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About Lwang

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  1. They sell the ones with the brass bolt snaps, which is what I use on my compact setup (except mine has a clip instead of magnetic clasp). I put the split ring over the ball onto its neck before putting the ball clamp on, thus it comes on and off relatively easily.
  2. I thought you bought the Meikon dome correcting lens? But what I see on the lens caddy is a Dome lens Unit II. Did you not try the Meikon dome?
  3. I had a stainless steel fishing line leader attached to a zip tie that was wrapped around the lens as tether. I was always afraid it would drop while the cable was somehow wrapped around the fiber optic cable and slice it through if I drop the lens. Then I made some floats that wraps all around the lens, thus making underwater re-attachment pretty much impossible given the float blocks all view of the mating area of the thread. For the new RX100 setup, I didn't use the float because the reattachment of the lens requirement underwater, but left the tether off. I meant I wanted to change the shutter speed since in re-taking a picture, I did not want to change the f-stop, which will cause the strobe to have to throw more light, possibily causing underexposure or the foreground subject becoming more bluish if the strobes maxed out in its light output capability. If I increase the shutter speed, only the background gets darker. Jumping to S mode to change shutter speed would likely not work since I shoot mostly in MR mode, and MR 1 is pre-configured for shooting wide w/strobe under M. If I jump to S and then to M, it would not have any of my settings in MR 1 (iso, metering mode, etc). MR 2 is shooting w/o strobe w/manual WB, higher ISO, Shutter priority, etc, and MR 3 macro w/strobe. So I either have to commit into memory how to change the front ring's mode from STD to Aperture so I don't forget about it when not touching that feature for many months, or get rid of MR 3's macro mode (a useless mode anyway, probably will just carry another P&S and use it to shoot macro with its built in flash..and put it on a pole so I can stick it into holes and get video that the big rig cannot get into) and have it similar to MR 1, but it will be in S instead of M, so as to let the camera's metering adjust settings so it exposes surface/sunball on par with forground exposure.
  4. With some strobes that has +/-EV settings in TTL, you can theoretically decrease the camera's internal flash power and still get a proper exposure. If you set your camera's TTL flash power to -3EV and your strobe to +3EV, the camera will send a pulse of flash 1/8 the duration of a proper exposure when taking the picture, but the external strobe will make that pulse 8X longer, thus properly exposing the subject again.
  5. you can't shoot TTL with shutter speeds faster than your camera's sync speed. Any shutter speed above that, the shutter curtain is not fully open when the strobe fires off (usually with duration in the thousandth or a sec). The fact it works in manual is probably a fluke since when doing a full dump of the strobe, the duration is a maybe 1/200 sec. So if you have your shutter speed set to something like 1/800 sec, your shutter curtain will open one quarter of the way before the rear curtain starts closing, and 3/800 sec later, the rear curtain closes. So for that whole duration of the shutter traveling across the filmplane, the subject was lit up by the strobe's 1/200 sec burst of light. If you turn down the intensity in manual mode, you will likely get cutoffs of light like your picture above.
  6. For doing snapshots, a YS-01 or even YS-03 would probably do. But if want to take more serious photographs, like lighting up something the size of a person, it would be much better if you get a wet lens and maybe a wet dome lens. Since with a regular camera's 28mm lens, you would have to be pretty far away for the subject the size of a person to fit within the frame, and you would need a couple of very powerful strobe to provide enough light to overcome ambient light. But if you had a wet lens or wet dome lens, you would probably only have to be a 2-4 feet from the subject, allowing you to use a strobe like the YS-01 to provide enough light. I was doing shots of my buddy swimming past a coral head with a dome lens and I had to keep telling my buddy to keep swimming closer in order for her to become part of the subject. I was looking at the viewfinder so I did not know where she was in relation to my camera but she was wondering why I wanted her to swim within a few feet of the camera.
  7. I went on a dive trip with the plastic housing. The lack of holes is quite a hassle. Having to unscrew the lens to let water in, then trying to mate the threads together in order to screw it back on could be a challenge sometimes. I actually dropped my dome lens and it fell 15 ft or so, luckily to a sandy bottom. I stopped having my lens on a leash since I never dropped my lens before, but now I will probably have to start using it again. Plus, I have to constantly screw the lens back and forth since that's what it takes to squeeze the excess water through the threads. The best method is probably to fill it with water in the camera tank before you go down, but if the camera is out of the tank too long, one never knows if any water leaked out of the gap and one ends up unscrewing the lens again while underwater. If the dive environment is a bit inhospitable, unscrewing/screwing the lens might be a bit harder. Plus the lack of rear dial, I could not figure out how to change the aperture in manual mode, thus on my upward shots, the sky/sunball were a bit too bright. Maybe I should just set it in shutter priority since that's how I had it on my old camera and the surface/sunball were less overexposed. Or I just have to get move dives with the camera, but then I only use some of these weird features when the camera is the housing, which is when on dive trips, thus I frequently forget how its done.
  8. Interesting. You also have to take account of the gap being filled with water instead of air, thus causing more magnification, thus less vignetting. Not sure how much of that would be true since in my last camera setup, I had no vignetting so that was never an issue. Here is how the lens fits on the RX100's plastic housing: You can see that the lens sits much further back probably 7-8mm from the rear of the glass port (at 28mm, when zoomed to 33mm (or 12mm, as picture specs indicates)), it is maybe a mm or 2 further back. It seems that Meikon was on a learning process in their design of housings, with the earlier housing the least thought out in terms of design and lacking the most features. Strangely, the beveled recess of that lens port mates perfectly with the UWL-100 28AD's rear lens protrusion. I did some measurements of the type 2 vs the bayonet mount depth and if I put a type 2 mount on the 28AD, the 2 lenses could mate almost perfectly once it is screwed down, avoiding the vignetting from the UWL-100, and being a much smaller lens. I tried to do the swap, but my screwdriver stripped and didn't want to do harm to the screws, so I will be using the UWL-100 for the upcoming trip.
  9. What I meant with all the gibberish above is that a camera with a 24mm lens zoomed in to remove the vignetting will not get you a wider angle of view than one with 35mm, nor should a housing with the lens butted right up to the housing's port. The only inconvenience is that one has to slight zoom in from the widest setting.
  10. From the little experiments I did, it doesn't seem to be how close the lens sits to the housing that is the only factor to whether it vignettes or not. It seems to be also based on the rear lens diameter of the wet lens and how big an image it can project to the camera's lens. I have a UWL-100 w/dome and no matter how close I bring that lens to the RX100's 28mm lens, it will vignettes (it looks like it is dome port or front of wet lens vignetting). Pulling it outward, maybe up to 10cm does not change the vignetting much, and zooming in to get rid of the vignetting does not affect the angle of view compared with the lens butting together. I put the same UWL-100 w/dome onto my old Oly c5050 w/35mm lens, the angle of view with the 2 lenses butted together is only a tiny bit wider than when the above lens setup when they are 10mm apart. I also tried a UWL-100 28AD, which has a smaller rear llens, with the RX100 and it goes from no vignette to vignetting before I could pull the lens 10mm away from each other, thus requiring zooming in and incurring a lost on angle of view. It was similar but slightly less so with the c5050. I had a panny w/24mm, and effect is similar to above scenarios. So in effect, zooming in slighly (from 28mm to 32mm) doesn't always cause you to lose 10% of your angle of view. Result could be different if I took the dome lens off, and I do in fact lose angle of view when the lens are farther away and I have to zoom in, but then if this test was performed underwater, the angle of view would be narrower and vignetting by the dome might become irrelevent, and water between the 2 lens more or less makes it an optical coupler, decreasing the angle of view of the camera's own lens, thus reducing vignetting. All you have to do is set your memory recall mode for it to zoom in just enough so it doesn't vignette.
  11. Did you try this dry diopter underwater? As a wet lens? I would think it being a achromatic double lens, water seeping into places becomes an issue, especially between the space between the lenses. I would think a single lens, even with its inferior image quality, would last longer as a wet lens.
  12. You probably should disassemble the dome and verify that the rubber gasket is installed right, as per the 2nd video. Good thing the thread is metal. Although from some video I saw, the sound it made while they were mating the threads sounded like plastic, though that could be the resonance of the hollowness of the dome unit. The metal thread is one part I am relieved about. I thought the thread was plastic based on the review here: http://www.dpreview.com/articles/7362232450/meikon-underwater-housing-for-sony-dsc-rx100-review/3 Given that I had a circular float on my last housing in which I had to thread the wet lens blindsighted and alot of the initial turns were just to get the threads to meet up. A plastic thread would have surely caused them to strip, especially if it has to be re-done underwater due to it not having venting holes for the air to escape. Plus having an extra heavy wet lens with a dome port on it, the rough handling of cameras when you hand it over to a crew when getting onboard is always a concern.
  13. From all the videos, they pick the dome by the sunshade with 2 fingers, making it look weightless. From video like this, they have a plastic protective film on the dome, which they only do on plastic items: Also, on this video, the person said it is arcrylic: Not sure if dome unit's thread is plastic or metal, which would likely affect its long term reliability, especially given that they recommend the port to be re-attached while underwater, where merging of the thread is alot harder. Maybe the light weight allows it to be neutrally buyoant, unlike all the glass ones. Officially launched? I was waiting for it for forever, and because I have an upcoming trip coming up real soon, couldn't wait any longer. I do kind of feel screwed that the RX100 housing is one of the first housing they made, given the lack of features. I see newer plastic models having access to the control dial, double o-ring and internal water sensor. I thought people said they if they are in M and can only control the aperture, they quickly jump to Shutter priority mode in order to change the Shutter speed, and jump back to M again. Less buttons to press than changing the function of the front ring. My fiber optic plug barely squeezes into the flash adapter port, even before the o-ring touches the hole. Maybe you got one with larger diamter adapter ports? Looking more closely at the camera's lens in relation to the port. The lens, instead of sitting flush to the lens port, is roughly 6-7mm behind it. This is likely why lenses like the UWL-100 vignettes. They could have easily avoided that issue by making the port glass sit more flush with the camera's lens. Maybe they are still learning on how to design these things for uses beyond the casual P&S divers.
  14. I got the camera a while ago, but have barely used it. since I didn't have a housing for it and I either use DSLR or camera phone for photos, depending on situation. So I haven't got to realize what the advantages of the rear wheel are (except for being able to adjust the shutter/aperature in manual mode). Which dome did you get? The Meikon plastic dome? If so, a wet lens would have probably been a better solution since they are glass and have a 0.6x magnification factor, while the dome just corrects for water's 33% magnification effect, which effectively makes it an 0.75x lens. As for that dome, I am not sure why they made it so big. I think they could have made a 3 or 4" dome and it would be much more compact.
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