controling colour "fringing"

[adrian tyler]

i'm studying the idea of doing a personal project with my d3, which i usually use for commissions.

i have been making some sketches and am finding some pretty obtrusive colour fringing which would seem to limit the kind of light i can work in, any advice on the subject would be greatly appreciated.  the camera is a d3 and the lens is a new pce 45 mm.

i use photoshop cs3 and camera raw.

thanks

http://www.adriantyler.net/

i'm enclosing a couple of details form the d3 which show the problem, also a picture made on a 4x5 from the work that i was thinging of doing, which exhibits none of the aforementioned problems.

[Panopeeper]

#1 and #2 are plain CA. #3 shows halos arond some branches, probably oversharpened.

Unfortunately, ACR is not very good in eliminating CA; try CNX2. I too have an otherwise excellent lens (a Canon) with horrendeous CA; Canon's DPP can remove the CA quite good, but I have to give it up sometimes with ACR

[DarkPenguin]

Use the CA controls in ACR.  Or use Nikons software.  Ptlens is another option as is DXO.

But I'd start with ACR's CA controls.

[adrian tyler]

thanks very much, as you can see i don't know my colour fringing from my cromatic abraision and i am not a computer whizz, what is CNX2? DPP? Ptlens? and DXO? is this site a good place to start? thanks!

[Slough]

thanks very much, as you can see i don't know my colour fringing from my cromatic abraision and i am not a computer whizz, what is CNX2? DPP? Ptlens? and DXO? is this site a good place to start? thanks!

Download a copy of Nikon NX2 from the Nikon site. You will have a trial period of 30 or 60 days, I forget which. My experience is that NX2 can remove CA that is present when using Nikon Capture 4.0 (an old version).

PtLens is a software package which used to be free but I think you need to pay now. But IMO NX2 should be best as Nikon know their lenses better than anyone.

[NikoJorj]

#1 and #2 are plain CA. #3 shows halos arond some branches, probably oversharpened.

Ditto.

I wonder though if #2 wouldn't be longitudinal chromatic aberration, aka purple fringing : it hasn't the "two opposite colors on two opposite sides" pattern of the transverse chromatic aberration, and it's MUCH more a pain to correct (sometimes impossible).
Transverse chromatic aberration is quite easy to correct (LR/ACR, PTLens, or any other decent image treatment program).
See http://toothwalker.org/optics/chromatic.html for more details on chromatic aberrations!

[BernardLanguillier]

If you are on Mac, you could also try Raw Developper.

The default conversion should have a lot less issues, and you can further tune that down using the color smoothing capability (you will need to overlay 2 images and mask).

Cheers,
Bernard

[adrian tyler]

thanks for all the helpful advice.

incidently i have made some tests with the d3 and a hasselblad distagon 50mm fle in similar light and have not experienced ca to this extent, so probably the best cure is to avoid the 45 pce for this project.

[Slough]

thanks for all the helpful advice.

incidently i have made some tests with the d3 and a hasselblad distagon 50mm fle in similar light and have not experienced ca to this extent, so probably the best cure is to avoid the 45 pce for this project.

Sometimes I get the impression that Nikon - and I presume Canon et al too - prefer to eliminate non correctable aberrations at the expense of correctable ones such as (some forms of) CA. That said, I am surprised at the degree of CA from your lens. The 45mm PC-E lens should be a top performer, and I have never noticed anything like that with the 24mm PCE or 85mm PC lenses. Misalignment of the elements could cause CA, though I would have thought it would be asymmetric. I would wonder if the lens is at faulty.

[JamesA]

If the lens doesn't say "ED" or have it in it, likely it will not be able to do justice to the D3 or any other FX sensor.  Chromatic aberration afflicts the image two ways, you see it on the edges of light-dark interfaces as a purple, blue, red, etc., fringe, but it also kills contrast (much like spherical aberration does) as a haze that suffuses the entire image because the blue and red light is actually out of focus across the entire image.  The most colour-free lenses I've seen (outside of pure mirror systems, mirrors don't split light into its component colours) come from Coastal Optics and incorporate a few fluorite (better than ED for control of colour error) elements and as a result cost about $4000+.

Other things that contribute to fringing are lack telecentricity in the design of the lens.  Most old lenses, that didn't matter because film didn't have "depth" or microlenses.

[adrian tyler]

james, the lens does infact have "ed" on the end of it: "pc-e micro nikkor 45mm f2.8d ed", but to be fair to the lens it was shifted to the extreme where the test crops were taken.

that said however the hasselblad distagon performs a dream in comparrison, to my taste, and the out of focus areas are much more agreeable than the nikon, but, as slough suggests, the design seems to be intentional.

adrian

[JamesA]

james, the lens does infact have "ed" on the end of it: "pc-e micro nikkor 45mm f2.8d ed", but to be fair to the lens it was shifted to the extreme where the test crops were taken.

that said however the hasselblad distagon performs a dream in comparrison, to my taste, and the out of focus areas are much more agreeable than the nikon, but, as slough suggests, the design seems to be intentional.

adrian

Yes, it is kind of impossible for them to maintain CA control when the lens is capable of shifting its elements like that.

[HarperPhotos]

Gidday,

I some times get colour fringing when I use my Mamiya 645AF 28mm lens with my Leaf Aptus75.

Power retouche soft wear does a very good job to remove it

http://powerretouche.com/Color-fringe_tutorial.html

Cheers

Simon