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Tom_Kline

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Everything posted by Tom_Kline

  1. From post 16: "With regard to the image above showing the dispersion pattern, I am wondering if the pattern in air is similar to what one would get under water? In particular should one expect a non-diffused Z330 to have such a pronounced cross shape in actual use?" The question was under water vs in air. Retra vs. Retra (the new ones) is more obvious. If both were used at full power the more powerful one would cover a bit more as you suggest but could be overexposed in the center. Should be the same if exposure was equalized.
  2. It will and is a variable due to the dome shape of the port used on the strobe. Like with the dome port of a housing the interaction with water results in a lens different from when it is used in air. Recall the difference in infinity focus position with dome optics. Some strobe domes are truer domes than others. Looks like there is a trend with new strobes more dome like, especially the Inons. I think the effect is not academic.
  3. One is continuous (like a regular light bulb) whereas the other one flashes.
  4. Alex M was able to make it work here: http://wetpixel.com/articles/field-review-retra-lsd-prime-snoot Do you have an older Z240 with a bulb rather than an LED? see this: http://wetpixel.com/forums/index.php?showtopic=51586 See what Oskar says in post 10: http://wetpixel.com/forums/index.php?showtopic=62595 An idea: swap your 2 Z240s so the one on the camera is now the slave. Maybe the other one lines up better????
  5. Sounds like you passed the mirror test, part 1. Repeat with snoot. Repeat again after each adjustment. I gather the LSDs have been problematic with Inons - there may be something on this somewhere on Wetpixel. There is a diffuser in the LSD that should help but having the aiming light in the center of the flash tube (may be the case with the 330) is better.
  6. Sounds like it should be working. First thing I would do is the mirror test. See my example. Remove the snoot first. You may have to do this with a spot next to you where you can place the slaved strobe. The idea is to make sure both strobes are going off and synch with the shutter. I took this last month in Hawaii.
  7. Make sure your main strobe is not using pre-flashes!! You might be seeing the slave responding to these. If the snooted strobe is not a slave you need a more complete description of your setup to figure this out.
  8. The color of the "fringing" is consistent with the shadow colors (light from strobes blocked). This suggests that you may have ghosting from ambient light as the snake moved during the exposure. Note the shutter speed is 1/60th of a second. Strobes mentioned in post 11.
  9. Yes they will fit. There are, however, newer viewfinders that are a bit slimmer.
  10. There is nothing like actually using a product! Even with the round flash tube of Seacam strobes I find that a diffuser is useful when shooting a fisheye lens. The Seacam 250D however did not have a diffuser so I improvised. I used a white almost transparent grocery bag tucked under the neoprene cover. It is in use in the attached pic. The main disadvantage of Seacam strobes, except for the latest model, IMHO is that they use proprietary batteries. These batteries might be described as anti-Eneloop because of their short shelf life and rapid self-discharge, basically most unlike Eneloops.
  11. I avoid shooting at full power for three reasons: 1. recycling is quicker, 2. more flashes are possible with a set of batteries, 3. flash duration is shorter. At full power a strobe may need >1 second to recharge its capacitors (recycle). Furthermore the flash duration at full power is most likely several milliseconds for most portable strobes. To stop action one may want to use 1/4 or less power. Few of any of the strobe manufacturers provide flash duration data for their strobes. For some applications these three points may not apply such as Alison's above. Shooting hundreds of pix of fish behavior (i.e., fast moving subject) over many hours of being powered up has different demands, my case. I am also an exception to paragraph two, above. I have shot tens of thousands of fisheye lens pix using just one strobe.
  12. My experience which was shooting the 10.5mm on the D2X so is a bit dated is that I could and did use dome ports from a 100mm diameter macro dome port to a superdome. That is a strength of using a fisheye lens. I used them according to shooting circumstances. The superdome produced the best results that were noticeable even with 12 megapxels.The tiny dome worked better in water too shallow for the larger domes - but note that the camera was very close to the subject.
  13. I use focusing lights while scuba diving and doing photography mainly for night photography and have not noticed an adverse effect from the light in my pix. I do tend to keep the brightness level of the light down but that is to get at least an hour of lighting. I also use focusing lights for my salmon photography when it is dusk. This does help with focusing with DSLRs as they reach a point where focusing is not possible due to low light. As well focusing becomes slower when they become light-challenged. This point can be detected if I forgot to turn off focus assist in the camera menu (done this a couple of times!) as the "pilot" light will come on (Seacam strobes).
  14. Thanks for the mention Chris. I have been shooting salmon UW for several decades and with digital for about 1.5 decades. I have posted some of my technique shots here on WP. Basically I am using a DSLR for digital. I started with APSC (Nikon DX) then added Canon full frame as it came out first. My most used lens for salmon with the Nikon was the 10.5mm fisheye and with the Canon the 8-15mm fisheye zoom (I got one within a week of it being available!). I have only a few salmon shots done without remote control, which is of the simple 3-wire release type. I use flash for a good portion of my shots. It is very dark here (sun less than 10 degrees above horizon at true noon and it is behind a mountain) when the Coho spawn. On the plus side water gets very clear once the air is at sub-freezing temperatures! Lots of examples on my website. The few vids I have done show shots being taken: https://www.salmonography.com/Salmonid-species-galleries/Videos/
  15. As well, you can also order from my Smugmug based website. Metal prints are an option but they are the most expensive type of print. If you want much less expensive go for paper prints, which might be shipped rolled up in a mailing tube, also cheaper.
  16. Another Nikonos starter. This was a few decades ago! I did not use it for diving, however. When I started doing UWP while diving it was a medium format housing.
  17. I use Smugmug. It checks off all your boxes except for blogging. One of the reasons I selected it was because of formatting for different devices. Smugmug provides an app for Lightroom making it very easy to add and subtract images. There are various gallery formats to choose from. I am using two of them. One, journal, shows the images at a large size that one can scroll down to see other pix. This is good until one has several pages - I find that not many go to the last page. So for large galleries (more than about 100 pix) I use a horizontal matrix option. This option also has a starting pic. I do not like the way smugmug generates watermarks so I generate them during the export from Lightroom. I have changed them slightly over time so I can see which pix have not been processed lately - it is easy to replace them - it is semi-automatic. One just has to work on the image in the develop module and then update the gallery with one click. One can set the max resolution by gallery. I am not using full size but this is an option. It has the right click block as an option for each gallery. Smugmug also provides site analysis so it is possible to see which images and galleries are most popular. One can dive in and see which sizes are being looked it and what sort of device as well as OS. A surprising number use their phones.
  18. A diopter is needed when a lens on its own is incapable of focusing on the virtual image generated by the dome. For example a lens with a 0.38m minimum focus distance may not be able to focus when using a dome smaller than a superdome. I have not determined if the S&S corrector changes the field of view angle; if so it must be slight. My experience is that a 16mm with the S&S corrector attached is still a quite wide angle of a lens.
  19. The S&S correction lenses we are discussing are NOT diopter lenses. They have in common being a piece of optical glass mounted in a threaded rim but any similarity ends there. I assume the cost has a lot to do with the R and D and the expected relatively low volume of sales of the product. As well there is an aspherical surface. The optical glass could be a more expensive type.
  20. 1. The correction lens was design to be used with 16-35mm zoom lenses made by Nikon and Canon. The largest deviation of the virtual image from the focused distance (assumed to be a plane) is at a corner. Therefore one can assume it is really made for the angle of view at 16mm so should work with other lenses of similar angle of view. As well it was designed for a specific Sea and Sea dome port that is large (I have not actually held this port). This is what the correction lens is designed to work on which is what you surmised. I have been using it with both C and N 16-35/4 zooms and a Seacam Superdome port which is also a large port but not an exact match to the design. The two sizes are to accommodate the different lens models. The current Canon f/2.8 16-35 (version III) uses the larger 82mm filters. I have not shot it. aside: {The earlier versions (I and II) have a bad reputation - I have not shot those either. I suspect the main reason for the 2.8 versions is for better AF and AF started with just one AF point in the center. Earlier lenses were probably designed to make AF better by maximizing MTF in the center. Hence these older lens are not so great in the corners.} 2a and b. Correct. The critical point is the entrance pupil which is typically a few lens elements deep into the lens. This website goes into this in detail: http://www.pierretoscani.com/fisheyes-(in-english).html I gave the English link. There is even more in French. Look at the animations (on the English page) and notice how the entrance pupil changes with angle of view with the different lenses. It moves along the optical axis and can tilt as well. Fisheyes are quite different from the non-fisheyes in the direction of the shift. I believe this is part of the problem with domes. When the lens is stopped down one is chopping off part of the problematic part (part away from the optical axis), hence we need to stop down.
  21. I would not use either of my 16-35mm lenses without it. Yes!
  22. f/2.8 does work better for AF with SLRs in many cases. However I have successfully used f/4 lenses in fairly dark water in much of my salmon photography. I use a focusing light after dark to help. Newer SLRs work a bit better but I have not done scientific tests. Mirrorless is a different story. With the Nikon Z the lens is stopped down to f/5.6 when set at f/5.6 and smaller apertures. One does not see the max aperture view in the viewfinder like an SLR when the lens is at f/5.6 and smaller (assuming an automatic diaphragm lens). Since we use smaller apertures when shooting under water, especially with wide angle and dome ports, the increased aperture of f/2.8 over f/4 becomes academic for focusing.
  23. This lens is collapsible like the 24-70 kit lens and some vintage Leica lenses. The photo on the left shows the lens in the collapsed state - zoom ring lined up with the dot to the right of "14" seen in the photo on the right. One cannot take a photo with the lens collapsed (reminder message shows up if ones tries). This difference in length is thus unimportant as to fitting behind a dome. It is useful for taking up reduced space when stored, which might be important for dive travel. What is unknown to me, however, is how much length changes when zooming actual focal lengths. I have not looked at all the on-line videos to find out. Many lenses in this zoom range do not change all that much in length.
  24. The 17-35/2.8 was discussed on this forum ad nauseam a few years ago. Look back a decade or so. A number of those who owned and used this lens switched over to the 16-35/4. They voted with their wallet. I have both Nikon and Canon 16-35/4 lenses. I only use them with superdomes and now (since it came out) with the Sea and Sea corrector. They work well with these conditions. I have a Z6 and have used some of my of AF-S lenses with the FTZ on it. Mainly the 50/1.5G and 300/PF. They work just as well as on a DSLR and maybe even better. For example I was using the 50 in MF mode to shoot fireworks as well as stars at night. Very easy to MF with EVF. One button press to 100% then back to normal (I have the lower one on the front programed to do this). Plus the EVF is much brighter since it is electronically compensated for the dark. Back screens on SLRs are not so good for focusing for us old greybeards with more limited closeup vision (compared to what it was) and very hard to see in daylight. That said for underwater action I suspect a DSLR is still the champ. Maybe in a few years we will have a FF mirrorless sports camera that works as well.
  25. The clouds parted today so tried free-lensing the Nikonos 15mm using a Leica M adapter as a spacer and an aid. To get this shot the lens was a few mm beyond the adapter. A bit awkward to hold with the knobs on the lens so far from perfect alignment. Where it was comfortable the lens shade was in the wrong position! Quite sharp in the center. Obviously blurry towards the edges. Not a topside lens!!
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