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Dear all,
My name is Anders and I have been certfied since 1988. My interest lies in the marine life and to document it with my camera. UK divers give me a really hard time for my dinky little tanks, but somehow I seem to cope with what I have, and I am glad that I can entertain you. Perhaps I should point out that I am normally not the one to give thumbs up first...

This seems like a really good forum (contrary to a swedish one that I frequent) and I just had to sign up. I hope I will contribute in a positive way.
Cheers,
Anders
 

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Hej Anders!
At last! Välkommen! You've a lot to contribute here, not least regarding u/w photography*. You can post pics on this forum by clicking on "Add file", e.g. on the "Surface interval" board. Do it! I'm sure people would love to see your seal images from the Farnes trip. I certainly would.
__
*Anders is a very keen and able photographer, folks, and he has first-rate (and very expensive
) photographic equipment.
 

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Street Cleansing Operative
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<font color='#000080'>Welcome aboard, Anders!

John tells us your photographs are as good, if not better, than those of Henrik's that we've seen recently. Pretty good billing as his pictures were awesome. I look forward to seeing some of yours soon.
 

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Gulp! I should not have registered if you expect my pictures to be better than Henrik's, they're not. I did get a few decent in the can and I will be happy to post some as soon as I get my hands on a scanner. May have to make an investment soon as I have lots that should be scanned.
 

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Snap Happy
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Hi Anders,

thats some big billing you got.  Its great to have more photographers on board.  I'm just starting to scratch the surface with this stuff so any more sources of advise are more than welcome.

So, welcome aboard - you'lll like it here.

Cheers,

Tim
 

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Hey Anders,

Welcome to YD mate. You're amongst friends, so please feel free to get in amongst it!

Cheers,
 

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Just not enough dive time.
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Anders, welcome from me too, you are too modest. I can understand you not wishing to be over sold by us, but your snaps were pretty good mate.  


Just post them on then let us judge, although I think maybe we are too polite to make our feelings known which one of you is the better snapper.

I'd back John up on the expensive kit bit too, but I think we all know its not just the kit that makes you good at something is it. As for the dinky tanks, they are minute 4l Twin jobs, so either he has gills or they are those 1000 bar jobs on 'future of diving' thread.

Matt
 

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Hi Anders and welcome to YD! Yeah, great "talking point" your tanks , never seen owt like em before.
BTW you should realise that saying you've "been certified" might case some strange looks outside of diving circles, in the UK we use that as an expresion for being declared mad
 oh, hang on a minute... cold water, bad viz, all that heavy kit... yeah "certified"
 

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Twin 4 L x 300 bar tanks are not uncommon here in Sweden. They're no good to the likes of me but Anders does seem to have gills. He always comes up with about 80 bars regardless of how long the dive is. Actually, the famous Australian u/w photographer Valerie Taylor writes in her book that she always uses the small Swedish tanks on her female models because they look so much less clumsy than an aluminium 80 on girls. Not that I'm saying Anders is a sissy  
 

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<font color='#728FCE'>Don't worry about your small tanks, size is not everything!!!!

Welcome to YD Anders, enjoy yourself and have a good time.

Cheers
Chris
 

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Ginger, Irish, sometimes stroppy
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Welcome aboard,

I am interested by this tank set-up, seems to make a lot of sense as a alternative to a single 12L at 210. But I guess the question is do you manage to outlast people on twin 12's, now that would be impressive


BTW is this maths right (I have left out the bar to ATM conversion, but assuming it wouldn't make much difference)?
2x4L at 300 bar = 2400 L at 1 ATM
12L at 210 = 2520 L at 1 ATM
i.e. 5% difference in content with the benefit of redundancy etc.
 

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If I might stick my oar in, the maths is NOT right. The Real Gas Laws apply and not the Ideal Gas Laws, because the compressibility of gases is not unlimited. At pressures above 232 bar (for air) you get less gas than you would if the Ideal Gas Laws were correct (90% at 300 bar).
Anders twin 4 L x 300 bar tanks therefore provide 0.9 x 8 x 300 = 2160 litres of air.
Here is a link that explains it all in more detail:
http://www.babilim.demon.co.uk/pages/gas_laws/gas_laws.html
By the way, Anders set-up does NOT provide redundancy as there is only one valve, if I remember correctly. Anders uses a pony bottle for redundancy.
 

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Ginger, Irish, sometimes stroppy
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I'm glad you 'stuck your oar in', I was hoping for a discussion


You are right, I was using the simpler version of the gas laws, but thats because to an accurate representation of the true state you would have to take into account all gas laws appropriately for the system, and I haven't attempted that for years.....and even then the empirical v theoretical results are still distinct.

Where does the 90% figure come from ? It seems quite low(oops said high originally, but I think you know what I mean....i.e. quite far from 100%), not disputing it just curious.

Thanks for the pointers
 

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For the figure of 90% (to be precise, 91.77%), look at the curves in figure 4 in the link I gave.
 

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Ginger, Irish, sometimes stroppy
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I ended up seeing if I could calculate it out, cos I never tust those graphs, and ended up at 91.8, not far off. Thanks for that it was a good mental excercise, I have learned something.

Sorry, if this was dull for everyone else, I was a chemist and its nice to see the stuff I learned all those years ago actually being applied.

Conor
 

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Hi Anders.

Bristol based, swedish, diving and photography...

I just happen to know of a fellow swedish diver, heavily in to photography based in bath..  Mikael uses these forums occasionally and you should be able to find him in the members lists.

I dive with Mikael quite often so if you want some contact details give me a shout and I'll dig them out.

Happy diving

Daz
 
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