/2.8, are small and light, don't cost a bomb, and while they may make me miss shots, I still really love the shots I do get.

Yeah. I use vintage manual focus lenses, too. And I don't mind changing lenses all the time. Swapping out a lens every half hour doesn't seem like a lot of changing to me. But then, for me, changing a lens only takes about five seconds, and since I use the body cap, I'm not rushed or juggling stuff.

[Colin Southern]

As I am new to digital, I was hoping to (eventually) replace my two kit lenses with a zoom covering more "range".

Hi Jim,

We get asked these types of questions quite often. Once upon a time primes may have had an advantage, but these days it's like saying "which is the better car - a 400km/hr Bugatti Veyron or a 350km/hr Ferrari Enzo" ... when all you want to do is go shopping at the supermarket down the road. You'll find test after test to show that a prime is sharper than a zoom - and I'll bet that every single one of those "tests" illustrates their results using 100% crops; that's fine for tests, but it's of no use in the real world.

With real world photography, what makes the biggest differences are:

- Photographer technique

- Lighting

- Post-processing, inc sharpening workflow.

My advice to anyone starting their collection is to start with zooms, and to think of primes as speciality lenses for those occasions where you need the extra speed or some other physical aspect that only a prime can provide (eg tilt & shift, ultra wide angle etc).

I do a lot of photography - and I actually own more primes than zooms - but it's still the zoom lenses that are on my camera 99% of the time (inc in the studio - on location - and for landscape shoots).

[Colin Southern]

have not heard of many modern or launched in the last year or so primes

There's been a few ...

- EF24mm

- EF28mm

- EF 500mm

- EF 600mm

[rpcrowe]

Frankly, when we are talking about zoom lenses, there are really probably three classes of zooms (at least for this discussion, I have arbitrarily divided zooms into three categories)

1. The relatively inexpensive "kit type" zooms. Far from disparaging these lenses, I consider them absolute marvels of engineering. Put them on a tripod and stop down to f/8 or so; and their quality at the price they sell for is amazing! However, when shooting at the edges of the envelope (wide open and in lower light levels), they really don't compare with decent prime lenses (or the better zooms for that matter).

2. The wide range zoom lenses. Wow, an 18-270mm lens that can produce fairly good imagery throughout the range! That is also a marvel of engineering. However wide open and at the ends of their focal range, the tend to have some problems. They have slower apertures than primes and the better zooms. Yep, primes (and the better zooms) will generally produce better image quality than the wide range zooms. They will, because of larger apertures and perhaps better focusing, be less suited to shooting in lower light levels.

3. Top-line zoom lenses that don't try for an exceptionally wide zoom range. I am speaking about the 17-55mm f/2.8 IS; 70-200mm f/4L IS; 70-200mm f/2.8L IS ii; and other lenses of equivalent quality both from Canon and from other manufacturers. These zooms are expensive! However, they also provide excellent image quality, fast focus and great versatility. The constant f/2.8 aperture and efficient image stabilization of my 17-55mm f/2.8 IS lens also makes this (IMO) quite a viable low light glass. Certainly, it will not allow the shutter speeds of an f/1.4 lens and IS will not stop moving subjects. However, I am also not working with a razor thin DOF and if the entire frame is sharp and the subject has slight movement blur - so be it. These are the lenses I am referring to when I sing the praises of zooms.

I have five prime lenses and three zoom lenses. However, I shoot probably 90% of my imagery with two lenses 17-55mm f/2.8 IS and 70-200mm f/4L IS. These two lenses provide all the image quality I need and provide me with exceptional versatility. I also don't feel that I am burdened by their slower apertures...

[arith]

A quick comparison of two top lenses I bet cost about the same;

http://www.photozone.de/canon-eos/15...review?start=1

http://www.photozone.de/canon-eos/17...review?start=1

But it is all about what you want it for; I wanted high resolution since I print around A2 size but also at the time I like to point into the sun.

By the way 100% photoshop view is bigger than 100% size, in fact more than 4x bigger and if anybody wondered why I'm mostly in portrait aspect it is because I mostly print A3+ size.

You can see here the zoom is as good or better than the prime in mostly everything except speed.

Another dumb irrelevant question I sort of resolved, I hardly ever look anything up; if you have two lenses a 50mm and 100mm primes and the exposure from a hand held light meter is f1 at 1 sec 1iso; how come it is the same for both lenses when one is four times wider than the other?

[Momo]

At the risk of hijacking this thread, I am going to answer this question...

By the way 100% photoshop view is bigger than 100% size,

It doesn't have to be this way. You can setup Photoshop to show an image at 100% print size. You may need a ruler. I watched Deke McLelland explain how to do this a couple of years ago and just now found it written up by someone else. So, here's the link on how to setup PS View/Print Size.

Last, let us not get confused between "resolution" and image "definition".

how come it is the same for both lenses when one is four times wider than the other?

Same aperture? FoV is not a part of the exposure triad -- aperture, ISO, shutter speed.

[Designer]

Kathy, thanks for the reply. I should clarify my frustration in changing lenses:

It seems that in order to cover most shooting opportunities, I swap between my "kit" short lens, and its longer f.l. partner. I have tried to do this under pressure from timing, particularly when the shot is rapidly disappearing. Also, at such times I rarely find the convenience of a table, bench, or some even some quiet place in which to change lenses. Furthermore, doing something like that, exposing the interior of my camera to the elements, sometimes forgetting to replace the lenscaps, a good chance of dropping a lens, or my camera, and all the while trying to do it quickly, I am thinking of aquiring a "super zoom".

While such an investment will be expensive, it would save me the trouble and the potential of dust, etc. entering my camera. I would not consider such a purchase if the super zoom would yield a poorer picture than either of my current zoom lenses. Obtaining a prime 50mm would probably not be in the near future anyway, but I was just wondering. BTW: I even think with today's modern optics, it might even be possible to simply use a fast prime for everything and do the cropping and enlarging on the computer, particularly if the high resolution is there to begin with.

Thanks again.

Jim

[Andrew76]

Hey Jim - I'm incredibly happy with my 18-200mm. For a general walk-around lens, and to capture some street shots, I think it's great. And, I think, for what you're looking for, it would be ideal. In my books, it gets better reviews than the 18-135, but that's just my opinion. In fact, the only trouble I've ever had with it, is that since it's fairly long, it always creeps on me. There's nothing I can do about it. So, for tripod shooting it's terrible, unless of course the camera is perfectly level with the ground. Even when you're walking around, if you have the lens unlocked, it will slip to the 200mm position.

Just to be clear though, if I was doing something specific like portraiture, or macro, I would opt for those lenses. Hope that helps!