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Tom_Kline

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Everything posted by Tom_Kline

  1. 7 + 5 = 12 ??? Could you elaborate on 'macro focusing and protection ring'? Does this narrow the beam and increase the GN? Thanks Tom
  2. Thanks for the added info. I did not think they rounded up empty Coke bottles to melt down to use as optical glass! However, it would nice to know how they compared in design to others on the market, which includes achromats. You description makes it sound like the manual setting is infinitely variable. I think Steve Frink may have a replacement for you snoot. I was actually more concern about travel weight but UW is important too . Tom
  3. Alex, I presume you are referring to section 6.3.2. He does not explicitly state that the 'correcting lens', (top of p. 155) is a diopter, but it might be implied from the previous page where he states: ' A converging lens (of about 1/(4R) diopter *) can be added to the camera lens for correction purposes', ???? The asterisk refers to a footnote with a neat formula. However, I cannot find any reference that states that curvature of field produced by a diopter is determined soley by its diopter. In fact Kingslake (in 2 different books) implies that diopter field curvature is a variable, determined by how flat the diopter is. This would suggest that optimal results would come from a custom made diopter lens for a given port and lens combination. Tom B)
  4. This is typical of large domes - large airspace with little metal and glass inside. To balance the effect Hasselblad put a second dome on the rear end of their EL housing so it balances very well. I do know of anyone else who has done this. Tom
  5. Not so sure of this myself being a MAChead, an upgrade will be needed for Aperture. I do not think my 2-year old G4 1.33 GHz is going to cut it even with the RAM maxed out at 2G. Tom
  6. Out as in prototype or out as available for sale? Sounds like a few folks there might be taking a short holiday in December. <_<
  7. The Hasselblad booklet on UWP showed something like what James' described. These are sold frequently on the bay. Be aware that there will be some pincushion distortion with a flat port but it may an acceptable amount given that the lens probably has some distortion too. It would be smart to do tests in a tiled pool. Assess the test pix for distortion using the squares. B) Tom
  8. With a dSLR there is not reason to do a suite of tests to make sure on the controls are operational before entering the water and test firing the strobe too if attached. Just delete the shots after the test. If everything is functioning then UW conditions are preventing AF function. IMHO the D70 AF is marginal. Nevertheless many on this board have shown that this camera can perform very well underwater, maybe not as well in poor conditions. I would not try it here in AK waters, it is tough enough here to AF with it topside! Tom
  9. Any specs on the wet diopters? Are they achromats, etc. ? To the strobe: 123 manual settings!!! Can someone elaborate? 120 degrees is pretty wide-angle and accounts for the low GN for the w-s of output. I would assume a meter-based GN. It would be way cool if the flashtube could be focused into a narrower beam ala Subsea MK150. This could make the GN go way up. How much does this puppy weigh! On land as well as in the sea! <_< Tom
  10. I have never forked over the cash for Langford though I am in my 4th decade of accumulating photo books. I have at least 50 on UW Photo. <_< My UWP bible is In-Water Photography by Mertens 1970 published by Wiley - I have used it to answer questions on this forum. There are a number of other very handy UWP books too. However I find myself consulting instruction manuals the most these days!!!!! Unfortunately they are not always comprehensive enough. I was totally stumped by the need to re-calibrate the battery of my D2H while overseas but could not find the instructions in the pdf of the manual. The calibration light came on when I charged the battery but the cam always gave me the same need to calibrate message after charging. I figured it out when I got home when I saw a somewhat oblique instruction in Moose Petersen's D2H book (I also looked up ALL the pages indexed for battery trying to find out!!! ). Of course it was very easy to do, just not obvious for an old-time analogger!!!
  11. I do not recall if it was google or not as this was a few years ago. I also saw Wetpixel mentioned in a magazine. Did not pay much attention to Wetpixel for some time as it seemed to focus on P&S cams whereas I have been generally an interchangeable lens cam fan, for decades. Did lurk for a quite a while before signing up and again before contributing. B) Far better GUI than the other UWP sites, especially an SLR fan!! I have been a long-timer on the UWphoto email group. However, I have been quiet there now for a number of years.
  12. Rest assured, camera companies will come up with new reasons to buy more of their product! It may not be MP in the future, DR may become the new litmus test, just not as easy to quantify. One must assess ones needs and whether what they have fulfills them given costs etc. If the upgrade consists of re-cycling the same body as Canon and Nikon have done with certain bodies, then one can update while retaining their UW housing. The older cam makes a good BU or cam for topside use etc. B) Tom
  13. Failure rate. Wire synch cords are rather prone to failure - make sure to always travel with spares. Fiber optics could potentially be more reliable and possible for user replacement by snipping off a length of FO from a bulk roll with a sharp instrument. No need for electrical pass through of housing too. Since FO uses light, the housing synch connection literally can become a port. Tom
  14. One can remove current camera CF cards with no problem from SEACAMs. The battery, however, requires camera removal! Tom
  15. They can attain lengths exceeding 0.5 meter!
  16. I hope this one is OK optically as I agree it could be an OK all-purpose topside lens with VR, and WA to tele covered. The main plus, however, is that one would not have to swap lenses, which could be a good way to prevent spray from getting inside the camera where it could find its way to the sensor. Tom
  17. I seem to recall (maybe from my undergraduate days) that the stalk is able use peristaltic action to dig itself into the sediment. Tom
  18. One needs to factor in the difficulty of housing these lenses. Wide-angle zooms are particularly difficult to place behind a dome port because the entrance pupil moves as the lens is zoomed. So take these 'topside' tests with a grain of salt in terms what you can expect to get underwater. B) Tom
  19. Check out the SEACAM S45 and S180 viewfinders, they are second to none IMHO! Tom
  20. I botched doing the link above. Too many open windows!!! So I have re-attached the straight FE shot (i.e., not de-fished) for comparison with the two above. Tom
  21. Here is de-fish #2 using the option available in version 4.3.2 of Nikon Capture. It retains more of the fisheye coverage when rectilinearized and may better illustrate the difference between FE and rectilinear. Note that version #1 is a tight crop of the middle of version #2. Tom
  22. http://wetpixel.com/forums/index.php?act=P...02&f=18&t=10261 The above link is to a 10.5 mm FE pic I posted here earlier this year. I have de-fished it using both Nikon Capture options. #1 is the normal de-fish that retains a rectangular frame.
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