Awful chromatic aberration with Oly 45 1.8

JamesCarruthers

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Not a brilliant photo - but it looks awful.

I haven't used the lens too much but noticed this for the first time yesterday.

Check out the coloured halos around the near and far out of focus birds — you may want to look at it full size.

Time to send the lens back?





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Former SLR junkie, m43 convert.
 
We don't have access to the original full size images.

You will need to zoom in on the anomaly - crop it - then post the crop so we know what you are talking about.
 
don't usually pixel peep. Maybe those ducks with halos were some kind of aquatic angels...
 
Sorry everyone!

I am certainly no pixel peeper — this is way beyond that.









Shot at 1.8 1/640

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Former SLR junkie, m43 convert.
 
I've made the same mistake - when you are logged in you can see originals of your own photos, but no one else can. Unless you go to your account settings and specifically enable viewing of originals. If you want to double check we can see them, just log out and view your post.

I can't see any CA in the largest currently viewable image, but I'm sure it is there as you say. This is not at all uncommon for wide aperture lenses. There are a few that can control longitudinal CA in out of focus areas but it is a pretty rare quality.

You can see it in this comparison between the 45/1.8 and the Canon FD 50/1.4. You can see it is a bit worse in the 50/1.4 actually:









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Ken W
See plan in profile for equipment list
 


Olympus M.Zuiko Digital 45 mm f/1.8
5. Chromatic aberration

Lenses with such parameters as the Olympus, tested here, often show noticeable longitudinal chromatic aberration. Fortunately the 1.8/45 model corrects it well. Perhaps it is not a perfectly good performance because you can still notice slight colouring behind the depth of field, but it remains really on a not bothersome level.

The lateral chromatic aberration correction is still better. Even at the maximum relative aperture it is on the border between low and medium values; on stopping down it becomes completely imperceptible. Such results we would like to see as often as possible.

http://www.lenstip.com/316.5-Lens_review-Olympus_M.Zuiko_Digital_45_mm_f_1.8_Chromatic_aberration.html

Olympus M.Zuiko Digital 45 mm f/1.8
11. Summary

Pros:

small, very handy housing,
sensational image quality in the frame centre,

excellent image quality on the edge of the frame, including the maximum relative aperture,
very low chromatic aberration,
low distortion,
slight astigmatism,
well-corrected vignetting,
efficient and accurate autofocus.

Cons:

pity the lens is not made entirely of metal.

The summary of our tests rarely can be so unambiguous. I really can’t imagine a situation when a Micro 4/3 body owner doesn’t have this lens as well. If you haven’t bought it yet, do make up for this complete mistake as soon as possible.

http://www.lenstip.com/316.11-Lens_review-Olympus_M.Zuiko_Digital_45_mm_f_1.8_Summary.html
 
Not a brilliant photo - but it looks awful.
this says it all.

Lens deficiencies such as chromatic aberration and distortion etc, although they exist, are never bothersome on decent photos.

They tend to be bothersome on awful photos - ones that are so compositionally and artistically empty that you have to look at individual pixels to find something of note.

You could send it back. Or take better pictures and not worry about it. Or even better, fix it in a photo-editing programme. It's just a case of moving a slider a few pixels across a screen.
 
It's a fair comment, but I would like to point out that I do take really good photos usually and I was certainly not trying to find anything other than checking the new lens over :)

I will take the camera and lens with me to work tomorrow and shoot some more shots to try it out some more. I hadn't noticed any of these issues in previous photos I had taken.

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Former SLR junkie, m43 convert.
 
Not a brilliant photo - but it looks awful.

I haven't used the lens too much but noticed this for the first time yesterday.

Check out the coloured halos around the near and far out of focus birds — you may want to look at it full size.
As kenw has already pointed out, what you see here (in the crops you posted later) is perfectly normal on fast lenses shot wide open or thereabout. And as far as I have seen, the 45/1.8 does slightly better, not worse, than average in this area.
Time to send the lens back?
Your choice, but I wouldn't expect another copy of this lens to do better than the one you have. Nor would I expect to find another lens of similar speed and FL that eliminates or significantly reduces the problem.
 
If you go looking for it.

Now that I've seen the crops you posted, I know what you are talking about. Doesn't seem like anything beyond what I would expect from most lenses that don't cost a mint.

Zoom in on the full size photo below and look at 'T' and 'F' of the license plate. You can clearly see some CA, but nothing I would ever consider beyond normal. You can also see some CA on the antenna of the red car. Taken with the Oly 12mm F2.0.



 
Oly outperforms the Canon FD easily. Not only the CA, but the micro-contrast as well. Not to mention the bokeh! :)

This Oly 45 1.8 is worth every penny. It is everything an 'amateur' could wish. It is very good at f1.8, and there's nothing to complain when stopped down to f2.8.
 
Is this your first large aperture lens? In my experience this is normal, even with much more expensive, very highly regarded lenses such as the Canon 85mm f/1.2. Notice that it only manifests in areas in front of and behind DOF, not for objects that are in focus, which is how it is with other large aperture lenses. I wouldn't worry about it.
 
I don't have the Oly 45 1.8 but I've seen much worse on most of my legacy lenses. If I stop them down a bit life is good.
 
If you go looking for it.

Now that I've seen the crops you posted, I know what you are talking about. Doesn't seem like anything beyond what I would expect from most lenses that don't cost a mint.

Zoom in on the full size photo below and look at 'T' and 'F' of the license plate. You can clearly see some CA, but nothing I would ever consider beyond normal. You can also see some CA on the antenna of the red car. Taken with the Oly 12mm F2.0.
What you're talking about is a completely different kind of CA than the one the OP worries about though. What he is concerned about is longitudinal CA in the out-of-focus area, which is common with fast lenses when used at wide apertures. What you are referring to is lateral CA in the in-focus area, which may appear on any lens at any aperture and (unlike longitudinal CA) can easily be software-corrected with hardly any drawbacks and close to perfect results. In fact, Panasonic bodies using Panasonic lenses will auto-correct lateral but not longitudinal CA.
 
It's not — I have 20mm 1.7 and 25mm 2.5 (ok, not that fast) — I have a Canon 50mm 1.8 Mk2 and 70-200 2.8L for my Canon 60D.

I just hadn't noticed longitudinal CA before.

I think the white of the birds makes it stand out a lot more.

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Former SLR junkie, m43 convert.
 
I think the white of the birds makes it stand out a lot more.
You are quite right about that. You'll always see it more clearly at strong-contrast (black versus white) edges.

As others have mentioned, you might also see longitudinal CA on objects that are in rather than out of focus, in which case it is known as "purple fringing" because the fringe will be purple (as on objects that are closer than the focus distance) rather than green (as on objects that are behind).
 
It's not — I have 20mm 1.7 and 25mm 2.5 (ok, not that fast) — I have a Canon 50mm 1.8 Mk2 and 70-200 2.8L for my Canon 60D.
If you repeat the test with those lenses you will see the same thing (to varying degrees unless you can tailor your subject to focal length, and place them well outside of the DOF). Heck, even stopped down most primes still have trouble with LoCA in harsh transitions. The best approach is just ignore it, experiment how far you need to stop down to make it acceptable, or become adept at the "replace color" options in PS. When I print large panels where it matters (300L + stacked TCs = LoCA city), I spend a couple of minutes toning it down in PS.

Suffice to say, it isn't a bad copy you have, just part of the fast lens equation.

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-CW
 

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