pdmphoto wrote:
The Samsung 85/1.4 (for NX) is near perfect, and has very low LoCA. It is the closest to APO quality of any lens I own that does not have APO in the name. Beats the Sigma APO's I own in that regard.
The 85 does have "ED" in the name though, signaling the use of special glass.
pdmphoto wrote:
The Samsung 85/1.4 (for NX) is near perfect, and has very low LoCA. It is the closest to APO quality of any lens I own that does not have APO in the name. Beats the Sigma APO's I own in that regard.
I'm a bit surprised. I had the Samyang 85/1.4 and used it with my 5D. Plenty of LoCA, one can't put it another way. Was there something wrong with my lens? Or aren't we talking about the same thing?
I definitely don't think this should be in. My recent tests showed it to have more than the Zuiko 100/2 and I was complaining how much that has!
The new Zeizss Z* 135/2 Apo is reported to be much better however and may make the list.
I made some thousand pictures with my ZF/100 and in none of these pictures I noticed LoCA that could bother me. In 99% of the pictures LoCA is completely absent and in 1% it is there, but only very minor. In postprocessing I could remove most of it in less than a second.
So, yes in test-situations it will show up. In real world photography hardly ever.
And I suppose this is the case for most lenses mentioned here.
this page I took from www.the-digital-pictures.com, where the comparison tools are provided.The better sharpness, contrast on 400L , CA about the same or nano advance on 400L also.
wiseguy010 wrote:
In 99% of the pictures LoCA is completely absent and in 1% it is there, but only very minor. In postprocessing I could remove most of it in less than a second.
I would love to know how, I have one or two lenses that I love which occasionally will cause a soft defocus fringing around complex shapes I would love to know how to remove it quickly.
contas wrote:
@alundeb: that is why they recommend prime than zoom + TC:
this page I took from www.the-digital-pictures.com, where the comparison tools are provided.The better sharpness, contrast on 400L , CA about the same or nano advance on 400L also.
Yes, the prime is better for sharpness and contrast (as clearly shown in my comparison as well) and lateral CA. But the zoom plus TC is better for defocus color fringing, something a two-dimensional test target cannot show. Also, the DoF is effectively much larger with the zoom + TC, if you define the DoF with a very small CoC. The two dimensional test target from TDP cannot show this either.
An example that there is no "best lens", they have different strengths and weaknesses.
thrice wrote:
I would love to know how, I have one or two lenses that I love which occasionally will cause a soft defocus fringing around complex shapes I would love to know how to remove it quickly.
I use Capture NX from Nikon for this. It is just a simple button with slider to increase or decrease intensity. In my experience it works good.
wiseguy010 wrote:
I use Capture NX from Nikon for this. It is just a simple button with slider to increase or decrease intensity. In my experience it works good.
Wiseguy, you're not talking about Longitudinal CA. LoCA, as it's generally abbreviated occurs in defocused areas of high contrast. It creates false colors in the bokeh, which are generally unpleasant because they're unnatural (magenta, almost neon green).
It is extremely hard to correct, and the correction has to be done manually.
Jon Guilbault wrote:
Wiseguy, you're not talking about Longitudinal CA. LoCA, as it's generally abbreviated occurs in defocused areas of high contrast. It creates false colors in the bokeh, which are generally unpleasant because they're unnatural (magenta, almost neon green).
It is extremely hard to correct, and the correction has to be done manually.
Latest LightRoom too if Im correct. But needs to be done by hand. Its pretty much impossible to write program function for something so random (tho I guess that if it was profiled for certain color of certain lens, it might actually work.. but not always).
Mirek Elsner wrote:
Yes, LR can do it. It may take a few clicks with the eyedropper, but it works on LoCA surprisingly well.
I see this operation as a compromissing manipulation only , although it's very easy, it doesn't give a radical color correction, it just replace purple fringing by greyish color to avoid dazzling your eyes, so you'll see color shift from green to grey on the 1st example.But as the rule of thumb small always better than none.
CA is measured and defined IN the plane of focus. Many of the Leica "APO" lenses that are atrocious at what should really be called "bokeh LoCA" or "exit pupil variance over wavelength" are very good at this point - among others. So answering the initial question is rather easy.
-That is, if you can agree on what the word "no" means. There's always CA, just more or less of it.
The only lenses that combine low CA, low LoCA and low variance are either slow (F4.0 or slower at <200mm focal lengths), very complex (the EF70-200F2.8IS2 23/19, Sigma 150F2.8OS 19/13) or very long - with lots of anomalous dispersion glass - like the modern 400/2.8's and the likes....Show more →
+1 @ optics are always a series of compromising decisions/choices ... choose your poison(s) according to how much you can tolerate and/or have the PP antidote for.
I wonder if any of you has experience with the exotic and expensive Kinoptik Apochromats, ( 75/2, 100/2 and others ). You can get them secondhand on Ebay/online sites at steep premium prices. Is that only because of the collector value or are they comparable or even better than modern glass from Zeiss, Leica, etc..?
CA is measured and defined IN the plane of focus. Many of the Leica "APO" lenses that are atrocious at what should really be called "bokeh LoCA" or "exit pupil variance over wavelength" are very good at this point - among others. So answering the initial question is rather easy.
-That is, if you can agree on what the word "no" means. There's always CA, just more or less of it.
The only lenses that combine low CA, low LoCA and low variance are either slow (F4.0 or slower at <200mm focal lengths), very complex (the EF70-200F2.8IS2 23/19, Sigma 150F2.8OS 19/13) or very long - with lots of anomalous dispersion glass - like the modern 400/2.8's and the likes....Show more →
Could someone elaborate on "exit pupil variance over wavelength"? Does that include "artificial vignetting variation over wavelength"? Are there references online discussing this?
The reason I ask is I'm trying to understand "bokeh fringing" from a geometrical optics point of view.
But then it occurred to me that artificial vignetting (cone of light limited by something other than the diaphragm) might possibly explain the wavelength variation.
Yes it works so well that it removes a whole load of stuff that isn't LoCA, I was using it recently and it decided the leaves of a tree were LoCA and turned them all grey. At first I thought the tree had a terrible disease, until I zoomed in to see what had happened.
I'd be more impressed had Adobe at least attempted to detect whether the area was out of focus before applying it's CA reduction!
