70-200 sharpness vs 85mm prime

I am in the process of deciding which of the 70-200 L lenses is right for me. I won't ask for general opinions here because there is plenty of commentary to be found for those who know how to use the search function.

I have heard that the 4 different 70-200 lenses vary in sharpness with the f/4 IS possibly being the most sharp. I have seen samples from all 4 so I know that they are all sharp, but I am trying to gauge how much sharper they are from my current setup.

My sharpest lens is probably my 85mm f/1.8 (love that lens), so that is my best lens for comparison. Can anyone help me get a better understanding of what the relative difference in sharpness is between my 85mm f/1.8 and the 70-200's? I know that primes are generally sharper than zooms, but L's are usually sharper than non-L's. I also understand the comparing the 85mm to a 70-200 at 200mm is not quite apples to apples, but any comparisons that you have seen would be helpful. Are all 4 70-200's sharper than my 85mm, or is it the other way around? Or maybe does the 85mm fit in the middle of the 4 somewhere? I have tried reviewing the MTF charts, and while I've learned a lot, I'm not quite to the point where I can make an educated opinion using them.

I am currently leaning toward the 70-200 f/2.8 IS and have high expectations for the IQ. Even if its not the highest IQ of the 4 70-200's the 2.8 and IS will be very useful for the type of shooting I do. But if the 2.8 w/IS is not as sharp as my 85mm f/1.8, then I may have my expectations too high.

Thanks for your help.

The 85 1.8 will be sharper (slightly) than the 70-200 2.8 at an aperture of 2.8. You have to consider though, that the 85 is stopped down 1 1/3 stops from maximum aperture at 2.8 and the 70-200 is wide open. Either way, the fact that they are close says a lot about the 70-200's. IS is icing on the cake.

subscribing - I own a 70-200 f/2.8 IS and am thinking about an 85 f/1.8 prime. I am very curious if someone who owns both can say whether the non-L prime is sharper than the L zoom (all other things equal - like f/stop and FL, body, etc.)

Good question

I have both the 85mm F1.8 and the 70-200L IS, and at F2.8 and stopped down from there, the 85mm F1.8 is sharper, HOWEVER the 70-200L has a bit better color rendition and contrast...as for sharpness differences, those differences are very small....but what makes the 85mm a keeper (and not redundant) is that it is faster in aperture....F2.8 for a zoom is very fast, but often still to slow for challanging light shots.

Wow, this is a good question. The 70-200 2.8 IS is sharp, but at 2.8 it's not nearly as sharp as my 85 1.8. So, I have both. In some low light conditions where 2.8 is still not enough, I use the 85. But for convenience in bright light, the 70-200 is really amazing. They both focus fast and are quite accurate.

The prime smokes at f2.8 http://www.pbase.com …s/image/4524612​4/original

LR, that link is great. I love my 85.

LightRules wrote in post #3815300
The prime smokes at f2.8 http://www.pbase.com …s/image/4524612​4/original

Ouch! I've not used my 24-70L in such a very long time, I have forgotten how much better the 85mm at F2.8 is....I knew it was better, but your pictures have refreshed my memory.....why I even keep all my L zooms is a mystery to me....I rarely use them, yet I hold on to them...go figure...

Thanks for the post of pics!

Richard_Miami wrote in post #3815241
subscribing - I own a 70-200 f/2.8 IS and am thinking about an 85 f/1.8 prime. I am very curious if someone who owns both can say whether the non-L prime is sharper than the L zoom (all other things equal - like f/stop and FL, body, etc.)

Good question

I currently own both lenses but honestly never conducted any test to determine which one is the sharpest (imagine that! ). They both look damn good to me. However, for the sake of satisfying curiosity, I'll be glad to perform a quick test to guage the performance of each lens at varying apertures @ 85mm. Problem is I'm cameraless for the moment, so you might have to wait a couple of days at least.

Steiglitz wrote in post #3815258
I have both the 85mm F1.8 and the 70-200L IS, and at F2.8 and stopped down from there, the 85mm F1.8 is sharper, HOWEVER the 70-200L has a bit better color rendition and contrast...as for sharpness differences, those differences are very small....but what makes the 85mm a keeper (and not redundant) is that it is faster in aperture....F2.8 for a zoom is very fast, but often still to slow for challanging light shots.

So you've got both the 85 1.8 and the 85 1.2L? Both are great lenses and all, but I personally wouldn't need both. Unless you use the 85 1.8 for indoor sports and the 85L for studio work?

The 85L for weddings for it's better color and contrast and aperture speed (candids sans flash).

The 85mm F1.8 for fast action indoor sports, events and such...the 85L would AF too slowly.

Two 85mm lenses for two completely different missions.

LightRules wrote in post #3815300
The prime smokes at f2.8 http://www.pbase.com …s/image/4524612​4/original

Nevermind. I see that answers the question.

Lord_Malone wrote in post #3815427
I currently own both lenses but honestly never conducted any test to determine which one is the sharpest (imagine that! ). They both look damn good to me. However, for the sake of satisfying curiosity, I'll be glad to perform a quick test to guage the performance of each lens at varying apertures @ 85mm. Problem is I'm cameraless for the moment, so you might have to wait a couple of days at least.

CameraLESS? Lordie...that's like driving around with no insurance...hmmm.....m​an, you have no coverage in your life now....please, lets not do this again!

Steiglitz wrote in post #3815483
The 85L for weddings for it's better color and contrast and aperture speed (candids sans flash).

The 85mm F1.8 for fast action indoor sports, events and such...the 85L would AF too slowly.

Two 85mm lenses for two completely different missions.

Makes sense. I wish I could be more "mission specific" with my glass, but sometimes I just have to make due with what I got in my bag!

I think it's more of a convenience decision. You don't buy a ZOOM lens for sharpness, you buy it for convenience. They are all perfectly usable by all standards. The real choice is which 70-200 you can afford. Yes , the f/4 IS is sharper and lighter but it's also slower and the AF is less accurate and slower on anything slower then f/2.8 So just buy the one u can afford. the only suggestion would be that for a 70-200 zoom lens you'd really appreciate IS