chromatic aberation

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

Quote:

Originally Posted by Rich Everitt

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

Quote:

Originally Posted by Rich Everitt

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

Quote:

Originally Posted by Jemore Santos

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?

January 17th, 2006, 05:36 AM	#23
Jemore Santos Major Player Join Date: Oct 2005 Location: Tokyo/Sydney Posts: 297	mike motion smooth was on. __________________ "eyes through a digital world"

December 20th, 2005, 05:50 AM	#16
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	That's really, really bad. One of the worst examples I've seen. Was that shot at full telephoto?

December 20th, 2005, 06:12 AM	#17
Jari Pakkanen Tourist Join Date: Dec 2005 Location: Finland Posts: 3	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

December 20th, 2005, 06:29 AM	#18
Diogo Athouguia Major Player Join Date: May 2005 Location: Portugal Posts: 282	Did you test it already? Better or worse than the other one?

January 16th, 2006, 10:15 AM	#19
Rich Everitt New Boot Join Date: Jan 2006 Location: Denver Posts: 12	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.

January 16th, 2006, 04:11 PM	#21
Rich Everitt New Boot Join Date: Jan 2006 Location: Denver Posts: 12	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!

January 17th, 2006, 03:16 PM	#25
Scott Anderson Major Player Join Date: May 2003 Location: Phoenix, AZ Posts: 327	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.

January 18th, 2006, 09:35 AM	#26
Michael Maier Trustee Join Date: Apr 2005 Posts: 1,269	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?