Dome port advantage?

Sorry for a basic question, but what are all the pros and cons with a dome port vs. a flat port?

As I understand, a dome port will not produce any image magnification, and there will be no cromatic abberation caused by different refractive index for different wavelengths. Is this correct, and is this all?

On a flat port on the other hand, is it correct to say that the "magnification" is 25% (exact figure?)? Is this magnification equivalent to a focal length extension or is it more like a narrowed field of view with the same perspective? (If you can follow my confused reasoning :-)

Cheers

/O

Well you got the reader digest version right,

The dome let's you take full advantage of your wide angle coverage by retaining the lenses original field of view, the flat port, AKA the macro port gives you the benefit of a narrower field of view (more close-up punch).

You could use a dome port for doing macro, but having such a large (in some case up to + 9") frontal surface doesn't suit small subject well, (sort of knitting with boxing gloves) and up to a certain point a flat port could be used for wide, but then you'd loose +/- 25% coverage and end with out of focus corners, not to mention that the tubular design would limit you to somewhat narrow field of view wide angle, that is less you like tunnel vision.

BTW Dome can suffer from abberation also, dome placement or should I say matching of both the lens & dome optical axis is primary to good result.

In the end, anyone taking his or her underwater photography seriously will get an example of both.

Oh and the dome, because it doesn't modify the field of view can be used for split shot, not that the flat port can't but try a flat port split shot of your mate in a pool and tell us if you survived :glare: nobody like having 25% added to their lower anatomy

nobody like having 25% added to their lower anatomy

Eh?

I keep getting email stating otherwise...

timo

Eh?

 

I keep getting email stating otherwise...

 

timo

Only 25% ? to me they promise much more.

you are pervert B) , i was refering to the rear end being 25% larger, that will get you a black eye

Only 25% ? to me they promise much more.

Figure it maybe depends on what you start out with ?

You know you can only expand an image so far before the jaggies get you.....

You all set for next week Timo ?

You all set for next week Timo ?

All psyched up here.

Will fly to London Friday night to catch the onwards flight nice and early.

timo

Figure it maybe depends on what you start out with ?

You know you can only expand an image so far before the jaggies get you.....

I should have known it was coming