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Port choices for Tamron 90mm

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Underwater I have been using only a 60mm macro with my Sea and Sea housing. This is using a compact macro base port. The difficulty that I have been having is getting tight close up (true macro) shots with getting too in-yer-face of the poor subject. I do already own a tamron 90mm for topside, which I love.

 

It seems silly to get a 105mm when I already have the 90mm.

 

The trouble is, which port?

 

Any suggestions?

 

Thanks

Daniel

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See nobody has replied and I can't really help as I use Aquatica. However, I reckon the 90mm will be good underwater, especially if you dive around the UK. A 105mm is often pushing it a bit with our manky viz.

As to ports, why not talk to Alan James or Cameras Underwater or even Sea and Sea direct at Paignton?

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See nobody has replied and I can't really help as I use Aquatica. However, I reckon the 90mm will be good underwater, especially if you dive around the UK. A 105mm is often pushing it a bit with our manky viz.

As to ports, why not talk to Alan James or Cameras Underwater or even Sea and Sea direct at Paignton?

I am waiting on Sea and Sea to get back to me. Apparently Sea and Sea UK have had to ask Japan (or whereever). It looks at though there may be a difficulty with the amount of extension in the lens when it close focuses. This may mean that the lens will only be any good for tight close up macro but useless should I need to move back a bit.

 

The lens appears to extend from 97mm to 145mm as it focuses through the range. This will leave the front element effectively 2 inches minimuim from the front of the flat port when when it approaches infinity. It looks as though this will mean that the port will be visible if shooting more than a foot or two away.

 

We'll see what S&S say when they come back.

 

Thanks for the comments though.

 

Daniel

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The lens appears to extend from 97mm to 145mm as it focuses through the range. This will leave the front element effectively 2 inches minimuim from the front of the flat port when when it approaches infinity. It looks as though this will mean that the port will be visible if shooting more than a foot or two away.
I used to use a Tamron 90 with my 20D in a Subal housing with the 145mm flat port. The distance from the front element to the port with this setup was about the same when focussed at infinity. The port was never visible with this setup. I don't know how Subal ports compate to S&S ports in diameter but I think there shouldn't be in problem in this regard due to the narrow field of view of the Tamron 90mm. Edited by Gudge

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I doubt that the port would be visible, you do not state which camera you use, but its most likely is either a 1:5 or 1:6 format and thats give's you a pretty narrow field of view to work with.

 

And easy way to find what extension lenght you require is to mount the vcamera and lens in the housing, lay the housing on its back, put a lens cap on the lens along with either a wad of folded lens tissue or kleenex, deposit the macro port on top of the lens and measure the gap between the sealing surface of the port and the housing and you should have a pretty ggod idea of what you need, next just peick an extension that is of the right lenght or longer. The wad of paper and lens cap removed, you should by now have the proper breathing space in between the front of your lens and the macro port lens so that they do not make abrasive contact between them.

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