Getting dark backgrounds

[Phillipus2005]

I have tried carefully to test that (in the water). I have the USAF test chart laminated and have shot it at all f stops (Canon 7d, 100 and 60 mm macro lens) from 2.8 to 22. Similarly I have shot the Olympus 60 mm macro lens at the same f stops. Not much sign of diffraction related softness in any of these tests. On land, in my hands at least f/16 is about the sharpest but underwater I couldn't tell. Perhaps my port is not as clean as it should be.

Bill

As for divinycell in the UK,
Diab Limited
Unit 1141, Regent Court
Gloucester Business Park
Gloucester GL3 4AD United Kingdom
Tel: +44 (0) 1452 614234
E-mail: info@uk.diabgroup.com is their office in the UK, they can tell you who stocks it.

BVA.

Diab were v helpful but only supply direct and will only supply a sheet at 2.3 sqrm at over £100 plus delivery. Probably more cost-effective to just buy commercial floats, e.g. Stixx, unless anyone is up for a group buy...

 

[MaxBottomtime]

I use the Ultralite buoyancy arms.

https://www.amazon.co.uk/d/Electronics-Photo/Ultralight-Double-Ball-Arm-Buoyant-DB-B08/B00DQU5ZXS/ref=sr_1_2?s=electronics&ie=UTF8&qid=1488053183&sr=1-2&keywords=Ultralight+Double+Ball+8''+Arm

They provide much more buoyancy than closed foam cell floats. Even with an aluminum Subal housing I can't use four arms or I fight to keep the housing from flying to the surface. Two arms are plenty.

 

[Phillipus2005]

I use the Ultralite buoyancy arms.

https://www.amazon.co.uk/d/Electronics-Photo/Ultralight-Double-Ball-Arm-Buoyant-DB-B08/B00DQU5ZXS/ref=sr_1_2?s=electronics&ie=UTF8&qid=1488053183&sr=1-2&keywords=Ultralight+Double+Ball+8''+Arm

They provide much more buoyancy than closed foam cell floats. Even with an aluminum Subal housing I can't use four arms or I fight to keep the housing from flying to the surface. Two arms are plenty.

Trying to figure out a way to do it without replacing all my arms at huge cost

 

[MaxBottomtime]

I got mine when I bought a new camera and housing. I figured i was that or save money for my old age.

 

[MaxBottomtime]

105mm
1/250
f20

This hermit crab, Paguristes ulreyi was on the top of a wall. I got under it and steadied my housing against the rock, pointing slightly upward with a water background. I had my strobes on half power but pointed slightly inward. I should have had them pointing straight ahead as I needed to clean up backscatter later.