Advice on Port for SeaFrogs case for Sony 6300

Now that we're about to resume global travel (fingers crossed), I am thinking about pulling the trigger on a SeaFrogs case for my Sony A6300.   These days I rarely use this camera for everyday photography and so I plan to convert it to UW use along with my Nikon AW1 and Sony RX100 III.    I have long owned the Sony 10-18mm E lens. I also recently purchased the 16-50mm PZ lens in anticipation I'd be converting the camera to UW use.  I assume the standard flat port is suitable for the 16-50mm lens.  Will it also work well with the 10-18mm lens or should I be thinking about getting an additional port?

I'll be buying the case with a vacuum system, a tray, and spare O-rings.   Any advice on other handy accessories, e.g., a video light?   The main usage will be for snorkeling (along with my wife, who does not dive).

The standard flat port will fit the 10-18mm, but if you use it underwater, distortion will be quite significant. This is 10mm through flat port:

Compare with the same lens, from roughly the same spot, but through SeaFrogs six inch dome:

And eight inch dome:

If you're snorkeling rather than diving, then your ability to get close to things will be limited, and 16-50mm is probably a better fit than 10-18mm. I use 10-18mm, 16-50mm and 90mm macro with my A6300, and I'm about to pull the trigger on a Canon 60mm macro + metabones adapter, but I do scuba diving rather than snorkeling.

As for a video light, I tried snorkeling with a pair of Archon D36Vs and they were mostly just extra bulk. If you're going to shoot from a few meters away, then even strobes won't have much of an effect.

Do get the vacuum system though, it is very very useful. I don't take my rig into the water without the green light flashing, and it has saved me from a significant capital outlay on numerous occasions.

Barmaglot_07 wrote:

The standard flat port will fit the 10-18mm, but if you use it underwater, distortion will be quite significant. This is 10mm through flat port:

Thanks for the photo comparison, which is very useful. I was planning to use mainly the 16-50mm. It's cheap and optically not a great lens, but it will suffice. I've never liked the 10-18mm because it has so much distortion. However, I noticed the standard SeaFrogs kit comes with zoom rings for both lenses and so I wondered whether I should consider getting another port. I may stick with the standard flat port and deal with the extra heavy distortion for the 10-18mm lens in post. I'm not planning to use it all that much, so it's probably hard to justify the cost of a second port.

Your other comments are also helpful. Thank you very much. Raja Ampat awaits (in early 2022, so there's time yet to add to a good starter kit).

Went ahead and ordered the standard flat port with a SeaFrogs housing.  At the same time, as I was looking around their Web site, I discovered an extended flat port is available for the Sony E PZ 18-105mm lens, which I own but no longer use.  I ordered that port, too.  On previous visits to their site I had failed to notice the A6300 housing supports manual zoom (and AF) for the PZ 18-105mm lens as well as the 18-135mm lens,  yet another Sony E lens I own.  So, I've found a way to repurpose both the A6300 camera and the 18-105mm lens, otherwise they'd  sit on the shelf or be donated to the audio/visual club of the local public school.

Thank you for your help.

I don't really see the use case for 18-105mm or 18-135mm underwater. Even in exceptionally clear water, you'll lose most of the color and contrast at the distances where that zoom comes into play. I don't know what the outer diameter of that SeaFrogs port is, but assuming it's the same as the basic flat port that comes bundled with the housing, which I just measured at 119mm, something like this should allow you to mount a diopter in front of it and turn it into an ersatz macro lens. A wet wide lens at the wider end of the zoom is unlikely to work - the large front element suggests that the entrance pupil is deep inside the lens, and M67-base wet wide lenses will produce severe vignetting.

At the wide end, the 18-105mm close focusses down to 1.5 feet; the 16-50mm focusses down to 0.8 feet, which is closer but not by a whole lot.  I haven't done a comparison yet, but I expect that over their overlapping zoom ranges, the 18-105mm is optically better than the 16-50mm, possibly even a lot better.  I will do a test to check that.  Since the cost of the extended flat port is fairly reasonable,  I went ahead and ordered it in anticipation I might want to use it on my trip.  Whether I eventually do use it or not, it's a tiny fraction of the cost of the entire trip.

Barmaglot_07 wrote:

As for a video light, I tried snorkeling with a pair of Archon D36Vs and they were mostly just extra bulk. If you're going to shoot from a few meters away, then even strobes won't have much of an effect.

I always shoot in RAW.  I can almost always find something in the field of view that lets me adjust the white balance to remove any color cast.  Very occasionally, when that doesn't work,  I do wish I had a light to get the colors right, but there's a tradeoff keeping the UW gear as small and simple-to-use as possible.  I think I'll forgo the light.

I placed my order on the 5th and it was delivered yesterday, on the 9th.  Lots of parts with no instructions included in the shipment, of course.  I thought, here goes, it's another DIY project.  Fortunately, before I began to assemble things, I found an excellent video tutorial on YouTube by Blaze Anderson, a dive guide and UW photographer on Maui, which provided clear instructions on how to install the 16-50mm and 18-105mm lenses along with the two ports I bought.  Now it's on to the testing phase.

Hello all,

I got the new Samyang AF 12mm f2 and was thinking about getting a dome port for it (and seafrogs salted housing + A6300) in the future.

Just for my understanding, it would fit into all three sizes (4, 6 and 8 inches)

So would the 4 inch be the best (less distance between lens and glass) or are there other things to consider too?

Would it make a difference for over/under photography?

Thanks!

Mkfb8 wrote:

Hello all,

I got the new Samyang AF 12mm f2 and was thinking about getting a dome port for it (and seafrogs salted housing + A6300) in the future.

Just for my understanding, it would fit into all three sizes (4, 6 and 8 inches)

Physically it should fit. I don't have the 12mm F2, but I do have the Sony 10-18mm which is about 4mm longer, and it fits into the 4-inch port, so the Samyang lens should be fine in that regard. Eyeballing the port curvature and the lens layout, it even seems to me that the nodal point should be in the ballpark. However, I'm entirely uncertain that it would work underwater - the small port will produce significant field curvature, so on a rectilinear lens, you will end up with very soft sides and corners, if it will focus at all - the virtual image produced by the dome might end up too close to the sensor for the lens to focus, and you might need to start adding diopters just to get any kind of image.

I wonder if the Frogports shallow dome ( https://handcraftedvideowate.wixsite.com/frogportsusa ) might be a good solution for this lens.

So would the 4 inch be the best (less distance between lens and glass) or are there other things to consider too?

You're conflating dome ports with wet lenses here. With wet lenses, it is important to have as little distance as possible between the camera lens front element and wet lens rear element, otherwise you get vignetting and, in case of close-up lenses, lose magnification. With dome ports, the important thing is to get the lenses entry pupil as close as possible to the geometric center of the dome, also referred to as the dome's nodal point. If the dome is a perfect hemisphere, as is typical for domes meant to be used with fisheye lenses, then its nodal point is level with its base, but if it is a smaller slice of a sphere (i.e. a shallow dish rather than a deep cup), then its nodal point is recessed further back towards the camera. It doesn't matter, in this context, how much air there is between the lens and the port glass/acrylic - if anything, more air is better, as it means that there is proportionally less water is present between your lens and your subject, although inversely, larger domes are more difficult to maneuver into tight settings.

Would it make a difference for over/under photography?

For over/under, you want as large a dome as you can get. My personal choice, with A6300, Sony 10-18mm and SeaFrogs Salted Line housing is the eight-inch dome. The six-inch dome that I originally got with the housing has been gathering dust on a shelf since I got the eight-inch one a couple years ago. The four-inch dome sees occasional use with the 7Artisans 7.5mm fisheye, but my go-to wide-angle solution is SEL1018 and eight-inch dome.

Thank you @kelpdiver and @Barmaglot_07 for your informative answers. Looks like I got to add another bulky item to my divekit eventually.

@Barmaglot_07 looks like that Frogport is for surface pictures mainly?

Hi @Barmaglot_07,
i saw you have som experience in Sony + Seafrogs underwater ... I have a couple of questions and would highly appreciate any help...

Which dome port did you use exactly for your comparison tests with the kit lens?

‎WA005-B With the 40mm tube?
Can i expect to get rid of missing sharpness and chromatic issues in the corners compared to the flat port?
How would you rate the chance to get the 1655G lens (which is my kit replacement for higher quality over-water photograpy) into the ousing maybe using a longer extension tube? Maybe i can 3d print a Zoom Gear myself...
Is there any optical advantage for the glass versions or is this just affecting durability (which is a good reason to go for these variant i guess)
Thank you in advance!!
Gilbert

GilbertH wrote:

Hi @Barmaglot_07,
i saw you have som experience in Sony + Seafrogs underwater ... I have a couple of questions and would highly appreciate any help...

Which dome port did you use exactly for your comparison tests with the kit lens?

https://seafrogs.com.hk/collections/glass-acrylic-dry-dome-ports-for-salted-line-housings/products/6in-dry-dome-port-for-salted-line-series-waterproof-housing-40m-130ft and https://seafrogs.com.hk/collections/glass-acrylic-dry-dome-ports-for-salted-line-housings/products/8-dry-dome-port-for-salted-line-series-waterproof-housing-40m-130ft

‎WA005-B With the 40mm tube?

That one targets their DSLR housings.

Can i expect to get rid of missing sharpness and chromatic issues in the corners compared to the flat port?

To an extent. You still need to stop down to get reasonably sharp corners.

How would you rate the chance to get the 1655G lens (which is my kit replacement for higher quality over-water photograpy) into the ousing maybe using a longer extension tube? Maybe i can 3d print a Zoom Gear myself...

SeaFrogs don't sell extension tubes, as a rule. I haven't seen the 16-55mm G on any manufacturer's port chart either, which makes me think there's something that limits its use underwater. If nothing else, the f/2.8 maximum aperture is wasted underwater, and 16-70mm f/4 gives a better zoom range at a lower cost.

Is there any optical advantage for the glass versions or is this just affecting durability (which is a good reason to go for these variant i guess)

Glass domes are more durable and less floaty - acrylic domes, especially big ones, tend to float up and wrench your camera upwards unless you weigh them down with something. I can't comment on image quality - SeaFrogs has some bold statements to that effect, but I haven't tested one personally.

Thanks for your Reply - find some thoughts below...

Barmaglot_07 wrote:

GilbertH wrote:

Hi @Barmaglot_07,
i saw you have som experience in Sony + Seafrogs underwater ... I have a couple of questions and would highly appreciate any help...

Which dome port did you use exactly for your comparison tests with the kit lens?

https://seafrogs.com.hk/collections/glass-acrylic-dry-dome-ports-for-salted-line-housings/products/6in-dry-dome-port-for-salted-line-series-waterproof-housing-40m-130ft and https://seafrogs.com.hk/collections/glass-acrylic-dry-dome-ports-for-salted-line-housings/products/8-dry-dome-port-for-salted-line-series-waterproof-housing-40m-130ft

‎WA005-B With the 40mm tube?

That one targets their DSLR housings.

Maybe the A6600 is a bit different here compared to the (quite similar) A6000..A6500?
My Lens chart here https://www.saltedlineeurope.com/products/seafrogs-40m-130ft-waterproof-housing-for-sony-a6600
Also shows the DSLR lenses and Ports - and the 16-55 Kit is not even listed.
Could it be that the A6600 has a bigger housing and a wider Port diameter?!?

Can i expect to get rid of missing sharpness and chromatic issues in the corners compared to the flat port?

To an extent. You still need to stop down to get reasonably sharp corners.

Yes - I expected that (especially using the cheaper lenses)

How would you rate the chance to get the 1655G lens (which is my kit replacement for higher quality over-water photograpy) into the ousing maybe using a longer extension tube? Maybe i can 3d print a Zoom Gear myself...

SeaFrogs don't sell extension tubes, as a rule. I haven't seen the 16-55mm G on any manufacturer's port chart either, which makes me think there's something that limits its use underwater. If nothing else, the f/2.8 maximum aperture is wasted underwater, and 16-70mm f/4 gives a better zoom range at a lower cost.

Well ... it gets sharper earlier - and most importantly it´s generally sharper.
But when zooming the lens gets quite a bit longer - that might be a reason... but not using the full range would also be OK up to a certain extent.
But i have no experience if the distance between Dome and Lens may lead to other issues too like focussing impossible due to the glass / acrylic dome in between, or distortions..

Is there any optical advantage for the glass versions or is this just affecting durability (which is a good reason to go for these variant i guess)

Glass domes are more durable and less floaty - acrylic domes, especially big ones, tend to float up and wrench your camera upwards unless you weigh them down with something. I can't comment on image quality - SeaFrogs has some bold statements to that effect, but I haven't tested one personally.

Just found this PDF
https://cdn.shopify.com/s/files/1/2244/3975/files/A6600.pdf?v=1608188336
Seems like A6600 is indeed an exception as the WA005 Dome is clearly shown in the image - anyhow i ordered the port at Amazon and will be able to send it back.
If i test my setup over water to check for vignetting with the Kit lens that should be the same over/under water, right??
(or do i have to expect any further surprises under water?)

Regards,
Gilbert

[Edit]
One more thought regarding the G Lens
The focus Ring (front side) is 3mm wider in diameter compared to the zoom ring.
That might make it complicated to get the lens through the zoom gear into the housing...
Anyhow there may be solutions to 3d-print e.g. a connectable split gear...
Also i found this:
https://www.aditech-uw.com/en/shop/4797-sea-frogs-extension-ring-er-d91x106.html 
So seems for the DSLR Domes there are extension tubes...

GilbertH wrote:

Maybe the A6600 is a bit different here compared to the (quite similar) A6000..A6500?
My Lens chart here https://www.saltedlineeurope.com/products/seafrogs-40m-130ft-waterproof-housing-for-sony-a6600
Also shows the DSLR lenses and Ports - and the 16-55 Kit is not even listed.
Could it be that the A6600 has a bigger housing and a wider Port diameter?!?

Yes, their A6600 housing uses 90mm diameter ports, same as the A1/A7 series housings.

To an extent. You still need to stop down to get reasonably sharp corners.

Yes - I expected that (especially using the cheaper lenses)

Lens cost does not impact this the way you'd think. The issue with domes is that they present the lens behind them with a virtual image which is curved, with the curve radius being proportional to the dome's radius. In effect, the corners are closer to your image plane than the center, and if you shoot wide-open, with shallow depth of field, they fall out of the in-focus range. As you stop down and increase your depth of field, they gradually come into focus. Larger domes help as the difference between center and corners gets smaller, but they get more difficult to handle, to pack when traveling, and to get close to subjects when shooting close-focus wide-angle.

Well ... it gets sharper earlier - and most importantly it´s generally sharper.
But when zooming the lens gets quite a bit longer - that might be a reason... but not using the full range would also be OK up to a certain extent.
But i have no experience if the distance between Dome and Lens may lead to other issues too like focussing impossible due to the glass / acrylic dome in between, or distortions..

Again, you can't directly apply land logic to underwater lenses. One of the most popular underwater wide-angle underwater lenses out there is Tokina 10-17mm fisheye - it performs magnificently underwater, but is regarded as terrible lens for land use.

Just found this PDF
https://cdn.shopify.com/s/files/1/2244/3975/files/A6600.pdf?v=1608188336
Seems like A6600 is indeed an exception as the WA005 Dome is clearly shown in the image - anyhow i ordered the port at Amazon and will be able to send it back.
If i test my setup over water to check for vignetting with the Kit lens that should be the same over/under water, right??
(or do i have to expect any further surprises under water?)

You have to test underwater. Doesn't have to be a full dive, but the rig needs to be submerged. The refractive properties of water effectively add another lens element to your setup. More than a few people hadn't read the manual and put together an underwater setup that works on land but fails to focus after splashing down.

Regards,
Gilbert

[Edit]
One more thought regarding the G Lens
The focus Ring (front side) is 3mm wider in diameter compared to the zoom ring.
That might make it complicated to get the lens through the zoom gear into the housing...

That is not a problem at all, you just attach the zoom gear to the lens before attaching it to the camera. You want to see a complicated zoom gear, look at Nauticam gear for Olympus 12-50mm; that one pretty much needs a degree in mechanical engineering to assemble.

The thing about 16-55mm is just that it's not a very good zoom range for underwater use. It's not particularly wide and it can't do macro. The 16-50mm kit lens has internal zooming, so it can be used behind a flat port with wet lenses, but 16-55mm zooms externally, so it isn't suitable for that either. Its bright maximum aperture is largely wasted underwater, the only scenario in which it'd come into play is shooting large pelagics in limited ambient light when you can't use strobes, such as the thresher shark dives at Malapascua, Philippines - it's six in the morning, you're at 30m, the sharks don't come particularly close, and you can't use any form of artificial lighting, but on the other hand your corners are just water, so you don't care about them - but this is a very corner case. Thus you have a $1400 lens that doesn't do anything that an $800 16-70mm f/4 won't do better in the 'generalist fish portrait lens' application, and the $300 kit 16-50mm with $1200 Nauticam WWL-C  or $700 AOI/Fantasea UWL-09F will beat it handily for wide-angle. If you want a quality lens to house behind a dome, look at 10-18mm or the new 10-20mm.

Thank you so much!

Really valuable information...

The thing with the 1655g is that i have it already (and i really like the lens)... indeed zooming may result in problems, not even sure if a Dome wouldn't limit the long end...

From what i quickly read - the 10-18 is a bit of a lottery to get a good one...

The newer 10-20G sounds more interesting  for non-diving photography.Are there any reports that it worked in a Sea Frogs housing? (ideally with an existing zoom gear)

I did not find it in the lens charts...

(by the way ... is the outer diameter of the zoom gears identical for Axxx and A6600 housings?!?)