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Barmaglot

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Everything posted by Barmaglot

  1. Meikon makes a pretty good housing for X-T3 - costs $655 with flat and dome ports, plus another $120 for vacuum system. Aside from lacking a zoom gear for 10-24mm lens, it looks like a fairly capable unit.
  2. No, I mean macro photography in general. To be honest, I've never even tried the 'macro' scene mode on the camera (I have an A6300, so pretty similar to yours); underwater I always have it in M mode. What I mean is, most macro subjects are found on or near some sort of surface, which means snoots are needed to isolate the background from the strobe light. If you happen to find a free-swimming one with meters of water behind it - great, although getting the shot becomes exponentially more difficult - but such opportunities are few and far between, aside from blackwater dives which are themselves not too common. I don't have any snoots myself, but I've read a lot of positive feedback about Retra LSD. Depending on your strobe model though, aiming a snoot can range between annoying and extremely frustrating. As I understand it - again, no personal experience thus far - strobes with a center-mounted modeling light such as Ikelite DS-161 make it easier.
  3. Snoots? In macro, your background is typically lit by strobes unless you silhouette your subject against water (not a very common occurrence); faster sync speed won't do anything, but snoots will limit strobe illumination to your subject, whereas the background should get only ambient light, which, at 1/160, f/11-16 and ISO100 will get pretty close to black in most circumstances.
  4. 1/160s is indeed the sync speed limit for A6xxx cameras. Basically, the way it works is that the shutter curtain has two halves - the first half moves down to open the frame, then the second half follows it down to close it, then they both move back upwards to reset for the next shot. However, due to movement speed limitations, in order to produce exposures shorter than 1/160s, the second curtain starts closing the shutter before the first curtain has fully opened it, producing a strip of light that moves across the frame. This works with natural light, because it's 'always on' so to speak, but if a strobe fires with a partially exposed shutter, it will produce a partially exposed image, with a black band on top, bottom, or both. The only way to overcome this is to use high-speed sync, where the strobe flickers on and off at a very high speed (I've seen 40kHz quoted as a typical number) while the strip of exposure moves across the camera sensor. Unfortunately, besides severely curtailing the strobe's power output, this mode has extremely limited support among underwater equipment manufacturers. To date, the only strobe that I know of that supports it is Olympus UFL-2, which has long since been discontinued, and it only worked with supported Olympus cameras to begin with. The also discontinued Sea & Sea YS-250 Pro has an atypically long pulse length which can function as pseudo-HSS to some extent. Finally, the upcoming Retra Flash Prime and Pro claim support for HSS with a compatible trigger (i.e. you won't be able to make use of that mode when triggering off the camera flash), but these aren't available yet, and neither are compatible triggers. What problem are you trying to solve by going beyond 1/160s though? Since you're shooting with strobes, and the majority of your light comes from them, the actual effective exposure speed is usually equivalent to the strobe pulse length (about 1/320 at full power on Z-330, for example), not to shutter open time. If too much ambient light is getting through, you can just close the aperture and/or reduce ISO.
  5. While I don't own an A7R II, my A6300 is from the same generation, and the controls are likely quite similar - it's possible to activate video recording mode by hitting the red video button on the right side of the camera while in any of the PASM modes; no need to spin the mode wheel.
  6. I've had mine for about 10 months now, ~40 dives to a maximum of 30 meters, no serious issues. Shooting it with 10-18mm and 16-50mm lenses in 8" dome port and 90mm macro in telephoto port. The issues that I have encountered are, in no particular order: 10-18mm zoom ring requires very careful alignment - if it contacts the housing, then the teeth just slip when you turn the knob, but if you pull it too far back, then it fails to contact. Usually takes me a few tries as I seal the housing to get it right. It was recently suggested to me to use silicone grease on its front edge; I haven't yet tried that. Left fiber optic socket is not as good at transmitting camera flash pulses out of the housing as the right one - with my strobes (SeaFrogs ST-100 Pro) this sometimes causes one of the strobes to miss its pre-flash. I suppose it can be mitigated by using a double FO plug in the right socket, but I'm waiting for UW-Technics LED trigger to come out before buying new FO cables. SeaFrogs does not offer extension rings for the ports, so you can't customize port barrel lengths to suit various lenses' nodal points. 10-18mm and 16-50mm work well enough with their ports, but corners are still somewhat soft - I don't know whether a finer adjustment of port length would have improved that. There is no focus ring for 90mm macro lens, so it's AF-only. I might, at some point, get my act together and 3D-print one. They only sell a neoprene cover for 6" dome port, not for 8" dome. The latter comes with a cloth cover in the box, and I dived with it off a boat, but it doesn't offer much protection. I got a generic 8" dome cover off eBay and it works well enough though. Otherwise, no complaints. It's got every feature except add-on viewfinders, port extension rings, electrical strobe sync and video monitor hookups. Ergonomics are fine, all the controls work. Their VPS-100 vacuum system has warned me about a poor seal twice now - one time, I found a little cat hair (I was staying at a house with lots of cats) on the main o-ring; the other time I don't know what it was, but cleaning and re-greasing the door and port o-rings has achieved a good seal and my camera survived to tell the tale.
  7. It's been that way for a long time now though, hasn't it? $300~450 for an entry-level strobe with a single straight tube (D-2000, S-2000, YS-01, YS-03, DS-51), $600~700 for a high-end strobe with straight tubes (Z-220, Z-240, Z-330, YS-D1, YS-D2), around $1k for some strobes (it's hard to call them low-end) with a circular tube (DS-160/161, YS-250), $2~3k for the high-end circular tube strobes (Seacam, Subtronic). I wonder, how much did Nikon's underwater strobes for film cameras cost when new?
  8. To be sure, the Retra Pro price ($961) is very close to that of Ikelite DS-161 ($999). Add a set of Eneloops to match Ikelite's included proprietary battery and they become identical, so $1k for a ~150J circular tube strobe isn't really new.
  9. Nope, because the improvement that is needed for LEDs to become competitive isn't incremental - it's three orders of magnitude. Nope, because the challenges are fundamentally different. At 1km depth, you have zero sunlight. At scuba depth, you have plenty of sunlight ruining the colors in your shot. Again irrelevant, because as you bump up the ISO, you let in more blue/green sunlight, and need correspondingly more white strobe light to compensate - and if you don't close the aperture to something ridiculous, you'll just overexpose the shot. The primary use of strobe lights in underwater photography is to expose the subject using white light delivered from close range, so as to avoid the blue/green tint caused by water absorbing the red/yellow part of the spectrum. This requires a substantial amount of energy (somewhere between 50 and 250 joules, depending on the strobe model) to be dumped into the water as light within, at most, a few milliseconds, so that the proportion of the light reaching the camera sensor is heavily skewed away from natural sunlight towards the strobe. There is no way to cheat this - if you want a colorful photo of a coral reef, you need lots of energy, delivered quickly. LEDs can deliver lots of energy slowly, or a little energy very very quickly - but not both, and the gap in capability isn't a matter of incremental improvement - it's a huge yawning chasm. If you hate strobes so much, why don't you drop a thousand pounds on a Vela One, put it in a plexiglass box, take it down to a reef and see how it fares? Or, just shoot in ambient light - it'll be much cheaper and you won't need to put up with those nasty, evil, dangerous strobes.
  10. No they can't. Vela One overdrives the LEDs far past their rated brightness for half a microsecond and no longer because pushing them any further would burn them out - and you'd need to push them several thousand times further in order to compete with a Xenon flash. Put it this way: if you take a fairly typical 1/250s exposure, that's 4ms - 8000 times the length of Vela One's maximum of 500ns, during which it shines at 1 million lumen. One million lumen divided by eight thousand is 125 - i.e. it will take a 125lm LED to deliver a 1/250s exposure equivalent to Vela One's super-fast super-bright burst. You can get a 125lm LED that fits on a keychain for a couple bucks.
  11. A7 series cameras do not have a built-in flash, and Meikon/SeaFrogs housings for the same only support wired triggering off the hot shoe. Pavel Kolpakov of UW-Technics has promised to release a Sony TTL converter board with both wired and optical triggering, including optional bulkhead replacements for Meikon housings. See here for the discussion. Alternatively, Retra is planning to release an e-opto converter for their new strobes, see here for details. Nauticam housings for A7 II cameras have a replaceable bulkhead and an optional non-TTL LED trigger, but that would cost many thousands of dollars. Or you can just run the light in continuous mode. The strobe effect with LEDs is very weak compared to Xenon gas-discharge strobes; it's primarily useful for not scaring away fish with a bright light.
  12. I have a 90mm with an A6300 in a SeaFrogs housing. Focus can be frustrating at times, but when it works, it's very rewarding.
  13. Again, a 500ns flash is thoroughly useless outside the realm of high-speed photography (speeding bullets and the like). Underwater, we use the flash to overpower sunlight, and flash sync speeds for interchangeable lens cameras tend to range between 1/160s and 1/500s. Even at the top end of that scale (and very few ILCs reach it), 1/500s is two million nanoseconds. That is four thousand times slower than this LED flash longest pulse of 500ns. In practical terms, this means that the flash is active for only 1/4000 of the time that your shutter is open - the other 3999/4000 of the time, the sun is merrily filling your image with green and blue. If you use a fixed-lens camera with a leaf shutter capable of syncing at 1/2000s, you can reduce that to 1/1000... still nowhere near short enough for the flash to make a meaningful contribution to the exposure. Vela One's guide number is five feet in air - do you really think this is anywhere near ready to compete with Xenon tubes? And don't forget that it costs almost twice as much as a Z-330 or YS-D2.
  14. The maximum pulse duration of this strobe is quoted at 5µs (five microseconds, or millionths of a second) - that's three orders of magnitude lower than the typical high-end underwater's strobes 3ms (three milliseconds, or thousandths of a second). In other words, while peak output is comparable to a xenon tube, the total energy delivered is somewhere between 300 and 1000 times less than, say, a Z-330. Since 5µs is quoted as a maximum number, I presume that overdriving those COB LEDs for a longer period will destroy them - might as well use the old-style flash bulbs. Like it or not, if you want to dump 50-250 joules into the water within the span of a photographic exposure, there is no real alternative to xenon tubes.
  15. Keep in mind that you can't sync strobes with a phone, as they lack a mechanical shutter required for that - you'd need to use LEDs, or ambient light.
  16. Missing Intova PX-21, SeaFrogs ST-100.
  17. For $1500 you should be easily able to get a used RX100 or G7X series camera with a housing, plus a pair of new Inon S-2000 or used Z-240 strobes. Here for example is a full SeaLife DC2000 kit (same sensor as Sony RX100 III) being sold for $1000 with a strobe and a video light.
  18. Phil Rudin has an underwater-specific review of the A6400 in UwPMag issue #108; you may want to check it out.
  19. Be that as it may, Oskar has explicitly stated, right here in this thread, that the optional battery pack will improve cycle time.
  20. The original Retra Flash did have the recycle time halved with the optional extended battery compartment (8xAA vs 4xAA); why would they drop this feature from the new generation? The fast recycle time is the primary draw of the extended battery - I mean, how often do you need 200+ full-power flashes in a single dive?
  21. SeaFrogs Salted Line housing supports A6000, A6300, A6400 and A6500 with a few part swaps, so you can upgrade the body later if you like, and keep the housing. In any case, the improved autofocus on A6400 is more useful for underwater photography than the in-body stabilization on A6500.
  22. Idle curiosity - might it be possible to use the HSS mode (40 kHz flicker, I presume) to sync with a housed cellphone? As I understand it, the slow electronic readout of phones precludes syncing with a regular Xenon flash pulse, and the LED flashes on phones use a longer pulse to compensate, so could the HSS flicker be stretched long enough to cover a phone's exposure?
  23. WWL-1 doesn't have any Nikon FX lenses listed as compatible (the only full-frame system that it works with is Sony FE 28mm), but you can use MWL-1 with 60mm macro to get a 150 degree field of view.
  24. If you want a combination strobe and video light, there is the i-Torch Symbiosis series. The earlier models were basically a strobe and a light clipped together, but SS-3 is a fully integrated unit.
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