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March 18th, 2004, 03:54 AM | #61 |
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Speaking of barrell distortion....
The Raynox HD5000 at full wide has quie a bit of barrell distortion but I can live with that. I guess, but don't know for sure, that all or most .5 WA lens will have significant barrell distortion ? |
March 18th, 2004, 03:58 AM | #62 |
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Barrel distortion is caused by poor engineering, I suspect.
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March 18th, 2004, 05:54 AM | #63 |
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No Frank, barrel distortion is caused by using spherical elements (ie lenses cut out of a sphere). They may well be beautifully engineered - as the Century 0.3x bayonet-on converter is, but they barrel distort because spherical elements are a LOT cheaper and easier to make than the aspheric (ie non-spherical) type.
If you go here Adam: http://www.fortvir.net/index.php and click on tom's photos, you'll get to see the damaging effects of barrel distortion vs the non-distorted (and very wide) views you can get with an aspheric. Lots of perspective distortion (good), but zero barrel distortion (bad). Dave Largent - how dare you! :-) The lens hood is the lightest, cheapest, easiest way to better your picture quality, period. Super-duper multi-coating helps, but stopping non-image forming light from hitting your front element in the first place is the way to go. tom. |
March 18th, 2004, 06:28 AM | #64 |
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Tom,
I see what you mean about the distortion and the spherical / aspherical. Wow, that Aspheron is massive. |
March 22nd, 2004, 02:03 PM | #65 |
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Can someone explain to me how the lens ratings work for cameras. Specifically, when I see wide angle lenses marked as 0.66x, 0.5x, or 0.56, which one is wider? (I'm from the photo side of things.)
I'm looking to get the widest lens I can get. I don't care how it performs under zoom. It will be used on my newly acquired 953 mounted on a sportbike, to capture action. I'm looking for a wide angle lens to capture the sensation of speed, as well as body position of the rider. |
March 22nd, 2004, 02:36 PM | #66 | |
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Quote:
Here's a good link about distortion: http://www.ferrario.com/ruether/vid_...htm#distortion |
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March 22nd, 2004, 09:22 PM | #67 |
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Witold,
The smaller the number, the wider the lens...for example, .5x is wider that .6x. You can get a .3x fisheye but it will really look weird on a sport bike. I'd suggest nothing wider than .45x. |
March 23rd, 2004, 12:47 AM | #68 |
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Thanks, Guy. I'm sort of trying to figure these things out. It's rather puzzling to me that the lenses for cameras are not measured in the same fashion as camera lenses. I'm sure there's a good reason for that, however.
I decided to go with Raynox HD-5000PRO, and plan to place my order tomorrow. I would've liked to purchase from Adorama or B&H, but one is out of stock, and the other is surprisingly overpriced. Instead, I will try my luck with bugeyedigital.com, as they are selling this lens for $90, and have good reseller ratings. (http://www.bugeyedigital.com/product_main/ray-hd5000pro.html) Once I get some footage, I will try to post some screenshots and maybe a short clip. This thread is most enlightening. |
March 23rd, 2004, 02:27 AM | #69 |
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At 5 pages long we could have it published as a book Witold. Converter lenses for camcorders are just that: they convert the focal length of the zoom to which they're attached. So a 6 to 72mm zoom will be converted to a 3 to 36mm zoom if you multiply its focal lengths by 0.5X. Simple, huh?
As to your bike shots, I'd say go for the wildest, widest converter you can get your hands on. Don't necessarily worry about vignetted frame corners either - you're after an impression of speed and excitement, and lens aberations shouldn't enter your head. You can also use some converter lenses on your still (film) camera. The Raynox 6600 PRO worked pretty well on my 28mm lensed Canon. Generally if you have a fixed lens on your camera your only option is to add a converter (wide or telephoto) if you want to see something different. I'm with you Frank, coming to movies from stills meant I was aghast at the barrel distortion the wide folk seemd to happily accept. Of course I'd used a full frame fisheye on 35mm, but I'd specially chosen that for the wild effect, and of course (being a Minolta Rokkor) it was beautifully engineered. :-) tom. |
March 23rd, 2004, 03:03 AM | #70 |
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Another one here. Stills to vid. Really wanted that stills
24mm WA, but went with the 28mm instead, due to concerns with barrel distortion. Same when I crossed to video. Everyone recommended the Canon 58mm as being fine for the VX, with the notation that there was some minor barrel distortion. So I spent more for the Optex. |
March 23rd, 2004, 03:06 AM | #71 |
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I used to shoot 16mm as well, but I never knew anything about them except with operating them and splicing film. Ugh.
I was mostly into Nikons, Leicas and old German rangefinders, but my first camera was a cheap Kodak, about 44 years ago. :-)) Oh, and I had one of those Yashica large format cameras. Can't recall the model #. Oh (again), I had a Yashica SLR and some Zeiss lenses for it, along with a few Yashica lenses. I really loved that cam. |
March 23rd, 2004, 03:36 AM | #72 |
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I mostly did Canon. I wanted, but couldn't
afford, a Minolta XKE, if anyone remembers that. Man, the accessories for that. "Backs" -- 200 exposures or something like that. Grips. Drives. Half dozen different finders. And *black*. And heavy. I hear the Minolta electronics haven't held up over the years. The XKE was Minolta's F1, if anyone still knows what that is. That Yashica. Is that the one that looked like an oversized 35mm. I wanted that one, too. |
March 23rd, 2004, 05:14 AM | #73 |
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The Yashica 35mm I had was the first semi-auto that took Zeiss lenses. The large format was, well, large.
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