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Everything posted by herbko

  1. Steve, I tried to replicate your ISO 800, +4 exposure shot with lens cap on and got a very boring image. No features at all except a couple of slightly hot pixels. I think you need to send your camera in. Also, I've pushed up the dark parts of some of sunballs shots I've posted earlier by probably more than 2 stops using curves and didn't see anything near as bad as your dolphin tails.
  2. The 300D / Digital Rebel has an EF-S mount. The more ancient 10D was the last 1.6x camera to have an EF mount.
  3. This is terrible. I know Kawika. He's extremely knowledgeable and helpful. A great diver and photographer also.
  4. That's new. I was there in Aug 06 and my passport has added pages, and they stamped those pages. No problems. These are pages added by the state department and looks just like the other pages, not pieces of paper I duct taped to the back.
  5. It's not necessary to renew. You can send it in and have more pages added. Do it a couple of months before departure date.
  6. Has it been around long enough to have housings? A quick check of the Ikelite site show an availability date of March, and they are usually the quickest.
  7. Nice shots Clinton. Love the rays. I'd be really jealous if it wasn't a very nice weekend up in the mountains also.
  8. The biggest impact will be wide angle lenses. You'll lose 10% coverage on the fisheye. 14mm will look like ~16mm and 16mm will look like ~18mm.
  9. No need to look elsewhere for examples of putting high frame rates to good use. Here's one of the best examples very close to home: http://www.echeng.com/journal/2006/07/12/g...each-false-bay/ More frames = better chances of catching that shark in the perfect pose. There is no substitute.
  10. Most of the lenses we've been using were designed for film cameras. I don't see what the lens resolution and distortions have to do with the discussion on dynamic range and sunballs. Better dynamic range than what? Have you used a Canon 5D? As I mentioned earlier, I think the 5D images are limited by the 12-bit A/D. It would look better with more quantization levels at the dark end. Canon claims to have preserved that with the reduction in the size of the photosites. Of course this claim can't be verified until the cameras are out.
  11. I think we've had a similar thread awhile back and found that some prefer heavy and some prefer neutral. I find my Aquatica 5D macro setup too heavy and plan to try adding flotation similar to James' setup. It's very simple to add weight and a pain to increase buoyancy. If you're in the process of buying parts for a system and are not sure what you prefer. I think it's best to try to make it as buoyant as possible.
  12. Nice chart. That's what I've been trying to say.
  13. 14-bit A/D does no good if the sensor it's sampling does not have enough dynamic range. I thought that was clear from my last message. I think you developed your rule from using sensors with insufficient dynamic range.
  14. It's often necessary to underexpose to keep from blowing out a sunball. The rest of the pic can be brought back up to a proper exposure at post processing. A low noise sensor gives you the good signal-to-noise necessary to push the underexposed water and subject a couple of stops and still not be noisy. The limit in the 5D in this process is not the noise of the sensor but quantization of the dark parts when brighten 2+ stops. Going from a 12-bit to a 14-bit A/D will make this quantization/banding problem much better. In summary, it takes a high dynamic range sensor (large charge bucket and low noise) and fine quantization levels(more bits).
  15. Here's my guess at what the high contrast mode does: 1. meter exposure at ISO 200 setting 2. process the sensor output at ISO 100 3. apply a tone curve to bring the mid tones and shadows back up to ISO 200 This has the net effect of reducing blown highlights at the expense of more noise and banding at the mid tones and shadows. Since the sensor has very low noise to start and now has a 14-bit A/D, the higher noise probably will not be noticed. The two extra bits will give smooth tones to the under exposed and pushed up parts. This essentially the technique for getting a good sunball. The dynamic range of the sensor is (maximum signal captured before clipping)/(noise level). The new 14-bit A/D does not change that. It just divides the signal into more levels and let you brighten the underexposed regions more and still have smooth tones.
  16. I think this is targeted towards the PJ's, especially the ones covering sports. Those making a living with a camera can work out the dollars and sense of the $4k price for their own business. For those who's got this expensive hobby, it cost less than a D2Xs.
  17. Here's a link to the official propaganda http://www.robgalbraith.com/public_files/C...White_Paper.pdf The auto focus is disabled in the live view mode. Lost in the all the attention on the 1DIII is the new 16-35mm lens which they claim to " ... specifically designed for improved peripheral image quality in wide-angle shots...".
  18. It's on dpreview: http://www.dpreview.com/news/0702/07022208...os1dmarkiii.asp Some of the early speculations about this being full frame is wrong. It's 1.3x cropped. It looks like they up the speed and resolution by ~ 20%. They also put in 14-bit image processing, the one feature that I was looking for. Hope that'll be in all their future high end cameras including the 5D replacement, when they get around to it. Oh Yea, and live view!
  19. Knowing Micro$oft, it's no doubt rigged up to launch these when you plug in something with photos on it. The real question is, who in their right mind would use a new OS from them before service pack 2.
  20. Not quite. Noise in the shadow is dominated by the output amp. Taking one large pixel and split it in two and recombine the outputs afterwards will increase noise by about ~1.4x compared to the original. Looks like Canon is giving you a choice. There's no reason at all to get the new 1Ds if you prefer 12M pixel over 22M pixel.
  21. That may be true; however, there are lenses that can resolve better than that in their sweet spots. So the small increase in resolution from ~17M to 22M may be an improvement for some. At 22M pixels it's still not as dense as the D2x sensor which would be 28M pixels if it's expanded to FF. I agree about the bit depth. The FF sensors really can use a 14bit to 16bit A/D converter. If these leaks are true, I suspect the new 1D will be far more popular than the new 1Ds.
  22. It's less than a month from the PMA gathering and leaks like this one are beginning to surface. http://www.imx.nl/photosite/comments/c031.html Looks like the new 1D will have a FF sensor with the same resolution of the 5D, very fast and ISO 6400 and an 1.3x cropped mode for $4500. The new 1Ds will have 22M pixels.
  23. I suppose it is hard to find underwater photos to fit the subject "drinking". Happy birthday. Beautiful shots as usual.
  24. Hi Fred, I was not disputing your conclusions about loss of resolution with magnification, and your example is probably technically correct. The reason that moving the lens twice the distance from image plane halves the resolution is that the aperture is moved twice as far away. The lens is stopped downed two stops, and the diffraction fringes are twice as big. If you open that up 2 stops you'll get back the resolution but your depth of field will be much worst. You're right that my example of focusing at 10m is not that good either. Please let us know your findings. From what I learned about optics in the classroom, at small enough aperture, ~ F/22 for film and sensors like the ones in the Canon 5D and 1DsII, you'll be diffraction limited and better glass won't help much. I really like to see a careful test of this.
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