Extreme Cam

I was looking at these yesterday, their spec looks very good and worth a punt at the price:http://www.ebay.co.uk/itm/1080P-Waterproof-Sport-Helmet-Action-Dive-Camera-Cam-DV-/320755558628?pt=LH_DefaultDomain_0&hash=item4aae8568e4

Interesting. If the sensor is exactly 16:9 then the sensor could be 2992x1683, which is 1.558 times 1920, more than enough for a good decode to 1920x1080. However, the difference in field of view between 720p and 1080 mode mean that 1080 doesn't use the entire sensor, but 720p probably does. So, at a guess, it uses exactly 1920x1080 of the sensor for 1080p, meaning that the resolution should be the same as the Sony A1. And at 720p it would, probably be using 2560x1420. That gives about the right relationship between the field of view figures. It's normal for a camera not to use the full pixel count, leaving some round the edge, covered, to provide the black balance data.

The camera sounds enough fun for me to be interested in one ...

You're not alone. They've sold out!
http://www.chinavasion.com/sports-action-camcorders/crocolis-hd-1080p-full-hd-extreme-sports-action-camera-waterproof-n1/

For me the really interesting part of that review is the price reduction on the Drift Innovation Stealth 170 down to £149. I bought one of these last Xmas when they were priced at £279 and used it whilst skiing at Easter. I carried out side by side comparison with my skiing chums GoPro & there were no major differences in performance between the two. (Pictures from both imported at 1080 into Avid MediaComposer). The Drift exhibits the same angle of view characteristics when switching between 720 & 1080. It's also equiped with a rotating lense & remote control that make it a delight to use. At the reduced price it's a great alternative to a GoPro.
http://driftinnovation.com/hd170-stealth-camera/

I think that the price drop is due to the introduction of the HD Action camera which is smaller and has a higher spec, (including HDMI output making it a competitor to the Replay XD1080).

Steve

The spec sheet says the Crocolis is a 'waterproof' camera but GoPro claim the same thing. Only thing is GoPro fail to mention their's doesn't give sharp pictures under water, so I wonder how this beast fares?

tom.

It should be ok, I guess. The sensor has to be tiny to get infinite DoF, and it's ludicrously wide angle as well, so I reckon it could still be focused in water.

But all those points relate directly to the GoPro Alan, and that camera's unsharp under water. Mind you, the GoPro has to be fitted inside a waterproof housing to submerge, and this ExtremeCam doesn't.

I noticed in the YouTube review he talked about the 'aperture changes being slow', but I'm thinking it probably shoots at full aperture all its life, and it's only the shutter speed that's varied as in the GoPro.

tom.

I suspect that's the case, no iris at all. And you've pointed out the one difference in those cameras that can affect focus. So, maybe it works, dunno, we'll have to wait and see.

Actually I thought the smooth slower aperture change looked quite alright. I have my EX1 set about the same if I'm in auto iris (not often)

Do you know why? The reason I ask is that I do a lot a lot of underwater photography, and can't see why any camera should give worse results underwater than on land - at least not if it has a flat glass surface furthest away from the sensor.

So why don't naked eyes work very well underwater? It's because the outer surface is curved, and is designed to have the outer layer as air, with the refractive index of air. Open the eye underwater, and the curved eye/water junction gives completely different optics, which the eye can't correct for. (At least, not unless you're a south sea pearl fisherman, and have been training your eyes to focus underwater virtually since birth. ;) )

Put a camera underwater, and the first thing to worry about is obviously keeping it dry. Second point is optics. There are basically two ways of doing it. Simplest is to make the opening a flat piece of glass, the camera will work just as on land focussing wise - but there will be a magnification effect, objects not being where you'd expect them to be. Exactly the same as looking into a pond - you can focus easily on objects on the bottom, but throw a spear and it won't go where you think.

Second method is to use a dome port (and the box in my hall has just cost me £150, not including the main housing). In that case, the water/air barrier is curved, though the glass is the same thickness throughout. (Hence it's not a lens.) The advantage is that with the camera lens at the centre of the dome, the view in every direction is at right angles to the glass - hence no magnification effect. Wide angle lenses stay wide angle with the same field of view.

But, the effect is to give a curved water surface, which DOES act like a concave lens. Most DSLRs have no problem with this - for an object at infinity, they will just focus much closer to compensate, though obviously the minimum focus distance of the lens will move away. It is recommended (and I must do exactly this......) to get something like a +2 diopter lens to screw on front. Restores the minimum focus distance and (apparently) reduces chromatic abberation.

So - if any camera is waterproof, and has a flat front glass, it shouldn't have any problem being used underwater with no adaptation. Just as all you need to see underwater is a flat piece of glass with air between it and the eye. You wouldn't even need that if the front of the eye was flat.

Good explanation! Now we know why you call yourself "Infocus" :-)

Infocus - Go-Pro know all about their camera's failings under water, and various other people have modified their waterproof housing to include a flat front glass that replaces Go-Pro's curved lens.

AFAIK the latest GoPros come with a corrected lens front.

Do they? News to me.

This looks good.
http://driftinnovation.com/drift-hd-action-camera/

It has a manual exposure mode and a mic input. Shame the shutter can't be manual as well.

Ah curved front - that fits in with the basic theory!

It's pretty silly to supply it with a curved port and no means of correction if the intention is to use it underwater - or did they just intend it to be waterproof but not used underwater?

An alternative method of modification to replacing the curved front (strictly, it's not a lens - it won't have any optical effect in air) would be to put a positive diopter lens behind the port and directly in front of the lens. This would have a the effect of maintaining the (wide) angle of view in water, whilst correcting the focussing - putting on the flat front reduces the u/w angle of view. Downside becomes that it would need the diopter removing for above water filming.

I'd hoped that you'd believe me when I used the word lens, infocus. It does indeed have a mild optical effect when used in air (why, GoPro?), but still leaves you with iffy standard def under water. So yes, Go-Pro correctly state it's waterproof, but are economical with the truth regarding is sub sharpness.

The flat glass modifiers have had to fit quite a big flat glass element, and even with it being so big you get slight vignetting in air. GP wanted to keep the combo as compact as possible, I'd say.

The GoPro is intended to spend most of its life inside its little protective water-proof housing. This is a shame as your front element now becomes an uncoated plastic injection moulding, rather than the beautifully coated front element of the camera's 5mm prime. The increase in flare is quite noticeable.

I think the south sea pearl fisherman you refer to use bright light (=small apertures) to see under water. We can all do this to a certain extent.

tom.

I should have known better than to doubt you..... ;) But then surely the people who replace it with a flat glass for u/w use still have a problem?

Well "waterproof" really only means it won't let water in - it's exactly what you'd want for such as a camera fixed to a surf board, say. But I have looked at the website and it does say "waterproof to 60m" - the implication I'd infer is that it's suitable to use whilst scuba diving. (And not just before you drop in the water.)

No, it's more than that, and at the depths they go to it's not that bright, even in tropical waters. (Relative to the surface.) What they do is exactly the same as my Canon 550D does behind it's dome port - focus what would be very close in air, such that it evens out the effect of the water on the dome.

http://www.bbc.co.uk/news/science-environment-12151830 - with a pretty amazing bit of u/w video.

It's worth mentioning that you can get diving masks in a curved (dome) shape. The glass thickness is the same, so no lens effect above water, they rely on the water-glass-air effect. The person I know who had one was strongly short sighted on land, and again the effects cancelled each other out.

I'm now long sighted and have to rely on positive lenses in my mask to correct underwater. The downside is that they only cover a fraction of the field of view - in my friends case the dome effect meant his field of view was actually much BETTER than even normal vision in a flat mask. So don't be put off scuba diving because of strong short-sightedness!

Back on sale.
http://www.chinavasion.com/sports-action-camcorders/crocolis-hd-1080p-full-hd-extreme-sports-action-camera-waterproof-n1/

I know they describe it as 'waterproof' but then so do GoPro with a camera costing nearly 3x as much. All I want to know is, does it give sharp images when submersed?

I'll let you know when it arrives. And I'll be pointing it at zone plates and all the rest of it.

This is NOT an underwater camera Tom.

As I'm sure you know, you need to spend a bit more than £100 to get "sharp images when submersed"
We've just used 6 of them on a hang-gliding shoot for NHK. The 6 cameras cost less than the Producers hotel bill for one night!
The crew couldn't be @rsed to go through the paperwork to take them back to Japan so they gave them to a charity shop in Cumbria.
I haven't seen the footage as the cards were all whisked off to DHL each evening but I gather NHK in Tokyo are very impressed.
"Waterproof" , perhaps - but you'd be a brave man to try and achieve "sharp images when submerged" with this camera.There are so many more expensive options available to achieve underwater clarity.
Having said all that, I haven't tried it underwater. Who knows? Perhaps Alan Roberts - nee "Cousteau" will enlighten us.:)

I'm so pleased to hear Alan's going to poke and prod it. Dugi - I only want to use this down to 3 metres or so, I'm not after documenting the raising of the Titanic. The GoPro I used gave such disappointing submersed footage (so who cares if it's waterproof to 60m?) and I'm just hoping this ExtremeCam will be better.

Infocus - my underwater Eumig Nautica (with its little in-built depth gauge) keeps the image sharp by allowing the water to flood the space between the aspheric wide-angle element and the camera's (3x zoom) front element. This water (I imagine) cleverly forms another element in the optical path, so keeping the image sharp.

tom.

PS, I note the GoPro Hero2 has been announced with 11mp chip (hope that hasn't damaged the low light performance) and external stereo mic socket. Their video shows sharp underwater footage, but it's not a bullet-point in the 2's spec.

Tom, that explanation sounds right to me. This camera is waterproof only as regards getting it wet (or, at least, that's how I read the spec). I seriously doubt it'll work well under water, and I'm not going to try total immersion to find out. Since it's sensor is tiny, and the lens extremely WA, to DoF is huge, and so I expect it to keep focus reasonably well, but I wouldn't use it for total immersion.

wouldn't care to let me know which charity shop would you Dugi :)

robo

If you're going there Brian, pick one up for me to will you?

Peter

Oh go on Alan, be a sport (unless, that is, the instructions say DON'T). Might make a good film to be put in the washing machine along with your socks. Could go viral on YouTube. :)

I'll wait and see what the instructions say, then work out something reasonable. You'll just have to wait ...

I just e-mailed the Vision engineer in Japan for you and he says he gave them to a charity shop near the hotel but he cant remember the name of the shop. The hotel was the Hilton, Newcastle Gateshead Bottle Bank Gateshead NE8 2AR.

many thanks indeed Dugi - sorry to say that's no where near (other side of the country) - I'll bet that nice Mr Nattrass is already standing outside the door :)

robo

Might have a look around Gateshead on friday, know where the Hilton is and there are not a lot of shops round them parts!:D

I know the GoPro will do time lapse in stills but what about video or am I being contradictory in that all time lapse is stills?

Ron

There's a difference between shooting photo-resolution stills, and video-resolution stills. Both work, but the photo version allows for pan-scan.

There are two aspects to this - is it waterproof, and how does it perform optically when submerged. I have to disagree with Alan as regards spec - go to the GoPro website and the spec (for the "surf" version - http://gopro.com/cameras/hd-surf-hero-camera/) specifically states "Waterproof Quick-Release Housing (197’/60 m)" That's exactly the same as my Ikelite housing, which safely made 35.9 metres a couple of days ago.

But they don't market it as an "underwater camera" - it's an assumption that others are making based on the 60m rating. (Very reasonably.) It's marketed as a "surf" camera. I assume that's because they are aware of the optical issues. Which just leaves me feeling it's a bit silly to construct it capable of withstanding 7bar of pressure, but not letting it optically focus underwater.......

I'm not going to comment on any of this yet, because I haven't got the camera or full specification yet. I don't make guesses unnecessarily. I'm not interested in the GoPro, I'm buying the ExtremeCam, which is now on its way.

How about post #1.
Pay attention Chrome boy, 'slap'. ;)

Well I trolled around every charity shop in Gateshead and couldn't find the camera's so either someone snapped them up or is pulling our legs, did see a nice RED MX in the Oxfam shop but they were using it to keep the door open!:D

Many charity organisations now sell some of the 'better stuff' through Ebay (I've trained a couple of charity staff on how to get the best photos for Ebay), might be worth putting a search on Ebay and saving it - Ebay will email you if anything matches your search terms.

Mine arrived yesterday. I'd have posted earlier by my phone line has been down since Friday.

The lens front element is flat, and so I'd expect it to focus normally under water. I tried in the car, using the suction mount, and couldn't find a way to fix it that allowed the camera to be the right way up, so all the shots are inverted (actually, rotated 180 degrees). It shows the expected jelly effect from vibration, and the sound quality is pretty dire. I'll be trying out the external mike later. Barrel distortion is considerable, even in 1080 mode, not tried the wider-angle 720p mode yet.

Incidentally, the charging lamp is red when charging, blue when done. The reviewer said it didn't change, mine does. BUT, I found you can put the battery in any one of 4 ways, and close the lid. Only one way makes the electrical contacts. That could be fun :)

I'll be trying to work out a way t test resolution later this afternoon (it's not obvious, because the magnification changes away from the centre, so it's hard to work out how to frame the test chart. But I'll finf a way.).

Overall, I'm impressed. It's a cute toy.

I'm getting all come-over excited Alan. All I need to know is does it focus in the bath water?

Dunno yet, but I guess it does, just wait. BTW, the video files are QT, I'm just looking at some now ...

OK, I've been testing. Not easy because the barrel distortion changes the scaling, but ...

The spec says that the sensor is "16 Megapixels for still picture (5 mega CMOS)". Still shooting can make images at 16/12/8/5/3 megs, which sort of makes sense. Stills are JPEG, movies are QuickTime MOV (AVCI H.264 at 8.069Mb/s according to Gspot, which is easily good enough in this case.

There is no iris, exposure control is by gain (upwards) and shutter (downwards). the lens front element front surface is flat, so it should keep focus under water. I haven't tried that yet. The spec says "waterproof design" but gives no hint at depth or pressure, but I'd guess a foot or so should be ok. I'm thinking about how to test this non-destructively.

I shot a 5M still, which turns out to be 2592x1944, and 2592x1944=5.03 Meg, so that's the size of the sensor.

Testing with a 1080 zone plate, I framed it to fill the image height, then moved the test card so the the bit I wanted to see was in the middle, where the curvature of the distortion filed is least.

1080p is available at 25 and 29.97Hz, at 29.97 it's delivers a 1920 image, at 25Hz the image is 1440 wide. In the 29.97Hz case, the delivered content resolution limits at 1268x810. The image is formed from a central cropped section of the sensor, 1920x1080, so the resolution can't ever get much better than this, same as in the Sony A1/HC1. I haven't tried the 25Hz version yet, but I'd not expect the resolution to be any different.

720p mode is from a larger part of the sensor, 2560x1440, exactly twice 1280x720, so you'd expect to get decent resolution, but, it delivers about 1050x670, which means that the Bayer pattern decoding isn't at all good, no surprise there in such a small cheap camera.

I'm neither surprised nor disappointed by all this, it's what I'd expect. I still like it.

Hi Alan,
Thanks for posting your test results to date. Very helpful. I took a chance and ordered one myself a few days ago. But on re checking it appears to be branded under the name of Wi Camcorder. All the specs and outward appearances and accessories are identical. So fingers crossed I have ordered the same as you.
http://www.ebay.co.uk/itm/130563418094?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Mick

According to the go-pro website the spec says "197′ / 60m".

See http://gopro.com/cameras/hd-hero2-surf-edition/

(Second line after "What's included")

It's not a Go-Pro
@Alan Roberts
Spec that I've seen says it's OK to a depth of 1 metre but, as I said earlier - this is not an underwater camera

Ah! My apologies, a lot of this thread is about a Go-pro, but I do now see that a little way back Alan said "I'm not interested in the GoPro, I'm buying the ExtremeCam".

According to this - http://www.exeros-technologies.com/extreme-cam-full-hd - ExtremeCam quote "This rugged and compact action camera is fully waterproof to 10m."

I would check those underwater depth claims because if you check the spec details on the same page it only claims the camera as waterproof to a 5 metres depth

Mick

5m or 10m it's academic.
Alans bath water never exceeds 18".. I understand. :D

This is not an underwater camera

Further quote from the Extreme Cam website: (my emphasis in bold )

Surely you're not saying that anything on a manufacturers website is less than 100% accurate with no exageration? ;)

£270 from the English address vs £108,34 from ebay for the same thing. But can it really be the same thing at 2.5 the price? And why the big red letters Dugi?

Gentlemen, let's just fix in our minds that I'm talking about the ExtremeCam, £106 from Hong Kong, and which is the subject of this thread, and not any other camera.

I have the camera's handbook in front of me, and on page 13, called "Technical Specification", near the bottom, it says "Waterproof - Waterproof design". It makes no mention of any depths to which it may be expected to work, none at all, zero, zilch, nada, kein, rien, null ... I don't care what websites say about it, I have the camera and the specification as real hardware.

I am not going to dunk it in water to find out, but I might just poke the lens under water to see if focus changes.

P.S. I said that Gspot identified the video coding as AVCI; it doesn't, it calls it AVC1. And, no, I don't know what that means either. But I confirm that it's H.264 and 8Mb/s. And that Edius has no problem with it.

H.264 is also known as AVC1 in some edit systems and as you say 8mbs is enough for this type of application.

It has to be 12-frame long-GoP, and 8 is perfectly adequate for it. H.264 is the official name of the MPEG4 coder, and AVC is a wrapper, this time inside the MOV wrapper, so not all the 8.03Mb/s is spent on the video, some is spent on the two layers of wrapping, and a little on sound (but not much).

Because the little black ones I used at first seemed to have no impact.
If you're still keen to see this camera submerged there's a video here - http://vimeo.com/29285015.
I haven't tried this but the Japanese sound guy was telling me that when you use the external mic. on this camera the internal mic is not disconnected so its sound is also recorded. If you separate the 2 mics out then you get a bit of quality improvement, not much though.

looks ok.

I assume that the misty lok at the end was due to water ON the lens, rather than IN the lens and he didn't bother to wipe it off?

Given that it has an internal mic, there must be a vent to get the sound in, and of course the external mic socket. They must provide a possible means of water getting in

Most definitely so, and that's why I'm not going to submerge it. The on-board mic records to the right channel only. Not sure yet what the mic sockdet records to, but I'd like to think it goes to the left. The recordings I've done so far all have sound track on the left and the meter bar in Edius shows a constant 0 level on the left.

I've just got back from a hectic bike ride with it on the handle bars. I took it out in the car a couple of days ago, mounted in the windscreen. It's interesting how polite other drivers (coming towards me) were :D

Maybe a little premature, given that the great AR's not posted definitive results, but I've just bought one.

I ride motorbikes so a few journeys may get recorded

I'd have thought that the dodgy audio could be got around by only using the built in as a guide and using a separate recorder should it be needed. I record a few live band gigs and this could be interesting mounted on the lead singers mic stand. the neck of a guitar or a cheap and easy overhead

Hopefully it will stay in sync!

I can confirm that the internal mic records to the right channel, and the external one records to left. Plugging in the external mic does not disconnect the internal mic, you get two channel recording.

I've noticed a lot of rattling sound when on the move, both car and bike. I don't think it's any hardware shaking in the camera, but can't think what else it might be.

After just being out on my bike too the rattling sound is probably your teeth..
.. or external mike cable, or it's socket not being a tight fit or socket housing rattling against cam body?

Neither. I get the rattling when it's stuck the the windscreen of my car, and my teeth certainly don't rattle. I haven't tried the ext mike on the road yet, so it can't be that either. I've tried shaking the camera around, and nothing inside it rattles. The mystery continues ...

Seems to work very well underwater for a camera which you claim (in big red letters) to not be an underwater camera!?!

The spec says it's 'waterproof' and the guy with the fish shows us that this means it works underwater (for a bit at least) - OK it's not a dive housing, but it seems to be a lot more waterproof than most cameras (a friend of mine put an canon XM1 in the sea once, that was the last time it worked, which is kind of the response i'd expect from a camera which is "not an underwater camera", this thing on the other hand seems to work for filming fish so i'd say it is waterproof at least!)

Anyway its so cheap that really who cares if they break it? Surly the point of these kind of cheapo extreme cameras (inc the gopro) is you can afford to treat them badly and thus get amazing footage which you wouldn't shoot with a 'real' camera due to the expense of replacement?

It probably depends on your definition of "underwater camera".

Go to somewhere like Cameras Underwater, and they tend to come in roughly three flavours. Those like ewa-marine which are really just intended for snorkelling with (so waterproof to only a few metres), then mid-range (typically rated to 40m) and then "true" uw cameras, normally rated to 60m and below.

Sounds like the ExtremeCam comes in the first category?

The specification just says, 'waterproof design', that's all, nothing else. And although it's cheap, I don't intend to risk my own money by dunking it deep into water just to find out if it goes bang.

You could always add a safety cover and stick a condom over it!:D

It rained when I was out on the bike yesterday (I've shed a stone that way this year), so it got showered on - no problem. It's use at depth for prolonged periods where I'd not even consider it as suitable. For that, a membrane cover would seem suitable.

Mine arrived this afternoon, although shown on ebay as a wI camcorder it came badged as an Extreme cam the same as the original youtube posting and would appear the same as Alan's. Only down side is that it didn't come with a UK adapter plug for the charger. I have one, but where!. At least the battery was fairly well charged so I can play with it this evening, hopefully finding my plug or buying another tomorrow morning. At first the video card would not stay clipped in the slot when inserted, but this now seems to work ok. Hopefully it just needed to loosen up the retaining mechanism.
Mick

Interesting. Mine has a universal mains adaptor, 13A plug pins and loads of sockets for various plugs worldwide, but there was no rubber band to hold it into the clip. Never mind.

Incidentally, I've tried the HDMI output into a Focus Enhancements MDSDI-1, which takes any sort of analogue, and HDMI, as input and delivers SDI/HDSDI. It didn't recognise the camera signal in 1080 mode. I suspect that's because it's genuine 1080p and not 1080psf. I think, but am not certain, that the genuine 1080p variant was developed after the FE box was designed. I'll try it again with 720p, that ought to work.

The focus boxes do indeed fail to do anything with 1080p - they were around before 3g SDI was.

I'd be interested in your opinion of the focus box - we brought a few of them, which we chose largely because you mentioned them in the BBC docs, generally they work well, but i've had a few issues with HDMI being converted - getting odd green flashes in the SDI (going into an Echolab ATEM switcher) using the component input rather than the HDMI has fixed it so i'm a little puzzled as to what the issue was.

I've not had any problems like that, but most of my use of it has been as an ADC rather than HDMI in. But I haven't really used it for a year or so, largely because I don't get to see cameras that have no SDI/HDSDI output at the level of cameras I'm asked to test. Analogue has long gone. Mine will be pensioned off very soon, when I get a new laptop for work, having HDMI out and USB3, so I can use the BM Ultrascope for monitoring, and capture uncompressed to that BM box that does it onto SSDs.

P.S. I seriously doubt the ExtremeCam is making a 3G output at 1080. I does 1080p at 25 and 29.97fps, not 60, which needs 3Gb/s. We're talking about 1080p/25 and 1080p/29.97 rather than 1080psf/25 and 1080psf/29.95, which are both in the 1.5Gb/s system.

Anyway, yesterday was too busy, but, today I've just tried it at 720p/50 and the FE MCSDI-1 recognises it, no problem. I'm going to take this as a confirmation tyhat the HDMI output, at 1080p, is indeed 1080p and not 1080psf.

Not long ago I watched a series of YouTube tests of 'helmet cams' which I thought were pretty good - the guy had bought and used a lot of these GoPro type cameras and set about testing them in a real-world sort of way.

Stupidly I didn't save the URL, but can any of you people help me find these tests again?

tom.

You're not referring to the intro of the clip linked by Dugi in post 1 of this thread are you?

No, I know the one Tom's referring to )but not the URL). He tried several different cameras, on bike, motorbike, helmet etc., the results were quite entertaining.

Davge R S - that's the one. Thanks for rounding me up and pointing me in the right direction (the sheep-dog bra, remember?)

The 2 Ronnies is unforgettable - including the Nuclear bra - IIRC that had alot of fall-out. :eek: :D

My Extreme cam came today, 8 days after ordering it from China. GPB 106.99 via ebay, delivered to my door. Looks perfect, I'm impressed. And so many accessories, brackets, adapters, wires, connectors - even a car socket charger. Lovely soft-feel paint surface with anodised bright trim. I'll be giving it a workout later.

tom.

The only two niggles for me:

1: the lid drops rather than raises, so it;s hard to see the screen when anything's plugged in.

2: the suction pad is meant for vertical surfaces, so is useless for car windscreens. I haven't had a car with a vertical dashboard for over 40 years now, the only way I can mount the camera in a car is upside down.

My only niggle so far is the lack of any sort of lens cap for that very vulnerable front element. I'm sure I'll find some sort of plastic cap that will fit, but when I look at the whole heavenly host of included accessories, the omission of a lens cap does seem rather odd.

Spare batteries forthe Extreme cam are 4.99 at 7dayshop, delivered. 3.7v 1800mAh. Not bad.

Note that it can go in four different ways, only one of which works :)

Now have a push-on lens cap. Top of one of those little WD40 aerosol cans. Perfect.

Neat, that gives me an idea.

Of course you're correct Alan, the front element is flat, but what we're seeing here is a plane-parallel sheet of (what appears to be) uncoated glass that covers the little 5mm prime's beautifully coated front element. The surface outside the prime's front element is coloured purple to make it look as though the flat glass is coated.

The flat glass has the waterproof seal around its circumference.

tom.

Yes, but I think that still means that it should be ok under water though.

Another find: with the rear door open the audio is immeasurably better than when it's shut (though the s:n ratio is still pretty dire), and I shall use it with the back door slightly ajar whenever that's possible. Makes sense - seal off the mic when submersing.

So what's that tiny hole for forward of the tripod socket and (useless 'Radiating') little screw? The hole is clearly identified as the mic in the instructions yet it appears to be exactly where the chip (focal plane) is situated, so I wonder if it's for an end-of-line tweak? Odd - I don't like the thought of a waterproof camera having little holes in it.

tom.

More findings about the Extreme cam. Firstly it's completely watertight down to at least 2m and the little mic works surprisingly well. You can delete your red-letter post now Dugi. Here's a few seconds in the local pool, shot in the 'full HD' mode of 1080/30p:

http://www.youtube.com/watch?v=8EiDeoSnTEU

This mode loses you a lot of wide-angle coverage, but looks slightly better than the 720/60p mode to my eyes. The GoPro has a faster lens (f/2.8 vs f/3.6) so handles this sort of lighting rather better, with less gain and noise. The GoPro is generally sharper too, though not when submerged.

Next - don't forget to format the SDHC card in the cam before you go out shooting. In my excitement I simply popped in a card I'd been using in the 60D Canon and went out shooting on the Extreme cam. I could replay all the movies and stills on the its tiny screen, but I couldn't find any computer that could access the files, either using a card reader or connecting the ExCam via USB.

tom.

A friend, who like me purchased one of these, decided to try his in a rock pool. In less than 4cm of water and in less than two mins submerged, it let in water and packed up. He is unsure where it leaked, but the lens fogged up and the memory card was wet, there was also traces of damp inside the back cover. It may have been a one off fault, but at the moment I am reluctant to try my in water. Beware !!!!!!

Mick

Sorry to hear that Mick and here's hoping your camera will turn out to be more watertight. Of course before you shut that rear door you should inspect all four sides of the rectangle, making sure there's no foreign matter anywhere on the rubber door seal, even under the difficult to see hinge part. You could use a smidgen of rubber grease all along the seal, though as I say I haven't found that necessary.

There's also the thought that the over-centre top catch isn't pulling the door tight shut - worth checking before you dunk it. I suspect that the tapered lens surround is simply screwed onto the body, so check that that's tight too.

BTW, the big metal screw just forward of the tripod socket is a heat sink, so don't mess with that.

tom.

Mick's experience confirms my reluctance to dunk mine in water. It says it's waterproof, and I take that to mean ok to use in a shower of rain (which I have done, I got wet on my bike).

Here is some raw footage straight off the camera of some 'bumper cam' chase car footage of drifting from the weekend.

Im pleased with the results, appart from the sound. Especially when he was following my car (im in the black bmw with impact videos down the side) as thats a V8 with cut exhausts so was hoping to really pick up the noise.

Anyone have any ideas on improving the sound on this camera?

http://www.youtube.com/watch?v=jpbYmw0WdB8&feature=youtu.be

Improving the sound on this camera? Yes, film with the LCD screen door open, as the mic capsule's in there. Though I thought it sounded ok.
Not really raw footage was it Mr I? Lots of dissolves in there. Shot in 720/50p? I could see its shadow on the film-car.

Well here's proof that my Extreme cam's waterproof - at least down to 2 metres. These three minutes were snipped out of about 30. Shot mainly in 720/50p for the greatest wide-angle (172 deg in air, so very nearly a FFFE - full frame fish eye). What's that under water - 120 deg?

The cam struggles in low light, and under water you must lose another 1½ stops or so. Footage looked underexposed and the GoPro did better in the same conditions. The 7.8mbps is borderline for fast action as you'll see. It's so-so hi-def, but clicking the 720 or 1080 buttons may make it look better your end.

http://www.youtube.com/watch?v=uDWimOLiQz8

tom.

Just done some low-light tests on the Extreme cam. The WVGAP 60 and 30 modes are awful. Next best is the 720/60p, then 720/50p. Best settings are 1440x1080/25p and 1280x720/25p. Use the latter setting if you want the greatest wide-angle coverage but with slightly lower resolution.

'Full HD' (1929x1080/30p) is a good stop less sensitive than 1440x1080/25p. Can't think why, but do these findings ring true with your resolution tests, Alan?

Best setting overall appears to be 1440x1080/25p at 7.83mbps A bit jerky in the pans of course but the 'more normal' 142 degree coverage makes the barrel distortion less of an issue.

tom.

Yes, all that agrees with what I found. And it makes scientific sense as well.