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(60mm) macro behind mini dome port

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Wasn't sure whether to put this here or in techniques/tips section, so if the mods want to move it feel free to do so.

 

In my late night Googling, I came across older Wetpixel threads and an UW Photography Guide article talking about using a 60mm macro behind a mini dome port. This is intriguing as I am just a very occasional macro shooter and if I could avoid dropping $$$ on a dedicated flat macro port I'd welcome that. Has anyone here used a 60mm behind a mini dome and if so, what were your thoughts on the resulting images?

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You will loose the flat port magnification factor if that is important for you.

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Downside of a dome: you can't use an accessory diopter with a flat port, you can easily scratch your expensive dome, you get less magnification, the lens does not focus quite so close.

 

On the plus side you get a 33% greater angle of coverage (I often use this combo when shooting larger macro subjects - e.g. octopuses on muck dives).

 

You also get corners free from Chromatic Aberrations - which are very noticeable in fine detail when using the Nikon 60mm AF-S G behind a flat port. Most people don't worry about this - because the important subject matter isn't in the corners - but if you look at your images you will see it.

 

This is an example of a very standard image shot with 60mm and curved port (unprocessed direct from camera):

post-713-0-53367400-1522224947_thumb.png

 

Here is the corner detail - screen grab from lightroom. See how all the detail is well defined right to the corner. This is the advantage of a curved port.

post-713-0-33441900-1522225019_thumb.png

 

This is a typical corner frame crop from a flat port shot with a 60mm, which shows all the detail is smeared by CA.

post-713-0-33628300-1522225298_thumb.png

 

Of course - most of the time this does not matter as the main subject is rarely in the corner of the frame!

 

I use both. The flat port most of the time. A curved port (a small section of a larger dome - not a mini dome) when I value greater angle of coverage and/or specifically want those perfect corners.

 

Alex

 

 

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Very interesting, I was always wondering why Olympus lists the 60mm Macro compatible with their domeport..

.

@Alex: what extension and which combination(s) are you using and how would you calculate (or estimate) the extension switching to another dome?

 

Wolfgang

Edited by Architeuthis

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I have used macro lenses behind smaller dome ports since my early years (late 1970's) in underwater photography.

 

There are many advantages. (1) The macro lens has a wider angle of coverage which allows you to shoot larger subjects with less water between you and the subject, which results in sharper images. (2) Because you are shooting "wider", you also have more depth-of-field in the resulting picture for any given f-stop. (3) With auto-focus lenses, the auto-focus is faster because what you are focusing on are the virtual images in front of the dome and the focusing "throw" between virtual infinity and virtual subjects that are closer is much less than the focus "throw" between actual distant subjects and closer subjects that you would have using a flat port.

 

It has been quite a while since I've dived with a 60mm Micro-nikkor, but using the 70-180 Micro-nikkor zoom behind a smaller dome is one of my favorite shooting combinations. One drawback in using a macro lens behind a small dome is that you cannot focus quite as close, which makes your achievable maximum magnification less. As an example. The maximum magnification of my 70-180mm behind a flat port is .75x. Behind the small dome port I use, the maximum magnification I can get is about .4x.

 

I feel that the reduction of this maximum magnification vs being able to shoot wider range of subject sizes, especially larger subjects like fishes and octopuses, is a trade-off I'm willing to make on many dives.

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Thanks for everyone's responses. This is helpful. It's good to know that this technique can work, albeit with trade-offs. For my own needs, I'm generally not shooting super-macro subjects so losing magnification isn't a big deal.

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Very interesting, I was always wondering why Olympus lists the 60mm Macro compatible with their domeport..

.

@Alex: what extension and which combination(s) are you using and how would you calculate (or estimate) the extension switching to another dome?

 

Wolfgang

Would love to know what extension length is used as well!

 

 

Sent from my iPhone using Tapatalk

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