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Algwyn

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Algwyn last won the day on October 24 2019

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About Algwyn

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    Moray Eel

Profile Information

  • Gender
    Male
  • Location
    Paris

Additional Info

  • Show Country Flag:
    France
  • Camera Model & Brand
    Nikon D7500
  • Camera Housing
    Easydive Leo 3
  • Strobe/Lighting Model & Brand
    Subal SN800, Sea&Sea YS-D2, Retra Strobe

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  1. Hi, I have shot film underwater when I started doing scuba diving, about 25 years ago. It was a totally different experience, and underwater the limitations of film photography are a huge impediment: you're limited to a film roll of 36 exposures. It's obviously impossible to change roll underwater, but also often between two dives (e.g. when you do two dives in a small boat where changing the film roll is not possible). So either you take pictures very parsimoniously or you end up without film at the absolutely worse moment, or both ... it is much more difficult to adjust white balance on film, and the range of adjustment is very limited. I never shot BW film underwater, but there may be other type of challenges with BW that I cannot describe. you cannot change ISO, and the exposure latitude of film is very limited compared to digital. So you will be in many situations where you cannot expose correctly with film, which would have been no issue with digital. you need to wait until the film is developed to see the results. With digital, you can check the result immediately and adjust settings if needed. Shooting underwater often requires a lot of trials and adjustments which is not possible to do with film.
  2. Regarding the cable, this will depend on which flash sockets were installed on the housing that you have purchased. In any case, you may change the sockets to better suit your setup. Most likely it would be 5 pins Nikonos sockets, but to be checked when you receive your housing. (or you may ask your seller) Flash sockets of any type are available for Subal housings http://www.subal.com/c70c20c1/Housings/Accessories/Flash_Sockets.aspx You may also consider using fiber cable connection to trigger the flash. Much easier to use and lighter than the cables. For the arms, this looks like a standard "bayonnet" or "T mount", for which you may get: https://www.carbonarm.com/en/balls-and-terminals/71-starting-bayonet-ball-0806808286574.html https://www.flex-arm.com/en/components/ball-and-adapters/1-inch-ball-with-universal-t-mount-60027bk If your housing hasn't already a leak detector installed, you should get a Leak Sentinel V5 XB.
  3. Do not blind the pygmy seahorse with a burst of flashes! Getting them properly in focus is a challenge, but it is achievable without resorting to such practices which are definitely not good for the creature which is photographed ... Seeking to get a good picture is no excuse for practices which are damaging for the fauna and environment. So instead of bursting 10 fps on macro, learn patience and shooting at the right instant, and accept that you may not always get the picture you dream of.
  4. Well, with the Stix float belt it should work. The float belt covers only 2/3 of the port circumference, so you may orient it to have the velcro on the side of you manual macro focusing knob. And you may end up not needing all the float segments of the belt.
  5. Too expensive, from a manufacturer with too many reliability issues ... Never again will I buy a Sea and Sea strobe. Manufacturing defaults may happens, but in that case, the manufacturer should put in place a repair program. Sea and Sea did not, the cost of repairing one of their strobe was too high to be worth it.
  6. I'm using one, I've had no issue with it so far. It's not "fiddly", quite easy to install. The segments enables you to fine tune the buoyancy if needed. If the velcro strap is too long, you may cut it to the right size. The belt also support the port outside of water: The belt may rotate underwater if the port body is smooth and you do not tighten the velcro strap. But once correctly set, it is holding for a whole trip. As an alternative, you could try the float ring from Flex-arm (other size) If the size does not fit your port, you can buy a rectangle of foam (Flexarm or Carbonarm), and cut it to your port size. But this would be less flexible and versatile than the belt.
  7. For macro? What about using a Stix Float Belt? It would provide the additional buoyancy without changing the arms. It impacts the housing balance, but I find in a positive way, as the macro port tends to be heavier that the body and the belt provide lift just where needed.
  8. @Pavel Kolpakov aren't some of the issues reduced when using on-board flash in "Commander" mode, like on Nikon cameras?
  9. Let's see... It'll probably depend on the success of the D780 ... and we may get a D7800 instead of a D7600!
  10. You may be mistaken on that point. While the D500 has indeed been rumored as not being replaced, this is not the case of the whole APSC DSLR. The D7500 may still be replaced, hopefully in the D780 fashion.
  11. I am afraid that using laboratory test poorly reflects the actual performance of the cameras in real life situation, even less in underwater situations. Imaging Resource warns that these low light AF are only relevant in stationary situations. Indeed, if you are shooting a reef in wide angle, the performance of the autofocus will not be an issue. In the other post, examples were given of situations where camera autofocus is challenged: black water diving: this is perhaps the most challenging. My experience of black water diving is that there is constant movement and very low light. macrophotography: here the issue is not that the subject is moving quickly, but that the depth of field is so shallow that the slightest move (current, etc.) will have a huge impact on the focus juvenile fish portraits: those little devils typically keep moving very fast. Another challenge for autofocus Performance in these real life situations cannot be measured in stationary laboratory tests. In term of difficulty of focusing, I am not sure that shooting a bird in flight is more difficult that focusing on a pigmy seahorse in a wavy sea ... Autofocus is an extremely complex topic, and different test protocols may get very different results. For example a French photo magazine (Chasseur d'Image, excellent publication, really independent minded and thorough test methodology) is using a moving target at 50 km/h and measure the ability of the camera to make shots as the target move from 50 m to 0m. Most modern cameras are able to focus accurately, at 5 to 9 i/s depending on their speed. But as the target gets near, some AF start to fail, as the nearer the target, the greater AF adjustment is needed between two shots. How relevant for our UW photography? Not much probably (more relevant for car racing maybe), but it shows the difficulty to test such complex features as AF. It also shows that thanks to progress, most good modern camera perform well in normal situations. However in UW photography, we are often far from "normal" situations. Therefore I would not draw any conclusions from these tests for UW photography. You are right to highlight the need to know the camera features, and how to select the right parameters depending on shooting conditions. It probably matters much more than the difference of performance between otherwise very good cameras.
  12. I believe that you are missing the point made by @oneyellowtang. There are other sensitivity measures than the main sensor sensitivity. Low light sensitivity of the Autofocus system is one of them. He was referring to the ability of the camera to focus in low light situations, and more generally of the autofocus performance of the various systems. Also, you cannot draw conclusions based on the performance of the camera sensor only. You cannot shoot a picture without a lens. What we need to take into account is the system: camera body + range of lenses available. That's the whole point, the system (camera body + lens) deliver more light to sensor, which results in better image. For a picture where depth of field is not significant, this matters.
  13. The article is interesting, and the theory described interesting. Overall, it is a good idea to debunk "myths". However, I think that some of the conclusions do not reflect actual photography usage, and should therefore be nuanced. If we take the first "myth", you draw conclusions from the theory based on the assumption that the photographer works at constant depth of field. In that situation, indeed there is no difference in signal to noise ratio between large and small sensors. When working at constant aperture, there is a significant difference, as illustrated in the Clarkvision article that you quoted: These two pictures are taken with the same parameters: ISO 400, f/4.5, 1 second exposure. In this situation, the larger sensor gives significantly better results. Depending on the situation, the photographer may have different objectives related to the depth of field (DoP). In some situations, the key will be whether one can shoot at the hyperfocal distance. In others, the objectives will be to minimize or maximize the DoP. Given these other parameters, the smaller sensors may be at disadvantage depending on the objectives of the photographer. So I believe that beyond the theory, your guide should take more into account the type of usage and photography. Your point related to the final output medium is also very relevant. To push the comparison a bit further, for most online media, the small camera sensors found on smartphones are totally sufficient. My own conclusion was that APS-C provides an excellent compromise between the various parameters. But I understand that others may have different needs and objectives and would weight the strengths and weaknesses differently.
  14. Do you then put these cubes in the checked luggage? For carry-on luggage, these cubes add too much weight ...
  15. Have you tried with multi-core fiber optic? From your ealier pictures, it seems that you are using mono-core fiber, which are typically more brittle than multi-core fibers, and therefore break very easily.
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