Say, in some ideal situation, you have a pile of copies of a lens that you would like to get. You have enough, but limited, time to pick the best copy out of the bunch. What's the most efficient way to do it? (I have a way to do it in mind, but would like to hear from you all first.)
And how do you actually do it when you're getting a new lens?
It depends what you want. If you want pixel level sharpness then youre best off buying several copies from a reputable dealer and spending the next 30 days shooting test charts and returning the ones that don't meet your expectations. Granted this will probably result in you returning all the lenses purchased because there is some new shiny red lined object of your desire that you read on some online forum was a million times sharper than your previous object of desire. If this is the case you are doomed to repeat this exercise again and again and again.
Ok I jest. Honestly just find a nice contrasty object/scene nearby and take some shots with each, make sure af is snappy, if you feel it's not on a few copies disregard them. Then for the rest just find the one that gives your eye the most pleasure or looks the best zoomed in on the back of your camera.
How limited is your time frame? If you are picky enough to want to choose the best copy out of many you probably also want to test the lens on a number of potential issues. That's going to require pixel peeping to see most differences and that means uploading files to a computer and doing painstaking comparisons.
I usually just take my new gear and photograph my step daughter riding her horse. Then grab some landscapes at the barn to see details at the edges and maybe some slow shutter speed shots if I have IS on the lens. That usually gives me a good idea as to how the lens is going to perform and the photos aren't useless afterwards. Brick walls are boring to shoot IMO.
It depends what you want. If you want pixel level sharpness then youre best off buying several copies from a reputable dealer and spending the next 30 days shooting test charts and returning the ones that don't meet your expectations. Granted this will probably result in you returning all the lenses purchased because there is some new shiny red lined object of your desire that you read on some online forum was a million times sharper than your previous object of desire. If this is the case you are doomed to repeat this exercise again and again and again.
Wahoowa wrote:
Say, in some ideal situation, you have a pile of copies of a lens that you would like to get. You have enough, but limited, time to pick the best copy out of the bunch. What's the most efficient way to do it? (I have a way to do it in mind, but would like to hear from you all first.)
And how do you actually do it when you're getting a new lens?
I would never go through a pile of new lenses looking for a "best" or "good" copy. There are a bunch of reasons for that, but I won't detail all of them.
Frankly, with a new lens I would just pick one and buy it and get on with shooting. If there is a problem, use the warranty to get it fixed.
Dan
Jan 10, 2013 at 12:11 PM
Lars Johnsson Offline • • • • • • • Upload & Sell: Off
gdanmitchell wrote:
I would never go through a pile of new lenses looking for a "best" or "good" copy. There are a bunch of reasons for that, but I won't detail all of them.
Frankly, with a new lens I would just pick one and buy it and get on with shooting. If there is a problem, use the warranty to get it fixed.
I have found that the sharper the lens the easier it is to determine the centre of front/back focus. With lousy lenses the sharp to blur is not as defined or graduated.
I test each lens I buy...call me whatever. I have a testing set up similar to lens align that I take with me. Not necessarily to test each copy to get the best one, but more to test to not get a lemon. This has become less critical with MFA. I pay a premium with taxes to get it locally, but I am assured not having to hassle with sending it in to get it adjusted later. I have had way to many hassles with Canon Service. I have been doing this for years and on the positive side most of the recent canon lens I have tried have been acceptable first copy try.
Other than a 24-70L, I've never found a bad lens. The 24-70 was not bad as defective, just not up to expectations. I eventually went thru five, all were about the same, all gone now.
Just buy a new one locally so you can exchange it if its bad.
focal is pretty good at helping you check out a lens to see if it is performing correctly and it also determines the best AFMA settinng to fine tune the autofocus.
Check the sharpness at each aperture to see if it varies as expected. Thats a quick way to spot a problem.
I'm quite surprised by the answers that many people didn't care, considering how often I got questions whether or not the lenses I've sold on B&S are sharp.
On the other hand, I didn't really care much either as I thought most lenses are sharp enough. I usually buy used lenses. But after I have learned that bad copies do exist (I did a test on my friend's 35L), I started to be more aware of it.
That said, I have never done a serious pick of a new lens before. But I'll have a chance to pick one out of 5. And it's such an expensive lens, so I think I'll try to choose the best one out of them.
PhilDrinkwater wrote:
FoCal by reikan.
Do FoCal give sharpness information for different lenses? I understand that it does AFMA, but does it provides enough information to tell which lens is sharper than which? Also, does it provide MTF chart?
Tripod in a quiet, well-lit (a challenge under shop lights) area with a detailed scene.
Lenses ready, in order, serials recorded.
Manual, low iso, live view 5x/10x mag. manual focus, remote, using the law of reciprocity shoot the lenses wide open, and in order of their serial #'s, e.x. 2.8, 4, 5.6, 8, 11.
Go home and figure out which one you think looks best.
Jan 12, 2013 at 07:25 AM
Lars Johnsson Offline • • • • • • • Upload & Sell: Off
Tripod in a quiet, well-lit (a challenge under shop lights) area with a detailed scene.
Lenses ready, in order, serials recorded.
Manual, low iso, live view 5x/10x mag. manual focus, remote, using the law of reciprocity shoot the lenses wide open, and in order of their serial #'s, e.x. 2.8, 4, 5.6, 8, 11.
Go home and figure out which one you think looks best.
But do you like to buy and pay for a new lens in shop. A lens in a box that have been opened 25 times and tested by 25 different people
I micro adjust a new lens if it has AF and during thst process I see if it is sharp. People who go through extreme care in getting sharp images without bothering to micro adjust their lens are wasting their time. Every lens I own needed some adjustments. Some much more than others.
Lars, that's a good point. And when running a business you don't want too many 'tyre kickers' lurking.
But I am fine with a lens that has been handled as long as it seems pristine and hasn't been damaged or dropped.
I do think that shops should be graceful enough to allow serious buyers to test a lens in a shop - however flawed the process may be - because we're often not paying insignificant amounts of money.
Jan 12, 2013 at 08:09 AM
Lars Johnsson Offline • • • • • • • Upload & Sell: Off
Paul Mo wrote:
Lars, that's a good point. And when running a business you don't want too many 'tyre kickers' lurking.
But I am fine with a lens that has been handled as long as it seems pristine and hasn't been damaged or dropped.
I do think that shops should be graceful enough to allow serious buyers to test a lens in a shop - however flawed the process may be - because we're often not paying insignificant amounts of money.
I'm also fine with a lens that has been handled. But I would not be fine with a lens that 10-15 people had tested before i bought it.
And some of Canons lenses can't be tested without breaking the sealing of the boxes Canon deliver them in.
Paul Mo wrote:
Lars, that's a good point. And when running a business you don't want too many 'tyre kickers' lurking.
But I am fine with a lens that has been handled as long as it seems pristine and hasn't been damaged or dropped.
I do think that shops should be graceful enough to allow serious buyers to test a lens in a shop - however flawed the process may be - because we're often not paying insignificant amounts of money.
Yep, I test drive a vehicle before purchasing. Why shouldn't I test a lens before buying?
Jan 12, 2013 at 08:29 AM
Lars Johnsson Offline • • • • • • • Upload & Sell: Off
chez wrote:
Yep, I test drive a vehicle before purchasing. Why shouldn't I test a lens before buying?
Do you really test drive ten different cars of the same model to pick the best copy Good luck. You should do that with memory cards, cameras and printers also..........
