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Posts posted by frogfish

  1. Let me also endorse the idea of diving in Bali at either end of your Komodo trip. The Amed-Tulamben area in the north has some great dives, including (but not limited to) the Liberty Wreck, which really should be thought of as not as a wreck dive, but as a great macro site.


    More to the point, since you're talking about September, this is the height of mola mola season at Nusa Penida. There are very few places in the world where one can see (and photograph) these magnificent creatures, but Nusa Penida is one of them. (Nusa Penida is an island in the strait between Bali and Lombok, and the main destination of dive boats based in Sanur. The faster boat will get you there in about 40 minutes. Mola sightings aren't guaranteed, of course, but with several days and a good operator, the chances are ver good. Email me if you'd like my recommendation on the best Nusa Penida dive op. (or just check out the ad in the current issue of UwP with my pic of a mola).


    One important matter : in September we get upwellings from Indian Ocean on all southern dive sites in the straits along the Nusa Tenggara archipelago, which means quite cold water, around 20-22 C.


    This not only applies to Nusa Penida, but also to all the sites in southern Komodo you will do, including Horseshoe Bay. It will still be very warm (about 29 C) at the northern Komodo sites, as well as North Bali, but Horseshoe Bay and Nusa Penida will be very cold at that time of year. I've been on trips where the boat abandoned the southern sites after only one day because the divers had only 3 mil suits and couldn't take the cold. You should think about bringing at least a 5 mil, as well as hood and gloves, for these areas.


    Robert Delfs

  2. The procedure is:  Create a new layer.  Select: Filter -> Other -> High Pass.  Select a filter value around 10.  On the Layer Palette, select Hard Light as the blending mode, and experiment with different opacity values on the new layer.   Something around 30-40 should work.  When you're happy, merge the layers, and you can ...


    Whoops! There's an error here. I should have written:


    Create a new DUPLICATE layer.





  3. Personally, I would have thought that a question about Photoshop should belong in this forum, rather than Techniques & Tips, which I've taken to be mainly about general techniques and methods for photography.


    If Photoshop (including questions about resources to learn about it) doesn't belong in under the topic "Image Prodessing", what does?


    (I've got a question about Photoshop I've been meaning to post myself, but now I really don't know where to put it.


    Is the idea that any question (as opposed to informative posts) should be posted to Techniques and Tips, rather than a specific forum that would seem to cover the topic of the question?


    It might be useful (at least to me) if the moderators were to come up with a somewhat clearer statement of the criteria they're using (and want us to use) in deciding what's on- or off-topic in a particular forum, particularly this one.


    Robert Delfs

  4. As long as the close subject fills enough of the image area, TTL can work very well, though I'm not convinced matrix metering works any better than center weighting in these situations.


    As ScottyB says, you definitely need to pull the strobes in tight for CFWA, but at wider apertures using powerful w/a strobes, the TTL logic may not be capable of shutting down the strobes in time to avoid over-exposure of the close subject. If this is the case, try moving the strobes back behind the plane of the camera. For really close subjects, you may need to elevate one or both strobes to get the necessary distance while at the same time avoiding shadowing the close subject by the housing and port.

  5. Digital cameras (like mine) that use a smaller frame format but use the same full-frame prism optics in the parent body unfortunately leave a lot to be desired in this regard. The worst aspect of this is that the data display remains at the bottom of the screen, separated from the viewfinder image, so housing manufacturers can't use optics to enlarge the viewfinder image without losing the exposure and other data in the viewfinder.


    I've become somewhat used to the small viewfinder image in the S2, but I don't like it, and I remember how much I don't like it whenever I pick up my F100 and see that wonderful huge viewfinder image inside.


    Among other things, I really can't see whether (or what part of) the image is in focus using the viewfinder on the S2 - making it necessary to rely on autofocus and/or the black ball. The black ball is pretty much all you've got when using manual focus for macro. Opening up an image on the computer is really the first time I can see how much of an image is in focus.


    If somebody offered replacement prism optics for the S2 that fixed this, I'd buy it in a shot.


    As to masks, if you need corrective lenses, unfortunately, you'll have to go with a mask with individual lenses. (I believe the Scubapro frameless has a single lens, and cannot be corrected except with internal stick-on lenses, which I understand don't work very well.


    Any low-volume mask that lets you get as close to the housing viewfinder port as possible should work. I use a Tusa Viewfinder. Black skirts (rather than clear silicon) are better in many situations where the viewfinder image may be dim, or there is a strong light source above or to the side.

  6. You might try high pass sharpening, either as an alternative or before using unsharp filter. It works like USM, but you can go a bit further without making the air bubbles look like shattered glass. I think you it might help help make the cuda pop out from the rest of the image, if that's what you're trying to do.


    The procedure is: Create a new layer. Select: Filter -> Other -> High Pass. Select a filter value around 10. On the Layer Palette, select Hard Light as the blending mode, and experiment with different opacity values on the new layer. Something around 30-40 should work. When you're happy, merge the layers, and you can consider also applying a bit of USM too.


    Robert Delfs

  7. Your article about color correcting green water gives a good introduction, but I would like to add something. The actuall work to remove the greenish water is does the hue/saturation tool. If you select the cyan channel and add +20 you get almost the same blue in the background but preserve the colors and the saturation in the foreground.




    I think there are some situations where the modifying the channels is the only way to correct color problems. One typical case is where there is already a heavy cyan/blue cast on white or light-colored objects which were beyond the range of strobe illumination. Simply adding more cyan across the image is unlikely to help.


    The channel Mixer is a convenient tool to play with channels, but Apply Image can be even more powerful, as you can select any of the standard blending modes, including selective modes such as darken and lighten.

  8. Hi, guys.  Can some of you who were having speed problems let me know if the newer skin is faster?


    (assuming you've made it out of rehab. :) )




    I've just clicked on a few forums and posts. Congratulations - this is much faster - as far as I can see, as fast as the old wetpixel site was. Great job!


    - Robert Delfs

  9. I'm trying to understand what is a typical gamut for a raw CCD sensor in modern digital cameras.  Since RAW files contain only the sensor data (theoretically), the concept of color space doesn't apply.  In all the discussions you see on what color space to use, no one seems to understand what the conversion is between the native imager gamut and the chosen space.  If sRGB can contain the enitre gamut the sensor can produce, why use a wider space?  If it is wider than all color spaces (unlikely) then why wouldn't you use the widest one available.  Just because a camera has an Adobe RGB option doesn't mean that the camera can fill it.


    Since gamut is effected by the color filters used, any of this data would be sensor-specific.  Anyone know of any links to discussions on raw sensor gamut?  I'd lke to see raw sensor gamut graphs compared to common color spaces.


    I'd also very much like to know more about what RAW image files really are and how the conversion programs work. My uninformed assumption is that the conversion program essentially maps the data in a RAW file to a specific color space, with parameters controlled by adjustment fields in the program. As I understand it, sRGB is a very restricted color space, and converters can map RAW files to much larger spaces (such as Adobe RGB (1998). But if the target space selected in the converter program/module is sRGB, then the RAW data will be mapped to that smaller space.


    Is there anyone who really knows about this stuff watching this thread?

  10. Robert -

    I use Mozilla Firebird which is amazing.  No pop-ups, fast, tabbed browsing, and accurate, to-spec HTML rendering.


    OK, I just got Firebird and tried it. Pages seem to load faster than IE, though I'm not going to say the problem is solved without trying a few more times.


    Nice browser, too - I think I'll keep it. Tabbing is definitely a nice thing, though I'm going to have to remember NOT to exit a tabbed window by clicking on the "X" in the upper right hand corner - which drops the whole program, all tabs.

  11. PNLite may help slightly.  


    So either the HTML is really confusing and it's slowing down slower machines, or the pipe between the server and people out there experiencing slow load times is really slow, or high latency.


    I'm running a new 1.6 GHz T40 Thinkpad, so I don't think the problem is "slower machines".


    Being techno illiterate, I'm not sure what "high latency" really means, though I can think of a few people this might apply to. But one thing I have noticed is - when opening a new window on a Wetpixel forum or thread, if I monitor the connection - there often seems to be no bytes/packets coming over the line for quite a long time, or else the bytes come in little dribs and drabs, at 50 or 100 kbps. With other sites, once the window is opened, there is an immediate and sustained flow of data at 3,000-6,000 kbps for 5-10 seconds until the HTML page is downloaded and appears on the screen.


    If that's at all helpful.


    I'll be in Singapore over 8-10 February, staying in a hotel that has broadband access in the rooms. If this is still going on, I'll be able to check it then.

  12. I used netscape on my previous laptop for years, finally reluctantly gave it up for Micro$oft's Explorer when too many sites wouldn't work with it.


    I've got a new laptop now, and am reluctant to install any superfluous programs on it - it sometimes seems impossible to really clean up registry on uninstall, so I'd like to leave this as a last option.

  13. After several sessions trying to use the new server, it's clear that speed is going to be a serious problem, at least for some people in my situation (which is using a dial-up connection from outside US). Perhaps even a serious enough problem to make it impractical for me to continue to participate.


    The contrast with the old board is quite dramatic. I often check wetpixel in the morning while looking at news stories that popped up overnight on Google News. That doesn't work so well now.


    This morning I went to the new wetpixel site first. After that finally came up, I opened new browser windows for a few forum areas I like to follow, then went to Google News and started opening new windows to read about the democratic primary, etc. After clicking on and reading half a dozen stories, some of the wetpixel forum pages were still nothing but dead white screens. Now, several hours later, the wetpixel connection seems a bit better, but it must have taken 15 minutes to get through all three pages of this "wetpixel migration thread" and then to finally get a "post a reply" screen.


    It's not the connection, and it's certainly not my computer. Other sites such as Google News, various newspapers, Marriard's site, and my own site all come up as fast (if that's the word) as before.


    Here's hoping this is temporary and all will be fixed once Eric disables the security filters the Dept. of Homeland Security has installed to monitor all traffic between wetpixel's routers and places like Indonesia.

  14. Just reposted an item (with image) that I'd posted late on the other board. Everything seems to work OK.


    Using a dial-up connection here in Indonesia, the new board seems to be more sluggish than the old one, longer waits for screens to fill in I was hitting a few pages on the old board at the same time, and the difference in response was quite noticeable.

  15. [Testing new board]


    Myself, I've always used the 105 mm with my film SLR. When I moved to digital, I decided to spend the extra $$ on upgrading the dome port to use with the 12-24 DX wide-angle zoom rather than buying a new 60 mm lens (or the big macro zoom) and a new port to fit it. (Both housings are Subal, so I can still use the manual focus 105 mm port I already have.)


    Shooting the 105 mm with the smaller framed Fuji S2 is definitely different than on a full-frame film SLR. Unsurprisingly, with the narrower frame size, the lens works better for smaller subjects, but its harder to shoot larger subjects. Backing off to get the same subject I used to be able to shoot into the frame requires repositioning strobes from the "default" positions I used to use, and/or wider apertures, which reduces depth of field.


    There certainly have been a few times when I've thought it might be nice to have a 60 mm lens instead, but the 105 mm is also better in other situations. It's really a matter of learning a new range of subject sizes and distances where this lens performs optimally. if somebody offered to trade a 60 mm lens and port for my current 105 mm set-up, I wouldn't take it.


    Provided the water is reasonably clear and you have powerful enough strobes, you can still use the 105 mm for "fish portraits" at a distance of up to one meter or perhaps a bit more.


    Manual focus is a bit of a problem with any lens on the Fuji S2 (at least for me, using Subal housing) because the viewfinder image is quite small. I mainly use autofocus, but manual focus works fine, e.g., when I need to lock on to a subject in the middle of other objects, or in shallow water and bright conditions where moving light patterns from the surface can confuse the autofocus system.


    Bottom line: you definitely can still take macro shots with the 105 mm. on a digital that you will be very happy with.




    "Skeleton shrimp" (Caprella sp.), Fuji S2, 105 mm lens.

  16. There are two spring-loaded pins in the Subal bulkhead ports which are very vulnerable to water damage. I had one bulkhead fail on me early in my housing days, due to corrosion at the base of one of the pins, presumably resulting from poor technique when removing/changing the synch cord.


    Since then, I've religiously carried a spare bulkhead in my u/w camera tool kit, even though I have twin bulkheads on both my housings (now), and usually use a double synch cord. The bulkhead port itself is not terribly expensive, and is not that difficult to change.


    Robert Delfs

  17. What this means to you and I as underwater shooters is that a true wideangle strobe may not appear as powerful in the center of the spread as a more focused-beam macro strobe.  That's why I believe your flash meter results are not useful to make conclusions like "X strobe is more powerful that Y strobe."

    This is an important point, and well explained.


    Robert Delfs

  18. I think a large percentage of TTL shots underwater require some compensation for a proper exposure.

    I don't fully agree, if your strobes are positioned correctly it will work every time and can be used in conjunction with aperture & shutter controls and ISO.


    Maybe not every time. For some shots under some conditions, getting strobes "positioned correctly" can be difficult or impossible without compensation. For example, CFWA in low ambient light conditions requiring large apertures. Positioning poweful strobes behind the plane of the camera can solve this problem for a wide-angle scenic of a relatively close larger subject (say, a sea fan), but not for a smaller, closer main subject close to the dome (say, a frogish or leaf scorpionfish), where the strobe light will be be blocked by the housing itself, as well as the shooter's head and body.


    Positioning the strobes so that the CF subject can be properly illuminated can result in over-exposure at wide apertures if the subject-strobe distance is to close and the TTL circuitry cannot shut the strobes down fast enough to ensure a correct exposure.


    Obviously this problem can also be solved by using smaller, less powerful strobes, but many of us want to be able to shoot CFWA subjects without necesarily having to change the standard wide-angle equipment configuation.


    For me, with both my digital and film rigs, -0.5 flash compensation seems to work

    best in most situations with Ikelite SS-200s positioned conventionally, positioned on 24" arms and aimed forward, at least up to f/8. At tighter apertures, and of course for almost any macro shots, the TTL circuitry can shut down the strobes fast enough without negative flash compensation. With my back-up strobes (Sea & Sea 90 DX) similarly positioned, no negative flash compensation is ever required.


    Robert Delfs

  19. For the 20 mm lens, if you're using the big Aquatica dome port, you may not need a diopter underwater, but it's worth looking into before you leave. Many wide-angle lenses need a diopter of a certain strength to focus on the virtual image projected on the other side of the dome port, or for CFWA. Whether and what you need will depend on the dome port. Check Aquatica's recommendation for your port and this lens.


    I personally prefer the Nikon 5T or 6T multiple-element diopters for the 20 mm. lens, which I find deliver a sharper image than standard single-element diopters, though they are more prone to vignetting and darkened corners at wide apertures due to their thickness.


    Robert Delfs

  20. Very glad to hear you're OK, and that the problem will not affect your diving. (I have a good friend who has had a stent, and who will be diving with us in Rajah Empat/Banda Sea in March. Another friend - he and his wife owns BIPD here in Bali, they are the people I do most of my diving with here in Bali, and who I plan to take some IANTD courses from - had a bypass operation a few years ago. It seems clear that heart conditions that have properly treated are not by any means an absolute bar to diving.


    But it sounds like you were very lucky. I cringed when I read that you were humping your camera gear etc. on and off boats and planes after the first incident.


    Like many people I know, I'm now taking a statin (Lipitor), a blood pressure med (Cozaar) and a small aspirin every day without fail, and everything gets checked several times a year. The criteria for what constitutes treatably high blood pressure are much more sensitive than they used to be.


    Non-divers often ask me whether we worry about sharks etc., diving in remote locations. When I take the trouble to reply, I tell them that my real worries about remote diving are ranked as follows:

    (1) traffic accident while riding in a car or SUV between airport/hotel/dock;

    (2) being hit or chewed up by a boat propeller while surfacing in crowded diving area (answer: don't dive in crowded places, and/or always launch a delayed SMB before surfacing);

    (3) heart attack, stroke or other major medical emergency;

    .....(996 risk situations omitted)

    (999) angr sharks


    Stan Waterman's daughter suffered a very serious medical crisis while diving with her father and others on the Pelagian last year in the Rajah Empat area. The situation required emergency surgery in Sorong, under conditions which could charitably be described as less than ideal. I read an account of the incident written by a professional nurse (fortunately on the boat) who stayed with her in Sorong during the surgery and recuperation, which was harrowing.


    Robert Delfs

  21. I feel I have to jump in, Cybergoldfish. SOME Poseidon regs are upstream, though I don't know whether this applies to the new model under discussion here. To my knowledge, Poseidon is the only manufacturer who still uses upstream designs. (Just to clarify for the unitiated, we're talking about 2nd stages here. Almost all diaphragm 1st stages are upstream, while most piston 1sts are downstream designs.)


    Apete, "not failsafe" in this context means that if the high-pressure seat on the 1st stage fails, a downstream 2nd will blow open, essentially causing a free-flow, which means that the diver will theoretically still be able to breath off the free-flowing reg and may be able to manage an emergency ascent or get to his buddy or another diver who can donate air before the tank is emptied. When this happens with an upstream first, the IP pressure can just build up, locking the 2nd stage and leaving the diver unable to breath until something blows.


    That's why downstream 2nd systems include an OPV (over-pressure relief valve) - to keep the IP from going to high in case of a problem or failure with the high pressure seat on the 1st stage. Older Poseidon upstream 2nds have the OPV on the 2nd stage itself, while more recent Poseidon models have the OPV built into the first stage. Without the OPV, even a relatively minor leak across the HP seat in the 1st stage could cause an upsteam 2nd without an OPV to overpressurize to the point that it could explode in the diver's mouth.


    That said, I think it's fair to say that the likelihood of a castrophic failure like this on a properly-maintained Poseidon that could cause cessation of air delivery is vanishingly low. It's also true that any design of regulator - upstream or downstream - can fail in many ways. Last but not least, getting a blast of 200 bar into one's mouth, as could happen in the case of a HP seat failure on a reg with a downstream 2nd - isn't an ideal situation either.


    I have great respect for Poseidons. But for me, particularly considering where we live and the locations we dive, the possible problems with servicing are more than reason enough to eliminate the Poseidon as a candidate for our next regs. Poseidons are tricky enough to work on that some Poseidon owners ship their regs back to Sweden for servicing rather than trusting even supposedly qualified local dealers in the US.


    Poseidons are one of the few regulators that Vance Harlow, in his book Scuba Regulator Maintenance and Repair, strongly recommends that owners not even consider trying to learn to self-service themselves. Even some very experienced regulator techs don't like to deal with them. The company frequently upgrades and revises parts, and servicing a Poseidon requires a number of special tools.


    I want to be able to do at least minor servicing and repairs myself if I have to - though only if I have to. That more or less dictates that my next reg will be another Scubapro - I've done their reg repair course and already have some of their special tools - or perhaps Apex.


    Robert Delfs

  22. Cybergoldfish, you had a heart attack? Very sorry to hear that, glad you're still with us, and hope that everthing is ok now.


    This does raise a topic of some interest to advancing-age divers such as my wife and myself. If you're willing to talk about it, how would you rate the capabilities and response of the resort people in assisting you and arranging evacuation, etc.


    Beyond carrying DAN cards, we take a fairly large first-aid-and-meds kit -including a good first-aid handbook - with us on every liveaboard trip or outing to any remote destination.


    Beyond the bandages, antiseptics, it includes an assortment of antibiotics, the usual range of things for gastrointestinal problems. And of course anti-malarials where they are indicated. (Malarone for prophylaxis in high-risk areas, Larium to be used only for emergency initial treatment if one of us actually contracts malaria - no diving once Larium initiated, obviously.) Antihistimine cream and tablets for jellyfish etc. or allergic reactions.


    It gets used on ever trip, though usually the patient is a fellow diver or someone working on the boat. I'm always very happy to restock the kit when things get used up on others, and a lot of the drugs have limited shelf lives anyway.


    Robert Delfs

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