New a6xxx housing from Meikon

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2018-09-14 06.40.46.jpg
I got my Leak Sentinel V4 from Miso and I'm happy with it!
So everything is ready for our trip to Siquijor Island/Philippines in October.
 
Hi all — new to the forum although I have read this entire thread. I just picked up the white housing with pistol grip and the 6” dome port.

Question: on the dome port, I swapped out the hood ring with the non-hood ring. However I noticed the ring is not completely flush after screwing it in fairly tightly. There is a very small gap between the ring and the dome port face. Does this need to be totally flush or will screwing it in tight push the acrylic sufficiently against the O ring for the dome port? I don’t want to overtighten the bolts.

Note I do have the positive / negative tabs aligned properly on the new ring.
 
I tested the dome as mounted in the pool and no leakage. Unsure of how it will fare at depth.
 
Aesthetics aside, is there a reason to buy the white housing and not the black one?
... or vice versa?

(did one have an issue early on - still an issue?, heat gain on uncovered boat in sun? UV resistance? One scares marine live less than the other? Apple vs Android? ... help me out here?)
 
The white one just looks nicer; though I haven't run a proper scientific comparison, nor am I planning to. Makes it easier to pick out your rig from a pile of cameras in a rinse tank, I suppose. Between the white housing, black ports, black tray and arms, and red strobes though, it's not particularly color-coordinated.
 
@Barmaglot : Thanks

About the 4" dome:
I undestand the 6" dome won't work for this lens. Did / does anyone use the 4" dome with the Samyang 7.5mm f2.8 e-mount (manual) lens?
Does it work w/o vignetting?
Or is that (I really don't know) a stupid thought to try to use a lens that wide (which of course would help for using it pre-focussed with fix-preselected Aperture) just because one hapoens to have that lens?

Another beginner kind of question:
What lenses do you like to use the 4" dome with or know from others or your own experience it works well?
If that same lens (not a 180deg. fisheye, one you like to use with the 4" dome port) were used with a flat port instead (if a good fitting flat port existed... what would be the difference between the dome port picture and the flat port picture, all else being the same?

In other words if either a dome or a flat port were to fit a particular lens well, why use a dome for UW (I get the split photography part)? Because it makes the view wider? Always, with any fitting lens (even a fisheye?)? Does one know how much? Are internal (or other) reflections more of a worry with a dome - or?

How does one handle a dome in real life to minimize the likelihood of it getting scratched?
 
I don't think there's a Samyang 7.5mm f/2.8 - there's an 8mm f/2.8 and a 7.5mm f/3.5; the latter only being offered in MFT mount. The 7Artisans 7.5mm f/2.8 works reasonably well in that dome, with the caveats of fixed aperture and manual focus. Focusing is possible with the zoom gear from 16-50mm lens and some padding; I posted pictures earlier in the thread. Focus peaking helps immensely. Vignetting is slight and easily corrected. Sony 16mm f/2.8 with fisheye converter should also work well, with AF and aperture control.

Regarding flat vs dome - there's plenty of articles that you can Google by the terms 'dome port theory' which explain it in depth, but the gist of it is, light rays hitting a water/glass/air boundary at an oblique angle get refracted and scattered, which causes image quality degradation, increasing with the angle. Past a certain angle, you can't see anything at all. Dome ports solve this issue by presenting the light that enters the port with a boundary surface that is always perpendicular to the rays' direction, or nearly so.

Avoiding scratches - the dome ships with a neoprene cover; best practice is to only take it off after you reach your planned depth and level off, then put it back on at the safety stop. Never leave the port uncovered while entering or leaving the water.
 
I don't think there's a Samyang 7.5mm f/2.8 - there's an 8mm f/2.8 and a 7.5mm f/3.5; the latter only being offered in MFT mount. The 7Artisans 7.5mm f/2.8 works reasonably well in that dome, with the caveats of fixed aperture and manual focus. Focusing is possible with the zoom gear from 16-50mm lens and some padding; I posted pictures earlier in the thread. Focus peaking helps immensely. Vignetting is slight and easily corrected. Sony 16mm f/2.8 with fisheye converter should also work well, with AF and aperture control.

Regarding flat vs dome - there's plenty of articles that you can Google by the terms 'dome port theory' which explain it in depth, but the gist of it is, light rays hitting a water/glass/air boundary at an oblique angle get refracted and scattered, which causes image quality degradation, increasing with the angle. Past a certain angle, you can't see anything at all. Dome ports solve this issue by presenting the light that enters the port with a boundary surface that is always perpendicular to the rays' direction, or nearly so.

Avoiding scratches - the dome ships with a neoprene cover; best practice is to only take it off after you reach your planned depth and level off, then put it back on at the safety stop. Never leave the port uncovered while entering or leaving the water.
Very helpful!
It might help if I knew what lenses I have...
:confused:
I meant Rokinon / Samyang 8mm F2.8

Might you know if that might work (optically) with the 4" dome?

I also have the Rokinon 12mm F2.0 in case anyone has an idea what port that might work well in.

@Barmaglot I saw your gear hack and like it... just don't have that lens... but once I figure "a start" I may try "some such hack"

I am a little gun shy here.
We have a Nex5n and a 3n in the family, but I won't buy a housing for either. That next Sony APSC camera I was waiting to learn about is not going to be forthcoming prior to a trip I would like to have a camera and housing for... So I am thinking A6300 and housing to leverage lenses we have (also 1650 and 1855, maybe 50mmf1.8, but wanting to try wider) ...
Or maybe an Rx100IV or VA with housing to minimize size, or...

So one thought was if I can find out if either or both of those Samyang lenses were known to work well in a port (of an affordable housing / camera system, of course I really want a Nauticam system with ab AIII or The R version in it ... which is not happening at all), like the SeaFrogs / Meikon that would give me enough reason to decide definitely APSC and buying a rather (in digital terms) old camera for it with the A6300 (I know it's not bad and it's likely quite better than my capabilities)
 
Optically, it will most likely work. Mechanically, I don't know how well the focus ring on it will line up with the gear in the housing. That said, I don't know about your level of experience in underwater photography, but a manual fisheye lens is not the right way to get started. Fisheyes are very challenging to properly frame, and for many shots they don't work at all - and using one with manual focus and fixed aperture adds another layer of complexity. While they're quite forgiving of focusing mistakes, they still need to be stopped down quite a bit to achieve significant depth of field, and this means relying on strobes extensively - and with a manual lens, you can't change the aperture underwater to adjust for changing conditions.

Forget about the 12mm f/2.0 - rectilinear lenses require much more precise focusing; autofocus is a must.

If you just want to dip your toes in it, Meikon housings for NEX5N are just $110 on Aliexpress - there's a version for 18-55mm lens and another for 16mm; both accept wet lenses.

If you go the A6300/A6500 route, the 16-50mm lens can be used in the bundled flat port, but it doesn't take wet lens attachments. If you want to use those, you'll have to buy the short macro port. Alternatively, you can use it in the 6" dome. I have shot it (the 16-50mm) in the old fixed-port housing with and without wet dome attachment, and on one dive, for a test, in the new housing with 6" dome. Unfortunately I got a regulator leak on that dive and had to abort, so I only go a couple shots - here's one for reference:

rxZRf3S.jpg


As far as size and weight go, the housing's contribution is relatively minor, and it helps that A6xxx cameras are quite small to begin with. After packing a tray, two arms, two float arms, six clamps, two strobes, two large lights, one small light, twenty 18650 batteries, sixteen AA batteries, two chargers, spare camera battery + charger, vacuum test system, spare o-rings, lanyards, half a dozen lenses, several ports, regulator, dive computer, BCD, wetsuit, fins, clothes, shoes, toiletries, laptop + charger, power bank and probably a dozen more things that I'm forgetting now, a camera housing is a fairly small addition.
 

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