# Is my 24-105mm f/4 L unreasonably soft?



## iKenndac (Mar 17, 2013)

I've had my 24-105mm f/4 L since 2006, and it's been my day-to-day walkaround for most of that time. I always found it difficult to get pin-sharp shots with it, but assumed it was always my technique.

However, I recently decided to check the sharpness of my lenses and perform AFMA calibration on them. What really shocked me is that my girlfriend's EF-S 17-85mm actually appears to be sharper than my 24-105 L!

If anyone here has the 24-105 L, and have done sharpness shots with it, would you mind chipping in? I wonder if this is a naturally soft lens or if mine is out of whack. I know the lens is weakest at 24mm, but mine seems to be pretty terrible! 

Standard Lightroom settings, sharpness turned down to 0.

100% crop at 105mm: 







100% crop at 24mm:


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## Mt Spokane Photography (Mar 17, 2013)

Bad lenses do happen, send it to Canon for repair. There are plenty of tests and comparisons around the internet to show that it is capable of being very sharp.



I try to test any new lenses I purchase for sharpness right away. I first adjust the AFMA, and then view a variety of images to check that the lens meets expectations.



I'd find it very difficult to judge sharpness with the images you show. Their only purpose is to check for front/back focus.



Use a proper target or flat brick wall and check not only the center, but the edges and corners.



Its hard to beat the 24-105mmL for the price. You can beat it with a prime, but not a zoom in that price range.


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## mvinson1022 (Mar 17, 2013)

Send it in for check by Canon. 



iKenndac said:


> would you mind chipping in?


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## RS2021 (Mar 17, 2013)

From your picture, at 105mm it seems sharp enough to me for this zoom... at 24mm it looks a bit off but as noted earlier this is really not the best way to check this.

Also, take several shots at the focal lenghts and see if this is not just AF "one-off" situation. Add to this the fact, this zoom struggles in general on the wide end on both distortion and sharpness compared to sweet spots higher up in the focal length range. 

If you do plan to send it to Canon...be specific to get things really looked at...just saying "I think this is soft" will generally result in them holding on to the lens for a couple of weeks, doing standard tests, and sending it back the same as you sent them with a terse note "within standard range".

24-105L from what I can tell does have some limited copy variation with some people very happy with theirs (I am one) and others really railing on it. It is also not one of those "super sharp" lenses ...if you have that expecation then it will never meet your expectations. I recently played with a friends 24-70 II and clearly the new zoom is spectacular in comparison. So, recognize the 24-105L for where it falls in the product line up...

Most happy users like me will tell you it is an awesome zoom all things considered. Love it.


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## tomscott (Mar 17, 2013)

I had the 17-85mm and it was awful. 

The 24-105 is very sharp in comparison. Maybe just needs some good AFMA


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## LetTheRightLensIn (Mar 17, 2013)

Mt Spokane Photography said:


> Its hard to beat the 24-105mmL for the price. You can beat it with a prime, but not a zoom in that price range.



Tamron 28-75 is sharper and costs less. And if you go to APS-C then tamron 17-50 2.8 too, probably sigma 16-50 IS too, etc. The new tamron 24-70 VC is also sharper (granted you can find so many kitted or dumped 24-105 that the 24-105 is effectively in a lower price bracket than that one though).


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## LetTheRightLensIn (Mar 17, 2013)

24-105L is NOT one of the sharper L lenses, it's one the very softest L lenses (although L lenses are a high standard keep in mind). That said the 17-85 was one of the softest non-L lenses and it seems surprising to hear it is sharper than your 24-105.


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## pwp (Mar 17, 2013)

After five completely doggo 24-70 f/2.8 lenses over a number of years, in desperation I bought a pre-owned 24-105 f/4is just to see me through until a revised 24-70 f/2.8II came out. The 24-105 was a revelation. At last, a zoom lens (in this focal range) that I could trust. It's not going to match it with primes if you start pixel peeping but delivers commercially completely viable files. It's _sharp_ at f/4. 

So while the new totally stellar 24-70 f/2.8II will have a permanent place in my bag, the old 24-105 f/4is is a keeper. The extra reach is great for any kind of event work, and it's my hands down favourite travel lens.

If you have strong suspicions that your 24-105 f/4is performance is sub-optimal, send it off to Canon for a service if a proper AFMA process doesn't improve things. A search through this list will show you that a vast majority of 24-105 f/4is owners while being fully aware of any obvious limitations are deliriously happy with their lens.

-PW


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## Sporgon (Mar 17, 2013)

At building Panoramics we have two 24-105's, both circa 2008. One is sharp across the frame ( within reason) whilst the other is incredibly sharp on the left side, but really blurred on the extreme right. As we shoot our panos with the left edge uppermost ( into the sky) we've only really just noticed it. Beauty of an L lens is it can be tuned - costs about £120 + tax in UK. 

Seems to bs a lot of sample variation with this lens, maybe because there are so many of them in use.


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## pwp (Mar 17, 2013)

Sporgon said:


> At building Panoramics we have two 24-105's, both circa 2008. One is sharp across the frame ( within reason) whilst the other is incredibly sharp on the left side, but really blurred on the extreme right. As we shoot our panos with the left edge uppermost ( into the sky) we've only really just noticed it. Beauty of an L lens is it can be tuned - costs about £120 + tax in UK.
> 
> Seems to bs a lot of sample variation with this lens, maybe because there are so many of them in use.



What you have described is a completely fixable condition. Send 'em off to Canon.

-PW


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## Tonywintn (Mar 17, 2013)

Is it normal for the 24-105mm f/4L to be a little soft in the corners when zoomed in to 105mm? I snapped a shot of my screen door at f/7. The screen mesh is crystal sharp in the center third, not too bad in the left third but a little soft in the right third and more so at the bottom corner. At 24mm, the screen mesh looks crisp all over. I just got the 6D and this lens a month ago and decided to do this test. My question is should I send it in for adjustment, or is this normal?


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## traveller (Mar 18, 2013)

LetTheRightLensIn said:


> Mt Spokane Photography said:
> 
> 
> > Its hard to beat the 24-105mmL for the price. You can beat it with a prime, but not a zoom in that price range.
> ...



Funny that you should mention this lens, because I have a copy of the Tamron 17-50 (non VC) that I have been a bit disappointed with. Not only is the AF a bit unpredictable (almost a given with Tamron lenses on Canon bodies), but I didn't find it overly sharp in the border areas even at f/5.6 (I could live with a bit of corner softness). I tested it against a friend's Canon 24-105 and found it quite noticably softer away from the centre at comparable apertures throughout most of the focal range. 

I've since bought this 24-105 from my friend after he got the 24-70 f2.8L II. I must admit that the 24-105 isn't nearly as good a lens on a full frame body, and I find it especially soft at the wide end, but this doesn't tend to be where I use this lens most, so I'm OK with that - YMMV. Full Frame cameras show up corner softness in a lot of lenses that are good performers on APS-C; I thought that my 50 f/1.4 was pretty good at f/2 on APS-C, but suffers from soft corners on FF unless stopped down to f/2.8. You can accept this and try to stop down a bit more or buy more expensive lenses.


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## Tonywintn (Mar 18, 2013)

After I made my post I started thinking about my set-up: It was hand held and the focal plane may not have been parallel to the screen door. So I did a proper set-up on the tripod and did some shots at wide open and with the zoom set at both ends and the middle. I got better results with the set up so that the focal plane was parallel to the wall. I see a bit of softening at 105mm in the corners with the aperture wide open and down to f/7; aperture doesn't seem to matter, but by 70mm the image is tack sharp corner to corner. 24mm is very sharp. I taped a cloth towel to the wall. The fine fibers make for a good image to resolve. I also found that when focusing manually, I did not get the image as sharp as the autofocus. I appreciate what I am learning on this website. I feel better about my new camera and lens after making this test.


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## RS2021 (Mar 18, 2013)

Tonywintn said:


> Is it normal for the 24-105mm f/4L to be a little soft in the corners when zoomed in to 105mm? I snapped a shot of my screen door at f/7. The screen mesh is crystal sharp in the center third, not too bad in the left third but a little soft in the right third and more so at the bottom corner. At 24mm, the screen mesh looks crisp all over. I just got the 6D and this lens a month ago and decided to do this test. My question is should I send it in for adjustment, or is this normal?



Screens are notoriously undulating... and at the longer end of the zoom and if you are close enough perhaps MFD, which I suspect you are, this would look even more uneven. This is why I prefer real world shots to access if the image is satisfying...not necessarily tack sharp...but sharp enough and pleasing and representative...don't take shots of brick walls and screen doors...you will never be happy.

Having said that, yes, the 24-105L can be a tad soft in the corners. From what I read here it seems to be uneven among different copies...my own is sharp on the long end and a tad softer in the corners at 24mm. But one doesn't notice this in real people shots. 

All said, I still love the zoom.


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## Mt Spokane Photography (Mar 18, 2013)

Tonywintn said:


> I appreciate what I am learning on this website. I feel better about my new camera and lens after making this test.



Be careful about what you read on this site. There is a large difference in experience and opinion and not owning or having even used a lens does not stop some from giving their opinion as fact.

Read the comments and compare them with those who know how to test and judge a lens, read all the lens test sites. Even those of us who have had a lens and found it bad should know that defective lenses happen.

I read photozone, lenstip, slr gear, and even DXO before I buy a new lens. The new lenses I've bought have always matched the reviews, good or bad.


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## RS2021 (Mar 18, 2013)

One of the unsung underrated aspects of this zoom is the beautiful contrast it produces straight out of the camera. With some lenses the images come out "fey". As a package, most owners come to love this zoom if not at once, with time.


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## iKenndac (Mar 30, 2013)

Thanks for your advice, everyone.

Well, I bit the bullet and emailed Canon's Swedish service partner, and they told me they'd want 700kr (£70, $110) to even look at it, at which point they'd tell me how much to would be to fix it, if it needed fixing at all.

Since I'm not 100% there's a problem, instead I bought FoCal, an excellent lens tuning and measuring application. First, I tuned the AFMA (which was a little bit out), then ran some sharpness tests vs. my new 40mm f/2.8 STM.

Attached are the results. As you can see, at 65mm or so my 24-105L is sharper than the 40mm, but at 24 and 105mm it's considerably worse, with 65mm being over twice as sharp as at both ends.

Now I know this, I'm less sure there's a problem. Now I know where the softest parts of the lens are I can avoid them. Still, I'm curious if such a large difference is normal.


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## Sporgon (Mar 30, 2013)

@iKenndac, apologies if I have misunderstood your data, but there is no way the 24-105 is anything like as sharp as the 40mm at f4, so there is something very wrong with your focal result.


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## zim (Mar 30, 2013)

That green curve does look strange to me, resolving better at f4 than f8 (I'm assuming the sweet spot would be around f8) and again better at f20, maybe I'm miss reading?


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## iKenndac (Mar 31, 2013)

No, you're not misreading. Just to make sure, I re-did all the tests multiple times today when the light was better (I needed to add non-natural light yesterday) — this time it's all natural light.

Interestingly, the 105mm sharpness rose to the same-ish levels as 65mm, although the shape of the curve stayed the same. Everything else was entirely within a reasonable margin of error from yesterday. 

Anyway, although the results for my 24-105L are kinda confusing between f10 and f22, they basically confirmed that my lens is behaving like one should expect — weakest at 24mm. Time to stop obsessing over numbers and go take some photos!


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## Hannes (Mar 31, 2013)

Your curves do look a bit odd. I would have expected them to be more like the 40mm in shape.

My lens on the other hand is sharper at 24mm than 105mm, at 24 it hardly improves on stopping down whereas on the long end it becomes sharp only after stopping down to f8. 50 and 70 are nearly as sharp as 24 but do benefit from stopping down to f5.6 when looking at 100% crops, for normal viewing it doesn't really matter. Probably just down to the good old sample variation.


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## Mt Spokane Photography (Mar 31, 2013)

Something is wrong with the curves, a lens always loses sharpness above f/8.

However, lenses with decentered elements do exhibit strange curves. That's one quick way to spot a lens that needs adjustment.

This are some typical curves. They doesn't go above f/11, but resolution continues to drop off slowly as aperture increases due to diffraction.


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