going back to primes!

Doesn't shooting with primes constitute frequent lens changes and doesn't this heighten the liklihood of dirt getting to your sensor. Also you lose the spontaneity of instant focal length changes critical in wedding photography? Unless of course you have three bodies hanging around your neck.

Halina

Good points Halina!

By the way, I should compliment Soumya63 on the photos. Very luscious! But I don't know what they have to do with the topic at hand. For all I know, these photos could have been taken with a zoom. They don't demonstrate any differences between zooms and primes.

But I guess we can't complain.

The point was to show even for a fast and demanding photo session. you can easily manage with a fixed focal length lens than zooming in and out to capture your subject.

I also have a 70-200L f2.8, but mostly use it in concert or similar low light and crowded situation where you cannot zoom by walking. It is a personal preference and style I guess.

Lastly, I must congratulate one of our previous poster for his idea of using a super duper zoom to use in a combat situation You get fresh ideas everyday!

Umm, I shot weddings for years with medium format using three primes, a 45mm, 80mm and 150mm. It didn't kill me or ruin my spontaneity. There are only recently zooms available for medium format and they are heavy and slow. Even with the weddings I shot on 35mm kit I generally shot the majority with primes and yes I did have a second camera around my neck with a quality zoom on it for backup.

Primes are optically better in almost all cases. Zooms are more versatile. Top quality lenses of both flavors have a place. Just pick the limitations you are willing to live with.

No scientific set-up attempted and no conclusions drawn, just adding a piece to the puzzle. Below are crops from two RAW-shots (350/s F/5.6 @ 50mm - no editing) - one with a prime and the other with a zoom.

I'm leaving the judgement to you regarding which is which. At Photodo the lenses are graded 1,6 and 4,2 -->

Byte size: ZERO | Content warning: NOT AN IMAGE

Sorry but it appears from the crop that none of them have critical focus and sharpness. Provide a shot with finer details. Broad patch of color like sky will not tell the story.

Provide a picture like this

HTTP response: 404 | MIME changed to 'text/html' | Byte size: ZERO

Well Jorge, at least you've made an attempt, but I tend to agree with soumya63 that the target is not ideal for such comparisons.

Unfortunately, I don't have my photos on a web site so cannot show you any, but I went through this process of comparing zooms and primes a few years ago and decided the benefits of the prime were, from a practical point of view, slight or non-existent.

However, it's possible to skew the results any way you wish. Zoom lenses generally tend to have their worst performance at the extreme ends. Compare a prime 28mm lens with the Canon 28-135 IS zoom and you'll probably find the prime is noticeably better in terms of resolution, especially in the corners, and barrel distortion etc.

On Luminous-Landscape there's an interesting comparison between the Canon 400mm F5.6 prime and the 400mm end of the 100-400 IS zoom. The prime is clearly sharper. There's no doubt about it at all. HOWEVER, doesn't the Canon 100-400 zoom have a reputation for being rather 'soft' at the long end? Yes, it does. Can we draw general conclusions about primes versus zooms from such results? No, we can't. The performance of zoom lenses varies depending on the focal length setting. We can't even make a definitive statement about all zooms being poor at their extreme ends. Some are, some aren't.

For example, the new Canon 17-40mm F4 zoom beats the much more expensive 16-35mm F2.8 zoom at 17mm. It's noticeably sharper, even in the corners, and shows less flare. However, the 16-35 is noticeably sharper than the 17-40 at the other end.

My experience is, most good quality zooms around the middle of their range at least, and sometimes beyond the middle of their range, will equal primes for all practical purposes.

I agree with both of you, that no single comparison can tell the story, however the story can’t be told without comparisons and I believe that every single one has something to tell in it’s own right.

I was reading this tread and thought that I’d make a quick side-by-side so I stuck the camera out the kitchen window. What surprised me was that the difference is not greater between my old Cosina 28-300mm/4.0-6.3 rated a lousy 1,6 at Photodo and my Canon 50mm/1.8 with a far better rating at 4,2. That’s it!

Very true! Other considerations when doing comparisons are the quality of the scanner, if using film, or the quality of the DSLR. My first attempt at such comparisons a few years ago was made using a Nikon 2700 dpi scanner. There's no way a 2700 dpi scanner can reveal any significant difference between the best prime and even a moderately good zoom. When I later compared the same shots scanned at 4000 dpi, there were subtle and very marginal differences - but nothing worth bothering with, in my opinion.

Likewise, a D30 is not going to reveal subtle differences that a D60 or 10D would reveal. There's a good reason why MTF charts don't give any results for resolutions higher than 40 lp/mm (and Canon's Lens Work book doesn't go beyond 30 lp/mm) and that's because resolutions higher than 40 lp/mm tend to be irrelevant. Such fine detail is 'faint' and tends to get lost in the general background noise.

I reckon the chief advantage of fast, heavy primes is their superior focusing abilities. More accurate and faster focusing is a big plus.