Jump to content

herbko

Member
  • Content Count

    2128
  • Joined

  • Last visited

Everything posted by herbko

  1. If you believe the 105mm macro can achieve 12M pixel in a 1.5x crop, 24M on a FF shouldn't be a problem except perhaps at the corners. The 12M pixel 1.5x crop sensor has smaller photosite spacing which places greater requirements on the lens as your lens designer friend has pointed out. Here a good test report of the Canon 100mm on a FF http://www.slrgear.com/reviews/showproduct...duct/157/cat/10 You can probably also get that resolution with a fisheye lens.
  2. If the D3x is 24M pixels FF as most are forecasting, there's very little downside to using it versus the D300. Think of the 24M pixel FF sensor as having a 10.7M 1.5x sensor built in. Nikon will probably have a crop mode that will give you just that, but even if they don't you can always do it in PP. The obvious advantages are: You may at some point want 24M pixel. If you are happy with 10M pixel resolution you can digital zoom, your 105mm lens effectively becomes a 105 - 157mm zoom. It's actually probably easier to do this with a larger sensor than building a good 105 -157 macro zoom. The less obvious are: As Craig mention earlier in this thread, the larger sensor will give an advantage in the trade off between DOF and resolution versus the smaller sensor. Better signal-to-noise and dynamic range. At least more room to trade resolution for dynamic range. Shallow DOF if you shoot wide open. This is probably not often done underwater.
  3. I've had some fun and games with similar schemes. There are a couple of basic problems. One is that depending on the position of the strobes, you may be triggered by reflected light and underwater you may not get enough reflected light from your subject. The other is that under bright conditions the slave sensor may be saturated by the background light and is not sensitive to the trigger. I found the scheme to work pretty well in dark temperate waters and not very reliable in bright tropical conditions on wide angle shots. Test your system outdoor in day light and see what you get.
  4. DNG is here to stay. I don't think Adobe will abandon it any time in the foreseeable future. That would really hurt their credibility. As long as Adobe remains a player in the imaging business the format will be supported. I'm not converting any of my Canon raw files to DNG. I don't see any advantages in doing so. There are far more raw converters for the Canon files than DNG, and I can alway do crw -> dng if I come across one that doesn't support crw. I am not loosing sleep over the possiblility that I'll see the day that Canon raw files won't be supported. The problem with DNG is that the biggest generators of raw files, Canon and Nikon, are unlikely to have native support for it. The result is that there are far more Canon and Nikon raw files than dng files and that will be the case as long as Canon and Nikon cameras do not have dng outputs. Third party software will generally have the best support for the most common format, so I expect the Canon format to always be better supported than dng. I think the smart people at Canon and Nikon knows this and are unlikely to offer dng outputs in the foreseeable future for this and other reasons. The bottom line is that I can alway do crw -> dng and not the other way. I see no reason to limit my choices.
  5. Like Larry said, bait. Nice shot Laz.
  6. Look at the dpreview lens test of the 12-60 at 50mm, F/11 and F/16. Diffraction is basic physics. The 50mm F/2 won't do much better. Did you think that Olympus just did a poor job on this $900 lens. On a 10M pixel camera all 4/3 lenses will be the limiting factor at apertures smaller than F/8.
  7. The dpreview lens tests show this clearly. The sharpness of the Olympus lenses drops rapidly at F/16. Diffraction limit their usefully range ( if you want good resolution ) to around F/11. To properly compare 35mm lenses and 4/3 lenses you have to factor in the 2 stops in the diffraction limited resolution.
  8. I thought you prefer 1.5x cameras. Why bother with this FF nonsense.
  9. I haven't flooded one, but did notice that the yellow O-ring will stretch over time, no doubt from rubbing against the cap. If you keep grease on it and replace it every couple hundred dives, I think the risk of flood should be very small.
  10. I would also add to the list 6" dome port smaller auto focus only macro port
  11. In practice, resolution of macro photos are often diffraction limited by the small apertures used to get large depth-of-field and all good macro lenses of a given sensor size format will do about as well. I don't think any brand can gain an advantage in resolution of macro lenses. Larger sensors have a slight advantage over smaller sensors. I've only shot 1.6x crop and 35mm DSLR's, and have not made enough big prints from either to really have much of a feel of how big the difference is in practice. The motivation for my last post is just to put in context the often seen claim that Olympus has the sharpest optics around which in itself is not incorrect. However, it seems to me those who repeat these claims always leave out the simple fact that because a 4/3 sensor is half the width of a 35mm sensor, the 4/3 lens has to be twice as sharp to get the same resolution in the final image. Again in practice, most people will be happy with the resolution of any of the current systems, but I would disagree with those who recommends Olympus over others on the basis of sharper lenses.
  12. It is true that the Olympus 50mm F/2 macro does resolve more lines/mm than 35mm macro lenses in that range which makes the claim that it's the sharpest optics around technically correct. However, that measure does not take into account the difference in sensor size. To capture the same details on a 4/3 sensor the as a 35mm sensor an Olympus lens has to resolve 2x the number lines/mm as a 35mm lens. In other words it has to be twice as sharp for the system to stay even. Taken as an overall package the Olympus system with that 50mm lens is not be best one for capturing the most detail.
  13. That's one way to make an impact. My first guess was NW, but upon closer inspection I think Cor is right.
  14. You're right about not needing those buttons underwater. However, I think it's likely that they'll end up moving quite a few things around to make room for the larger LCD and put in live view. I wouldn't say a magnified VF is a need. I'm fortunate to still have close to 20/20 vision. However, I wouldn't trade mine for all the new 5D II features on that list.
  15. It's very unlikely that it'll fit without modifications. I don't think they can put in a 3" LCD in place of the current 2.5" LCD without at least moving some buttons around.
  16. It another name they use for the elite class that jcclink asked about, between Economy and Business. http://www.evaair.com/html/b2c/english/tip...eluxe_class.htm For my last SFO -> Bali -> SFO trip, I think it was ~$1500 vs ~$1100 for Economy with all the fees and taxes added in.
  17. My first choice in flights to Asia is EVA Evergreen class, a nice big roomy seat for a little more over Economy class. I've used them for 4 trips to Thailand and Bali without any problems. The food is only fair, certainly not up to business class standards, but everything else is very good.
  18. I don't think you're giving sharks enough credit. The crew of the Shearwater have noticed that the reef sharks will show up whether they chum or not. They, the crew, think that the sharks have been trained to associate the sound of the Shearwater's motor with food. On my trip we saw many sharks on the one dive where we did not chum. Of course I don't have a baseline for the number that usually show up at that reef. Someone should go and dive there off a sail boat and see if there are differences.
  19. It's usable but hover color is still white and makes it hard to read against the light blue. An even worst problem is the sub menus are not offset enough from the main drop down which makes selecting the next item on the main drop down difficult. You have to put the cursor almost against the left edge to be off the sub menu.
  20. I'm using Win XP home. It works on Firefox 2.0.0.12 and Opera 9.25 but not on the old IE 6.0
  21. The reality is that underwater is a very small fraction of the DSLR market. The rest of the camera buying public wants the latest and greatest technology when they shop for a camera and don't care much about minor differences in body shape and control locations. The camera makers will probably continue to replace their products with new models every couple of years driven by competition if nothing else. The problem this creates for underwater photography is that a 2 year product cycle leaves no time to refine housing designs. Since I'm new at this and never owned a refined film housing, I don't know what I've been missing, but I can't imagine this is a big impediment to photography. We can choose to get off the upgrade cycle any time. I'm with Steve. I'm don't plan to replace my 3 years old Canon 5D in the foreseeable future.
  22. It's probably 2 different A/D converters, 12 bit and 14 bit. You can't get 13 bits out of the 12 bit converter, and unless it's designed for it, you can't clock the 14-bit converter faster. Agreed. That does not look believable to me. Wonder why dpreview hasn't reviewed the D300 yet.
  23. The higher resolution 14-bit A/D will not increase dynamic range which is still the ratio of the maximum signal level and noise level of the sensor. It will make better use of that dynamic range. Craig and I went over this awhile ago here: http://wetpixel.com/forums/index.php?s=&am...st&p=138797
  24. I frequently use the 500D with the 100mm macro. It works very well. The 500D is a +2 diopter and will limit focus to 1/2 meter or closer.
×
×
  • Create New...