Canon Lenses (Page 3): Why would the 2.8 be sharper than the 4.0?

gemlenz Loc: Gilbert Arizona

Why would the 2.8 be sharper than the 4.0?

wylie wrote:

I am considering the same purchase and from all the info I can gather, there is no comparison in the sharpness of the two lenses. The 2.8 is much, much sharper.

philo Loc: philo, ca

I had the f4 and sold it for the f2.9 and I'm glad I did. I loved the 24-105 and now I love the 24-70.
I also have the 70-200 to cover what I gave up.

Effate Loc: El Dorado Hills, Ca.

I have an f4 that I use for back packing only but I can tell you that to my eye my new 2.8 II is sharper, faster focusing and better (cream like OOF probably due to blade count) than the original f 2.8 I owned or the f 4.

oldtool2 Loc: South Jersey

gemlenz wrote:

oh yes IS is a must..

Does the f4 have IS, I can't remember. You will find that the f2.8 does have better IQ, and sense you are doing this professionally I would go for the f2.8. If you watch Adorama and B&H you may find one used. I bought an f2.8 version I used and am very happy with it.

As for a FF, take a close look at the 6D. It won't break the bank, much more reasonably priced and takes great photos. I haven't seen a bad review on it yet.

Jim D

swedephoto

I asked myself the same question and I came up with the following thoughts: 1) do I really need the extra f:stop, especially shooting with a Canon 7D & 5D Mark II - I don't have a problem with higher ISO settings - so I could get away with the f:4, 2) the size of the 2.8 compared to the f:4 is much bigger and heavier, and can be a problem if you are slinging the lens for a long time - so I preferred the f:4, 3) optically both lenses are rated excellent and some tests claim the f:4 to be actually better, and 4) the price - $1000 is not something to take lightly. I chose the f:4 but make sure you get the IS version. If the 2.8 is your thing, one thing you might consider is the new Tamron VC f:2.8. The quality is excellent and much less than the Canon. Good luck with your decision

jteee Loc: Montana

gemlenz wrote:

oh yes IS is a must..

I opted for the 2.8 without IS, making the rationalization that I would be using it on a tripod most of the time anyway (saved about 1K). Am really glad I went 2.8, use it alot, but really don't do a lot of portrait stuff, so only you can decide.

gemlenz Loc: Gilbert Arizona

The 6D would be my choice also. I saw a refurbed one on Ebay for $1,399. I just can't do both right now. I'm leaning towards the f4.0

oldtool2 wrote:

Does the f4 have IS, I can't remember. You will find that the f2.8 does have better IQ, and sense you are doing this professionally I would go for the f2.8. If you watch Adorama and B&H you may find one used. I bought an f2.8 version I used and am very happy with it.

As for a FF, take a close look at the 6D. It won't break the bank, much more reasonably priced and takes great photos. I haven't seen a bad review on it yet.

Jim D

gemlenz Loc: Gilbert Arizona

The 24-70 would be my next one after the 70-200.

philo wrote:

I had the f4 and sold it for the f2.9 and I'm glad I did. I loved the 24-105 and now I love the 24-70.
I also have the 70-200 to cover what I gave up.

stevebein

I do mostly wildlife and outdoors, but weddings can be pretty wild. Anyway, humor aside, some report that the Canon f4 , in their hands is actually sharper than the f2.8. Benefits of each are one stop wider for the 2.8, a hell of a lot lighter and more convenient with the f4. I have used both and each has its benefits and detriments. The only person who can answer which is best for you is you. As a suggestion, rent both and compare, or go to a store and try each one on your 7D. With the crop factor, you are already reaching out 1.6 times the focal lengths anyway.
The answer is for you to decide, all else is suggestions by people some of whom have had lots of experience and others who just have opinions.

rocar7 Loc: Alton, England

Bloke wrote:

I saw something like this in a tutorial video, but it didn't register until later... How does this work - the constant aperture I mean?

Surely, this means that you are limited to a single choice of shutter speed? How else can you control the exposure?

Constant aperture means that the maximum aperture doesn't change from one end of the zoom range to the other. With a lot of zooms the maximum aperture gets smaller as you approach the long end of the zoom - Canon's 15-85 EF-S lens is f3.5- f5.6, so you have a smaller aperture at 85mm than you do at 15mm. Other than that you have a full range of apertures at all focal lengths, from the maximum down to, say, f22. But that depends on the lens.

Lenses with a constant aperture are more expensive to make, and more expensive to buy.

jeep_daddy Loc: Prescott AZ

Don't skimp for wedding photography. Many images are taken in low light situations. You will want the IS and f/2.8 lens.

SharpShooter Loc: NorCal

gemlenz wrote:

Why would the 2.8 be sharper than the 4.0?

Gem, I don't think this debate will ever be settled. I don't know anybody that has all the lenses to compare them all(I don't), so for myself, I have to depend on the professional testers to seek truth. My tester of choice is 'The Digital Picture'.
According to his tests, only the 2.8 mkll is sharper than the f4, non IS. The rest are either less so or a dead heat.
And most fast lenses are NOT sharp wide open. Almost all need one more stop or so. But one does not buy a fast lens because it is sharpest wide open. One buys it for the speed, and gives up the wide open sharpness.
If you are not shooting it wide open and without flash, they are all sharp.
But since it's SOOO expensive to make a lens fast, they DO optimize the build and the elements, to make them as sharp as possible.
The question for any lens, is not how sharp is it at f8, but wide open. At f8, even the kit lenses are almost as sharp. I know, I have a few.
Just 2cents more! I think this make 4cents for me.
SS

Poke Loc: West Virginia

Gem,

I was just pondering the same thing. I just got a 1dx and have the killer Sigma 120-300/2.8. However, I wanted a 70-200 to provide some more versatility and a lighter/smaller option. I was getting the 2.8 with no questions asked until my buddy who has both of the lenses (actually his f4 is not image stabilized). He told me to come over and look at them before I decided. I like to shoot sports and action type events and I love to shoot at f/4. 2.8 for me is only used when light is so atrocious that I have to go to 2.8. He shoots a lot of portraits so 2.8 provides him better blurring ability of the background. The image quality he reports is near identical. The weight difference is very significant. I could see wanting to use the 2.8 for portrait work at a wedding but I would rather haul around the f4 all day (the 2.8 will get very heavy). It was much lighter. I went with the f4 so I could start saving for the 85/1.2.

gemlenz Loc: Gilbert Arizona

I use my 100mm 2.8 for portraits. Works like a charm.

Poke wrote:

Gem, br br I was just pondering the same thing.... (show quote)

infocus Loc: Australia

gemlenz wrote:

I'm trying to decide to buy a 70-200 is usm 4.0 or a 70-200 is usm 2.8. There's about $1,000 in price difference between the 2. Is the 2.8 worth the difference?

Absolutely - in my opinion. I have the 70-200 L f/2.8, IS USM. Having the f/2.8 through the range of magnification is just wonderful. makes for a nice fast lens.