View Full Version : chromatic aberation
Jemore Santos December 17th, 2005, 11:52 PM Hi everyone,
Today at work while I was capturing I saw Chromatic Aberation, My heart broke in 2! My HD100 skipped the issue of SSE but when I saw it, I thought it can't happen to me, but it did :(
Anyways is CA caused by the lens, the ccds or some other factor?
and if it is the lens or the ccd is it a fault and therefore replacable under warranty?
Help me out fellow HD100ers, btw the footage is great if it didn't have CA pink tinge up on top and aqua tinge down the bottom.
Barry Green December 18th, 2005, 01:30 AM It's caused by either the lens or the prism. I think it's mostly due to the lens, but haven't had a chance to play with the optional $11,995 13x3.5 wide-angle lens.
The aberration is omnipresent in all HD100 lenses. It's part and parcel of designing a high-def lens at an $800 price point. You'll notice C.A. more on the telephoto end -- the longer you zoom in, the more you'll see it.
Jemore Santos December 18th, 2005, 01:55 AM so Barry you're telling me all Fujinon lenses that came with the HD100 has CA? Therefore it is not a fault under warranty? JVC won't replace the lens?
sorry about all these questions.
Barry Green December 18th, 2005, 04:26 AM That is correct. Unless your lens is extraordinarily defective, that is. But if it's performing like all the others, then no, it would not be a warrantee-able defect. You can of course ask your JVC service center.
I would expect that if you had a seriously defective lens, you would have noticed it right away. You might try posting some pictures here and fellow HD100 users can tell you if what you're seeing looks comparable to what they've been experiencing.
Jemore Santos December 18th, 2005, 07:45 AM Barry have a look
http://www.sakproductions.net/chroma.html
Give me your verdict, Settings WB temp was on 5600, blacks and everything else was on standard, see if you look at the third pic, the camera tilts down yeah, well that green spot you see on the second pic is now now pink on the third.
Have you seen worse? or is this the average?
Thanks for this Barry
Diogo Athouguia December 18th, 2005, 08:40 AM Avoid using full opened iris, you'll notice a big difference in CA without losing much light. Those CA from your camera are similar to the ones I have on mine when iris is fully opened. I read somewhere that there are no CA with the other lens.
Diogo Athouguia December 18th, 2005, 08:49 AM I found where I read it:
http://www.dvinfo.net/conf/showthread.php?t=53148
Jemore Santos December 18th, 2005, 09:00 AM so how open can we have the iris at?
Is yours worse or better?
I guess we will have to live with it, wonder if the XL-h1 has any CA
Diogo Athouguia December 18th, 2005, 09:28 AM Keep it somewhere between opened and 1.4. You'll see the difference on the VF, just point it to a white wall.
I think mine is not better or worse, it has that pink tone when iris is fully opened. Xl-h1 also have some CAs, but not so many. It may have better glass, but I prefer working with a manual focus one. As Barry said, it's a limitation of a cheap HD lens.
Jemore Santos December 18th, 2005, 09:51 AM Hey Diogo thanks for that dude, I hope and pray that fujinon will release another lens for this camera priced between the 16 times and the 13 times widescreen, I remember someone on this forum speaking to a rep for fujinon and they were saying they will release one, If its goin to cost about 2 or 3 grand it might be worth it.
Diogo Athouguia December 18th, 2005, 10:07 AM Lets wait and see. Keep us posted if that iris trick worked for you.
Tim Dashwood December 18th, 2005, 10:27 AM This is something beyond the typical form of CA. It looks like the top half has a 'purple haze' and the bottom is green. That's not right!
What type of lighting? Flourescent, Halogen, etc?
Jemore Santos December 18th, 2005, 10:50 AM This was shot at an exhibition centre "tokyo big dome" it was for the biggest art festival in asia, funny enough my panny 3chip cam had no sign of colour disfiguration and it was a cheap cam, so I'm guessing it's not the lighting but just for trivia what lights would an exhibition centre have?
Tim by the way, I have finally installed your recipes in my memory card for the JVC will try it soon. Thanks for that, and just for the record I shot a wedding piece but my iris wasn't fully opened and I saw very little or no CA at all. Hmmmm, What do you reckon Tim, call JVC tomorrow?
Diogo Athouguia December 18th, 2005, 06:23 PM Well seen Tim. I didn't notice the green area, I was looking at the 'purple haze' because it looks like my camera's CA. No such green like that on mine.
Jari Pakkanen December 20th, 2005, 04:02 AM Hello
My first post here :)
Some examples of my HD101E camera and CA
http://www.ideavideo.fi/pic/harakat_hdv.jpg
And one wmvhd video (60MB)
http://194.100.194.44/hdv_test1.wmv
Jari
Barry Green December 20th, 2005, 05:50 AM That's really, really bad. One of the worst examples I've seen.
Was that shot at full telephoto?
Jari Pakkanen December 20th, 2005, 06:12 AM Yes, open iris and full zoom.
I couldnt renew situation, JVC sent me another HDV100 to test.
Video is shot f4 and almost full zoom. (720P25)
Jari
Diogo Athouguia December 20th, 2005, 06:29 AM Did you test it already? Better or worse than the other one?
Rich Everitt January 16th, 2006, 10:15 AM Hi there! New here...
Just wondering what you are seeing in the file. I do not have a trained eye and cannot see what you all do.
Mike Marriage January 16th, 2006, 11:32 AM Hi there! New here...
Just wondering what you are seeing in the file. I do not have a trained eye and cannot see what you all do.
Look for the purple and green fringing, especially around high contrast areas. It's like riding a bike, once you know it, you will ALWAYS see it.
Those first grabs are particularly bad. The whole picture has a green/purple gradient over it and there is some serious ghosting too. The ghosting could be due to the CCDs though (or was "motion smoothing on?).
Rich Everitt January 16th, 2006, 04:11 PM Oh yes I saw that right away! I was wondering about JARI's. I was thinking that Barry Green was responding to his posted file... My bad!
Mike Marriage January 16th, 2006, 04:57 PM Oh yes I saw that right away! I was wondering about JARI's. I was thinking that Barry Green was responding to his posted file... My bad!
On Jari's, look at the purple fringe around the white wood work of the hut.
Jemore Santos January 17th, 2006, 05:36 AM mike motion smooth was on.
Mike Marriage January 17th, 2006, 06:49 AM mike motion smooth was on.
Ah, do you think that is what is causing the double image?
Scott Anderson January 17th, 2006, 03:16 PM Jari's .wmv is a good example of "traditional" CA. The green fringing in one direction, magenta fringing in the other. Look at the bright highlights on the guitar frets, and the first wine glass shot, where the doily is out of focus.
As for Jemore's problem, I can't see this as being due to CA. I've never seen that type of color shift over an entire image. Could this be some sort of mis-alignment of the prism, causing some sort of internal reflections to one or more of the CCD's? Or, more likely some element of the lens out of whack causing this shift over the whole image? If it only becomes pronounced at telephoto, the lens is more likely the culprit.
If you bring Jemore's 1st and 3rd images into Photoshop, then look at the red, green and blue channels independently, it looks as if the problem is not isolated to a single CCD, as it might be if it were a prism problem. The CA in shot 3 (the out of focus element behind her shoulder) looks pretty standard, but the color shift on the wall in shot 1 is not typical at all.
Michael Maier January 18th, 2006, 09:35 AM As already said, CA can be greatly avoided by not shooting wide open or full telephoto. Combining both of course is signing your death sentence.
But all lenses in this price range of under $10,000 will exhibit some form of CA, so that’s not the end of the world.
If you can’t afford the 13x, the only way is to learn how to work around it. But look at it from the bright side, at least you have a fully manual broadcast style lens with a full HD resolution camera and all that for under $6,000. If you look at it that way, it’s not a bad deal at all now, is it?
|
|