Canon 85mm f/1.8 Purple Fringing

toxic wrote in post #10290871
This is not LoCA. LoCA is green/purple fringing before and after the focus point. Even if these are not properly focused, they aren't OOF enough to explain all the PF, and LoCA is never that deep of a purple anyway.


DPP automatically corrects for vignetting and CA with Canon lenses.

I used a single point to AF on the Canon logo. Unforunately the JPEG conversion blocks up the highlights more than what shows on my screen in LR.

Poe wrote in post #10290887
Will the fringing occur not at the exact object distance but within DOF or outside of the DOF entirely?

Sorry, there is no such thing as DOF for me.. so I cannot answer your question (or have I ?).

Poe wrote in post #10290887
I haven't done any micro adjustment to this lens. I suppose I should try that as well as shoot a flat surface? (Just printed off an ISO 12233 chart to use).

Try with careful manual focus using Live View at maximum magnification. Then try with auto focus to see if you have the same results.
If results do not match, then either your lens or you are not working properly.

EDIT: I just noticed you have a 5D classic, no Live View. You probably know someone who has a body with Live View to test with.

toxic wrote in post #10290871
This is not LoCA. LoCA is green/purple fringing before and after the focus point. Even if these are not properly focused, they aren't OOF enough to explain all the PF, and LoCA is never that deep of a purple anyway.

That thing looks like LoCA, behaves like LoCA, almost smells like LoCA
What else could it be ?

Note: I never had a 85/1.8 so I cannot say if that amount of LoCA is normal or it is due to issues on the OP's copy or processing software.

CheshireCat wrote in post #10291017
Sorry, there is no such thing as DOF for me.. so I cannot answer your question (or have I ?).


Try with careful manual focus using Live View at maximum magnification. Then try with auto focus to see if you have the same results.
If results do not match, then either your lens or you are not working properly.

EDIT: I just noticed you have a 5D classic, no Live View. You probably know someone who has a body with Live View to test with.

DOF = depth-of-field

I took a picture of the Canon logo on a 5D, but I used the 85mm on a 7D to take the photo in Av mode and processed in LR 2.6 (adjusted WB and exposure, since the camera meter didn't keep the overall EV the same when I cycled through apertures, cropped the canon logo and exported to 600 x 900 JPEG with max image quality), so I do have the ability to use live view.

CheshireCat wrote in post #10291057
That thing looks like LoCA, behaves like LoCA, almost smells like LoCA
What else could it be ?

Purple fringing is not LoCA. LoCA only applies to OOF elements, and the image is clearly in-focus, or close enough that a LoCA would not be a solid purple bar. LoCA is also not that deep of a purple, at least without gross overexposure.

edit:
https://photography-on-the.net …hp?p=9736704&po​stcount=20

The first image is about how much PF you should see wide-open.

Poe wrote in post #10291102
DOF = depth-of-field

Sure, but there is no such thing as "depth-of-field" for me.
The concept of DOF is to be taken with a grain of salt... or better ignored altogether.

Anyway, based on most people definition of DOF, LoCA happens both in and out of it.

When I had this lens, the fringing was HORRIBLE. Even stopped down to 5.6, which was unnacceptable. Took it to Canon Irvine and a day later, AMAZING results. Color fringing was all but gone, even wide open, and it was tack sharp.

sickboy11 wrote in post #10291199
When I had this lens, the fringing was HORRIBLE. Even stopped down to 5.6, which was unnacceptable. Took it to Canon Irvine and a day later, AMAZING results. Color fringing was all but gone, even wide open, and it was tack sharp.

It is promising to read this. I'll likely send in this lens to Canon repair in Irvine. I'll take a few more test shots when I get home later today and share.

The ONLY times I get fringing on my 85 is in OOF areas. I took a picture of a silk butterfly to send to my granddaughter. It was dark purple (her favorite color) with whites dots. The dots in focus (within the DOF) had no fringing. The areas OOF (outside the DOF) had fringing.

IMHO that is the case here. There is no reason to panic. Learning how to use the 85 was as steep a learning curve for me as going from a P&S to a DSLR. Part of that is learning what NOT to do and what to avoid.

toxic wrote in post #10291137
Purple fringing is not LoCA. LoCA only applies to OOF elements, and the image is clearly in-focus, or close enough that a LoCA would not be a solid purple bar. LoCA is also not that deep of a purple, at least without gross overexposure.

edit:
https://photography-on-the.net …hp?p=9736704&po​stcount=20

The first image is about how much PF you should see wide-open.

The amount of LoCA "noticeability" is not only dependent on overexposure (e.g. focus distance, focus precision, unaligned lens elements, background color, ...).
Apart from saying it is NOT LoCA, I think you should at least suggest what it IS.

CheshireCat wrote in post #10291242
Apart from saying it is NOT LoCA, I think you should at least suggest what it IS.

It's purple fringing.

tested one in my local shop, and it was horrible, so i didn't purchase..

toxic wrote in post #10291299
It's purple fringing.

Yeah this is the effect (it's in the thread subject).
And the cause happens to be ?

I haven't noticed it in my photos yet, but I have avoided strong backlighting. I don't shoot bar codes very often.
I am sure that you can produce it, but it hasn't shown up yet.

CheshireCat wrote in post #10291364
Yeah this is the effect (it's in the thread subject).
And the cause happens to be ?

See post #39...OOF or out of DOF.