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December 22nd, 2008, 10:39 AM | #16 |
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From what I've seen the EX lens seems no worse than even some of the mid-range HD lenses. In fact, I use the Canon HJ40 a fair bit, but only recently did some tests and blew them up in FCP and the Chromatic Abberation was as bad or worse than I've ever seen!
David, it could actually be that he might need to open up a bit, as it would start to soften below about f8, and as for CA changing the aperture shouldn't make any difference. Steve |
December 22nd, 2008, 11:09 AM | #17 |
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Michael,
If you're not happy, sell it. Life is to short for banging your head on this stuff. You can get decent $$ for that camera. You just bought it two months ago. I own the EX1. Someone would have to take a crowbar to me to get it out of my hands! The image quality is excellent. You showed two bad frames. We've all shot bad footage regardless of the camera. Has it ever shot anything that looked good enough? If you answer no or question this, don't waste your time. Sell it! |
December 22nd, 2008, 12:19 PM | #18 | |
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Quote:
As for CA, Actually, it does. Most fringing happens at wide open. I use a lot of still lenses (f1.2-1.4) wide open and i recognize the symptoms :) From his pics, its seems like its shot wide open rather than almost closed as diffraction usually occurs across the frame and not only on the sides like his seem to be. But then again, i could be wrong as to the settings so I may stand corrected. |
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December 22nd, 2008, 12:43 PM | #19 |
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I'm sure I read an optics paper that showed that the aperture had no effect on Translateral CA (colour fringing), perhaps the reason you notice it more at wide stops is that the more out of focus something is the wider the fringing will apear.
Steve |
December 22nd, 2008, 02:51 PM | #20 |
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Michael,
The camera has to go back to Sony in Sydney and there is only one 'authorised' service centre for the EX cameras. Were those images taken when the camera was static? How close were you to the post? Perhaps the camera/lens combo needs to be re aligned. There is an option in the maintenance menu (non user access, so don't go looking for it) The camera should be lined up on a resolution chart and once activated, the alignment can take up to a minute. This may help your situation. I had to have this done with my XS lens/camera combo (which I ended up have done in Melbourne) and it fixed all of the lens issues. Are you using the standard lens or an XS or HS half inch HD lens? I can't remember the name of the (Sydney) service centre, sorry but it is not Sony themselves that carries out the EX servicing.
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David Issko Edit 1 Video Productions |
December 22nd, 2008, 02:52 PM | #21 |
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Hmm. I'm pretty sure it does. When I stop down, it disappears for whatever reason it may be. But hey. I only use lenses. I don't make them and these are only my experiences.
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December 22nd, 2008, 03:42 PM | #22 |
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The appearance of CA is affected by the iris. At least that was what i was told by a Canon engineer. This may well be related to what Steve was saying. Ie it is more noticeable due to various factors rather than 'actually' being increased or decreased. But since lens engineering goes over my head I'd probably be better qualified not to comment :-)
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December 22nd, 2008, 05:20 PM | #23 |
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Hi
Thankyou for taking a look. This is not an example of skew, it's not a pan. All I was doing was focussing in on the cloths line and zooming in and out. Not fast, not slow. However, I wrote this post at 0100 in the morning and may have reversed what was going on, ie. as I zoom out the post bends to the left and then at full zoom, it bends to right. For mine, I could possibly accept a consistent bend, be it right or left, but it makes it look like it's a rubber post in real time. The dealer issue is a bit difficult as Adelaides's population is about 1 million, as far as I know we only have one "Professional" type dealer here, there is "Sony Central", but it's more geared up for Vaio's, walkmans, still cameras etc I will begin ringing Sony in Sydney and Adelaide and will start annoying them about where the camera is. Cheers Michael |
December 22nd, 2008, 05:25 PM | #24 |
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I'd have thought you could still get skew when zooming as the frame is still changing.
Steve |
December 23rd, 2008, 02:23 AM | #25 |
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December 23rd, 2008, 02:48 PM | #26 |
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Michael,
The problem you see here is strictly optical, it has nothing to do with skewing or the rolling shutter effect as others have said. When you're at full wide, you'll see barrel distortion, which makes the image seem to bulge from center. At around Z20, the distortion changes to pincushion, which is the opposite. This is normal. I have the EX1 and just confirmed the same distortion you have. Just about every lower cost lens has this distortion if you look for it, although some are worse than others. For example, my Z1 has prominent barrel distortion at full wide, but doesn't pincushion as much halfway. The easiest way to see this is to shoot a brick or hollow tile wall, staying perpendicular to it at all times. Slowly zoom in and out, and you'll see the lines seemingly bend at the edges and corners of your screen. This is perfectly normal. |
December 23rd, 2008, 03:12 PM | #27 |
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I would tend to agree with Warren. Even with still photography zoom lenses with a long focal range you will get barrel distortion when wide and pin cushion when fully zoomed. That's why my wife always stands in the middle of the picture when there is a group shot. Ha! The folks on the edge tend to get a little weight gain. This is one reason why for best optical performance photographers prefer prime lenses over zooms. The convenience of a zoom comes at a cost. It's just physics at work.
The better the glass in a zoom lens (which is much more expensive and typically much heavier), the less the effect. For my footage I find the distortion acceptable. I don't think your typical viewer will notice it like you would, especially if the zoom is slow. Obviously to minimize the effect you can try and avoid vertical objects on the lens edge as much as you can, or minimize the zoom focal lengths in those situations. I think the glass is quite good so I don't think you'll find a comparable camera at this price range with a stock lens any better (assuming equal focal zoom lengths). |
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