Canon Ef 85/1.8 chromatic aberration problem

[vladimir_ucekaj]

Just want to know if anybody has the problem with CA with this lens

or is the one I own a lemon? I can send a photo if interested.

Thanks<div></div>

[ted_kostek]

Are you referring to the color fringing all around the letters on the box?

 

I thought CA showed up worst at frame edges and had one color on one side and another color on the other side. What I'm seeing, however, is sort of a constant halo. That halo is at an edge: bright highlight to a dark shadow w/ a sharp boundary. Seems more like some lens flare.

 

Take my comments w/ grain of salt (or silver), however, since I'm still learning all this lens stuff.

[jon_austin]

CA at the wider apertures (> f/3.0) is about the only criticism found of this lens among the end-user reviews @ the Fred Miranda web site:

 

http://www.fredmiranda.com/reviews/showproduct.php?product=32&sort=7&thecat=2

 

One user (roanjohn on 5/4/04) claimed that he returned his first copy of the lens, and that the replacement he received was better.

 

I'll be buying one of these later this month.

[PuppyDigs]

Hmm, I see it only occurs around the edges of bright highlights adjacent to dark areas. Are you sure it's not electrons "bleeding" from the highly charged highlight pixel to the lessor charged shadow pixels? Alias, sensor bloom. Wouldn't real "CA" cause spectrum halos across the entire image? Even monitors and film scanners suffer from pixel bloom under said circumstances.

[PuppyDigs]

Shoot some slide film and view with a quality high power loupe or low power microscope. Like I mentioned above, scanners, like digital cameras, exhibit sensor bloom when bright highlights border dark areas. You can't properly judge via scan as it introduces artifacts. My Nikon LS-1000 was terrible in this respect. My Canon FS4000US only has a slight amount of sensor bloom.

[lotsawa]

I've had no problems with my 85/1.8. Never noticed any color fringing or so. A beautiful lens, though a bit long on my 300D because of the 1.6 crop factor. Instead, I tend to use the 50/1.4 as a portrait lens, which is beautiful too.

 

Here's an example of the 85/1.8 (1/320 f3.2)<div></div>

[vladimir_ucekaj]

As written above, the crop is taken from the middle of the picture. I also tested Tokina 28-70/2.8 SV and Canon EF 24/2.8 using the same scene, film (the same roll) and scan. There was no problem like in the picture from 85/1.8 .... Of course I have noticed this problem earlier in some pictures and therefore performed the test. Thanks for all opinions. Vladimir<div></div>

[yakim_peled1]

I have it but never noticed it. Maybe I'm not picky enough......

 

Happy shooting ,

Yakim.

[joshchapman]

Hmm... I have the lens and I've never noticed any problems. Just a thought, but it's a nicely high contrast lens and maybe the bright white is causing your sensor bloom in your scanner. Like Puppy Face I'd suggest taking a close look at some slides to be sure.

[awindsor]

This looks exactly the the usual CCD purple fringing that you get from scans/small pixel digital cameras.

[ted_kostek]

Some people are saying it looks like purple fringing from small sensor CCD's, but if that's the explaination, then why only on the 85? Vladimir posted several other scans from different lenses, and the other ones didn't show much purple fringing at all. I suppose it's possible for the lens and scanner to be interacting, it seems unlikely.

 

I have the 85/1.8. I've never noticed anything like this, but I've also never looked. I haven't taken that many photos with it, either. The ones I have taken are portraits, and didn't have any of the super-aggressive highlight-shadow transitions from the test shot.

 

I'm afraid that right now I can't be much help, but do want to emphasize that this test really is pretty aggressive. I'm not sure it's indicative of realistic usage. Even so, I'd be annoyed about finding such a nasty surprise.

 

Best of luck. Keep shooting.

[ted_kostek]

I just noticed all the test shots were taken wide open, always the worst case for a lens. What happens if you stop down? I've read that the 85 is best about f4.

 

If it goes away, then I would say it's a lens issue. Whether it's CA or flare or whatever is less important than knowing it comes from something in the lens.

 

I'm also intrigued by how much sharper the 24 looks. The magnification is strange (24 looks bigger than 85). Is that because the camera moved closer to the subject?

[vladimir_ucekaj]

Unfortunately I noticed this problem for the first time, when taking portrait shot... Backlit (just cloudy grey sky) black dressed person at f/4 and there was obvious fringing (even in the centre) seen even on 10x15 cm photo... What a surprise! This forced me to further testing and you see...

Lens was sent to Canon service this week, so I?m curious what they?ll say.

Yes, test shot with Canon EF 24/2.8 was taken from shorter distance. I must say this lens is just great. Especially center sharpness is simply superb even wide opened. Edges are little soft wide opened but get sharp from f/4 down.