Is this expected performance from an L lens?

LaurenceGough

LaurenceGough

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Laurence
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LtiIO.jpg


100% crop from an image with my Canon 70-200mm F/2.8L IS II lens.

ISO 800
1/25sec
f/2.8

Is this expected to happen? It happens in quite a few pics.

This is a new lens so a little concerned.

Cheers,

Laurence

Edit:

Taken at 70mm, no processing.
 
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Somebody way well be along to correct me, but this is my take on it (from someone who's never owned a lens longer than 55mm). It looks like pretty bad Chromatic Aberration, or blue fringing. This occurs when a bright white area (light source or surface) butts up against a much darker area or surface with a hard transition. With that lens on a crop body I wouldn't shoot with a shutter speed any lower than 1/125 at 70mm, up to 1/320 at the long end, and to be honest the only reason you've got an image even resembling sharp is the three stop (or is it four?) stabilising system, which isn't something you can always rely on. If you keep it above these shutter speeds depending on your zoom length (lens length x 1.6 on a crop body) you're much more likely to get a sharp shot. Obviously at iso800 you're pushing the limits of the lens and the camera for this kind of shot and there's not a lot you can do but it's worth bearing in mind for the future. As far as the CA is concerned - most lenses tend to have it to some degree, especially wide open, but some more than others. I can't comment on how prevalent it is in the 70-200mm f/2.8 but if you shoot in RAW it can be eradicated with a simple slider adjustment in seconds.
 
Also gotta remeber that this is a 100% crop.

Pushing the limits and then viewing at 100% is highly likely to show things that otherwise wouldn't be too much of an issue.
 
I have this lens and nothing like that ever happened ... your shooting at far too low a shutter speed for a 70-200 and even moreso if shooting at 200

you should be focul length+crop at least

the purple would alarm me..
 
woof woof said:
It is wide open and a 100% crop.

Shouldn't you expect some CA with that lighting, wide open and at 100%?
Click to expand...

i ahve never seen it no.. not on any of my L lens...what lighting? looks like natural light yes?
 
i would be very suprised if i could reproduce that problem on mine..
 
If that's the true Exif from a 100% crop, then I'd suspect that the shot was taken on a tripod - or monopod at the very least.

It looks like fairly normal CA given the exposure and light, although its possibly been made worse/enhanced in PP.

Easy to fix in post.
 
Can't see what ISO that is, but it looks like you're pushing the exposure (from the noise) and have upped the xposure in post. If so, I wouldn't be worried. Try in a more natural light.
 
DemiLion said:
Someone needs to go to Specsavers!! :lol:
Click to expand...
Oops.. Looks like it's been upped in post though. Look at the noise in the leaves in the upper left corner...
 
Surely you must have had it on a tripod at that shutter speed? :)

However... purple fringing, NOT uncommon even on very expensive lenses. I certainly had it on occasion with my 85mm f/1.2

But fairly easily sorted in photoshop, see this link.

Hope it helps
 
Hand held and no processing at all, just 100% crop. Also appears in other areas of the image..

To be honest I expected very little CA from this lens like all the reviews had said. Ok the conditions were kind of dark, but this is why I got such as good lens with IS.


Even when zoomed in a little you can see it.

Picture was taken at 70mm.

Edit:

Pic #2 at 40% crop from original image, no post work done again.

RYYXx.jpg
 
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Another picture @ 40% crop.

1/125
f2.8
ISO 800
70mm

Bv3A6.jpg
 
There are two types of aberration, purple fringing which is a combination effect of sensor and lens coating when viewing high contrast boundaries. Older lenses sometimes suffer from this, but more modern coatings designed for digital can counter it. This type of aberration can be seen all over the image and is very difficult to correct in post processing.
The other type is lateral chromatic aberration which is where a lens acts like a prism, splitting the components of white light into its constituent parts. Lens design minimises this but doesn't often get rid of it totally. It commonly manifests itself as either magenta/cyan or blue/yellow fringing, or a combination of both. It is usually absent near the centre of the image, steadily worsening as you get closer to the edges.
The addition of an IS/VR element to a lens can add to potential problems of CA because it is not fixed in place. Decentering is a fact of life with such lenses, and it's a pretty clever piece of design that this is minimised to such a degree that it is usually not a problem.
Longitudinal CA can also sometimes be noticeable where out of focus areas have magenta or cyan fringing depending on whether the focus point is behind or in front of the OOF area. Can sometimes be a problem with primes and usually disappears when stopping down.
Your problem looks to me to be Blue/Yellow lateral CA. I would take a series of test shots with high contrast boundaries both sides of the picture. Use a tripod and turn IS off.
If the problem goes away, or is reduced to insignificant levels, then you just have to accept that it's the IS element that is causing it.
If the problem remains but is equally bad at either side of the image then it's either typical of the lens or you have sample variation. You may have difficulty replacing the lens, and a replacement might not be any better. But as already pointed out, shoot raw and correction during processing of the raw image is very simple and effective.
If the problem is not uniform, i.e. worse on one side than the other then the lens is decentered, possibly by an IS element that is not optimally positioned. You can still correct for this in post processing but you might also have better grounds for getting a replacement.
HTH,
Mike.
 
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KIPAX said:
i ahve never seen it no.. not on any of my L lens...what lighting? looks like natural light yes?
Click to expand...

It's a sharp contrast, as you can see. Just the sort of thing that can cause CA in my experience.
 
Right guys, found the problem. At 70mm this lens performs awful in my opinion, it doesn't do this half as bad with 18-135mm kit lens.

I must have read about 30 reviews before purchasing this lens and none mentioned CA as bad as this, if it's going to be in the back of every picture with the sky in at f/2.8 then I'm not going to be happy.


At 200mm it seems fine, in between it gets worse towards 70mm and vice versa.

I thought it was IS, because the lens moves splitting the light as explained above, but today I used it with a tripod when I got home (IS off).

All pictures were taken at 100 ISO and from the same spot, tried with IS on and off with no difference.

2sec delay in shots.


Please note especially the focus in the 70mm pictures, depending on which side you focus on the purple fringing appears!!!

I'm so unlucky sometimes... What are the chances of receiving a bad L lens... :(

It's been on my mind all day at work, not something you should have to put up with after paying this much.

I presume this should be replaced?


Here is the gallery link: http://imgur.com/a/y7ZAM


VzD3rh.jpg


3QiXYh.jpg


1htdKh.jpg


Thhlrh.jpg


Ln3Tch.jpg


VXVaJh.jpg


All these pictures are either 70mm or 200mm at ISO 100 tripod mounted.
 
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In such a high contrast situation wouldn't expect anything but that result, especially around the edges. The oof shots arent going to do the lens any favours either....

Shoot something less high contrast and if there is still something awry, then start thinking about replacements....

EDIT: had a chance to look on my laptop and some of them do look excessive, but I still think you're asking a lot when judging what is essentially the ugliest scene known to man. The question I'd ask myself is does it happen on regular shots (i.e. those that have less contrast and difference between the tones)?
 
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Even when in focus, there is still some nasty CA which I don't expect really, even my old standard lens did not experience this.

Also it appears to be slightly worse on the left side, but still does appear on the right hand side too.
 
Have to say, that does seem to be rather more CA than you'd expect with a 2 grand lens, even given the conditions. My Nikon version had very little and the Canon by all accounts is better still.
 
That does seem extreme to me even given the conditions which will exacerbate it.

The OOF shots are a different type of CA though, longitudinal CA (eccles mentioned it) which is normal to see a bit of in lenses shooting wide open, getting purple fringing on one side of the plane of focus and green fringing on the other. But that looks more extreme than I'd expect as well.

CA can normally be easily corrected, but in my experience those glowing purple bits can be very hard to remove.
 
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I have to say, normally I'm a big subscriber to the "don't be silly and just get on with it" school of thought but for me those images have FAR too much CA from such an expensive lens.

I can't think of any of my lenses (none of which are particularly expensive) that have CA that bad - even my kit lens is better.
 
I agree, it's not even pixel peeping, you can see this clearly, never mind in print - it will look bloody awful.

After looking on the net it seems quite a few 70-200mm IS II's have this issue - but no conclusion. I'm hoping my next lens will not have this problem.
 
Does the fringing ease when stopped down from wide open? Shooting such a high contrast scene with sharp dark/light edges wide open and pixel peeping is asking for visible CA IMO. I've seen colour fringes like those wide open on much more expensive lenses than this one.......
 
Yes, it's a bit better at f4 but still there, although I bought this lens to be pretty much used at f/2.8 mainly all the time.

If I have to use this at f4 to stop ugly purple fringing (well stop it a little) then I should have just purchased the 70-200mm f4...

It's just one that's slipped QC, at least I hope so.
 
answer #3 from someone who owns the same lens... 25 answers later and you may as well loop back to answer #3


send it back!
 
KIPAX said:
answer #3 from someone who owns the same lens... 25 answers later and you may as well loop back to answer #3


send it back!
Click to expand...

Thanks mate doing so.

Also thanks everyone who has replied in this thread!


Other than this issue I do really love this lens, amazing build quality and the IS performance is amazing!
 
At the end of the day its a top of the range L lens the latest model.. I paid 1.8k for mine... had I any issues and especialy to the point i wouldnt use wide open then it would be going back honestly...
 
KIPAX said:
At the end of the day its a top of the range L lens the latest model.. I paid 1.8k for mine... had I any issues and especialy to the point i wouldnt use wide open then it would be going back honestly...
Click to expand...

Looking at on line reviews there is CA in high contrast scenes so the only questions are how much is normal and is it acceptable to the user.

How about a couple of wide open high contrast shots from your lens? That could help the OP decide.
 
In the 2.8 IS II lens? I haven't seen one review which says there is high CA anywhere.

The more I look the more wrong my lens looks.
 
All I did was Google the lens name and added "review."

Yours may be wrong, but to help you decide it'd be nice to see similar wide open high contrast shots from other lenses.

PS. I didn't say "high." I really don't know what is acceptable from this lens.
 
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The only review I can find that mentions CA is with the old non II version, even when searching for "Canon EF 70-200mm f/2.8 L IS II USM".
 
I had no problem finding reviews, and I did read text but if you can't find any mention of CA in the text look at the example images.
 
DPReview say...
"Chromatic aberration is exceptionally low. If you look really closely there's a tiny bit of fringing at the extremes of the zoom range, but it's unlikely ever to be a problem in normal use."

And if you look at the test images you can see CA in the 100% crop of the tree.

The questions are... is your lens normal or not and is it acceptable.
 
True, the DPReview site does mention a small amount, but the images are absolutely nothing in comparison to the vivid purple I was experiencing which distracts from the original image.

Thanks.
 
In those conditions I could only expect that purple fringe. These conditions are likely to result in awful images anyway, so you may as well enjoy your lens and use to its strengths. Just make sure it is equally sharp across full frame.

I am very picky for glass by the way.
 
If your that unhappy send it back there's such a thing as a 7 day buyers remorse.


Personally I'd try it in a different setting and not in such extreme contrast settings any lens/camera pushed to its limit will start to exhibit weak links, now I know your not going to want to hear this but to me it sounds like your trying to find something wrong with it as you thought it was going to be super dooper yet hasn't lived up to your expectations.
 
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