best way to go about testing a lens for softness/sharpness?

So I bought a Canon 24-70 f/2.8L from B&H yesterday, and am only a little worried about getting a soft copy. Seems as though the many people that received soft copies were due to poor QC a few years ago when the lens first came out. Looks like people now are regularly getting sharp copies.

I'd like to test it out the day I get it, if possible, to make sure it's as sharp as it should be. What's the best way of doing this? Are there focusing charts somewhere?

I've seen this chart (bottom of the page) quite a few times - is this what I should be using (set camera at 45-degrees, etc)?
http://www.focustestch​art.com/chart.html

Sure, you can do charts.

I have several L lenses. I typically take it out for a shoot (anything...walk around the hood, go to the zoo, whatever) then check out the results. If I don't see anything funky, then I won't bother with charts, or batteries, or whatever.

The one time I did have to do further testing was for a soft copy Tamron 17-50 i used to own. I took it out for a spin and detected obvious softness which was later confirmed by Tamron. Got it back tack sharp.

Again, charts are fine, just don't obsess over them. Go out, take real world pics, then evaluate.

One thing I've learned is to never underestimate my own incompetence. I've had some truly awful blurry out of focus pics which were entirely down to user error.

JoYork wrote in post #4709742
One thing I've learned is to never underestimate my own incompetence. I've had some truly awful blurry out of focus pics which were entirely down to user error.

I feel the same - I had some really dodgy shots with the 300 F4 L at first.

I now test all new lenses with flash (as it effectively increases the shutter speed to a minute fraction of a second) & also stop them down a little from max aperture to allow for minor focussing errors. I also normally use a human face as the subject as this has lots of critical details to judge sharpness.

When I first took a few portraits with the 24-70 wide open they looked a little soft - my error! After a very short while I learnt to nail really sharp shots with mine - make sure you do lots of tests before sending it back!

Phil

but how can you see softness by testing if you, for example, have never used used the lens (brand for example) before? by comparing them to pics of the forum, or personal 'feeling'?

prinspaul wrote in post #4710553
but how can you see softness by testing if you, for example, have never used used the lens (brand for example) before? by comparing them to pics of the forum, or personal 'feeling'?

My method at this stage is not terribly scientific, but if I look at the shot and think - that looks lovely & crisp & then go to 100% view in Canon's DPP @ sharpness setting 4. If everything then still looks crisp I think it is good enough for me.

I don't do formal resolution testing - I just want to be comfortable that the lens can perform for me.

I keep a folder of sample images from each of my lenses that are very sharp. When I want to remind myself how sharp they are (after I've taken a soft shot - usually poor focussing or low shutter speed) I look back in the folder.

Phil

JoYork wrote in post #4709742
One thing I've learned is to never underestimate my own incompetence. I've had some truly awful blurry out of focus pics which were entirely down to user error.

Agreed. Just go take a bunch of photos and you'll be able to tell from different shots. Make sure to use a tripod and great lighting if you're really skeptical

I usually use 3 cereal boxes. Place the boxes on a table near a window light. Place the boxes about a foot apart but staggered so that about 2/3 of the middle and back boxes are in view when looked a straight on. Place the camera and lens on a tripod, shoot wide open or other aperture you're testing, AF using center point, aim at the middle box straight on (not at a 45 degree angle), manual exposure mode (this is what I like) and shoot. Back/front focusing and sharpness problems become evidently right away.

ace3 wrote in post #4709657
So I bought a Canon 24-70 f/2.8L from B&H yesterday, and am only a little worried about getting a soft copy. Seems as though the many people that received soft copies were due to poor QC a few years ago when the lens first came out. Looks like people now are regularly getting sharp copies.

I'd like to test it out the day I get it, if possible, to make sure it's as sharp as it should be. What's the best way of doing this? Are there focusing charts somewhere?

I've seen this chart (bottom of the page) quite a few times - is this what I should be using (set camera at 45-degrees, etc)?
http://www.focustestch​art.com/chart.html

I don't bother too much with testing these days. Usually a good test of the optics (not the AF though) is just to shoot something with Live View and see how 'crisp' it looks then do it again with AF (two or three shots) and if they are both sharp then I don't bother doing any further testing.

Shoot in the real world (for several days or weeks), evaluate the shots, if you don't see any issues, it's all good. If, and only if, you see issues with real world shooting, then consider more specific tests. But whatever to do, follow a process that you can document, minimizes the variables, and provides repeatable results.

I recommend that you NOT pay as much attention to these forums, and NOT worry "...what if I get a soft copy?" When you get the lens, start shooting real pics of the images you bought that lens to capture. It will take a little while to get used to. A fast lens like that has a LOT of glass in it, hence the reputation as "the brick". ... I am convinced some people have received less than expected performance because of initial user-error , that gradually goes away as they get used to the weight.

Once you are comfortable with the lens, if you are pleased with the results, consider it a "good copy". ... Considering how many of these lenses Canon sells, most are certainly good. I don't think you paid over a thousand dollars to shoot charts at 45 degrees!!! You bought it to take REAL pics. ... So go out and shoot.

If you have a poor copy (doubtful), you will know. If you can't tell if your copy is bad, STOP READING THESE FORUMS; they cause unnecessary hysteria!!!

BTW, I'm sure you will be thrilled with the new lens. Take lots of pics in REAL situations and post the ones you're proud of!!

Tripod with good light (a must)
Use remote if you have one
Try to eliminate any camera shake.
If you dont have a tripod... you can shoot at extremely high shutters speeds and handhold. 1/500-1/1000

On a tripod id recommend using at least 1/50 for 24mm and 1/150 for 70mm. Even higher wouldn’t hurt.

Take two sets of shots
wide open and at f8

Examine them for quality.
Pixel peep a bit. For me it is a judgment call at this point.

Then you can check for front or back focus issues.
Do a search for how to do that.

Lastly, if you deem it necessary.
Send the camera and lens to canons service center.
Have them take a look and calibrate it.
May as well get a cleaning for the body while its there =)

I agree dont let these forums get you worried about soft copies.
But also dont let people shame you or blame you into not doing tests and trying to determine the quality of the gear you invested your money into.
One of the most offensive terms in threads like these to me is "user error" and "pixel peeper".
People here like to sling them around with nose held high and way too often.
(Not saying anyone in this thread has yet)

thanks, Uhland.

this brings up another item ... how do i go about sending lenses to Canon's service centers before they're out of warranty for cleaning/checking/etc? I have no clue.

Here is my way of testing it...
1. Place cam on tripod
2. place in front of table
3. go to silverware drawer
4. grab a huge searing knife
5. take picture of knife.
6. look at image....... ITS SHARP!!!!!!!!!!!!

hhahahahah im sorry i had to. go take pictures, if you notice you are getting soft images then test it, until then just go shoot. *I never check my lenses before using them. Use them then if you notice something concerning then test it.

^^ awesome!

i wasn't planning on taking it out of the box then testing it immediately. just looking for some ideas to find out if it's "unofficially" soft or not, i suppose.

thanks for the tips, guys!