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jeztastic · 01-08-2011, 04:45 AM

Hi,

I have noticed a lot of purple fringing on this lens. I am shooting with a 1 1/2" lens hood and no filter.

Is this because it's an old lens, something about the K10D, or a fact of life when shooting under these conditions?

OK, I am a noob, but I would like to know what I am working with in this regard...

jpeg straight from the camera, taken wide open. Picture taken as an example, it ain't art! I got much more fringing yesterday against cloud.

Thanks.

Jez

Attached Images

**Canada_Rockies** · 01-08-2011, 12:20 PM - **1 Like**

You will find the purple fringe to be quite common with older lenses particularly. The PF is actually a sensor artifact rather than chromatic aberration. I use Lightroom and find the PF can be reduced to almost none by simply turning the purple down in post processing. Whatever processing program you are using should be able to do something similar. This fringing shows up mostly when there is a high contrast break.

**Lowell Goudge** · 01-08-2011, 02:19 PM

It's funny but I don't see any PF in the shot but only a little
Lateral CA

**Canada_Rockies** · 01-08-2011, 10:12 PM

Originally posted by Lowell Goudge

It's funny but I don't see any PF in the shot but only a little
Lateral CA

I did not see any either, but assumed it disappeared in the size reduction. Good catch Lowell.

jeztastic · 01-09-2011, 03:10 AM

Thanks all for the replies. I can see what I assume is PF above and to the right of the pigeon, around the branches. I was actually trying to replicate a shot that I took the day before, which had loads of purple fringing. It was a bit over exposed, and this one it a bit under. Maybe that has made a difference.

Will google Lateral CA, and try the PP trick.

RioRico · 01-09-2011, 05:42 AM

I have a simple way to test lenses for PF. In a corner of my office, atop a white indented cabinet, is a brass tin-can lamp with a CF bulb sticking slightly out its top, adjacent to some figurines (articulated wooden art models). From my desk, I focus on the figurines and shoot. The resultant image also contains the lamp and the cabinet edges. After shooting, I chimp and enlarge the image. Some fringing where the CF bulb emerges from the can is tolerable, to me. Fringing on the cabinet edges is not. Some lenses show no fringing at all; with others, the fringing is thick and bright. I don't keep such lenses unless they have redeeming features.

**Lowell Goudge** · 01-09-2011, 05:58 AM

I think what you see is lateral CA. It is easy to take out in PP

Note most legacy lenses exhibit this. It was only in the 1980's that makers started with aprochromatic designs

jeztastic · 01-09-2011, 10:08 AM

Found a great explanation of Lateral and Longitudinal CA. I include it here in case others find it useful.

Chromatic aberrations

I took some nice pictures with the Cosina today, I'll post one later. May also add to the reviews page at some point.

stevebrot · 01-09-2011, 05:27 PM

Yep, I see the PF, but it is pretty mild and not like the great blue bloom present with some camera/lens combinations.

Steve

jeztastic · 01-11-2011, 05:12 AM

Better photos with this lens on flickr...

Toddler's Cove - a set on Flickr

01-08-2011, 04:45 AM	#1
jeztastic Veteran Member Join Date: Nov 2010 Location: Canterbury Photos: Gallery \| Albums Posts: 596	K10D, Cosina M42 135mm f2.8 and purple fringing Hi, I have noticed a lot of purple fringing on this lens. I am shooting with a 1 1/2" lens hood and no filter. Is this because it's an old lens, something about the K10D, or a fact of life when shooting under these conditions? OK, I am a noob, but I would like to know what I am working with in this regard... jpeg straight from the camera, taken wide open. Picture taken as an example, it ain't art! I got much more fringing yesterday against cloud. Thanks. Jez Attached Images

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01-08-2011, 12:20 PM - 1 Like	#2
Canada_Rockies Loyal Site Supporter Join Date: Nov 2007 Location: Sparwood, BC, Canada Photos: Gallery \| Albums Posts: 12,385	You will find the purple fringe to be quite common with older lenses particularly. The PF is actually a sensor artifact rather than chromatic aberration. I use Lightroom and find the PF can be reduced to almost none by simply turning the purple down in post processing. Whatever processing program you are using should be able to do something similar. This fringing shows up mostly when there is a high contrast break.

01-08-2011, 02:19 PM	#3
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,892	It's funny but I don't see any PF in the shot but only a little Lateral CA

01-08-2011, 10:12 PM	#4
Canada_Rockies Loyal Site Supporter Join Date: Nov 2007 Location: Sparwood, BC, Canada Photos: Gallery \| Albums Posts: 12,385	Originally posted by Lowell Goudge It's funny but I don't see any PF in the shot but only a little Lateral CA I did not see any either, but assumed it disappeared in the size reduction. Good catch Lowell.

01-09-2011, 03:10 AM	#5
jeztastic Veteran Member Join Date: Nov 2010 Location: Canterbury Photos: Gallery \| Albums Posts: 596 Original Poster	Thanks all for the replies. I can see what I assume is PF above and to the right of the pigeon, around the branches. I was actually trying to replicate a shot that I took the day before, which had loads of purple fringing. It was a bit over exposed, and this one it a bit under. Maybe that has made a difference. Will google Lateral CA, and try the PP trick.

01-09-2011, 05:42 AM	#6
RioRico Veteran Member Join Date: Jun 2008 Location: Limbo, California Posts: 11,263	I have a simple way to test lenses for PF. In a corner of my office, atop a white indented cabinet, is a brass tin-can lamp with a CF bulb sticking slightly out its top, adjacent to some figurines (articulated wooden art models). From my desk, I focus on the figurines and shoot. The resultant image also contains the lamp and the cabinet edges. After shooting, I chimp and enlarge the image. Some fringing where the CF bulb emerges from the can is tolerable, to me. Fringing on the cabinet edges is not. Some lenses show no fringing at all; with others, the fringing is thick and bright. I don't keep such lenses unless they have redeeming features.

01-09-2011, 05:58 AM	#7
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,892	I think what you see is lateral CA. It is easy to take out in PP Note most legacy lenses exhibit this. It was only in the 1980's that makers started with aprochromatic designs

01-09-2011, 10:08 AM	#8
jeztastic Veteran Member Join Date: Nov 2010 Location: Canterbury Photos: Gallery \| Albums Posts: 596 Original Poster	Found a great explanation of Lateral and Longitudinal CA. I include it here in case others find it useful. Chromatic aberrations I took some nice pictures with the Cosina today, I'll post one later. May also add to the reviews page at some point.

01-09-2011, 05:27 PM	#9
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Yep, I see the PF, but it is pretty mild and not like the great blue bloom present with some camera/lens combinations. Steve

01-11-2011, 05:12 AM	#10
jeztastic Veteran Member Join Date: Nov 2010 Location: Canterbury Photos: Gallery \| Albums Posts: 596 Original Poster	Better photos with this lens on flickr... Toddler's Cove - a set on Flickr

K10D, Cosina M42 135mm f2.8 and purple fringing

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