How to find a good copy of a lens?

I am new to the forum and hope this question is not redundant. I have been reading on the forum about good and bad copies of various lenses. I plan to aquire several lenses in the near future, including a Canon 85mm 1.2 L, a Canon 70-200mm 2.8 L IS, a Sigma 120-300mm 2.8 and a Sigma 150mm macro. These will cost a bunch of money and I want to be sure I get good copies. Do I purchase several of each lens, test them, and send all but one back? Are some stores aminable to this? Could I go to a place like B&H, test several in the store, and pick the one I want? Do I even have to worry about the good/bad copy issue? Thanks for any help.

Canon 20D, Sigma 70-200 2.8, Sigma 28-70 2.8, Sigma 17-35 2.8-4.5, 1.4 TC, Canon 500 diopter

You buy one. And if you are happy with the results, there you go.

Reading a forum will make you more paranoid about getting a good copy versus a bad copy. Obviously you read more threads on this board that say "my camera is soft" or "my lens is soft"

Yes, there are stories where the lens was at fault. That will always happen, but the percentage is small than what it appears to be on this board.

But if you want to test your lens out, make sure to do it in a situation where there's good lighting. If you can get good results in a real world situation, then your lens is doing you well.

I agree with Mr Grego. The chance of getting a duffer is very small but, unless it's all just hot air and lack of 'the craft', which it may well be, there are some models which may increase the likelyhood. I don't see any on your list. I think you're pretty safe. Of course, you could put aside a day and check them all one after the other when they first arrive. Any problem then take it back and get another, or mail it back and get an exchenge.

Thanks guys for your quick resonse. I will take your advice. I am so far happy with all my lenses except, perhaps, the sigma 28-70. I'm glad to know that I don't have to be paranoid. All best.

The Sigma 28-70 is an older model and has been said not to be that good. The 24-70 on the other hand is said to be stellar along with Tamron's 28-75 for that midrange zoom.

That's probably why you aren't happy with that one lens.

Thanks grego. I wondered if that might be the problem. If you could afford any lens what would you get in the 24-70 range.

Well obviously, if price isn't a factor, the 24-70 2.8L is the best of the bunch in terms of overall quality(not just IQ).

However, Sigma's 24-70 or Tamron's 28-75 have seemed to leave many very happy. Obviously there are some compromises compared to the Canon, but then are they worth like 3 times more to most people? For most, no.

But those two 3rd party lens are more than capable of putting out fine images.

I had both the Sigma and Tamron Grego mentions and both do a great job. The Sigma is more practical on a 1.6 crop body if you need a tad wider. It's heavier but balances well. The Canon didn't convince me for the money tho' I appreciate it's well built and some do love it. Truth be told, if money was not an issue, then I would buy a set of top quality, fast prime lenses across this kind of range and then a 24-105 IS L for travel and single lens solution usage.

I agree,. I don't think the odds are strong at all that the lenses you mentuion will be in any way less than perfect. The 85mm,. I've NEVER heard of a 'bad copy" and the 70-200mm I've only heard of mechanical failure,. not a bad copy out of the box.

I think your also safe with the Sigma Macro prime.. it's a gem.

the 120-300mm though I have heard of reports of copies that are excellent at one focal length extreme and less so at the other end. This can be one of the best lenses around,. so when you get it,,. just be sure it satisfies your expectations ... if you buy a U.S. model,. you only have four years to decide if it is a good copy or not

Following lenses I have owned or own. 17-40L (X2), 24-70L(X2), 70-200L F2.8 IS, 50.18, 50 1.4, 85 1.8 How many returned due to bad copies. None.

I've tested extensively on them as I was paranoid to. Sold most of them to other photographers and none has complained.

The above advice is well worth paying attention to. I also had been reading all the horror stories of 'bad' lenses and was concerned about it. Knowing how to use the equipment you have is the key. I'm sure that if more people knew this there would be FAR fewer reports of 'bad' lenses, or defective anything for that matter. I'm not saying that a lens can't be 'bad' from the factory (as in anything that's produced), but I wouldn't be too concerned about it.

When I thought I had a 'bad' copy of my 70-200 f/4 lens I was upset about it, then finally happy to find that (as I believe in most of the internet reports) the problem was actually user error. Oops! Now that I've figured out what I was doing wrong the 'problem' has gone away, and my 'bad' lens is once again a 'good' lens.

My advice is to buy the lenses you want, learn how to use them properly and ENJOY!!