Prime vs. Zoom test

Since getting back into photography, I've noticed comparisons between prime lenses and zoom, and wanted to do a test of my own. The idea behind this test was to get a 'general' idea of the detail and contrast between the Canon 50mm f/1.4 and the Canon 35-135mm f/4-5.6.

1. For starters, this picture is simply of the fireplace mantle in my own home. The idea of using this shot is because there are quite a few different items which have good detail, and depending on the resolving power, of the lens, may or may not show up in the cropped picture.

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I think you are going to discover that the 24-70 has a lot more in common with the 50/1.4 for IQ than it does with that 35-135.

Thanks for taking the time to do this test - but it should be no surprise that a good prime will have better IQ than a mediocre zoom at the same FL/aperture and other settings...especially the older 35-135mm. However, some of the new L zooms (ie. 24-70, 70-200, EF-S 17-55, etc..) have closed the gap a bit and have come a long way.

No surprise here - you've got a fast prime stopped down more than two stops vs. a zoom wide open.

The results are exactly what one would expect. With the 24-70 you might have a little more apt a comparison just because that's a lens somebody could reasonably use in place of the 50mm f/1.4.

folville wrote in post #11651662
No surprise here - you've got a fast prime stopped down more than two stops vs. a zoom wide open.

The results are exactly what one would expect. With the 24-70 you might have a little more apt a comparison just because that's a lens somebody could reasonably use in place of the 50mm f/1.4.

The idea behind the 24-70L is for my wife. She loves to zoom, and the 35-135 doesn't cut it when taking pictures in-doors. So, I'm hoping the larger apature of the 24-70L and resolving power, will make her happy.

folville wrote in post #11651662
No surprise here - you've got a fast prime stopped down more than two stops vs. a zoom wide open.

The results are exactly what one would expect.

This is what I would have expected 30 years ago maybe. The zoom in this comparison is so soft I doubt I'd ever use it personally.

(as an aside, in tests like this where a lens gets sharper when stopping down, a lot of people assume that this shows that the lens is soft wide open. What is more common is that the lens or test has a focus error and the image improves while stopping down because the DOF is getting larger.)

My 24-70 is as very nearly as good as my 50/1.4 was.

My 70-200/2.8 IS II is better than either the 85/1.8 or 135L that I owned. It has less CA, better microcontrast and was more sure footed when focusing on tough movement in low light.

People who think zooms are a noticeable step down in IQ from primes are living in 1977.

JeffreyG,

There has already been a documented instance between the 24-70L vs. the 50mm f/1.4 prime as well as the 28-70 (old model).

The results are pretty darn close.

Take a look here >http://www.fredmiranda​.com/24-70/.

I like like and use primes for the main fact that they are fast and have a wide aperture.

I shoot at f/1.2 - f/2 90% of the time depending on the lens

I realized that I actually have two shots between the 35L and 24-70 that are remarkably similar and which were taken with cameras that have similar pixel densities.

Here are the two shots. One was taken with the 35L at f/5.6 and the other was taken with the 24-70 @43mm and f/3.2. In the next post I'll also put up the 1:1 views. A good zoom is very much comparable with even high end primes for a lot of things.

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And here are the 1:1 views. I do not think the prime is sharper than the zoom even though the zoom is only 1/3 stop down from wide open while the prime is four stops down. Which is which?

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Yep, the quality of today's zooms have definitely come a long way, especially some the available L's. My 70-200mm give my L primes a run for their money at the same FL and aperture as well.

Well, the 50/1.4 will beat out the 24-70 hands down at f1.4 and f2, every single time .

Also, you're comparing a $1300 zoom that's 5 inches long (sans hood) and weighs over 2 pounds with a $350 prime that's 2 inches long (w/o hood) and weighs 2/3 of a pound.

They both have their time and place. That's why I have and use both.

Price shouldn't come into the discussion, imo.

If something is better, it is better... the price, etc. doesn't change that fact.

amfoto1 wrote in post #11653410
Well, the 50/1.4 will beat out the 24-70 hands down at f1.4 and f2, every single time .

Also, you're comparing a $1300 zoom that's 5 inches long (sans hood) and weighs over 2 pounds with a $350 prime that's 2 inches long (w/o hood) and weighs 2/3 of a pound.

They both have their time and place. That's why I have and use both.

For 1300.00 it should out-perform a prime costing 350.00. I suppose it does since it zooms!

davidc502 wrote in post #11653919
For 1300.00 it should out-perform a prime costing 350.00. I suppose it does since it zooms!

Nope, it should not. Price doesn't have to be into the equation of testing one lens's sharpness.