I would appreciate some advice on the pros and cons of these two ports when used with the Panasonic 8mm fish eye lens. I have a NA-EM5 housing and will be getting the Pany 8mm FE, but not sure as to which dome port to go with it, primarily for CFWA. What are the respective close focussing distances for these two ports?

Nauticam 3.5 versus 4.33 dome port for NA-EM5 housing
#1
Posted 23 April 2014 - 10:37 PM
#2
Posted 24 April 2014 - 01:08 AM
You should really get the wider 4.33" dome as the other port has vignetting at 4:3 aspect ratio according to the port chart
Based on the size of the glass the smaller dome should focus 4cm closer 17 vs 21 cm however the design of the two devices is different as the dome is flat on the housing and the port has an extension already built in so it is not possible to calculate what is going to happen on paper
#3
Posted 24 April 2014 - 05:00 AM
It will not vignette
http://wetpixel.com/...c=46536&page=15
https://www.facebook...4086315/?type=1
3.5'' dome = closer focus + make smaller subjects look bigger + dome is smaller
4'' dome = more depth of field at same aperture
#4
Posted 24 April 2014 - 06:24 AM
#5
Posted 24 April 2014 - 12:59 PM
Thanks Oosanto for that earlier reference. Makes the 3.5 rather compelling according to Alex Mustard.
Not sure what you mean Interceptor121 about it being more a macro wide angle port than a proper dome? The photo Alex took of the diver photographing the sponge looks pretty wide angle to me.
#6
Posted 24 April 2014 - 01:45 PM
- Nautilus Cairns likes this
#7
Posted 26 April 2014 - 12:22 PM
I have both and for CFWA the 3.5" is fantastic. The size is also a big plus compared to the 4.33". I would use the 4.33 only for over/under shooting.
#8
Posted 28 April 2014 - 12:37 PM
I would use neither for over/under. they are both too small
In fact I find very disappointing that nauticam has not made a large dome to be used with fisheye lenses
#9
Posted 06 May 2014 - 03:56 AM
It will not vignette
I use the 3.5" dome with the NA-EM5 housing and I have vignetting with the 8mm Pana in 4:3 aspect ratio.
-Sven-
#10
Posted 06 May 2014 - 03:06 PM
I use the 3.5" dome with the NA-EM5 housing and I have vignetting with the 8mm Pana in 4:3 aspect ratio.
-Sven-
we have the same but mine will not (even in RAW)... strange
#11
Posted 06 May 2014 - 11:06 PM
#12
Posted 06 May 2014 - 11:44 PM
nudibranco, would it be possible to do some pool tests with the panasonic 8mm behind both the 3.5" and 4.3" domes sometimes? I'd really like to look at the corner sharpness at different apertures with these two domes.
Cheers!
#13
Posted 08 May 2014 - 01:26 PM
dont have a pool but the sea ... unfortunately i just started the dive season and have little time for now... but will do more testing eventually.
Anyway Alex M. did a test in the pool which showed both in the pool
http://wetpixel.com/...c=46536&page=16
You can see the depth of field in the back of the pool improved by using the 4.33" but the CF of the 3.5" is fantastic...Corner sharpness seems Ok in all of my shots also.
#14
Posted 08 May 2014 - 09:04 PM
Are you sure that the "improved" DOF has to do with the dome?
When you take a photo with the 3.5 dome, the same f/stop and the same aspect ratio (= poor duck is the same size in the pic), DOF should be the same. Please correct me when I am wrong.
Corner sharpness - well, I am still spoilt from my old Nikonos RS lenses. Until I switched to digital, I did not even know that this was something to talk about... With my 3.5 dome and the 8mm I do get unsharp corners, especially noticeable when viewing the corners at 100% at my monitor. Does it matter? Not so sure, because in a CFWA pic your view is caught by the more or less dramatic subject, so why care too much about the corners? Just my 2 cents.
And the same here, on my photos taken in the field I did not notice any vignetting. So unless one is into taking pics of tiles in a pool, I think vignetting is neglectable when deciding which dome to buy.
Jock
Edited by Jock, 08 May 2014 - 09:06 PM.
---
http://www.dive-images.de/
---
Olympus OM-D EM5, Inon Z240 and Nikonos RS, Ikelite SS200
#15
Posted 08 May 2014 - 09:32 PM
Edited by Interceptor121, 08 May 2014 - 09:34 PM.