Canon 70-200 L f/2.8 IS vs. 70-200 L f/4 IS

[Alis]

I have been debating with a friend of mine which one of these is better in terms of sharpness. All I have heard from people up to this point have been that the f/2.8 is sharper than f/4 at similar apertures.

I have had both of them myself, not at the same time though, but I am not really at a point to tell which one was sharper, as the IQ with both of them looked great and I never did or knew how to do a formal test.

Now that I look at this on the net, the opinions are divided. Some people think f/4 is actually sharper. What do you guys think? And I am asking for a comparison regardless of weight or price or maximum aperture.

Thanks,

Alis

[hoffstriker]

"Which flavour of canon 70-200 lens?" is a good thread and kinda answers the same question you are asking here. I would highly recommend looking this thread up. I think it might answer your question. If you need help looking it up let me know.

[Alis]

Thanks. I thought there should be a thread for this somewhere. I will look it up right now.

Alis

[Colin Southern]

Hi Ali,

The long-standing debate over the sharpness of these two particular lenses - in my mind anyway - is the PERFECT example of the old "can't see the forrest for the trees" saying.

The "correct" way to compare them is in terms of weight - in terms of speed - in terms of IS generation even, - but not in terms of sharpness.

A couple of things that come to mind ...

1. Correct capture sharpening (*yawn*) (which most don't bother to do anyway) will have a far far far far far greater influence on the result than any inherant difference in sharpness between them, and

2. I put both lenses into the "so more than adequate it's not even funny" category in terms of sharpness.

Honestly, it's like comparing a Ferrari to a Porche, and choosing the Porche because it uses a lighter grade engine oil -- it just doesn't make any sense.

[klf]

Hi Ali,

1. Correct capture sharpening (*yawn*) (which most don't bother to do anyway) will have a far far far far far greater influence on the result than any inherant difference in sharpness between them, and

I've used them both and I personally like the sharpness from the f2.8 better. I will admit I don't know alot about photography, but I am slowly trying to change that.

Showing my ignorance, Colin, what do you mean by correct capture sharpening?

Kim

[Colin Southern]

I've used them both and I personally like the sharpness from the f2.8 better. I will admit I don't know alot about photography, but I am slowly trying to change that.

Showing my ignorance, Colin, what do you mean by correct capture sharpening?

Kim

Hi Kim,

Most camera manufacturers deliberately introduce a degree of blur into the image via the anti-aliasing filter in front of the sensor to prevent moire type patterns in certain sorts of images. The conversion from a RAW shot (be it in camera or via a PC) also introduces more blur. To get around it we apply capture sharpening.

I wrote a wee bit about it here if your interested.

Does this help?

[Jim B.]

Hi Kim,

I started using the 3 pass sharpening technique that Colin describes a few months ago and it really makes a big difference.

[Alis]

Thanks, everyone, for the comments. I am reading them.

About the sharpening issue, Colin, I found this:

http://www.adobepress.com/bookstore/...sbn=0321637550

Looks like the new edition of the book you intorduced. You may want to update the link in your thread.

[klf]

Thanks Alis and Colin--I think it will help. I've been using the unsharp mask only (I think) and the equivalent in lightroom. Will have to try the 3 pass method when I get time. I have to do a bit more reading from the links as well. Thanks again

[Colin Southern]

Thanks, everyone, for the comments. I am reading them.

About the sharpening issue, Colin, I found this:

http://www.adobepress.com/bookstore/...sbn=0321637550

Looks like the new edition of the book you intorduced. You may want to update the link in your thread.

Thanks Ali -- Man I "hate" one-click ordering ... you just cost me about $60 (NZ) Bucks!

[Alis]

Thanks Ali -- Man I "hate" one-click ordering ... you just cost me about $60 (NZ) Bucks!

Sorry!

I will wait for a second hand version, I am patient!

[Colin Southern]

Sorry!

I will wait for a second hand version, I am patient!

I thought you were the Doctor?

Patient doctors - Doctor patients - patient patients - maaan it gets confusing!

[Alis]

I thought you were the Doctor?

Patient doctors - Doctor patients - patient patients - maaan it gets confusing!

You know they say you don't have to be a doctor to have patience...

[rpcrowe]

Pixel peepers will tell you that the f/4L IS lens is the sharpest of the Canon 70-200mm L quartet. Objective testing seems to back this up...

However, I sincerely doubt if anyone could differentiate between images shot with these lenses if they were viewing a selection of images shot with the various 70-200mm lenses.

I have owned the f/4L (non-IS) and now own the 70-200mm f/4L IS version. I have also used both f/2.8 versions.

The major difference among the the four versions is not sharpness nor image quality. The differences are:

Size and weight: Both f/4L versions are considerably smaller in size than the f/2.8 versions. The weight difference is quite significant. The f/2.8L IS weighs 1,470 Grams while its seemingly diminutive sibling, the f/4L IS lens weighs only 760 grams. I can carry the 70-200mm f/4L IS mounted on a second 40D camera at the same weight as the f/2.8L IS lens alone. The f/4 versions (especially if used with a round screw-in lens hood) attract considerably less attention.

Aperture: Obviously the f/2.8L brothers are a stop faster than the f/4L brothers. However, with the high ISO capability of today's DSLR cameras, I have no great problem shooting in most venues using my f/4L IS lens. In fact, here is a link to night American High School Football shot with an f/4L IS lens.
http://photography-on-the.net/forum/...d.php?t=746074
The f/2.8 lenses will, of course, allow for greater control of depth of field since the DOF of an f/2.8 version is a lot shorter than that of the f/4 versions. However, this shorter DOF is a double edged sword since it is sometimes too short for practical use. Of course, you can always stop down an f/2.8 lens but, you cannot open an f/4 lens past that aperture.

Price: Obviously, there is quite a difference in price. I won't go into the actual pricing of the 70-200mm family of L glass but, in the U.S. the prices of the various lenses are that the f/4L (non-IS) is the least expensive; the f/2.8L (non-IS) and f/4L IS lens prices are pretty close in price; and the f/2.8L IS lens is the most expensive. In fact, the f/4L IS lenses average only about 2/3 the price of the f/2.8L IS versions.

All of these lenses will provide great quality. I chose the f/4L IS because I carry two 1.6x cameras with 17-55mm f/2.8 IS and 70-200mm f/4L IS lenses attached. This, in itself is a pretty heavy load which I carry with the neat OPTECH Dual Harness:

http://optechusa.com/product/detail/?PRODUCT_ID=87

Although the dual harness is a great way to carry a pair of bodies/lenses, I believe that the extra weight and bulk of the f/2.8 IS lens would be the straw that broke the camel's (in this case I am the camel) back.

[I Simonius]

I have been debating with a friend of mine which one of these is better in terms of sharpness. All I have heard from people up to this point have been that the f/2.8 is sharper than f/4 at similar apertures.

I have had both of them myself, not at the same time though, but I am not really at a point to tell which one was sharper, as the IQ with both of them looked great and I never did or knew how to do a formal test.

Now that I look at this on the net, the opinions are divided. Some people think f/4 is actually sharper. What do you guys think? And I am asking for a comparison regardless of weight or price or maximum aperture.

Thanks,

Alis

In my OWN experiments I found that the f4 out resolved the 2.8. I tried with two 2.8 and 3 f4s.

[Colin Southern]

In my OWN experiments I found that the f4 out resolved the 2.8. I tried with two 2.8 and 3 f4s.

However - in "real world" shooting situations - I take the position that both are clearly (pun intended!) in the "more than adequate" category

[KentDub]

Thanks Ali -- Man I "hate" one-click ordering ... you just cost me about $60 (NZ) Bucks!

You and me both!..... It'll be here Friday...

[I Simonius]

I have been debating with a friend of mine which one of these is better in terms of sharpness. All I have heard from people up to this point have been that the f/2.8 is sharper than f/4 at similar apertures.

I have had both of them myself, not at the same time though, but I am not really at a point to tell which one was sharper, as the IQ with both of them looked great and I never did or knew how to do a formal test.

Now that I look at this on the net, the opinions are divided. Some people think f/4 is actually sharper. What do you guys think? And I am asking for a comparison regardless of weight or price or maximum aperture.

Thanks,

Alis

The 2.8 has higher contrast and so appears sharper, but when you get to pixel peeping the f4 has it. That's the conclusion I came to after pixel peeping using shots of the same thing at same apertures, although I only tested from wide open to 5.6

I would also agree with everything that rpcrowe said in his last post