[RioRico]

Each lens is its own "window on the world" and those windows determine how you see what's around you. I prefer my 18-250 to a 18-55 + 55-300 pair because it's a larger window. I value my fast 16-24-28-35-50-58-85-100-135-200 manual primes because each has its own distinct window. I value my slow 21-35-40-50-100-127-135-180-200 primes because each has its own unique qualities, especially preset lenses with many iris blades.

Each lens makes me look at the world in its own way. So I use my few newer AF zooms to TAKE pictures, and my many old manual primes to MAKE pictures. These are quite different approaches. Zooms and primes can each do things the other can't, just like the different abilities of film and digital sensors. And using enlarger lenses on bellows gives even more viewpoints, more possibilities.

There's more to optics than just coverage and IQ. Yes, I could 'cover' a vast range with just 3 zooms: T20-24, DA18-250, S170-500. But they just don't deliver the qualities of superb and/or idiosyncratic primes. That's why many of us prize those bits of old weird glass. Just arrived yesterday: Isco-Gottingen Westar 100/4.5 in Exakta mount, 10 iris blades, ten bucks plus shipping. Slow aperture; smooth, long-throw focus; crisp wide open, rich tonal rendition, zero fringing, a real delight.

Then there's cost. Average (mean) cost of my AF lenses: US$327. Mean cost of my MF lenses: US$20. This matters to me. But hay, it's only money, right?

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Last edited by RioRico; 02-28-2011 at 01:21 AM.

[GeneV]

The last point mentioned here, is often underetimated, I guess.
As stupid as it may sound: By limiting your possibilities on purpose, you approach things differently!
With a large zoom your eye sometimes 'looks' for any interesting motive (at different distances/scales).
But with a prime on your camera your eyes adapt to the frame of this lens and you start to hunt much more for suitable motives.... this really gives different results and a very different feel!

So true. Even more so if you carry only one prime or have a fixed lens camera. I was surprised at how many more interesting the photos come from my Olympus XA sometimes.

[JHD]

From photozone.de

DA 15 F4:
Barrel distortion: 1.5%
Vignetting @ F4: 1.3 EV - 0.33
MTF @ F4: 2308 - 1580
MTF @ F5.6: 2352 - 1716
Chromatic Aberrations: 0.69 - 0.8

DA 16-45mm @ 16mm:
Barrel distortion: 2.5%
Vignetting @ F4: 1.17 EV - 0.59
MTF @ F4: 2281 - 1741
MTF @ F5.6: 2321 - 1863
Chromatic Aberrations: 2.3 - 0.52

The zoom lens does have really strong resolution figures, but falls to the prime in barrel distortion and CA. For all intensive purposes they would produce similar images, except for the gigantic amount of CA the zoom might render.

CA - nothing that a little bit of PP can't take care of.

The barrel distortion is hardly evident.

Neither of these two points justifies the premium one must pay for the DA15. The fact is in the real world of taking pictures and not looking at numbers, I cannot for the life discern with my own eyes any appreciable difference with shots taken by those two lenses. Glad I fell off that wagon and sold mine. The DA15 is ridiculously overrated - largely due to the novelty of shooting the sun - which gets old real fast. Yawn.

[harmonica2]

To build on RioRico's points, if you make a choice to buy a few quality zooms, you can certainly achieve excellent IQ at the expense of physical size - not a bad tradeoff. But when you develop a collection of primes from different brands and eras as is eminently possible with a Pentax body, choosing a lens becomes more than just finding the appropriate focal length: Each lens has its idiosyncratic qualities that contribute to the mood of the shot. Being able to pick from my own DA, FA, A, M, Sigma, and Tamron primes has provided me a richer artistic experience than I could ever achieve with the best zooms that cover the same focal lengths.

[Emacs]

The sharpness isn't the only parameter. There are others, both objective and subjective. The first thing tests don't cover even objective parameters. For example, they shows FA 43Ltd has maximal sharpness at f=4.0. But the reality is its maximal sharpness depends on the distance of the focusing point. It's sharpness sucks when focused at infinity at f=4.0, but it's outstanding when stopped down to 8.0.
As I said, there's other parameters. The color reproduction: zooms usually suck in this area, but this parameter can't be measured. The rendering itself: when I compare shots A* 135 f1.8 vs Canon 135L f2.0, I found the Canon to be overrated, it's sharp, etc, but it's boring as hell. The image from this L looks much worse than with that old stunning star lens.

[Eruditass]

But they come at the cost off having only one focal length. The fact is you can't always zoom in (or out) with your feet and if you can, buy then you may have lost the shot. And unless we're talking about pancake primes, the size difference hardly matters. So whatever perceived advantages one may have with prime lenses, they are out weighed by their limitations / disadvantages.

Not even just lost a shot, but you simply may not be able to get a shot. Moving with your feet changes the perspective distortion. You may not be able to get the composition you want. Here's a thread I made a while ago: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/81135-careful-...ng-primes.html

That said, I still love primes.

[Emacs]

CA - nothing that a little bit of PP can't take care of.

The barrel distortion is hardly evident.

Neither of these two points justifies the premium one must pay for the DA15. The fact is in the real world of taking pictures and not looking at numbers, I cannot for the life discern with my own eyes any appreciable difference with shots taken by those two lenses. Glad I fell off that wagon and sold mine. The DA15 is ridiculously overrated - largely due to the novelty of shooting the sun - which gets old real fast. Yawn.

Man, I guess you don't know what are you talking about. 16-50 can't stand against that limited at the wide end.
The color reproduction, the counter light handling, the light rendition is way better on the prime.

[JHD]

Man, I guess you don't know what are you talking about. 16-50 can't stand against that limited at the wide end.

No sir, you are the one who doesn't know what you are talking about as I never mentioned the 16-50.

[Pablom]

I don't share the general approach of this thread. I prefer primes because they can have much more character than zoom lenses as the latter I assume are made for general purpose and primes, well, they are for fun

[krp]

It would be interesting to make a poll asking which you prefer. Or has that already been done? I prefer zooms because I would rather not have to carry and change so many lenses. Plus I like autofocus and good prime lenses with af cost a lot of money. I would like to buy one good prime lens sometime though, maybe the FA 43.

[Eagle_Friends]

CA - nothing that a little bit of PP can't take care of.

The barrel distortion is hardly evident.

Neither of these two points justifies the premium one must pay for the DA15. The fact is in the real world of taking pictures and not looking at numbers, I cannot for the life discern with my own eyes any appreciable difference with shots taken by those two lenses. Glad I fell off that wagon and sold mine. The DA15 is ridiculously overrated - largely due to the novelty of shooting the sun - which gets old real fast. Yawn.

i guess some people just don't "get it".

[rparmar]

On the other hand, the IQ of good zooms has increased so much that it seems to me that almost all the lenses are capable of IQ that is as good as I need.

An intelligent way of evaluating a lens is relative to one's own requirements, as you have done. Amazing that others don't get this!

Each lens makes me look at the world in its own way.

Spoken like an artist and someone who appreciates the subtleties in life.

I would like to buy one good prime lens sometime though, maybe the FA 43.

A good plan. Then you would know what all the fuss is about.

[sjwaldron]

The single focal length point is quite a bias statement. I, like many other here, actually prefer primes over zooms because it only has one focal length. Speaking for myself, prime lenses are more focus, you know it'll be sharp and you'll need to know your surrounding and frame to compose a great image. I am actually on the other camp, I bought a 16-45mm and sold it to get a 15mm. The zoom is a great lens and the IQ is very good, but the 15mm just felt right for me. The size, the color rendering, the flare capabilities and having only a single focal length.

I agree.

The only two zooms I currently own are the 50-200mm WR and 10-17mm Fisheye.

When I need range, I just carry two camera bodies.

For example I used this setup at a convention with success:
K-5 with the 14mm f2.8 (full body shots)
K-7 with the 55mm f1.4 (portraits)
The K-5 around my neck and the K-7 in a small bag that's easily accessible.

On the other hand I also used this setup at the same 3-day event:
K-5 with the 50-200mm WR for sit-down events in the main programming area (left in the bag until the event started).
K-7 with the 31mm f1.8 for general photos (usually 3/4ths body and portraits).

The K-5 is able to manage with a slow zoom lens like that. The K-7 works wonderfully with the 31mm so I don't have to switch out lenses.

[twitch]

I have both, but no zoom is ever going to match the FA31 bokeh, and my DA70 is just a joy to use compared to my DA*50-135. People do change their behaviour when my 50-135 comes out and it always gets comments on how big it is, my DA70 is a better candid lens for that reason alone.

Primes and zooms are different; speeds, size & weights, rendering and yes even IQ. I prefer shooting with primes in the main due to better handling, better IQ and wider apertures (for some of my primes anyway). I shoot with zooms at events when to some extent quantity is more important than quality.

[JHD]

i guess some people just don't "get it".

Oh yes, why of course... The DA15 Delusion. Had it and done with it!