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Paul Kay

Member Since 27 Nov 2003
Offline Last Active Yesterday, 12:21 AM

Posts I've Made

In Topic: Custom tripod legs attachment for Nauticam housing

15 March 2018 - 08:42 AM

You might also try www.thorlabs.com who produce opto-mechanical parts which can be used to build stuff - using 1/4" x 20tpi which fits tripod threads, or M6 - some of their parts could be used if you like mechano! I use them for all sorts of things - they manufacture in stainless steel and anodised aluminium.


As an example: https://www.thorlabs...ectgroup_id=223


Not cheap but probably cheaper than getting stuff machined unless you diy.

In Topic: What lens for canon FF for rhinopias

06 February 2018 - 09:59 AM

Not enough justification for me to buy the 60 EFS lens IMHO. I have (at least it was cheap!!) and have used the Canon 50 macro under water as well but that is no justifcation for Canon not having brought this lens up to date.

Its tricky because the design ethos of the 60EFS and the old 50 macro is quite different. The 50 macro works well on extension tubes at reasonable magnifications whilst the 60EFS is already soft on the 25mm tube. The optical design is quite different with different characteristics. So whilst the 50 certainly should be updated, the newer design of the 60 makes it easier and faster to autofocus and it does so without the lens changing length. My guess is that the 50 macro could all too easily be discontinued without a similar replacement because it represents 'old' technology. Which will be a pity because the new design of macro lenses does not lend itself to increased magnification well with extension tubes.


Perhaps I should add that there is hope. Sony's 50/2.8 FE macro recently released is of the older style design so perhaps Canon might just do something?

In Topic: What lens for canon FF for rhinopias

04 February 2018 - 11:14 AM

The Canon 60mm EFS macro will work on a Canon FF body if used with the 12mm MkII Extension tube. It will allow for focus up to about 40cm which may be a little tight for your needs. The Canon 50 macro is a good little lens too and despite its slower mechanical focus, works very well in many situations (how did we work with such lenses on film?). The 50 macro is optically good and myself and my wife have both used it successfully on subjects such as jellyfish in temperate waters which are somewhat murky. Either may work for you, and my only reservation on the 100 macro is that it can sometimes be fussy and hunt a little in my experience.

In Topic: Need help hugyfot D7000 cannot removed ext. port

07 September 2017 - 06:30 AM

What I found increases the problem, is leaving the ports or rings in situ for multiple days.

I think that the problem is that the lubricating grease can get displaced away from the sealing 'O' ring when pressure reduces leaving an 'O' ring rubber to metal/plastic contact only. When this happens the resistance to the rotational movement required to remove the port is vastly increased as there is no lubrication and as stated it can be very difficult to remove the port (I've actually used two substantial policemen to do so, which worked a treat but policemen are rarely around when you want them ;)). In my experience, as Craig says, leaving a port or extender in place for many days and dives seems to make things worse - probably by displacing a little more lubricating 'O' ring grease on each dive as pressure reduces and increasing the area of rubber to metal/plastic contact. I have a strap wrench now too for this problem.

In Topic: Thoughts: Sony A7R II from D810

06 September 2017 - 06:24 AM

I've been trying the Sony 28/2 with the wide converter (21mm effective) behind Seacam's CompactPort. Not bad although corners not perfect - the Superdome would probably improve things but its too vulnerable in Scottish waters. Good vis helps though - who needs fisheyes? (Only kidding).


Pink encrusting calcareous algae in a Scottish sea loch and, would you believe, sea loch anemones (Protanthia simplex) - glacier worn rock.


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