Zooms VS Fixed: Canon Lenses

I'm about to invest in lenses. I was chatting with a knowledgeable salesperson at Leo's Camera Shop in Vancouver who swore that Fixed Focal Length lenses were invariably sharper than Zooms. Canon L quality.

I like fixed because they are simple: less mechanical stuff. But zooms are more flexible.

Does anyone have knowledge as to the sharpness of fixed vs. zooms?

Thanks for any opinions.

Tim Stenning
Forks, Washington

Experts like George Lepp say that even though there is a slight difference in the corners it is very hard to see unless you are wide open. I know that have used both and have had no problems with the zooms. Actually I have gotten rid of all of my fixed lens except for the 500 f4. The Canon L series are excellent.

In my experience, the differences in sharpness are small to a casual eye but definitely noticeable. We as photographers sometimes magnify these differences, I believe. That being said, I've shot the 400, 500 and 600 L series from Canon, and am able to notice better sharpness wide open than my Canon 100-400L offers.

I chose the 100-400 partly because of budget, but also because I really need that flexibility in both my wildlife/avian shooting as well as my wedding/action portrait shooting.

If I had the budget and could concentrate solely on avian (my favorite), I'd have the 600 f4L and 1.4 TC on one body and the 100-400L on another. Best of both worlds there. The 600/TC for those tight portraits that avian shooters seem to drool over and the 100-400 for BIF and looser environmental portraits.

If your shooting wildlife the large (500f4/600f4) fixed lens are the way to go, they are sharper.
If your shooting scenics I would go with a zoom for the flexibility. As Steve says the best combination especially for wildlife is to have 2 bodies one with a zoom (100-400, 80-200 etc)
this allows you to shoot your subject with some background and to capture it as it moves towards you. The large lens will give your great sharp full frame images.

I agree with your salesperson and Steve's comments. If you can shoot at smaller apertures, those differences decrease. But, I still prefer to shoot with primes for landscapes or long telephotos.

However, as Steve pointed out, with wildlife and other moving subjects, you really like the flexibility of zooms. Also, even for landscapes, there are circumstances where changing lenses is a major PITA. For example, very dusty environments (Antelope Canyon, African safaries come to mind). Or, in my case, I bought the Canon 24-105 L IS for a Grand Canyon raft trip. Accessing and changing several prime lenses on a bouncing, wet raft can be challenging.

Also, on a backpacking trip, where weight is an issue. carrying a zoom or two can be much more enjoyable than carrying a half dozen primes to cover the same range.

So, Tim, face it, eventually you will have a full set of L primes and L zooms.

Where should you start? Well that depends on your subject matter, and your need for flexibility.

It really depends on your shooting style. If you're looking at landscape, I prefer primes. Actually, I use only the TS-E's (tilt/shift lenses). There will be most always less flare with primes. The TS-E's will also allow you to shoot at f/8 (by tilting) where a fixed will need to be stopped down to it's maximum apertures for DOF, where diffraction softens the image.

Thanks everyone for your observations about lenses: the endlessly fascinating subject. TIm

I think it would be important to know what you shoot (there's only the "all posts" button here, not the "all photos" or something like that, unfortunately, so sorry for the stupid question).

In any case, from my experience (I'm a Nikon shooter), the primes I've shot have always been sharper than the zooms in the same range, at the same aperture (which often means more heavily stopped down for the prime because they tend to be faster). But as you say, there's the flexibility trade-off. So I guess the question you should be asking yourself is whether a 5 % resolution increase (that's just a number, no facts behind it) will benefit your images more than the zoom's flexibility (e.g. by being able to frame the image more accurately). That, only you can answer. Also, if you shoot everything perfectly composed on a tripod with a remote release and MLU, the prime may be able to show its superiority. If you tend to shoot hand-held at borderline shutter speeds... well... Seeing that you apparently have shot larger formats previously, I guess you're more likely to do the former.

Also, zooms tend to become better and better. Seemingly, Nikon just managed to release a lens (14-24/2.8 AF-S) that's better than any of their fix focals in that range.

In any case, good luck with your decisions...

Basil

One of the greatest reasons to use small-format systems is flexibility, and you can't beat zooms in that department. I can go hiking or backpacking with a single camera and a single zoom lens and get wonderful images. I may lose a couple of lines-per-mm compared to primes, but that's part of the deal. I doubt anyone will be able tell the differences in a print between a prime and a high-quality zoom.

Guy

There are rules of thumb, then there are exceptions. Your salesperson was using a venerable rule of thumb, and, for the most part, his recommendation is accurate. However, there are certain zoom lenses that, for one reason or another, just produce exceptional results, and indistinguishable from prime lens results. The Nikon 80-200 and 70-200 are prime (no pun) examples. Prime lenses in this range do not necessarily produce noticeably better results. There may be some handling issues that will affect the final product, such as lens collars and tripod mounts, etc. but optically, this range is legendary in its quality. So your needs are best served by examining your shooting style and material as others above have already stated, then start by finding reviews for the zooms in the focal lengths that you are looking for. Then comparing them to the fixed length offerings. In some cases the zooms will be equal to if not better than fixed, and vice versa. You should definitely look at this on a case by case basis to maximize your bang for the buck.

My setup includes a Sigma 10-20, Sigma 150 2.8 macro, Nikkor 18-200, and 80-200 2.8. From a sharpness and IQ perspective, the 150 and the 80-200 produce the best results. It is interesting to note that the Sigma 10-20 has better overall IQ at 20 mm than the 18-200 at 18 mm, wide open, but if you stop the 18-200 down to 5.6, the max aperture for the Sigma at 20 mm, the differences are significantly reduced.

Digital processing has all but eliminated concern over distortion and to a lesser degree chromatic abberation. If a lens has somewhat lower contrast it is not hard to enhance that as well.

If you are using film without a digital component to the workflow, then lens quality and overall image quality becomes more of an issue.

Thanks for the thoughtful opinions and ideas.