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Lwang

Member Since 20 Sep 2012
Offline Last Active Nov 24 2012 01:37 PM
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Posts I've Made

In Topic: Sony Rx100 Housing Choice

24 November 2012 - 01:36 PM

Thanks that was a good explanation! What are the actual exit diameters of the Inon UWL-100 variants? I have a S&S lens made for 24mm equivalent that may work then with the RX100.

Further to the optics discusion. What hapens to the effective aperture of the lens combination? I suppose it is the same as the original lens or is it atually a larger aperture (lower f-number)?


The exit aperture would be roughly the diameter of the rear element of the wet lens, at close distance. And what your camera's lens sees is its diameter and the distance to the rear of the wet lens.

The wet lens works almost like binoculars, which doesn't focus the subject into an image, but changes its magnification factor, and your eyes, acts like the camera & lens. The eyepiece lens of the binocular has to be bigger than the pupil or else you have problem seeing a full image. When using it at night, your iris dialates and the effective pupil diamter is larger, making it harder to see the whole image unobstructed. Also if you pull your eyes farther away from the eyepiece, the problem gets worse, and you see a smaller diamter of the image (as in vignetting).

As for light gathering capability, it should not negatively impact. But on some tests, they said it is 'dimmer'? I guess it is pretty easy to test.

In Topic: RX100 - strobe recycle time

24 November 2012 - 01:26 PM

Do you think this A-S gun and brush can help me make my housing more dust free ?... I mean the sealing area where the o-ring is.
I currently use UV lamp to spot fine contamination from cloth and sometime our dried skin !!!
UV lamp is sooooooo good to use.


There were brushes that had p01iu^^ at the base of the brush, which constantly shoots out alpha rays, which attaches to excess electrons and neutralizes static on whatever particles they are on.

So how do you lower RX100 strobe power? Do you dial down the fash exposure compensation i suppose, how low can you make it and what's the recycle time then?

In optical TTL mode, one possibly to lower camera's internal flash power is to dial the flash exposure compensation on the camera and dial up exposure compensation on the strobe, so at the end, they balance each outher out. Although not all external strobes has that feature.

In Topic: YS-01 Dead? Video!

24 November 2012 - 01:16 PM

gone back to sea&sea or the original seller?

In Topic: RX100 - strobe recycle time

20 November 2012 - 08:34 PM

SPP,

interesting results. Although I don't know if the Inon is doing any brainwork here. It is more or less like a giant optical repeater. If your camera has really bad TTL metering, then even with a Z240/sTTL or YS-D1 and its latests DS-TTL, it will not improve your picture (maybe it would, by allowing bounce/indirect lighting capability, but that is another topic).

Shooting at 1/2000 sec would allow the background to stay dark in your picture, but then it limits your camera's max flash duration to 1/2000 sec (maybe its max duration is already less than 1/2000 sec). I don't know what the max duration of strobes like the Z240 or YS-D1 are, but I remember some of my big land strobe had a duration of 1/500 sec. The main point is that the advertised GN of the strobes might be limited by how long the max flash duration is on your camera. If you got a little toy one that has a max flash duration of 1/8000 sec, and another camera that has max flash duration of 1/1000 sec. When you hook up the Z240 to either of them, the setup with the latter camera could power the Z240 to 2 stops brighter. This is one of those spec that is mentioned in camera's built in flash or external UW strobes, so there is no definitive answer.

I use to have one of those static remover for records (zerostat) when I was a kid, and I can zap people unspspectly. It use to also wreak havoc on electronic equipment, thus I would play pranks on people playing those arcade games and I would just point it at a metal bolt or nut and pull the trigger. The game would go nuts, sometimes reset and other times the screen would flip upside down, they would flip out, not knowing what was happening and have to continue while the screen is completely distorted.

In Topic: Sony Rx100 Housing Choice

20 November 2012 - 08:16 PM

Wow, don't you think that is rather waste of money if maximum wide angle is what you are after.
I just read about ur lens, it is actually for 35mm yah ?
http://www.inon.jp/p...ens/lineup.html

Holy cow, so many variations and Inon should code it more obviously differentt. Inon seems to love to use description which if 1 digit or alphabet is missed, we could end up buying the wrong product.
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You are not really wasting of money, since these wet lenses are not converting a 24mm lens by 0.6 and turning it to a 15mm lens (both 35mm equiv). The way they work is that they create a smaller image of a certain exit diameter, and the way they specify it, a UWL-100 would allow a camera with 7mm lens a certain distance from the wet lens be able to see 100 deg field of view. If your camera just so happens to have a 5mm lens of the exact same spec, you will not be seeing images of 140 deg field of view, but instead will see the edge of the lens, which is often referred to as vignetting. So you zoom in the lens until the field of view from the zoom lens covers exactly the exit diamter of the wet lens.

Inon produced variations of these lens because some have a wider exit diameter, allowing a 28mm lens to capture the 100 deg image, or the camera does not have internal zooming, causing the zoom lens to be a bit farther away from the wet lens, thus the zoom lens sees a smaller image, which includes the edge of the wet lens (vignetting). That's why they tell you to zoom in a little.