Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation

0 Neutral

About DirkG

  • Rank
    Sea Nettle

Additional Info

  • Show Country Flag:
    South Africa
  • Camera Model & Brand
    Canon G9
  • Camera Housing
  • Strobe/Lighting Model & Brand
    S&S YS90 auto due
  • Accessories
    Arms and Trays
  1. Phil Great report and nice photos
  2. This question seem to solicit some ambiguous answers. One need to calculate the extensions required. The dome diameter at the base is 145mm with a rise of 47.5mm. The calculated radius of curvature of the dome is thus 79mm. (sorry all calcs were done in metric units Imperial has gone out of fashion in the 60's in SA) You have to use the lens field of view and front element diameter to calculate the nodal point of the lens. at 17mm the Canon 17-85 IS EFS lens have a nodal point at 62mm from base (If the Sigma is of the same dimensions the values should be similar) The calculated extension length for my Housing (S&S DX30/60), Camera (D60 or 30D) and lens combinations ( Canon 17-85 and Sigma 10-20) is 49mm. In our conditions the 10-20 will probably see little use. In my opinion the nodal point is more important in limiting aberrations at the short end of the zoom but less so at the long end. I hope you have some better idea. Reef said to me I wood need the 40 for the 10-20 and the 40+SX extension for the 17-70. I did not get round to get the 17-70 we will see what the outcome will be. Regards Dirk
  3. Paul If you are still looking for a better option on the silicone sealant give "Sika South Africa" a call I am sure the technical department would be able to help. They provide most of the sealants to the motor industry. Regards Dirk
  4. I would go for the 100-400 on the boat. As far as safari work is concerned you can rent the long canon lenses in SA at reasonable rates. The best guys I have had dealings with is Outdoor Photo in Pretoria. http://www.outdoorphoto.co.za
  5. Could you get the knob removed without any damage
  6. Hi all Any chance of having the pictures re-linked Regards Dirk
  7. Hi The sardine run is a bit fikel at best but try African Dive Adventures http://www.africandiveadventures.co.za/welcome.html I have dived with Roland on many ocasions on Protea Banks and they are excelent and profesional. Also try Bitten by Sharks http://www.bittenbysharks.com/ I have only dealt with them over the phone but very freindly. Hope you see sardines
  8. Protea Banks is best dived from Mid April to end August. This is winter time in SA but KZN is still not to bad during this time. September and October can be rainy. November to January is the SA holiday season and you will get nice weather with the normal crouds. As for cameras on RIBS I go for a Pelican case. If you are still intrested in SA I can put you in contact with the operators on Protea Banks. Aliwal Shoal can be dived during the same times.
  9. What port for the Sigma 17-70 Macro or Canon 17-85 IS, the last lens does not realy work well in makro though. Body 350D Regards Dirk
  • Create New...