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Bevanj

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Posts posted by Bevanj


  1. Hi everyone,

    Just wondering what everyone's thoughts on this are. I'm currently shooting with a 5D MK3 in a Nauticam housing usually using a Sigma 15mm  fisheye lens. 

    Right now, I'm trying to decide which way to go -  I can upgrade my camera body to something else (A7R4 tempts me), or I could buy a WACP? 

    Right now, I'm very much tempted by the autofocus system and dynamic range of the Sony, but at the same time I know full well that putting that camera behind a dome port will have serious limitations on the quality of image it can produce.  This makes me tempted to go and get myself a WACP for use on my 5DIII. I already have a mint Canon 28-80mm 3.5-5.6 MKV that I scored for <$25USD specifically for if I chose to buy one. 

    With the WACP, I'm guessing it also follows the above water rule of that glass is more important than the camera behind it. If I was to buy a WACP, I'm guessing that the value retention is going to be far far better than a new camera and housing which seem to depreciate sharply. 

    I gather the WACP is a brick to travel with, but I can live with that. 

    Also, does anyone know if the front element on the WACP is replaceable if it gets scratched? 

    Thoughts?
    Bevan 


  2. Hi All, 

    Have any of you got the forementioned dome port handy and a set of veriners (or a ruler at a push)? 

    I've just scored a Sigma 12-24mm F4 on the cheap in hope that it will fit. However, I don't have my port handy. 

    Unlike most of their other ports, Nauticam don't seem to have the opening diameter listed for this port. Hopefully it'll fit. The lens is 102mm in diameter. 

    If anyone could check the port opening diameter, it would be much appreciated. 

    Bevan 


  3. Hi Everyone, 

    I've just been having a play around with my RX100VA, and 7d, along with my Z330 strobes (via optical connection), and have come across a puzzling problem. 

    In STTL mode, no matter what I do, I can't get any FEC control via the EV control knob on the back of the strobe! All exposures come out identical! 

    It would seem that in EV comp, the Z330s are cutting or adding output on the preflash pulse as well as the main pulse. So, the camera gets less return from preflash pulse, aims for +-0EV flash compensation (where the camera is set), then compensates for the Z330s diminished output - thereby nullifying the FEC set on the back of the strobe. This is confirmed if I put a sekonic light meter in front of the strobe, and hit the flash exposure lock on the 7d to produce a preflash. The Z330 EV control knob is 100% having an effect on preflash strength. 

    I've tried the strobes with both the preflash magnet in and out. No difference. 

    Any ideas?! I'm starting to wonder if my strobes have a bug. I've only ever used them in manual mode before now. I know they were from pretty early off the production line. 

    Bevan


  4. Hi Kraken,

    I could do... let me give it some thought. It took me quite a while to design and tune the circuit for optimum performance.

    Also, all of the components are only available in tiny packages like SOT-23 which there is pretty much no way to use without hot air soldering and custom designed PCBs.

    In short, it is some schmitt inverters, logic gates, and an RC circuit to control the time length the LEDs turn on for when triggered.

    I've got the Canon E-TTL protocol completely worked out now, and can get a Attiny chip to read the communication (MOSI/CLK) from a 5dmk3 to a 580EX2 speedlight and give the correct output responses (MISO) - proving my modeling of the protocol is correct. It is incredibly similar to the SPI protocol, but I have had to do some trick work to get it to function correctly with the Attiny chip.

    I've also tested this protocol model with other Canon cameras my family own such as a 7Dmk1, 20d and G12 - it successfully works for all of them. Now I just need to design a circuit board to fit in my housing...

    Bevan


  5. Ok, Z330 0.1T numbers - these I am sure are correct. Wolfgang, light output is not linear relative to time. Have a look at the PDF, you'll see what I mean.

    Some interesting reading...
    https://strobist.blogspot.com/2010/06/rise-and-fall-of-machines-understanding.html

    -6.0 = 37us = ~1/27000
    -5.5 = 47us = ~1/21000
    -5.0 = 57us = ~1/17500
    -4.5 = 67us = ~1/15000
    -4.0 = 84us = ~1/11800
    -3.5 = 105us = ~1/9500
    -3.0 = 137us = ~1/7250
    -2.5 = 179us = ~1/5600
    -2.0 = 230us = ~1/4300
    -1.5 = 312us = ~1/3200

    -1.0 = 421us = ~1/2400

    -0.5 = 577us = ~1/1750
    Full = 2.06ms = ~1/480



    Some interesting stuff to be read from this - especially for those shooting mirrorless or point&shoot... If you are cranking up your shutter speed to 1/500 and above, at full power, you are starting to cut into the flash output and loose light in that way. For the rest of us shooting through an actual shutter maxing out at 1/200 sync speed, it's not so much of a concern.

    Z330 T.1 output.pdf

    • Like 2

  6. Yep. Pretty sure they're correct. For example, here's a scope plot for @ -6.0. The photodiode saturates, so I can't take 0.1T measurements where the duration is specified as on the rise at 10% of maximum brightness right through to falling at 10% of maximum brightness.

    I guess I could put the photodiode a larger distance away from the flash...

    Bevan

    post-67761-0-96403200-1543619467_thumb.jpg


  7. I got bored and have just been doing some testing on my Z330s with an oscilloscope and some photodiodes. If anyone is interested, and as curious as me... here's a rough table of the flash durations of the Z330! They're not T.1 measurements, but are pretty close.

     

    FULL = 3300us = 0.0033sec

    -0.5 = 680us = 0.000680sec

    -1.0 = 534us = 0.000534sec

    -1.5 = 430us = 0.000430sec

    -2.0 = 348us = 0.000348sec

    -2.5 = 300us = 0.000300sec

    -3.0 = 257us = 0.000257sec

    -3.5 = 221us = 0.000221sec

    -4.0 = 186us = 0.000186sec

    -4.5 = 165us = 0.000165sec

    -5.0 = 130us = 0.000130sec

    -5.5 = 110us = 0.000110sec

    -6.0 = 97us = 0.000097sec

    For an interesting comparison of output power.... with the standard -0.3 soft diffuser in place, the Z330 somewhere between -2 and -1.5 (348us-430us) settings puts out the same amount of light as a 580EXII on full power (5600us!) with the wide angle 14mm diffuser flipped down. Impressive! The colour temperature is very different too - but that is to be expected. :)

    Bevan

    • Like 1

  8. I should point out that if you are wanting to use this LED trigger (or any LED trigger for that matter), you NEED high quality multi strand fiber cables. Single strand wont allow enough light transmission to trigger strobes.

     

    With a bright flash from a cameras intetnal flash tube, you can get away with higher losses in the fibre from single strand cables and still have enough light left at the far end to trigger a strobe.

     

    With a relayively weaker pulse from an LED, the cables need to be as efficient at passing light from one end to the other as possible.

     

    Personally, I'm using the howshot brand multicore ones.

     

    Bevan


  9. Well,

    I changed the design. Now, no matter how long you've got the shutter open for, the LEDs will pulse ~2 milliseconds regardless, instead of staying on for the entire shutter duration. It also has incredibly low current draw when in storage still. The result is that the batteries should last over a hundred years in storage, or over a million shots. I suspect the batteries will corrode before they go flat.

    I can still make them for $45USD. Right now I've got 3 assembled and sitting in front of me.

     

    Cheers,
    Bevan

    I've also got another design in the works which should fit housings with a smaller prism area.

    post-67761-0-45166900-1542841552_thumb.jpg

    post-67761-0-76662200-1542841560_thumb.jpg


  10. Hi Emilio

     

    I’d suggest wiping your house out with a mix of white vinegar and water 1:1. This should remove the mould.

     

    Leave it open to dry thoroughly. Retreat if necessary.

    Retreat if necessary? Is that if the mold fights back or multiplies with the application of vinegar and water? :D


  11. Kraken,
    I meant the OEM Nauticam Nikon hot shoe cable that links it with a tiny round connector to their OEM Nikonos connectors. That new fancy TTL board which they come with is different.
    The one I was meaning for a continuity check looks like this...
    https://www.backscatter.com/Nauticam-Nikon-Hotshoe-Plug-to-Single-Nikonos-Conn

    Scubaslr,
    I take it that is the NA-7D MK1? You could ask a Nauticam dealer if those tiny integrated prisms are removable?

    Bevan


  12. Scubaslr,

    Yes, the prism is removed from my housing. I've attached some photos of it. It's a piece of cake to remove - 3 hex screws, and comes out in two pieces - there's the prism, and a prism mount.

    One screw holds the prism onto the prism mount, and it has some feet that latch in at the top. The prism mount is held onto the aluminium housing by 2 screws.

    For anyone else going the DIY route - the screws are M3.

    Hope it helps.

    Bevan

    post-67761-0-04473300-1539117685_thumb.jpg

    post-67761-0-44357300-1539117809_thumb.jpg

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