Checking out if you got a good copy for Canon 70-200 F2.8 L IS USM EF Lens

[vpolisetty]

Hi,

 

Iam a newcomer to the 'L' Series lenses. Is there a set of tests that you can

perform to make sure you got a good copy of the lens.(I know 70-200 IS is one

of the best there is).

 

Better still, Is there a place where I could send my lens and get it checked

out thoroughly. This is obviously a very expensive lens and I dont want to get

caught with a bad copy of the lens and not even know it.

 

Appreciate your inputs.

 

Thanks,

Venu.

[mike_earussi1]

Some camera repair shops have an optical bench/analyzer that can tell if a lens has any decentering or not. Other than that you can always test it out yourself with an old airforce test chart. Edmunds Scientific used to sell one. You could compare it to a lens you have of known quality.

 

As a whole, I've never heard of anyone getting a bad copy since Canon is much fussier when constructing their L lenses than their regular consumer lenses.

[digitmstr]

>>not even know it.<<

 

If the lens was defective you'd know it after taking a a few shots with it, believe me.

 

Don't get too paranoid about it. After all, if you go down that road you must also ponder the possibility that the shop doing the testing may damage the lens and...if they do, they won't certainly tell you about it.

 

Where does it end?

[awindsor]

There are certainly bad copies of the 300/4L IS and 70-200/4L. While I haven't heard about them I would be surprised if there were not bad samples of the 70-200/2.8L IS as well. There is significant sample variation even among L lenses. It is somewhat disappointing.

 

Try getting Imatest and doing your own testing.

[peter_white2]

How about taking a few pictures and looking at them?

[vpolisetty]

Alistair Windsor Wrote.." Try getting Imatest and doing your own testing."

 

Thanks for the tip about IMATest. My problem is, I have a Canon 17-40L which I am not very happy with but not sure how to check it out thoroughly. Now I am getting the Canon 70-200 IS and Tamron 17-50 f2.8.

Is it worth spending the $99/- for the software, considering that I am primarily a advanced amateur or Are there other alternatives.

 

If it is really good, I wont mind purchasing it.

 

Thanks,

Venu.

[digitmstr]

>>which I am not very happy with but not sure how to check it out thoroughly.<<

 

What is wrong with it? Is it under warranty? Did you send it to Canon?

[todd_fox]

There seems to be a paranoia about finding "good" copies of lenses.

 

"...caught with a bad copy of the lens and not even know it."

 

If you can't tell something is wrong, then why would it matter? If you can take the pictures you want with the lens, then it is good.

[vpolisetty]

>>which I am not very happy with but not sure how to check it out thoroughly.<<

>>What is wrong with it? Is it under warranty? Did you send it to Canon?<<

 

So far, I just took pictures with it and Did not do any detailed tests at various focal lengths. I do know that I have back focussing issues and also, lens seems to be soft, even compared to my Tamron AF 24-135mm f/3.5-5.6 lens. Just looking at the pictures.

 

I am getting ready to send it to canon. They want me to send some sample shots in RAW proving what I think is wrong. My concern is, would they just address the problem I reported or Would they run a complete lens test to check it out thoroughly.

 

Thanks,

Venu

[erin.e]

Don't worry, buy the lens, take some pics.

You can rest assured that there are infinitesimally more chances of running accross an incompetent photographer who follows the school of thought that the lens must be at fault instead of their own capabilities and techniques that own 'L' lenses, than there is of finding a 'bad copy' of an Canon 'L' (Professional) lens.

 

The 'L' series have been around since long before the advent of the internet and have gathered a well earned reputation for build quality, reliability, and a high standard of quality control from WORKING photographers.

 

Most of the complaints about Canon 'L' (or Nikon pro lenses) on boards like these are from incompetents who don't know what they are doing, so just buy the lens and enjoy it without buy into the internet bullshit!

[eric_chi1]

Hi Venu,

 

I think the best place to check is the Canon service center. Or if you have a friend that's very good at photography.

 

When you send it to Canon, they will typically do a projection test and follow by a calibration. If not so sure, you can request them do a calibration of the lens in the letter you send with the lens. Most lenses come back are very sharp.

 

I'd also recommend you to read:

http://www.focustestchart.com/chart.html

 

It tells you about the sensors and how they work. This will help you to improve AF and not make user mistakes. And then at the end, it gives you a chart to shoot with so you can tell the Canon service center whether your lens is front or back focus and by how much.

 

Eric.

[digitmstr]

>>My concern is, would they just address the problem I reported or Would they run a complete lens test to check it out thoroughly.<<

 

Well - they will ck the problems YOU list of course. For example, backfocusing. However, you may need to have the camera body and lens "matched" or "calibrated" with one another. That's NOT necessarily a lens defect per se.

 

I have never "tested" any of the lenses I bought for any of my cameras, not ever: not my medium format cameras, not my older 35mm cameras, not my view cameras (when I used to have a couple centuries ago), not my EOS lenses. I have never done it. Certainly not it a deliberate, technical sense.

 

I just shoot the pictures I need/want to and if nothing horrendous "jumps" at me I assume the lens to be up to specs.

 

With the 70-200 you should assume the same. Get it, use it and if nothing "jumps" out and screams "defect" you will be fine.

[yakim_peled1]

Send it to me. I will examine it thoroughly for you.

 

Happy shooting,

Yakim.

[chris888]

Ask them when testing to fill the frame with objects increasing in size as it increases the real distance and see how it holds up to 50 meters for sharpness, using tripod, mirrorlockup, and remote release cable, then decide if you are happy with the results achived related to distance at any focal lenght, aperture, or shutterspeed settings. Because of this I don't take MTF charts too serious..Infinity possibilities.....Comparing lenses, the real distance in meters is never mentioned, or refered to in compatsons. I feel this is very important to know..

 

How sharp do you think this finch is compared to Prime lenses ?<div></div>

[jeff_plomley1]

I guess this is why companies like Leica are still in business. Every lens is meticulously tested

before it leaves the factory so tht you are insured that lens number one from a production

batch is the same quality as lens number 500. There are some advantages to buying from

small manufactrers like leica where volume is low, but quality is exceptionally high. If you

are really that concerned about lens quality, and do not need AF, perhaps you should

consider a Camerquest adapter and a few Leica optics. You will not be disappointed.

[KenPapai]

So Venu, why not post a couple sample pics?

[doug_landrum]

Venu,

 

Listen to the contributors that encourage you to take pictures. Look at them and see if you see any trends reflecting detects.

 

I think the "good" lens "bad" lens discussions on the Internet are most frequently user error problems.

 

If you think the focus of your lens is off, then put your set up on a tripod and get a favorite model to sit for you. Take some portraits - take many shots. Use one of the eyes of the model as the focus point on autofocus. Use the center focus point only and don't use the nine point array. Remember or write down the eye used for focus. Then look at the results on your computer and see if the focus is on the eye or someplace else. You will see if your lens focuses correctly.

 

I have had Canon FD lenses, Leica M and R and now use a Canon 24-70 f/2.8 L USM and Canon f/2.8 70-200 IS L USM for my 20D.

 

I think the Canon L's are superb. Mine are spot on focus. I cannot yet compare my Leica Rﾒs with the Canons on the same body but I think that the Canon lenses would acquit themselves well.

 

The Canon repair facility in Irvine, California is just down the street from my home in Laguna Beach. I have been there many times for repairs to my son's video cameras and twice to get my sensor cleaned for my 20D. I overheard an encounter between a service tech and a man who wanted a single lens calibrated to his camera. The service tech wanted the man to bring in all lenses that he owned. The man was warned that calibrating a single lens to a single camera might cause the camera to be incompatible in focus with other lenses.

 

If you believe that your lens does not focus correctly and you want to have it calibrated, then send your camera and all lenses that you own to Canon (I don't think they will calibrate your Tamron). Call their help line first and describe what you want. Unless you are absolutely sure that your lens does not focus correctly, don't send anything in. I am sure that the factory calibration is most likely correct.

[vpolisetty]

Chris, That is a very nice pic.

 

I would also like to thank everyone for all their valuble inputs and suggestions.

 

I will update here when I get my 70-200 f2.8IS lens and also on my experience with canon customer support for my 17-40L.

 

Thanks,

Venu.

[vpolisetty]

Doug,

 

I am going to do exactly what you suggested regarding taking many pictures.

 

You bring up a good point about calibrating a lens and Camera together by Canon. I did ask Canon support about throwing off focus on other lenses that i have. He said that shouldn't be a problem, but you never know.

 

Thanks,

Venu.

[eric_chi1]

When you get your lens back from Canon, you will receive a statement of what they did. And you will typically see "calibrated to factory spec" or something like that. They are not going to just make your opne camera and lens match. If they calibrate, each is to its factory spec.

 

Eric.