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ProfF last won the day on July 16

ProfF had the most liked content!

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About ProfF

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  • Birthday October 9

Profile Information

  • Gender
  • Location
    Israel / USA

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  • Camera Model & Brand
    Olympus OM-D EM1
  • Camera Housing
  • Strobe/Lighting Model & Brand
    Inon Z330 X2
  • Accessories
    Sola 1200, CMC2, WWL1
  1. Thanks! I thought about this solution. I was worried that optics will change UW (due to differences in refractive index of water and air). Moreover, the prisms I managed to get were rather bulky and heavy.
  2. 1. I used the SOLA800 and at night it was very strong. Didn't try in a bright mid-day. I guess this has to do with the quality of the beam splitter 2. As I wrote in the description, I bought one of the Khet (a laser board game) extension pieces that had two beam splitters. I see them on Amazon (US) for a hefty price right now. Didn't look elsewhere. I am sure that many other plastics have semi-transparent properties that can be used for this design... Good luck with the print, and I will be happy to hear how it came out.
  3. So far so good (more than a dozen dives for the mirror, I used the same one in earlier prototypes). It is a relatively cheap piece of plastic. Regarding the optics, would love to hear suggestions for improvements.
  4. Hi, It seems that the enthusiasm for a better/cheaper snoot never runs out. I usually find it hard to point the beam of light on the subject, and even a slow moving one escapes by the time I get it. So I wanted a light guide that will show were snoot actually points to. I tried the 10Bar laser focus and found it unreliable and inaccurate. I did design a version where the laser projected on the same line as the strobe using beam splitter. But the laser was annoying. Then I realized that the same design can work with a strong focus torch. The benefit is that I get to see the whole beam and that it is much brighter than the little red laser dot. Here is the result. It is a modular snoot that can either have a fixed head (at different beam diameters) or a fiber-optic attachment that can be manipulated by hand. An example of a photo made with this snoot. I had 12-50mm (Olympus EM-1) + wet diopter lens (nauticam CMC2). The focus light was on red, and my dive buddy was aiming the optic fiber snoot at individual skeleton shrimps.... Would love to hear your comments and suggestions. The design is uploaded to https://www.thingiverse.com/thing:3749151
  5. I can read R4006/1302 on one of the packages (the one adjacent to the one marked "f2m"). There is another small 8-pin package on the other side but as far as I can see (with magnifying glass) it does not have any marking.... The R might be a P and then this might be P4006 which is actually a code for another (older?) IGBT from RENESAS with very similar specs. https://www.renesas.com/en-us/doc/products/transistor/004/rej03g1865_rjp4006ageds.pdf
  6. Trying again (was away on a trip so did not have the LM2 under my hands). Hopefully pictures w/o tape would help. Any suggestions on where to start (my electronics knowledge is minimal) would be great Thanks!
  7. Hi, cool idea! I am wondering whether a similar mod can be done to the FL-LM2 (the smaller flash of Mark I OM-Ds). Anyone with electronic background can comment on whether this mod will work? If it helps, I disassembled my older LM2 and attached photographs. As far as I can tell, the xenon tube assembly is similar to that of the LM3. Any suggestions how to proceed will be appreciated...
  8. Can you say a word or two on these "lightpipes"?
  9. Hi, As a photographer and 3D printing enthusiast I created several snots. Usually I find them hard to work with and did not use them much. I recently read article/review about 10bar laser guided snoot. I liked the idea and purchased the laser unit alone for 75$. The laser unit is nice. It is basically a small box with a laser and a flash detector for autoshut-off. I started playing with the design of my snoot and looked at the 10bar original. Their design has the laser unit "riding" on the snoot, and the user has an adjustable knob to adjust the angle of the laser. This means that the beam intersect the actual snoot output path only on one point. Elsewhere it will be off center (and probably off target in the thin version of the snoot). An ideal solution for this would have the laser run through the center of the snoot, this will make it precise at any distance. I knew similar solution from microscopes using beam splitter. The idea is simple. A beam splitter is half-mirror, where 50% of the light pass through it and 50% bounce off. In this design the laser is positioned perpendicular to the strobe. The beam splitter is setup at 45degrees to both beams. The price of this solution is reduction in 1/2 of both the laser beam and the strobe light. Since this setup is used for close macro situation, I reasoned that this will not be a big problem. The next question was finding a beam splitter. A professional grade one is expensive (100s of $). However, I found that there is a game "Khet - Eye of Horus" that uses lasers and beam splitter. For about ~$5 I could buy two beam splitters pieces. A quick test showed that these work fine on the laser beam and on the strobe. Removing the plastic frame, I had a nice beam splitter (and a backup one). I designed a snoot and set out to test it. However, the laser beam was lost somewhere in the snoot. Revisiting my components I discovered that the laser beam was not aligned with its housing. The few degrees of offset were sufficient to cause problems. This required having an adjustable mount for the laser that allowed tuning of the beam. The final design in my CAD visualization: The yellow object is YS-01 strobe. The blue ring is attached to the strobe and allows quick attachment of the snoot. The red box is the laser. The tip at the end is exchangeable and is held in place by magnets. (I did not take a proper picture of the snoot, but can load one later on) Last month I had a chance to try it on a short visit to the red sea. Using the snoot with a macro lens was harder than I expected. The problem was getting the damn red point into the frame. I practiced on a pair of nudis, and finally managed few shots. Opening the images on my computer, I realized that the laser was visible in the image, the auto-shutoff did not work. I set the sensor on the laser to point into the strobe, and expected the bounced light to reach it. It seems that the black plastic was doing a good job of absorbing the light. Taping a piece of white plastic on the inner lower wall of the strobe solved that problem. The next day I tried the snoot with a fisheye setup. This made it easier to find where the laser is pointing and positioning it. Two attempts: Not perfect, but something to work with. Since my trip was short, I did not have too much time to get more experience with the snoot. Next time hopefully I will get a better sense of it.
  10. I am not sure if I understand the graph, but I assume the y-axis is capacity and the x-axis is time (it would help to have a scale :-) Anyhow, just wanted to report that after ~12 dives with the modified flash I have many TTL shots that came perfect on and some that did not. I am not sure if this is due to my errors (e.g., positioning of the strobes) or due to the flash output capacity. I did not hold a careful comparison. Here are two examples, shot with TTL with the 10uf mod and two external strobes (Sea & Sea YS110a + DS-Y1, both set on TTL). Didn't change the exposure in development from RAW In some cases I had to set the exposure higher in Lightroom. So the mod might be under-exposing in some situation. Regarding my earlier comparison, I did repeat a similar test with a full housing, and it seems that having the fiber-optic cable in the right positioning helps... and the results are better.
  11. Jock, I am not sure. Actually, I was surprised to see this. I just revisited the YS-D1 manual (I usually don't shot TTL, so never checked this option), and it seems that maybe I should have used the Slave-TTL rather than the normal TTL mode (which assumes preflash). I don't think the E-PL3 pre-flashes. Nir
  12. As an E-PL3 owner, I thought I will give it a try. I modified one of my two strobes, and indeed got a much weaker light. To test the effects on TTL, I did a semi controlled test (see attached pictures). My conclusion is that there is little difference between the two strobes when using an external strobe in TLL mode. The differences are mainly at the extereme ranges of apartures. Setup: E-PL3, Olympus 60mm lens, T 1/160 throughout. External strobe YS-D1, set on TTL with the TTL dial on 0. The strobe was on the right of the camera facing so that the edge of the beam was on the object. The strobe was connected with fiber optic cable. I was holding the other end of the cable about 2cm in front of the camera strobe. I checked that the hand blocked any light from that strobe (you can also see that from the shades in the images). I varied the strobe setting of the camera and aperture, as noted in the attached picture. I converted the images from raw to jpeg without any adjustments. My conclusion is that the camera changes output by modifying duration of the flash. The modified strobe had slightly lower exposures throughout the test.
  13. I am aware that lenses lose between 1/2 to 3/4 of their power due to differences in refraction index. I am thinking of sandwiching a diopter lens between two clear ones (UV filter). If I can get this contraption to be waterproof, the diopter should not lose its power, as far as I understand. (This how Subsee lenses are built.) The optics are terrible with cheap filters, but since it is only a viewfinder, this will not show in the final images :-) I am wondering if there is a way to make the diopter power adjustable. Any ideas?
  14. Hi, With the advances of age, my near sight is going down. I realized recently that I shoot underwater with arms fully extended, otherwise I don't see the LCD in focus :-( While this extends my reach, it does not help the quality of the shooting. Nauticam recently came out with an LCD magnifier that has diopter adjustment (which presumably can solve my problems) -- see http://wetpixel.com/articles/nauticam-releases-lcd-magnifier-and-sunscreen However, my housing model (NA-EPL3) is not supported for this magnifier, and as far as I can tell it would clash with some of the control buttons that are on the screen periphery (in the newer housing models they moved these further from the screen). I am thinking of building a DIY version. Designing a shell that fits the screen and button layout was easy (and I plan to print one). The question what type of glass to put on the viewing end (right now the top holds a 55-52mm stepdown ring (in light gray), that allows me to put in 52mm filters. One option is to use standard close-up filter (say +10). However, I am not sure how well this will perform underwater and it definitely would not be adjustable. Any suggestions on a better mechanism? Thanks Nir
  15. If you have a lathe, why not produce one from metal (aluminum)?
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