Are there really such things as bad copies?

Jman13 wrote in post #7079033
...however. I had two consecutive bad Sigma 30s before getting my good one. By bad, I mean it would front focus by several FEET on anything over 6 feet away. My current one is stellar, though.

So you had a 66% failure rate.

Rubberhead wrote in post #7075761
...Canon is the world's leader in quality photography equipment..

In terms of sales volume, maybe, I don't know.

In terms of quality, Hasselblad, Linhof, Mamiya, Leica, Zeiss, and for that matter, Nikon, just to name a few, are not exactly trailing behind, some might actually be ahead…although I assume they all suffer from 'bad copies' once in a while.

gjl711 wrote in post #7079040
That certainly was the case of my 100-400. I was moderately happy with it on my XTi, but very disappointed with it on my 40. Both lens and camera took several vacations at Canon service and though Canon returned them both times claiming the lens and body to be within spec, I was never happy with it. When I upgraded to the 50D, I dialed in just a tad of micro adjustment and WOW did that lens pop. it was as it I was given a whole brand new lens and for the first time ever with that lens I understood why so many were raving about it. Thing is, it didn't need much adjusting at all.

Ditto for my 85 1.8. Went to canon twice and returned both times "within specs", even though I wasn't quite happy with it (on my 40D). Put it on my 5D mark 2, micro adjusted it and WOW! Good enough for me to get rid of the 40D and pick up a 50D for the same Micro Adjustment feature.

I used to think every new lens I bought was defective until I played with them for a bit. Now I simply realize that each lens is different and 99% of my intial impressions are user error.

I did have a soft copy of the 24-105L that I lived with for about 6 months. If became apparent when I'd shoot with two different lenses and the 24-105L just didn't have the same pop. Sent it in for repair and it came back great. I don't think I'll wait so long in the future.

Yes! I got my first one. My sigma 20 f/1.8 front focused severely that i had to send it in for a new one. I love it though... so much I'm trying to sell my sigma 10-20!!!

I made a thread like this recently, I've put it down to 40% purchase regrets/high exceptions etc, 40% user error, and 20% real bad copies.

maybe lol

There are such things as bad copies. My 70-200 2.8 was rear focus. Here's the original words from Canon Factory Service Center:

"We have examined the product to your request, and, it was found that the adjustment of the mechanical chassis was incorrect causing rear focus. Electrical adjustments were carried out on the mechanical chassis. Other electrical adjustments, inspection and cleaning and mechanical adjustments were carried out."

Glad that they have addressed the rear focus issue and now the lens is perfect. So, yes, there are such things as bad copies.

Rubberhead wrote in post #7075761
I know, I do it too. I hold my breath and with shaky hands I attach a virgin lens and take a test photo hoping that I got a "good copy" of my latest lens.

Canon is the world's leader in quality photography equipment. I'm sure they've got an outrageous team of engineers and top-notch manufacturing facilities. Do they really have "bad copies" of their best glass? Is there no quality assurance? Is it impossible to test for a bad copy in the lab? Do they have to send it to a customer and hope for the best? It just seems a little odd that of all the modern technology we purchase lenses are the only ones we worry about getting bad copies.

As a slightly seasoned newbie I was scared to death of getting a "bad copy" of anything. Mostly because I've read so much about lenses going back and back again as they didn't meet expectations. After a time, buying different lenses I learned each one has it's own personality and because I'm new I figured I just didn't quite know how to use it to it's full potential yet. So far so good. It's a costly endeavor and any improvement in glass is a milestone to me. I now have a 70-200 f/2.8 on the way. If it's bad it's bad, I'll send it in.

My last three trucks have had recalls. There's bound to be an occassional defect in anything, I have a Rubik's cube with two green sides it takes the fun out of it, we get tainted meat from time to time, and messed up car seats for babies

I don't expect perfection every time because it ain't gonna happen. And as long as it's not a constant problem and the manufacturer makes it right, I'm ok.

Phil

Bad photographers + pixel peeping = majority of "bad copies!"

Ok there are absolutely some bad copies out there. Like someone said before unless you can do QC on 100% of your products a bad one will slip through. Maybe they can do this with some low volume MF cameras. In fact the tooling in any factories is made slightly too big, then as it wears down, its perfect for a while, then it wears down slightly too small, then eventually it wears to a point where it is considered out of spec, and the parts it produces are also out of spec. Some have to go out of spec, before you know to replace that tooling. So a few bad ones have to go out the door, in order to keep the other 99% at the quality required.

Its telling that most people suffer "focus issues". I've had 2 bad lenses. One Canon (out of 2) and One Sigma (out of 5). The Canon was a 50 1.8 II, it left the factory with 2 large spots of lens glue on the elements in the middle, the effect was that between 1.8 and 5.6 the left side of any image was really soft. There service was slow and useless, luckily my local camera store replaced it for me. Replacement was perfect.

My Sigma was a 50-150 which is notorious for front focus issues (f/2.8, ability to focus within 1 metre at 150mm = razor thin DOF). Mine focused perfectly, but the centre of the image lost all centre quality at 150mm, if you did a battery test it looked front focused, if you shot a flat target you would see the centre was really poor, outside that was fine, and outside that again was poor. Like a really strange field curvature effect. It went back, they found an issue with an element, and rather than make me wait for a part from Japan, they sent me a new one. This is good service. The new one is a million times better. I gave it to a "Canon only" man the other day and after 3 shots he said "Wow, how much are these!"

I've had bad copies of many computer components, can't tell you how many computer fans (mechanical also) that have failed on me. I expect at least 1 hard disk failure every 2 years. Some of the major car manufactures that pride themselves on reliablity still have 9% of there customers need a mechanical fix of some kind not related to wear and tear within the warranty period.

Life is full of copy variation.

KarlosDaJackal wrote in post #7080889
Bad photographers + pixel peeping = majority of "bad copies!"...
I've had 2 bad lenses. One Canon (out of 2) and One Sigma (out of 5). ....

So, concidering that you had a 50% failure rate with Canon and a 20% failure rate with Sigma, and since the majority of bad copies can be attributed to bad photographers, do you then consider yourself a bad photographer?

I don't see how anyone here can attribute most bad lenses to some inability or short coming of the photographer as seems to be so common here. POTN has a fairly educated poster base and many here are very aware when a piece of their equipment is not performing as the expected. To say that the majority of those folks are just bad photographers is grossly unfair.

So I bought a new SIgma lens. The focus was off a little. I sent it to SIgma. They fixed it right away and free. It works great. I do not consider that a "bad" copy. Just because something isn't perfect are we going to yell at QC? Has anyone gotten a new car that was perfect?

gasrocks wrote in post #7081716
..Just because something isn't perfect are we going to yell at QC? Has anyone gotten a new car that was perfect?

Yes.. exactly.. That is a clear example of a QA/QC failure. It is also an example of a service/customer satisfaction success. Any time an item leaves the factory and is delivered in anything less than perfect condition to the end user, QA/QC has failed to do it's job.

gasrocks wrote in post #7081716
So I bought a new SIgma lens. The focus was off a little. I sent it to SIgma. They fixed it right away and free. It works great. I do not consider that a "bad" copy. Just because something isn't perfect are we going to yell at QC? Has anyone gotten a new car that was perfect?

This is exactly what I consider a bad copy. It did not perform as it should out of the box. The fact that you sent it back, it was adjusted or fixed and now works great screams that it was a bad copy, a result of bad QA/QC. Your case is interesting, and common. Your did not send it back with your body so they could be aligned and calibrated, but rather they just adjusted the lens, presumably to their spec's. It should have arrived this way the first way.

I accept a certain amount of QC failure. Most of us could not afford any lens from a company that guarantees 100%, all the time. It is frustrating that certain lenses, especially a L over a grand USD (such as the 24-70) that seems to have some many poor copies floating around. I love my copy, it is my favorite lens but it was a lot of work to buy it.

I always though that when it came to mass produced goods, something produced in very large quantities, QC's job was to sample items and watch out for any problems. Not necessarily to test each item. Therefore, some less than perfect ones are going to get released. One price we pay for mass production. Of course, if it was a very expensive item, we might expect each one to be tested. I doubt that happens much these days.

Yea that's what I would of thought, the higher priced pro range lenses would be tested individually.