bghazzal

Thanks Jochen, glad you find the discussion interesting! For the grey card, I would say yes, if you can be bothered to do it. It will be more precise, and having the same exact same reference (especially a good one like a wb card) on different clips make life easier in post. The only issue is that white balance is also relative to the distance to a subject, and you will be holding it at arm's length on a cam with a relatively wide lens, which might be a little close, but it still usually works quite well. And even if it doesn't, it's only one possible reference point. Since you'll be picking the WB setting point in post anyway, so if you find it doesn't work as well on a shot, you can always choose another one. I didn't carry a card for most of the GoPro footage I've shot, but found myself using mostly the same references in post for tropical ambient light, mostly: Other diver's tanks (works really well, especially aluminium tanks like AL80s), diver's bubbles, also the classical sand (sand can be a bit of a hit and miss depending on conditions and sand type), or bits of white rocks in the sand. Certain light skin tones / fin colours (white Gull fins...) can be good as well. If there is a reef, there's often a piece of bleached coral somewhere (tips) or other whitish elements in the substrate. But filming a proper WB card will help with consistancy - just film it a couple of second at the start like you said, holding the card as far as you can reach and in the direction of your shot and ideally with the sun in your back, like you would for manual white balancing. Looking forward to seeing the results. DaVinci is great for grading - if you put sufficient time learning to use it. I'd started working on it but unfortunately my current laptop isn't powerful enough to get fluid playback, even running from an external SSD and using proxies, whereas FCPX works fine natively that way. There was the option to edit in FCPX, export to DaVinci to grade, but with no fluid playback on DaVinci it's a nightmare. Planning on jumping in again when I have access to more processing power. cheers b

Problem is it's not clear if actual corruption, or (over)zealous application of existing (but in this case, certainly questionable) laws... To give another non-tax related example, most non-US citizens have to purchase an ESTA to transit through the international area of any US based airport for instance - this is something which is rarely found elsewhere, when only switching planes and not leaving the international transit area (ie. not clearing immigration or customs). Yet this paying process is part of US regulations, and something travelers transiting through the international area of an airport on US soil have to comply with to switch planes in the USA. The ESTA is valid 3 years IIRC. Another example in Indonesia, this time: people planning to use their mobile phones in Indonesia for more than 90 days (tourists visas go up to 180 days) have to register their IMEI / phones at customs (phone is blocked beyond that) There is a $500 USD value-allowance for the phone. Beyond that, the phone is taxed, based on its value (looked up online). Taxation rate is 40% of the remaining value after being discounted $500 USD. People who have a residence permit and/or an Indonesian tax number ID (ie residents and Indonesian citizens) pay 30% instead of 40%. However, tourists / people staying less than 90 days in Indonesia can use their phones without registration (or tax payment), which constitutes both a free allowance and a grace period. Back to photo/video equipement, if you look at the 2019 WeP thread, you can see pictures of the import forms photographers were given, which look quite official normal (16% import tax for the import of "photo and video recording items) As a foreigner, it's generally quite difficult to file a complaint for corruption anywhere, but given the forms issued here, it seems very unlikely to lead to anything. What would be the base of the complaint other than one is not actually "importing" their personal equipment in this case? While there might certainly be some corruption and abuse of authority by customs officers, I'm suspecting that they're just being (over)zealous in this case, and that, as Chris suggested, existing, enforceable laws are actually in place. There's quite a lot of surveillance / security at major international airports, which tends to discourage basic, bill-in-hand type corruption. And previously mentioned, it's a general trend, and Mexican travellers entering their country are also getting hit pretty bad by the same regulations. The way out would be for the authorities to define / clarify the parameters for tourists, and set an allowance (based on value, visa type, time in the country, like in the Indonesian mobile phone example...) for personal goods to be used on a holiday in Mexico. But this would require pressure from Mexico's Secretariat of Tourism, and tourism operators... b

I agree, but keep in mind it's not uncommon for "electronics" (computers, phones, cameras...) to be taxed differently (heavier) than sporting-goods. And things are changing, I don't know about bicycles, but there are reports of tourist's dive gear getting taxed on arrival , as well as golf-gear ( see this Reddit thread from two months ago, a tourist paid 19% import tax on his golf clubs in Cancun, for example) It's a general protectionist trend, and not really new (the BCS camera-tax became more systematic in 2019) When I was living/working in Mexico in 2018, importing dive equipment from the USA already incurred non-neglibeable customs duties (I remember being surprised by the amount when buying an SMB fron Jim Carter in Florida - free shipping to La Paz, but hefty import duties...). Beyond Mexico a couple of years back I sent back my (well-used) hiking shoes, from Japan to EU Europe and had to pay import tax (on my own used, personal goods, which had been bought in Europe, so tax paid...) The main issue I see here is taxation of tourists' personal, used gear (electronic or otherwise) which is to be used on a holiday and taken back out of the country on departure. This doesn't really make sense (as it is not an import per se) and is definitely detrimental to the country's tourism industry.

Ooh that's very nice - it looks like height can be adjusted, which was my main issue with flip-mount options As previously mentioned and illustrated, I use cheap readers for macro, and they work great - but it's important for me to be able to adjust their position easily (bottom half of the mask when I'm spotting, right in the middle when I'm shooting). I have mine with a strap, but this looks like nice and solid alternative! However I use mine on my single glass frameless mask though, and these look like they're designed to make use of the frame on double-lense mask Great idea though. Keep readers close to the glass and it just... works

It's a little bit more complicated than that. If you read up on this WeP thread and Scubaboard thread you'll see that some operators had actually created a printout in Spanish for divers to show at customs, and it wasn't much help. In 2019 customs were hitting divers with 16% of value for photographic items (housings, domes, strobes etc...). So far Quintana Roo wasn't concerned, it was mostly a Baja California Sur habit, but it seems to have spread first to DF and now Quintana Roo. I would recommend avoiding confrontational attitudes as much as possible in these kind of situations, do try to talk things out, but avoid confrontation, as customs agents have quite a bit of power, and xenophobia is growing in the global South as well... My Mexican friend almost ended up in a lockup for attempting corruption after offering to "even things out" with the customs officer - as is often done with authority figures in these kind of situations - so don't count too much on the power of well-earned (yankee) dollars 😉

As a side-note, it's not just the camera tax - import (?) taxation and enforcement has generally become very severe recently and this encouraged governmental guidelines. I was taking to a Mexican friend about this a couple of months back, he had some pretty chilling experiences at Mexico city airport this year, travelling on a Mexican passport (not diving / camera related, but this does seem to be a general trend in the country - I'm not surprised it is spreading) Similarly, Indonesia introduced some pretty drastic customs measures for "passengers entering from abroad" this year (e.g. electronics: maximum 5 units and with maximum value FOB US$ 1,500; see details here ) but has since backtracked on these measures, which were unclear and doomed to cause chaos at airports...

I was shooting in MF and following with focus peaking - I switched on AF to see if it helped but given the chaos it was easier to track with peaking (which I don't have with AF, unless focus is locked) But once light position is set, it should be a question of keeping them in the light, like snooting a moving critter. But these are super fast indeed, and small... My main worry is actually that I might have bumped into the LX10's lens limitations when it comes to size/movement for video... Zooming-in, which I must do to get the proper magnification, works fine for filming tiny critters when they're stationary or slow, but when they're flying around like this, even if you keep them in focus long-enough, the speed of the background blur makes for an uncomfortable, sea-sickness inducing watch... It's something I noticed shooting during the day as well - I have some stable, in-focus shots of small fast moving critters that are not nice to watch because they're zoomed in, and you have a background like a fast-flowing river, which is not a pleasant watch... My hope for black-water is to try to isolate them more, so that the background is black, which might be a way to get around this issue. However, a major issue remains: the movement patterns of such tiny planktonic critters (which I believe are actually feeding in the light) is very erratic. During the day, the fast moving critters where moving in a relatively straight line, but these guys are way more random, which means more camera movement to follow. Unfortunately, even if the shot is stable and in focus, camera movement is amplified when zoomed in / long focal length, and not really nice. Solution would be not to zoom and use actual macro lens, but I can't on a compact... Tricky, tricky... Especially if i drop resolution to 1080p to get 60fps, meaning I can't plan on cropping in post... Filming fast movement zoomed-in is really my main concern at the moment, not sure if I can find some way to make it work for fast-moving tiny critters (other than focusing on slower / bigger ones, if they exists!) The subject-background-movement problem is one of those specific video-shooting issues, really marked for longer focal lengths / telephoto... You're right for the light position - I need to find a compromise between a workable focusing area to track the critters and isolating them more. Plan is to do some dry testing to see what the options are! cheers b

To illustrate this post, as it might be a little abstract, here is some rough footage of yesterday's chaotic "bonfire" swarm, showing what critters show up in only a couple of minutes... Nothing fancy but promising, and some interesting looking dudes, especially for ony a few minutes of testing in the water column... Certainly challenging, but also welcome change from what I've been shooting lately! - The first shot is swarm building up around 2 dive lights (roughly only 1000 lm in total) in the sand, after maybe 2 or 3 minutes or so only. Rest is the chaos around the camera when using my main camera mounted light as the lure (which made life difficult, as the swarm was on me, rather than me coming up to the swarm... Nothing is great, and it was difficult to isolate subjects in the swarm and get/keep them in focus, and their speed means that 60fps slow-motion would be in order rather than the 30fps I'm shooting in here (1080p it will have to be...), but I kind of also like the chaotic energy these tiny critters have. It could be fun slowed-down quite a bit... Regarding light position, looking at last night's footage, more frontal lighting lights up more backscatter, which in the darkness gives a dark-green particle hue. It's ok, but I can tell which shots are top-down and which ones are more frontal, and top down is cleaner. To work on light position and focal, I'm thinking of doing some dry tests by creating a small mobile with bits of transparent plastic hanging from a fishing line. Plan would be shoot this contraption in the darkness with a fan on to generate movement, see what works best, so there's a little less to figure out in-situ. cheers! ben

As an update, I finally got to try out a little “black-water” video. Not sure the name is really appropriate, as what I’m going for is not a open-ocean deep-water lights on a line config, but rather a type of “bonfire” dive, i.e. a relatively night dive where you focus on small larval/ planktonic critters in the water column, attracted by the lights. As such, the dive is actually done in the shallows, but hovering in the water-column instead of staying on the sand, and while the water certainly is black, it's is more of a water-column macro night dive than a glide over the cold abyss... It might not sound as adventurous or exciting but logistics are way easier, budget-friendly, and I currently have the chance of diving on outskirts the Lombok Strait , which is extremely an extremely rich, deep through-flow environment. Also there's quite a learning curve for shooting black-water video, and I'm happy to work on figuring things out this way before committing to much more expensive true black-water logistics... The general idea is the same, lure lights to attract critters, and waiting for the food chain to reconstruct itself around these lure lights. First impressions is that it’s definitely possible, and a welcome change from the usual critters, but there's a lot of experimenting to be done to get some nice video footage. As I didn’t set out to do a full black-water type dive (and my wife was busy calling spotting in the sand and calling me for funky cephalopods, frogfish etc), so didn't spend the full dive on it (and kept changing light positions and settings). The plan next time is to focus on water-column critters only, to try and figure things out. I didn’t try tying lights to a deeper mooring, as I'd said I would in the thread above, and instead just hung around at 15m on the slope facing the channel. We'd missed the new-moon, but night was still quite dark yesterday (waxing gibbous moon), and a lot of stuff in the water. I tried two things, just waiting for the swarm to form itself around my camera’s lights, and the other, placing a small (tiny) lure light in the sand for a few minutes. Please note that I have nowhere near as much power as what is typically used for these types of dives – I’d emailed NAD Lembeh’s Simon Buxton to ask for more info on the logistics of their bonfire dives and didn’t get anwer, but from what I gather they have a setup in the hundred-thousands + of lumen, assembling a large bunch of old video lights. I was on a much more modest 4300 lumen video light on camera, two 800 lumens\ and 1000 lumen dive light, but even with this ridiculously small amount of light, it’s amazing how much critters this can attract in this area. Still, I came back excited by the potential, and also with more questions than answers, so they’ll have to be a lot of trial-and-error before I can get proper video footage... Since this is a work-in-progress and I believe in sharing info, I’ll share some of these raw first observations and interrogations here. As a reminder, this thread is on black-water video rather than stills, as there are very specific issues when trying to capture moving-pictures of small critters in open water, rather than freezing their movement. Video lighting - First basic observation is that well, continuous lighting of small fast-moving critters in a black water column isn’t easy, as it’s difficult to get a good reference point to best position the light(s)... - Because of this, practical and efficient video light positioning isn’t super clear – I used the MW4300 as a main central light and two weaker lights on both sides, as I usually do for macro. This lightbox type config (weaker lights on the side, in earmuff position) seems to work well for following focus (peaking), but for the main light, it wasn’t clear if frontal was more efficient/practical than top-down... - For the main light source, it's not clear if a wider beam is preferable to a narrower beam (the MW4300 has wide and macro spot) – a narrower beam would make it easier to isolate a critter from the swarm, but speed of movement makes it more difficult to track. A wider-beam is more flexible, but the swarm is much more present, and this is not practical if the lure light is the cameras. - How much light power is really required to shoot these small, mostly transparent critters? - The swarm groups around and follows the strongest light source. This is connected to the “how much light” question above, but if the shooting video light is stronger than the lure light, the swarm will reform around the camera's shooting light. This is something to be wary of, for people with minimal lure lights... If the swarm forms around the camera's main light, shooting critters in the swarm around the camera is not practical (too close, and too dense to isolate a critter, since the swarm follows the main light) But maybe it’s possible to shoot with less light on camera, I could perhaps work with a narrow-beam snoot light and use my primary 4300 lm video light as a lure, detaching it from the camera… Or maybe th MW4300 light’s narrow beam be used to follow critters without attracting as many critters as the light’s wide mode? Lens / focal / diopter - it's not super clear what lens works best – I was shooting with an Inon UCL165 +6 diopter, but wonder if a +12 / +15 might not be better. Big issue, when a critter is not fully isolated against a black background, is background movement speed. Zoomed in and following a small critter, the speed of background-movement (which in my camera-light-as-lure-light situation are all the other critters) is quite disturbing. But it's difficult to get enough magnification without zooming in… So maybe a half-zoomed stronger diopter? Hmm... Lure-light setup - Suspended light (facing down) or in the sand facing up? Not commiting fully to water-column shooting, I didn’t try the suspended version (hanging lights on a deep mooring line, roughly at 15m depth), but placing the light in the sand in the "bonfire" config results in an upwards-shooting beam of light, which could be more problematic than a downwards facing one - this is something to check, as it might depend on lure-light power (maybe it's possible to stay on the side of the "bonfire" of lure lights and follow interesting subjects around) Framerate This is a purely LX10 / compact issue, but I don’t have 4K 60fps – while I don’t usually slow down footage, the speed of these critters makes it necessary, to really get to see the movement, and extend the encounter… For me, getting 60fps means dropping down video quality to 1080p, unfortunately… But given the speed of the critters, maybe 120fps “high speed video” might even be worth it… Other observations - I was afraid that I would be attracting lots of lionfish, but in the open water column this seems ok, none showed up, whereas they often get close to hunt near the light when shooting close to the sand Anyway, more questions than answers for now, and lots to dig into... cheers ben

Agree with all the above. And keep in mind that all "cheaper" clamps are not made equal. Speaking from experience, do stay away from non-branded generic products. The alloys (?) / material and sheer design of the super-cheap generic ones will lead problems after a while (corrosion, fusion of screw / washer elements etc) as they are not made of the proper material for salt-water use. Be very very careful with these, wash, vinegar, lubricate (WD40) regularly and never ever leave them tightened for extended periods of time (or you might have to hacksaw it...) Overall, best stay away unless you're ok with "disposable" clamps for experimenting / testing your setup (especially floats), and then get properly made ones as soon as that's settled. What you can also do is stay away from the cheapest-generic ones and get intermediate branded ones like Kraken, Weefine, Big Blue, Carbonarm instead... These might not be as solid as ULCS or Nauticam, but are roughly half the price, design is coherent, and they offer options sometimes not available in Nauticam (open clamps, especially 4 or 3 ball open-ended clamps, which are super useful for some applications...). If necessary, you can upgrade these gradually once your kit is set. That said, carbon-fiber floatation arms don't seem to have the same issues. I've been using a Puluz 900gm float and other generic floats for a few years now and they're perfectly fine. There are no-moving parts, and other than the rubber ring wearing down (you get spares with Puluz) especially when usign open-clamps, there have been no issues whatsoever with the carbon arms (cracks, etc) - as new. So this piece of kit might not be as critical. Just look for proper buoyancy data and brands that label their products (Puluz does), as most online vendors will have no clue as to what they are selling... cheers ben

SUMMARY Returning to the filtering / transmission info we now have on the UR-Pro Cyan filter, we can try to summarize the data as is: - In terms of spectrum, the UR-Pro Cyan does indeed function like fluorofilter, with a similar profile. The filter blocks the UV spectrum, and strongly restricts cyan to green transmission, while maintaining a medium transmission of dark/purple blues, and strong transmission of orange/red wavelengths, thus having a marked warming effect and smoothing spectrum alterations of ambient light in blue water (which helps the camera white balance). Practically, the working result is that UR-Pro Cyan preserves some deep blues for the water column, while nudging the cyan/green cast to a warmer yellow-orange tones, which gives a good base for colour grading to aesthetically pleasing results. In this, it is not the most colour-accurate (the Keldan Spectrum filter is clearly more accurate), but is nonethless great and very practical for underwater video use (which explains its popularity). - The UR-Pro Cyan induces a general light loss in the roughly -1.6 to -2 stop / Ev range (being a colour filter, this is also relative to wavelength transmission, as discussed here) - Physically, the UR-Pro Cyan was made of acrylic or glass (not gel), with an orange to reddish tint, and was the steepness of the curve seems to indicate that it was an optical grade filter. If we take the available transmission data from the filter patent and order it on the wavelength/colour spectrum, we end up the following: UR-PRO CYAN FILTER WAVELENGTH TO TRANSMISSION, MAIN DATA POINTS Below 370 nm: 0% UV ULTRAVIOLET: BELOW 400 nm Below 400 nm: 25% VIOLET: 400-450 nm Below 410 nm: 27% Below 450 nm: 12% BLUE: 450-500 nm Below 470 nm: 8% Below 500 nm: 4% CYAN: 500-550 nm Below 520 nm: 7% Below 550 nm: 18% GREEN: 550-580nm Below 570 nm: 50% YELLOW: 580 - 600 nm Below 600 nm: 87% ORANGE: 600 - 650 nm Below 700 nm: 90% RED: 650 - 700 nm - We are also given a rough visual representation of the UR-Pro Cyan filter's transmission curve, which can be rendered as is on the wavelength spectrum: UR-PRO CYAN FILTER SPECTRUM TRANSMISSION CURVE - Combining these data sets, we can add the following projections for wavelength transmission cut-off (known data point are in bold type, projections are in italic type) UR-PRO WAVELENGTH TO TRANSMISSION, KNOWN DATA POINTS AND PROJECTIONS ALTERNATIVES In terms of possible alternatives, there seems to be a marked difference between optical grade photographic filters, which have might tighter, precise cut-off points, and design specificities like fully cutting off the UV spectrum, and lighting filter gels, which have a more sloped curve, with less marked cut-off points. - A relatively cheap and somewhat more accessible option would be to combine existing lighting gels such as fluorescent filters (FL) / orange colour temperature adjustment filters (CTO), or orange to pale red colour conversion filters (CC), with a UV blocking filter to steepen the curve. This seems promising, as illustrated above. However, one thing to look out for when combining lighting gels would be light exposure / stop loss. A loss -3 stops / Ev would be a reasonable limit. For smaller sensor cams like action cams, it would be best to stay in the -1.5 to -2 Ev / stop range, as anything stronger would introduce to much noise when shooting in ambient light. Some options to look into would be Lee and Rosco filters, such as the (discontinued...) Lee Pale Red 166 combined with the Lee 266 UV, or the Rosco Cinegel 3310 Fluorofilter, or other CTO / CC filters of their respective ranges (Rosco 166 Pale Red, Roscolux and Cinegel CTOs, etc.) - Another option would be to look into existing optical grade filters for photography (color correction, fluorescent filters, such as the Tiffen 47B filter for example) or those designed for other optical applications (microscopy, astronomy...). These would require no additional UV filters, but these will usually be in glass form, so less flexible, and more expensive. - Lastly, there would be the option of trying to tweak existing photo filter gels (Magic Filter or Keldan) to bring them closer to the UR-Pro Cyan, combining them with a minus green lighting gel for instance. From my tests on grading flat action-cam footage, Magic Filter's handling of magenta (inverted, when to other filters) is problematic at depth for my video grading use (more details here and here) but a filter like the Keldan Spectrum SF-1.5, combined with a gel giving it a bit more "bite" (a minus green gel?) seems like a promising base for experimentation. cheers! ben

Thanks for sharing this, really interesting. AF is doing a great job at staying on the crab and ignoring the smaller shrimps and bigger clownfish. However at 53 seconds in it loses focus as the crab is moving to top left of the frame, and regains focus when the camera moves in. Same at 1:56, would you know what is going on here? In the first instance, it looked a bit like the crab has reached the dof limit, but seems too shallow for this critter size - for the last one I'm wondering if AF is confused by camera movement? It almost looks like there's a weak artificial light source at the begining (I'm guessing it's sunlight), so I'm wondering if it's actually changes in illumination angles that throw it off balance twice. Do you think using a video light would have helped the AF lock-in on the crab by increasing contrast data? Anyway, it’s very interesting to see AF in action, doing a good job 5 years ago already.

from no-picture=didn't-happen to I-think-this-happened=picture 😁

IIRC the Nauticam GH6 housing works for the GH7.

Wow - AI augmented footage, or to quote the article Imax will "utilize its AI algorithm to explode the images". Boom 💣 The revolution is well underway - guess we can go soon go back to shooting in 1080p and let AI do the rest (including bringing bleached coral back to life and turning that trout into a bull-shark perhaps?). It will be interesting to see how we transition from capturing reality as best as we can to generating a computer-assisted reality we like better (and if we go all Black-Mirror, eventually choosing to see, inhabit and intereact in some sort of filtered and customized enhanced reality ).

Perhaps – in this type of scenario, where you’re following fast moving medium-sized action, not having to worry about focusing would certainly be a relief, but I’m also not convinced results would be that different. It would for sure make life easier if it works, but I think there might also be a risk of AF loss and tracking when the subject is out of the frame / lighting - which is bound to happen at some point - in which case staying focus-locked-in might actually be easier. Hard to tell – I know on my cam it wouldn’t work, but if Sony AF is as good for video as it is for stills, it could be very nice indeed in some cases! I chose this specific example as it was technically more challenging because of the fast moving of medium sized subjects, with little time to adjust. This might sound a little paradoxical, but for smaller macro to supermacro subjects I find it somewhat easier (MF examples of all sizes here or here). Based on my experience and the setup I use, but in the 10mm to 5mm critter size-range and below, depth of field gets so shallow that AF doesn't have much to offer. You basically have to move (nudge) the camera if the critter moves out, there’s just not enough range to focus-follow. But for fast-moving middle-range subjects (which are not that common actually), and also more tricky applications like small subjects free-swimming in the water column (black-water beckons...), I can definitely see the appeal of fast and efficient AF tracking. Tricky enough following the show and being stable! 😅 Bring back 80s home-video zoom-shots! 😁 Joke aside, I agree, it would be great to have some illustrations of latest AF tracking-technology being put to good use for underwater video. Animal-eye AF on the eye of fish moving in a school would be amazing, and I would love to have access to the extended-range / helping hand an efficient Sony AF system could give if it works as it's rumored to. AF seems like a no-brainer for stills, since you are effectively freezing the movement, but for video nailing the 10-seconds-minimum of focused, stable footage required for moving pictures ofen requires a different type of control over the camera. Really curious as to how others approach the issue and what works best for them.

As a follow-up to the Ultimate Filter Quest, the Rosco Cinegel 3310 Fluorofilter also seems like a good base for UR-Pro cyan recreation. Here are the specs: UR-Pro Curve is close – however a major difference I see with the Cinegel 3310 (as with the Lee Pale Red) is UV transmission. The UR-Pro cuts transmission below 370 nm to 0% helping with the strong blue/magenta cast we have underwater. Transmission of the greens, which is another big cast-generating headache underwater is down to 4% at 500 nm, so the UR curve is a bit sharper. I think combining the Cinegel 3310 with a UV filter gel (something with less than 50% transmission at 410 nm dropping to 0% at 350 nm or so, similar to the Lee CL 226 UV) should help with this as well, and give very close results.

Wow, indeed - I wasn’t aware DJI had a cine-cam range... 😅 This is good, as there is an in-house link to more professional applications, spanning beyond that of the stereotypical action cam user-base. Let's see if this feeds into their action range. Professional productions use action cams as backups, B/C cams and for dedicated application (the BBC /blue planet crew I saw in Palau in 2023 had GoPros setup for certain boat mounted angles, I think it was the GP5 and GP9), so DJI might be on to something if they ease up on the be-a-hero pov immersive-social-media angle and offer a more-rounded “rough-cam”… That said, regarding sensor-size/focus I’m a little worried at how workeable AF would be on such a cam underwater (particles…) – seems perfect for correctly tracking a “talking head” like in the Insta360 clip, but it could also mean trouble in our less than ideal underwater conditions…

Hear, hear! I'm also placing my hopes on DJI - 1" with AF please -- overall, judging by the user manuals, the DJI seems more like the kind of product I would want (for shooting in flat) for an upgrade than the Insta360. Speaking of the DJI Osmo Pocket 3, what's up with this product? looking into it, there's no underwater housing for it - is it just the shape factor, and DJI focusing the bulk of UW product offer on its waterproof action cam line?

Very interesting subject indeed, looking forward to reading more real life feedback, especially from Sony-AF users! I don't have much experience/feedback to contribute, as while not being professional nor having a cinema rig I also shoot in manual focus both for wide and macro. This is not because I think using AF is amateurish in any way, but because in my case AF just doesn't work underwater. Lumix LX10 autofocus is slow, and CAF tracking uses up way too much of the cam's very limited battery power. Other major issue is particules in the water, water movement, there are simply too many things leading AF to tracking in the void and missing shots. What works best for me is manual with back-button focus AF (AF/AE lock, set to single area AF) and focus peaking for visual feedback. - For wide angle, it's mostly hyperfocal and not an issue at f/8 to f/11 with the Inon UWL-H100, just back-button lock and good to go, reefs, sharks, mantas etc... I shoot wide in ambient light with a filter, so peaking info is more limited, but there's usually enough feedback to judge how much is in focus. - For macro/supermacro, there's more going on on the focusing front, and getting small critters both in focus and properly lit is critical - I acquire general focus, and then use peaking to see where I'm at. I was using the focus knob at first, but while it's very useful for fine-tuning the focus point on an already acquired focus, it doesn't really work for acquiring focus for tiny critters - backbutton AF and nudging the camera (on its quadripod) really works best. So it's usually nudge/backbutton acquire> nudge > fine tune In macro shooting's full artificial light, focus peaking is generally wonderful, and once the focus point is acquired you can really adjust to your liking. For tiny critters, DoF is super shallow already, so aperture considerations tend veer to the artistic (the how-shallow-can-you-go focus-limbo dance 😁)... If there's a little surge, most tiny critters will swing in and out of focus and DoF is so shallow CAF wouldn't make much of a difference... - Focusing is, however, much more tricky for closeups/portraits of medium-sized critters in movement - but I find this is also very much size/behaviour dependent. This crab clip was in constant fast motion, roughly 10cm wide critters, but there was use sufficient leeway to keep things in focus, following the show and reaquiring critical focus with backbutton AF when needed, and while this wasn't really macro, it was sufficiently artificial-dominant lighting for peaking to work great and see when I was nailing it. Even if playing with aperture and depth of field, UW action is usually slow enough to reaquire focus and get a decent clip, especially with larger to medium subjects like turtles, octopuses etc - The trickiest bit, and one where I would love a super-fast autofocus, is tracking fast-moving small critters, say in the 5cm range, especially of the free-swimming variety... This is hellish, as it's combining shallow DoF with fast movement, and this is where I'm missing the most number of shots. I haven't found a good solution, and if the critter doesn't slow down it's very difficult to get usuable footage - and even if it's in focus and stable, on my cam zoomed-in shallow dof + movement makes for some very sea-sickness inducing clips, as the sharp/stable critter is moving in front of a blurry fast moving background, and quite the roller-coaster ride.... Fun watch (weeee!), but I've never used those shots, as it's just too much... Would probably need a lens with more depth of field to shoot something less psychedelic and useable... Classic free-swimming critters like ghostpipefish (usually in the 5 to 10 cm range) can be tricky, as while they don't move around too much, staying close to their camouflaged habitat, they can have a tendency to move in and out of focus - partial hand-held, ie using one or to legs for support but allowing follow movement works well (or fully handheld if stable). But then it also depends on conditions and the subject itself - some are also nice and cooperative and stay in one place to allow for multiple shots with different focus areas (eye closeup, mouth closeup, shallow dof...), nice and easy. I'm also concerned about black-water video shooting scenarios, which combine hand-held, small moving, critters and lighting considerations (critical with transluscent critters). This is where efficient AF definitely sounds like a good idea (so you can focus-pun intended - on lighting), and I'm not sure how things will go IRL. I do have a hunch that a "light-box" type config might be good enough - if you know that the central part of your "light box" square is in focus, then it's mostly a question of keeping the critter in there as you follow the movement. But this is just a theoretical projection for now, never-try-never-know as they say... All this to say that MF + backbutton AF works for me, and tracking animal eyes hasn't been much of an issue - if it's big enough, you can follow peaking points handheld, and if smaller then a semi-handheld solution allows for the small movement required to do so... Then again, I've also never been in more cinematographic shooting scenarios where I had to track the face of diver swimming towards me for instance, for which a good autofocus or solid manual tracking option would be absolutely necessary.... *** I'd like to add that while the video forum clearly has a really limited reach, it's really refreshing to take part in this type of concrete, practical technical discussion! I really wish there was more of that (along with more aesthetic/artistic discussions to even things out, of course...). I've been reading into WeP archives recently, digging for historical info on a filter, and there was a bit more of this going on 20 years ago, when you had a lot of users experimenting with video rigs and sharing practical, technical info with their peers. Then it all seems to have died out a few years back, with video discussion flatlining, paradoxically exactly when sharing video was finally becoming possible... I have a feeling this is linked to the rise of bandwidth-enabled commercial video content, where semi-professional video-shooters started working as "content creators" sharing their content online (liveaboard-based videos, for instance, were no longer limited to trip-recap videos sold to customers, but became promotional content actively shared online, like professional advertising content for resorts or locales), and were thus much less inclined to share information (maybe not so much out of pride as out of protectionism?) This dying-out of practical discussion also happened at the same time as the rise of social-mediable clips of vloggers and YTubers, which probably accounts for 80% or more of video content found online, and mostly 1-shot-stand affairs. Industry, truly professional UW cinematographers have always been more secretive, and working in a world of their own, with techniques closely linked to the equipment (and teams...) they have access to - inspiring, but a little out-of-reach...

As a follow-up, sales-pumping "rumours" strategically circulated online hint at the upcoming DJI Action5 having a 1" sensor, like the InstaAce or the already existing DJI Action3.

Looking into alternatives, on the Lee Filter side, the Lee 166 Pale Red is somewhat similar: Lee filter's customer service suggested this gel could be combined with the 226 Lee UV to block the UV spectrum, combination which would give the following curve: There are differences - the 600nm wave length with its warm yellow/oranges, is already at 87% transmission on the UR-Pro, as opposed to 64% on the Lee Pale Red 166 + 226 Lee UV combination. In the blues the UR-Pro's 410nm peak at 27% transmission is moved to a greener 420nm at 22% transmission, but otherwise it's quite close (with some blues but also a strong filtering of the 400nm greens, 5% for the UR-Pro for 4% for the combo). I'm guessing it will be a little cooler and with a bit more green, which doesn't sound too bad! Anyway, should be worth a try... b

Following up, I tried to find a blank light spectrum file I could plot values onto to give a visual rendering of the filter data, but couldn't find anything to work with... So I made the most of my fragile photoshop skills and adapted the filter curve given above by scaling it to an existing filter spectrum graph... (if anyone knows practical way to render the available data in a more accurate manner, do let me know!) Anyway, here are the results: UR-Pro Cyan filter spectrum transmission, based on available patent data As a reminder, known values for light wavelength (nm) to % of incident light transmitted are: Below 370 nm: 0% Below 400 nm: 25% Below 410 nm: 27% Below 450 nm: 12% Below 470 nm: 8% Below 500 nm: 4% Below 520 nm: 7% Below 550 nm: 18% Below 570 nm: 50% Below 600 nm: 87% Below 700 nm: 90% **** While this quick-and-dirty visual is far from perfect, it does give a good idea of how the filter is acting in blue water, and affects spectrum transmission and colours making it to the camera sensor. Some observations: - As noted in empirical tests, filtering of the blue-green spectrum is quite pronounced, with only 4% transmission at 500 nm (which removes the greenish hues, pushing them to yellow-orange) - There is a strong transmission of the orange-red spectrum, 90% transmission at 700nm+ (warming effect, to compensate for the filtering effect of water and restore colour balance) - The filter does let some deeper blues hues through (25 to 27% transmission in the 400 nm zone, likely to avoid losing water-column blue tones), while also strongly filtering out darker blues and,importantly, almost all the purple/magenta hues (0% transmission below 370 nm!) This strongly marked section of the curve seems to be the UR-Pro's most characteristic spectrum filtering feature, and would be the one to focus on when looking for alternatives: cheers! ben

Good to know, thanks - I have the AOI wide lens and find it almost too wide, but image quality gain is worth the transfer to a wider-angle / smaller subjects than what I've been using over the years (medium, then linear fov - the AOI lens, like the two others is designed to be used in wide mode).

As a follow-up, I ran some tests today on the GoPro with a combination of two stacked gels, one original Magic Filter gel and one Keldan Spectrum SF-15. Tests were done on an overcast morning, in murky greenish-blue water, in tropical ambient light only (east Bali). As in the previous tests, GoPro7 was on flat profile (WB native and GoPro colours), auto ISO locked at min 100 and max 1,600 (which is what I usually use for wide angle tropical ambient light shooting with the GoPro, max 800 if possible), 4K, 60fps, medium fov. Note: AOI wide lens was not used as the person handling the camera for these tests - who happens to be my wife - couldn't be bothered with the extra weight 😅 Quick summary: not usuable / a practical solution at depth. - good in the shallows (the Keldan gel evens out the Magic Filter), but too much light loss at depth (combined exposure loss should be Keldan -1.5 Ev and Magic -1.6 Ev so a total of roughly -3 ev - too much to handle for the GoPro at depth in today's murky conditions, footage was grainy, meaning the camera probably pumped up to 1,600 ISO around 15m) The other issue is the Magic Filter's orange/magenta spike at depth, already noticed on the previous test. The Keldan gel doesn't help with this, and simply reduces the colours data making it to the sensor. Here are some quick screenshots: - 8m depth, on a flat plateau worked well given conditions - white balanced and quickly graded in FCPX (looked good just after setting the WB, plenty to work with...) However, deeper and with less light on the slope, things got ugly... 18m depth, on the slope While the footage isn't pure garbage, it's quite desaturated (which looks ok-ish) but the issue is really that's there's really not much left to work with. The marked orange/magenta dayglo boost of the Magic, already noticed on the previous tests, is still there, waiting to be revealed.... All it takes is boosting the highlights+midtone saturation to the max, to see what colour info we really have to work with: Ouch... The other issue being the grain - ok, conditions were really not great and got worse during the dive, low light and particules, but it's still very grainy - other footage is worse in this respect. This is something to keep in mind when working on stacked filters - on my aging GP7 at least, -3Ev is too much for the camera to be practical, unless staying above 10m in tropical light. I guess a loss of -1.5 to -2 Ev is the sweet spot.