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700u still scratching my head

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Alan Hotchkiss
700u still scratching my head
on Mar 16, 2010 at 7:32:44 pm

My brand new GY-HM700u is still giving me weird RGB color shifting in the contrast areas, such as outlines of buildings, tree tops, traffic signs, etc. I can see a faint color shadow next to both vertical and horizontal lines. Kind of like the old 3-tube days. Also, I'm getting a yellowish hugh generated in the blown out luminance areas, like a blown out sky, instead of a nice clean white. Is this a known problem with the 700? I know I've posted this before and got one response with someons having this problem too, but wanted to see if more are seeing this.


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Paolo Ciccone
Re: 700u still scratching my head
on Mar 16, 2010 at 8:27:44 pm

I don't have that camera but it is a direct successor of the HD100 which I have. This problem sounds like too much sharpening, which is often an issue with the factory config.
Have you checked the detail settings? At what level do you have it?

--
Paolo Ciccone
Pret-A-3D
http://www.preta3d.com
http://www.paolociccone.com


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Alan Hotchkiss
Re: 700u still scratching my head
on Mar 16, 2010 at 9:28:47 pm

Its set at normal.


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Paolo Ciccone
Re: 700u still scratching my head
on Mar 16, 2010 at 9:37:06 pm

OK, if that is like the HD-100 then normal is a misnomer, it's usually several notches above normal. On the HD-100 the details settings has a range of +- 10, that is from -10 to +10 with "normal" being in the middle. I usually keep it at -9 or MIN. Check the range on that parameter and if it goes negative then move it to "MIN", shoot some test and see if it makes a difference.
Just FYI, the "Detail" circuit is the plague of many cameras. The factory defaults lead to think that the camera shoots blurry images unless they are sharpened. In reality that is not the case. As long as your focus is correct the images will be perfectly sharp. What the so-called detail circuit does is to artificially darken the areas of high contrast, something that you can do easily in you NLE if you desire that kind of edge "enhancement".

Give it a try and let us know.


--
Paolo Ciccone
Pret-A-3D
http://www.preta3d.com
http://www.paolociccone.com


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Alan Hotchkiss
Re: 700u still scratching my head
on Mar 16, 2010 at 9:59:20 pm

All sounds reasonable. I'll give it a try Paolo. thanks!


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Ryan Mast
Re: 700u still scratching my head
on Mar 17, 2010 at 5:48:26 pm

The color fringing is probably chromatic aberration, exacerbated by the detail setting. Can you post images?

--
Meteor Tower Films
Video creations for music, art, & theater.
http://meteortower.com/


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Alan Hotchkiss
Re: 700u still scratching my head
on Mar 17, 2010 at 8:00:13 pm


Here's the hard evidence, even after putting my detail setting to minimum. Interestingly, I swapped out the Canon lens that shipped with the 700 with a lesser quality Fuji lens that shipped with our JVC GYHD200 and the fringing was still there, but slightly less pronounced! Hmmm. We also use prime lenses on our 700 ad there is no chromatic aberration present in that footage. Unless there's something we're missing, sounds like either a more expensive lens might do the trick or I'll be living with this.


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Ryan Mast
Re: 700u still scratching my head
on Mar 17, 2010 at 8:06:12 pm

Yeah dude, that's definitely chromatic aberration. It's a result of inexpensive glass. Which Fujinon lens did you try on it? Is it the 18x?

What primes are you using on the 700? With the CA13U, I presume?

--
Meteor Tower Films
Video creations for music, art, & theater.
http://meteortower.com/


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Paolo Ciccone
Re: 700u still scratching my head
on Mar 17, 2010 at 8:07:04 pm

Alan, sorry to ask but, from your example, I'm not clear what the issue is. The photo is out of focus and badly overexposed in the top left corner, with the result that the street lights are "eroded", which is normal in this situation.
Also, since you're swapping lenses, have you checked your backfocus?


--
Paolo Ciccone
Pret-A-3D
http://www.preta3d.com
http://www.paolociccone.com


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Alan Hotchkiss
Re: 700u still scratching my head
on Mar 17, 2010 at 8:27:54 pm

Not the clearest example I realize Paolo, but I deliberately shot this rather unpretty scene blown out to enhance the aberration on the pole in the upper left hand of the frame. I just needed something down and dirty to show. Although you can't tell with this pic, the back focus is fine, but the image goes soft with the ND filter. This has always been a problem I've noticed with these JVC cameras. I hate using the built in ND filter, but I'm often forced to without lens filters.


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Lou Caputo
Re: 700u still scratching my head
on Mar 25, 2010 at 9:04:54 pm

Which lens are you using?


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Alan Hotchkiss
Re: 700u still scratching my head
on Mar 25, 2010 at 9:26:54 pm

Canon KT 14X4.4 KRSI. the one they're selling with the camera.


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Lou Caputo
Re: 700u still scratching my head
on Mar 25, 2010 at 9:39:07 pm

Hmmm, that must be something new then. I have two GY-HM700's and both have the 17X Fujinon lens on them. I can tell you that we haven't had that problem with our lenses...


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