Copy to copy variation

A friend of mine who recently purchased the 200L 2.0 wanted to see how his lens compares against mine. We downloaded the Imatest's trial version and ran a series of tests. When we saw the results, we were so shocked that we ended up doing the tests over and over and over again under various conditions (multiple flashes, single flash, no flash, different shutter speeds, mirror lockups, different picture styles, and so on). The result was the same in every single one of them. My copy of 200L 2.0 was about 10-15% sharper (10% in center and 15% around the corners) than his. This is based on purely the numbers provided by Imatest (Cy/Pxl, LW/mm, LW/Ph, etc). There is also a visible difference between two pictures shot by two lenses if you look at them at 100% crop. How is this possible? This is a $6,000, how can there be such noticeable difference. The center performance is one thing (I still think 10% is a lot), but corners are different as much as 17% in one area. How the heck is canon producing these lenses and checking them properly in QC?

It wasn't just MTF numbers that were very different. The CA and SQF numbers are also very far off. My lens fares extremely well when it comes to CA (0.004%), his is twice and sometimes three times as worse. SQF numbers are no different, there is a 5-6 units of difference.

My friend got his copy from a retailer I am not going to name here (not Amazon). He is seriously considering returning his lens.

Happens with every lens. Lenses are extremely complex from the glass manufacture to how they are secured in the lens barrel and all that fun stuff. The tolerances stack up along the way, especially when you have dozens of elements inside. They (Canon) can only do so much to make them all identical. They have to have a range otherwise if they were THAT tight on QC, lenses would cost a lot more because they would constantly be remaking the glass and framework inside the lens.

I have had a few 70-200 II's for example over the years. The first two were comparable, 70mm extremely sharp, 200mm still very sharp, but not quite as sharp the other end. My third was opposite though, with 200mm having insane sharpness, while slightly softer at 70mm (still excellent mind you). I get my next one tomorrow (used). Curious to see how it will compare.

I have had (3) 35L's as well, but all those were very consistent. Never saw much difference between them.

I had a 17-40L years ago and didn't like it much (kind of soft, mushy looking). I bought one new a few months ago and its like a whole new lens. Very sharp wide to tele. Like a whole new lens.

I am on my 3rd 135L I believe as well, but all of those have been consistent. I have not noticed any more sharp than others, all very sharp.


**Note: Yes, I go through lenses often... I constantly like to change my setup at different times so my gear constantly changes... So I end up buying lenses back I had a few times

^^^ Nice work on you FlickR page Steve

I have seen variations of sharpness of same lens I owned on different occasions.

It pays to buy in person if you can, so you can check, and see if you are happy with the copy... or buy from the likes of Amazon, if you return, there are no questions asked.

Did you test in live view too?

Curious, did you also test the two lenses by swapping them, i.e., his lens on your body and vice versa? -alex

Now hopefully you will believe us when we said that your 70-200mm f2.8 IS II wasn't good.

bobbyz wrote in post #16133545
Now hopefully you will believe us when we said that your 70-200mm f2.8 IS II wasn't good.

On another note...... Have you completed a full MFA between the lenses and bodies to make sure whichever lens is performing its best on whichever body? You have mentioned before that you did an MFA on your gear, but did you or your friend MFA his lens on his body or your body? The focus could have been slightly off and could misinterpret as soft.

http://www.lensrentals​.com …s-is-soft-and-other-myths

We did the MFA, it was the first thing we did and both lenses were sharp without any MFA. I used the same body for tests.

bobbyz wrote in post #16133545
Now hopefully you will believe us when we said that your 70-200mm f2.8 IS II wasn't good.

I quickly did a test with my 70-200 IS II as well, and it seems to be 5% better than the one they had in lens rentals when they posted the MFA results comparing that to the 24-70 II. That is in the center the zoom is around 850 and mean average is around 700-750. The prime however is over 1100 in center and around 1000 mean average. That is more than 25% difference between the two. I don't think my zoom is bad

I did another test run with the 2x converter attached, the prime can hold itself pretty well and gets around 900 @ F5.6 400mm. Zoom though falls below 550 @F5.6 400mm.

TheLensGuy wrote in post #16134235
II don't think my zoom is bad

Here we go again. So copy to copy variation doesn't apply to your zoom?

I know 200mm f2 is good, very good. But man so is 300mm f2.8 IS. And I did test my 70-200mm f2.8 IS II and 300mm f2.8 IS (no TCs as I hate TCs, focus too with 2x).

LensGuy, I honestly don't think I have ever seen anyone else on these forums so afflicted with GAS (Gear Acquisition Syndrome) / PPS (Pixel Peeping Syndrome).

You really need to use the $10K in lenses you have now, put away the test charts, put away the flashlight, quit peering into the innards of your lenses looking for problems, quit running endless tests to see how sharp your lenses and if your MFD is the same as your buddies lenses, and start actually using your equipment and honing your photography skills. Stop posting in the Lenses sections and start posting in the Photo Sharing section. Accept that you now have a damn good set of tools and start *using* them.

bobbyz wrote in post #16134277
Here we go again. So copy to copy variation doesn't apply to your zoom?

I know 200mm f2 is good, very good. But man so is 300mm f2.8 IS. And I did test my 70-200mm f2.8 IS II and 300mm f2.8 IS (no TCs as I hate TCs, focus too with 2x).

My copy of zoom scored a little above what roger posted in lens rentals in his MTF comparison (both center and avg). My copy of the zoom is normal. What nobody has suggested is the possibility of my copy of prime being much better than average.

My friend's 200L is a lot closer to my zoom.

jrbdmb wrote in post #16135124
LensGuy, I honestly don't think I have ever seen anyone else on these forums so afflicted with GAS (Gear Acquisition Syndrome) / PPS (Pixel Peeping Syndrome).

You really need to use the $10K in lenses you have now, put away the test charts, put away the flashlight, quit peering into the innards of your lenses looking for problems, quit running endless tests to see how sharp your lenses and if your MFD is the same as your buddies lenses, and start actually using your equipment and honing your photography skills. Stop posting in the Lenses sections and start posting in the Photo Sharing section. Accept that you now have a damn good set of tools and start *using* them.

I am doing that. I just wanted to share what I found about copy to copy variation. 10%-15% on a $6000 lens is a lot. Lets just say the person with the bad copy may as well use the zoom. Heck if it were my copy I would use the zoom!

TheLensGuy wrote in post #16132969
My copy of 200L 2.0 was about 10-15% sharper (10% in center and 15% around the corners) than his.

You should swap lenses with him since you don't shoot anything but walls anyways.

Just kidding.