EX1 visible chromatic aberrations on slashcam
There is a nice german article on slashcam.de about the chromatic aberrations of the EX1.
http://www.slashcam.de/artikel/Scoop...EX1-Optik.html or (quite bad) translated. http://www.google.com/translate?u=ht...&hl=en&ie=UTF8 My english is not as perfect as my german but here is a short summary: The Fujinon lens of the EX1 produces a lot of chromatic aberrations, but (!!) the Cam has a build in digital CAC (chromatic aberrations correction). But the CAC is only active when there is no lense movement like zoom. So you can see the aberrations clearly while you zoom. The page has two nice 200% slpitscreens, where you can see the difference. Many people heard about the CAC before, but here you can see the difference. So maybe its important for someones buying decision... Happy Christmas Dieter |
This is nuts. Even SD cameras have this. Why even point it out anymore? They talk about how thsi is some type of defect but it is just something we have to live with. Now that so many people have high quality cameras every little imperfection they see gets blown out of the water and made into such a big deal.
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interesting discovery! on the example QT movie there is a real jump right at the end of zoom, is that just an operator thing or is that the CAC kicking in? Because if it's the CAC that's pretty distracting...
The aberation isn't too bad bearing in mind the scene and that they are pixel peeping... cheers paul |
I've seen lens that cost 3X the cost of the EX1 have CA. I agree, why bother.
Also, from what I see, regardless when it "may" occur, it's by far better than my previous cameras. |
On top of that...
I'm looking at some of my footage during zooms right now, and I'm not really seeing much... If it's there, it's not jumping out, so it's not a problem. My JVC HD100 had FAR more CA. |
I think I can live with it - zoom is nothing more than a way to reframe for me 95% of the time.
With my XH-A1 I recently shot an interview with someone in a black shirt against a white wall, sitting on one side of the frame...the thin pink line outlining one side of their shirt is pretty distracting - that's the kind of CA I'm concerned about, the kind that jumps out of a static shot where the viewer's eyes have a chance to focus on it - and it looks like that's exactly what the CA correction of the EX1 eliminates. |
CA is even more difficult to tame with HD lenses. I read this somewhere while researching the causes of CA in general.
The biggest offender is running wide open on the long end of the lens. -gb- |
So, exactly what is it that causes the CA. One arguement is that it's caused by optical distortion of the different wavelengths of light thru the lens. A high quality $1500 still camera lens corrects out CA. Another arguement is that it's related to using 3 sensors. Which one is it?
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I'll see if I can dig up the links to the pages I was reading. -gb- |
Greg..
So, what you're saying is that it's easier for a 35mm lens to correct out CA because it doesn't have optical elements that correct breathing? I have some very nice Canon EOS zooms that don't show a hint of CA at any zoom or aperture setting. These zooms are very complex designs. |
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Required reading: "HDTV Lens Design: Management of Chromatic Aberrations" http://www.usa.canon.com/industrial_...WhitePaper.pdf |
Thanx, everyone.
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http://www.canon.com/bctv/faq/chrab.html This not the the page I was recalling... still looking for that one. |
Thanx, Greg. I already knew what causes CA in lenses. I didn't understand why videocam lenses had so much more CA than 35mm cam lenses. I think you and Chris gave me the answer. Videocam lenses have much harder optical problems to neutralize, namely long zoom ratios and mitigation of breathing effects.
Actually, it makes a good case for having an interchangeable lens camera and small zoom ratio lenses. |
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-gb- |
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