Lens/Port Advice: Buy or Use What I Have

[Dont_Hold_Your_Breath]

I need help thinking through my lens/port choices for two scenarios (photo only). Camera is a Canon 5dmkIV and Nauticam housing (N120 port). I’m pretty sold on the lens/dome setup for the split shots, but trying to understand if it makes sense to buy a dedicated lens/port for shooting fully underwater or if I should just save my money. If I do buy a setup just for underwater, I’m not set on the 8-15/140mm dome but reviews suggest it will take sharp photos. Two shooting scenarios are:

• Split shots: Plan to use Canon 16-35mm F2.8/Zen 230mm dome
• Fully underwater while snorkeling: Considering using something like the Canon 8-15mm/possible teleconverter/140mm Optical Glass Fisheye Port

For the fully underwater shots I’m planning to mostly snorkel and some diving in freshwater to photograph trout and salmon in streams, ponds, pools, fast moving water, and sandy/rocky river bottoms. I’m wondering if the large dome I plan to use for split shots will be too difficult to move around with in the water or I’m if likely to scratch it, which is why I’m considering something like the Canon 8-15mm and a 140mm dome.

However, I know if I had the 8-15mm I would leave it stuck at 15mm all the time. Then I think I already will have a 16-35mm so is there any benefit to buying a 8-15mm? Nauticam port suggests the 230mm dome for the 16-35 and 140mm for the 8-15 so I’m weary to just put the 16-35 on a smaller dome but that's an option too. The 16-35mm at 16mm is basically the same image as the 8-15mm at 15mm plus a little distortion from the fisheye right? So I’d get a smaller dome but it would cost me $700 (used 8-15mm lens) + $900 (used dome if I can find one) which is starting to add up really quick. Or perhaps I could use a cheaper dome such as a 150mm acrylic with the 8-15mm to save money but then that's starting to approach the 230mm dome size so at that point maybe it's not worth it or maybe it is just to protect my larger dome. Any advice on buying a dedicated underwater setup or jsut sticking with the big dome as the primary setup would be appreacited.

 

[WS007]

Hi Brightnight,

I do not have the Canon, but Sony FF. The procedere should be similar. I use the Canon 8-15mm with Nauticam 140mm dome, but I know many who just use this lens with the 230mm (since they already have the 230mm for their rectilinear WA lenses and do not want to carry another domeport with them). 230mm is just heavier and more bulky, IQ should be at least as good as with the 140mm. The 230mm dome is (almost) a fisheye domeport and advertised by Nauticam as a "fisheye" domeport...

Using the rectilinear Canon 16-35mm behind 140 domeport is not advisable, as the radius of curvature is too small and the sharpness in the corners will not be given. E.g. I use the Tamron 17-28mm with a 170mm Zen domeport, but this lens is an exception. Most lenses in the 16mm or 17mm range require a 230mm domeport for FF (250mm may even be better, depending on actual lens)...

I, personally, have a preference for glass ports and do not own plastic ports. Plastic ports are easily scratched (o.k. you can repair by yourself) and are less performing, especially against the light (flares)...

Here two example images with Canon 8-15mm/Metabones V/NA140/Sony A7R5:
@8mm:

@15mm:

Wolfgang