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Interceptor121

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Everything posted by Interceptor121

  1. Xacti is 24 Mbps at 60 fps that is quite a lot however it does not have optical stabiliser which is the baseline issue of that camera, you do need a gyroscope before you can go and do software technique Any software stabilisation either done in camera or in editing crops the picture, what I meant in the blog is that by using the steady shot active mode you can do it in camera. I would not expect to stabilise the clips further in editing again as this would introduce a warping effect as the various algorithms try to make sense of the footage I would not capture footage at 720p but always at the highest resolution so that the cropping still results in a fairly defined image I guess all is relative however if you dive in low light a lens with F3.5 is not going to help and noise will creep in as the camera pumps the ISO up like it happens in your lost blue hole bahamas video, however if all you do is diving in the caribbean or warm atlantic maybe that is fine too Your videos look good and it seems that the key ingredient of buoyancy control is there, I think you will do fine with the RX100 but is going to be difficult to extrapolate without directly testing A question though why do you leave all the bubble noise? Is it intentional or what?
  2. I calculate the focal length multiplier through the ratio between chip diagonal and 35mm diagonal it is a standard formula in camera optics. The 2mm space does not change but due to water magnification is like zooming in and therefore loosing field of view as if the lens was more extended than it really is. This is pretty crystal to me am not sure why it isn't to you but maybe you can have a word with Inon yourself to be more happy also cameras underwater website is quite helpful
  3. Those two cameras you mention HX30V and HX9V are high zoom camera with very slow lens that are not going to be better than the xacti for video except the stabilisation The RX100 is a camera with a small zoom high picture quality and good lens I don't see the comparison really
  4. My purpose is not to compare the RX100 to another camera but to check if it is better to have standard or active steady shot I have done the walking test and the active mode is definitely worth it If I manage I will do some tests in the pool with the zoom
  5. The quality of the image will depend on how close the back of the lens is to the port. If you get hold of a Nauticam housing it is worth trying
  6. The lost field of view compared to air depends on the water between the port and the back of the wet lens. Say that in air that distance is 2mm once you put it with water that becomes 2*1.339=2.678 As the camera has a focal multiplier of 2.7 is like you zoomed in additional 1.83 mm at 35mm equivalent so you are now at 30mm before hitting the lens and not anymore 28mm as you were in air. This explains why you still loose some field of view End of the lesson!
  7. There is indeed an equation that you can apply to calculate the relationship between the distance between your strobes and the distance of the subject You need to know the angle of coverage of your strobes which is given by the manufacturer This equation assumes you point the strobes straight forward and that they are in line with the port the distance between the strobes in your case is 2.85 the subject distance So if your arms plus clamps are 14" each and the tray is 12" the total is 40" and you can get 14" close to a subject. To go further away you need longer arms as the strobes need to be behind the port
  8. So the lens field of view in air is 179 degrees with a dome added and in water it comes to 144.8. If the dome was meant to keep that fov where are have the 34.2 degrees been lost? Coverage underwater with dome lens is less than coverage in air because water filling the space between the housing port and the UWL-100 rear element increases the effective focal length of the camera lens
  9. Wow must have been quite an effort to empty the pool and fill up again to test? XD
  10. I am good with the considerations around the zoom but you can't assume that putting a sealed dome on a wet-lens give you the air field of view regardless of the zoom as that stays the same and is well inside the housing What creates the difference is that thin layer of water that will still have diffraction. In order to have the same field of view in air you would need to seal it For what concerns field of view and vignetting the consideration is the size of the lens in front of the camera and the distance between the front lens and the glass at the required zoom setting. The RX100 at the widest setting is actually at the same distance from the glass than in telephoto so it is an ideal condition not to vignette at 28MM in fact I am pretty sure that the UWL100 28AD will not vignette and that the UWL100 will stop vignetting pretty soon around 32mm. I have this camera so I can tell you that is the case and you can check it At 35mm the difference in the distance lens port is only another 1.5mm I am going into the pool this wednesday and I will test both lenses I have from the tests on land I can tell you the behaviour is the same of the Canon S95 that is a 28mm equivalent with a 1/1.7 sensor on my tests on land Although the best quality is probably with the UWL-H100 that require no zoom the RX100 with the right adapter can probably work with any Inon wide lens For video specifically when you use the active steady shot there is some sensor cropping and an equivalent length of 33mm, I bet it does not vignette at all with an UWL100 at the widest zoom
  11. I am sure I can re-use my AD lenses, even with the image quality of the UWL-H100 is better than my old UWL-105AD I will stick with this latter as it is only 142grams in water against the 332grams of the LD lens
  12. In the sanyo is best case Menu-set-set-menu and can be more if you have lights and go from auto to Custom Still a 100% increase of steps in the best case is far from exciting
  13. The SONY RX100 does offer better quality video than our Xacti, mainly because the Xacti has a 1/2.5" sensor that gets further cropped to 1/3" in video. I have found a way around for the file format as you can see in the blog and to be honest the same issue was with the xacti too, I shot at 60 fps only to reconvert to 30fps as I want to watch the clips on the appletv not on the computer. Also things are not as fast as they look underwater and when I was comparing some scenes I could not really see any benefits in 60 fps mode unless I have to slow it down in editing I am a firm believer that compact camera will kill low end camcorders and high end video equipment will be only for professional. Right now former video operators are switching to SLR because of superior quality. I think the RX100 will be just fine I am going through the learning process on land before taking the camera in water, this weekend I could not go diving as it was very dark and my second sola had not arrived I did not want to have the incomplete set up to test I am confident that the RX100 will give me the best video currently on the market with a human size housing once I get through the niggles and annoyances, just stay tuned I am in the pool this wednesday to play with wide angle and fisheye lenses stay tuned
  14. I hope you find this useful http://interceptor121.wordpress.com/2012/10/28/sony-rx100-tips-for-uw-video-part-3-setting-custom-white-balance/
  15. OK we are not connecting here maybe my example was not the best but you should get the point anyway There is a layer of water between the port and the wide angle lens. The lens remains a wet lens, you can reduce that layer but still there is water in between so you can't consider the lens as if it was enclosed with the camera in a dome. So you can't extrapolate field of view as you did as that will not be correct
  16. I don't think you can and am not convinced by the explanation of lwang It is not the flat port that magnifies is the water so that thin layer of water between the back of the lens and the port does something, although little but it does have an effect You can take the lens in a swimming pool and put it close to your mask you see that as it gets close things get better but it is never going to be exaclty the same as if you had the whole of the lens inside the mask If the dome was restoring the field of view in total Inon would declare 179 not 144.8 I guess Either way 144.8 is plenty of fov equivalent to a 7mm behind a dome and is border line of what you can light up with two strobes I would not be concerned too much
  17. Hope you guys find it useful... http://interceptor12...r-dial-buttons/
  18. The dome is sealed but the lens remains wet as there is still a air-water-glass-air boundary on the back So even if you have a dome on the lens, the lens itslef remains a wet lens and you can't do the same calculations as the interface between the port and the back of the lens still needs to be accounted for. You can't interpolate that as the lens on land is 179 it will stay like that in water because the combination of camera and lens is not behind a dome. Besides the 179 referer to the lens without dome, the dome itself has no purpose on land. Also once you put the dome the lens performance on land deteriorates so you can't really use it Am not sure if this is clear to you but maybe you can have a look at flat port theory?
  19. Good tip the AEL For UW video you exactly need exposure lock...
  20. Because Adobe Premier Pro costs £810 and Vegas Pro similar. I actually pay for software don't get it illegally as some people do How much did vegas cost you?
  21. Stay tuned as I will come up with the best workarounds in the blog...still Sony has to put hands to a firmware update there is plenty that can be improved
  22. The memory mode is a combination of modes you could use the various settings to jump from one to another keeping at least the mode dial still is painful Setting the custom white balance in video mode is not possible on the RX100 you need to go to a camera mode and come back to use it In general those basic features AF lock, exposure lock, custom white balance are easy to access on cameras worth 150$. It is a shame that in video mode program shutter or aperture mode the RX100 does not use either the front ring or the shutter to bring those functions easily to life The excuse this is more a camera are poor, camcorders are disappearing, compact camera eat into that segment and sony knows it otherwise would have not come up with all the other features for video
  23. This is a wet lens not a sealed dome. The back of the lens still remains wet so you can't just estrapolate as if it was a fisheye behind a dome port
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