Which lens for this Ikelite port?

Hi, I'm new to this forum, and am making the jump to DSLR by buying someone's Ikelite D70 housing and port. The port that comes with it is a #5503.80 domed port, and I'm trying to choose a lens that might go with it. It seems a compact zoom would what the port is designed for, but it also seems a fixed macro lens would also physically fit inside.

I'm new to this whole ports thing, so a few questions:

1) The Nikkor 60mm micro seems like a good macro and portrait lens, and Ikelite says it fits the #5503.50 dome port, which is 1" shorter than the #5503.80. Aside from the fact that a flat port gives more magnification for macro, is there a downside to using a dome port with this lens? Would there be any optical problem with the additional length of the longer dome port, such as cutting off the edges of the frame? Or would the main downside of the additional 1" of length of port be that it sticks that much closer to your subject, already intruding on a fairly short working distance?

2) The Nikkor 105mm micro is not listed as being compatible with any dome port, but it fits into a 5.5" long flat port. Is there a reason why it doesn't work inside a long dome port?

3) The D70 18-70mm kit lens (which I also don't have), fits the #5503.55 dome port, which is 1/2" shorter than the 5503.80. Again, would there be problems using a slightly longer port?

4) Finally, on to zoom lenses that Ikelite says actually fit this port, the Sigma 28-70 2.8 seems recommended by several folks here, so perhaps the right choice. Does anyone here know if the Tamron 28-75 2.8 would be similar in quality and features?

5) Lastly, probably a really odd question, the reason I ask about the Tamron that both compact zooms require a +4 diopter closeup lens according to Ikelite. The Tamron uses a 67mm filter size. I'm trying to see what I can adapt from my P&S accessories. Does anyone know what would happen if you screw a UCL-165 or PCU-01 which are +6 diopter WET closeup lens onto the lens INSIDE the port? Both are apparently nice high-quality two-element wet lenses, but have a curvature that assumes water between the port and lens, and also contact with water.

Sorry for the beginner questions. I'm sure some things might get a lot more intuitive once I actually have the housing in hand and can start playing with it, but I have about three weeks before an upcoming dive trip and want to have sufficient time to order whatever I might need. Thanks!

Hi, I'm new to this forum, and am making the jump to DSLR by buying someone's Ikelite D70 housing and port. The port that comes with it is a #5503.80 domed port, and I'm trying to choose a lens that might go with it. It seems a compact zoom would what the port is designed for, but it also seems a fixed macro lens would also physically fit inside.

You can find what lenses go with which ports on Ikelite's port chart.

http://www.ikelite.com/web_pages/2port_nikon.html

Though I must say that spending $400 so that you can use a $100 port is sjust stupid. Buy the lenses you want and dont worry if they are compatible with the port you have.

I'm new to this whole ports thing, so a few questions:

 

1) The Nikkor 60mm micro seems like a good macro and portrait lens, and Ikelite says it fits the #5503.50 dome port, which is 1" shorter than the #5503.80. Aside from the fact that a flat port gives more magnification for macro, is there a downside to using a dome port with this lens? Would there be any optical problem with the additional length of the longer dome port, such as cutting off the edges of the frame? Or would the main downside of the additional 1" of length of port be that it sticks that much closer to your subject, already intruding on a fairly short working distance?

Optically a dome is allways better. The reason why flat ports are recommended for macro is that using a flat port does not cause the the same problems it does for wide angle and dome ports tend to get scratched when you get close for a macro shot, especially when you are using a short macro with very short working distance.

Now using a dome port that is too long. Yes that could cause a problems.

2) The Nikkor 105mm micro is not listed as being compatible with any dome port, but it fits into a 5.5" long flat port. Is there a reason why it doesn't work inside a long dome port?

The (optical) center of a lens is supposed to be in the center of the dome. It is possible that it is not possible to mount a 6 inch dome close enough to the lens to place the center of the dome over the center of the lens. Just picture trying to place the center of a 500mm lens in the center of a 6" dome. The optimal dome placement would put the dome inside of the lens....

That said, it could just be because no one ever wanted to put the 105 behind a dome, so no one has tested it to determine which port works best.

3) The D70 18-70mm kit lens (which I also don't have), fits the #5503.55 dome port, which is 1/2" shorter than the 5503.80. Again, would there be problems using a slightly longer port?

Imporper port placement can cause big problems.

4) Finally, on to zoom lenses that Ikelite says actually fit this port, the Sigma 28-70 2.8 seems recommended by several folks here, so perhaps the right choice. Does anyone here know if the Tamron 28-75 2.8 would be similar in quality and features?

I have not used any of the lens you are talking about so I can't reallly answer this, however the sigma is more popular.

5) Lastly, probably a really odd question, the reason I ask about the Tamron that both compact zooms require a +4 diopter closeup lens according to Ikelite. The Tamron uses a 67mm filter size. I'm trying to see what I can adapt from my P&S accessories. Does anyone know what would happen if you screw a UCL-165 or PCU-01 which are +6 diopter WET closeup lens onto the lens INSIDE the port? Both are apparently nice high-quality two-element wet lenses, but have a curvature that assumes water between the port and lens, and also contact with water.

You will be using the zooms behind a dome port. You can not mount wet diopters to dome ports. Even if you could mount the wet diopter on the dome, no it would not do what it needs to.

Sorry for the beginner questions. I'm sure some things might get a lot more intuitive once I actually have the housing in hand and can start playing with it, but I have about three weeks before an upcoming dive trip and want to have sufficient time to order whatever I might need. Thanks!

Though I must say that spending $400 so that you can use a $100 port is just stupid. Buy the lenses you want and dont worry if they are compatible with the port you have.

It's pretty easy to sell used ports either at Wetpixel or on e-bay. I sold all my 6" dome ports on wetpixel when I upgraded to the 8" dome. I got over $100 each for lightly used Ikelite domes.

Select the lenses you want for underwater. The most popular 5 lenses for Nikon are:

WA: 10.5mm ~12-24mm (Nikon Tokina, Tameron or Sigma versions in this range) Sigma 15mm FE

Macro: 60mm and 105mm

Some people also like midrange zooms like the 18-70mm. I don't use these because I think its better to optimize for one kind of shot and focus on that. Different strokes...

Don't use a dome thats not recommended for your lens. It can cause vignetting (where you see the edges of the port in the lens), softness or not even focus at all.

A diopter is no problem at all. Just pick up one of these at your local camera store. They are also called close-up filters. They are basically a magnifying glass that screws on like a filter. They usually cost less than $40. Since the lens is focusing on the virtual image behind the dome not the actual image, sometimes zooms do not focus close enough to focus on the virtual image. The close up diopter allows the lens to focus closer and therefore to focus inside the dome.

You want a flat port for macro. In addition to what was stated above, you also get some extra magnification behind the flat port that you usually want with a macro lens.

Thanks for the sage advice; I guess I probably should've more accurately worded my question as "Will this port fit any of these lenses", as these are the lenses I am interested in. I'm understanding a lot more about the how the lenses and ports must match now, and it seems this dome port is not really a match for most of these.

I did conclude the 60mm lens fit most closely with the fish portraits I mostly do, and will also let me get more into macro shots, so I picked up both a lens and port on eBay. Plus it sounds like decent prime lens for topside portraits to complement my existing zoom lens.

Interestingly enough I tried to squeeze my Tamron 18-200 ultrazoom into the long dome port; it's a tight fit but it can zoom from 18 to about 70 mm without hitting the dome (including accounting for a requisite +4 close-up lens). It also protrudes far enough that there's no vignetting at 18mm. I know this wouldn't be a quality setup one would normally choose for underwater, but since I already have all these pieces and would't be buying a wideangle setup right now anyway, I might experiment with it on a dive or two. It focuses fine from 18-70 on land, but I'm not sure underwater whether you can extend the lens all the way to the dome and still get focus.