Wet Macro Lens

[JackConnick]

A diopter lens allows you to focus closer, doesn't really magnify. The amount of magnification varies depending on how close, or far away you are. Optically there is no real correlation with a "2x magnifying lens" and a "+5 Diopter" for instance.

Nauticam took this concept and added in some extensions to optically increase and improve the power of their lenses. Better underwater macro lenses are "air-sealed" and are much more powerful than "water contact" lenses.

Good quality macro diopter lenses are available from ReefNet, Nauticam, Saga and others.

We have a free Handbook on Underwater Macro Photography in our Resource Center that may help.

 

[stuartv]

A diopter lens allows you to focus closer, doesn't really magnify.

Excellent clarification! (so to speak) The name makes much more sense now. So a "diopter" is more like an eyeglass lens than a magnifying glass. It doesn't make the image larger, it just lets you move the camera closer and still be able to focus on the subject. Very cool.

 

[Lorenzoid]

Excellent clarification! (so to speak) The name makes much more sense now. So a "diopter" is more like an eyeglass lens than a magnifying glass. It doesn't make the image larger, it just lets you move the camera closer and still be able to focus on the subject. Very cool.

From Jack's link above: "Used with a macro lens or setting, they can allow you to back off and still achieve the same magnification level, but allow getting light on the subject."

 

[stuartv]

From Jack's link above: "Used with a macro lens or setting, they can allow you to back off and still achieve the same magnification level, but allow getting light on the subject."

Well, isn't that confusing!

 

[dfx]

Excellent clarification! (so to speak) The name makes much more sense now. So a "diopter" is more like an eyeglass lens than a magnifying glass. It doesn't make the image larger, it just lets you move the camera closer and still be able to focus on the subject. Very cool.

They're both the same thing. If you're farsighted (hyperopic), what you have in your eye glasses (reading glasses) are magnifying lenses. You just don't get a (strong) magnifying effect because the lens is so close to your eye. Move it away and you have a magnifying glass.

So a macro lens will not magnify, as it's sitting (more or less) right in front of the camera's eye. It allows it for closer focusing, particularly when zooming in (which does magnify).

 

[mattia_v]

A diopter is a unit of measurement for lenses. Like eyeglasses. If you have -3 and -5 for your eyeglasses, those numbers are diopters. The net effect is magnification (and magnifying glasses can be measured in diopters) but what they do is refocus light to a closer (+ diopter) or further (- diopter) point. The amount of magnification this yields also relates to the distance of the lens from the camera's lens, and said camera lense's properties. See also the physics behind bellows or extension tubes for macro photography on land.

Regardless, wet lenses work quite nicely indeed

 

[JackConnick]

Well, isn't that confusing!

Not at all. You can get closer and get a larger image, or back off and get the same size image as if you were closer. But then you have room to light the subject.

 

[stuartv]

Not at all. You can get closer and get a larger image, or back off and get the same size image as if you were closer. But then you have room to light the subject.

It is, to me. Earlier you said they don't magnify, they just let you get closer and still focus - meaning that the image is larger because you're closer, not because it's magnified by the lens. Now you're saying they do magnify - a la "back off and get the same size image". Or, at least, that's how I understood it.

 

[JackConnick]

Generally there are two focusing points/areas. I think you just need a little experience with it and you'll see what I'm saying.

 

[stuartv]

Generally there are two focusing points/areas. I think you just need a little experience with it and you'll see what I'm saying.

Understood. I am sure you are right. At least, I hope you are. I AM sure that if I don't "get it", it will be me with a problem, not what you're saying!