New to UW photography - looking for something particular

Hi there,

I've been reading these forums for the past few weeks getting ready to jump into uw photography, I've learned a lot - thanks to everyone who contributes.

I am looking for advice on the specific kind of diving I do: I am mainly a freediver and I spend a lot of time in the cenotes of the Yucatan. I have heard with freediving, a vacuum pump system is a good idea due to constant pressure change. Cenotes are dark, but have very clear water and are calm/easy to dive.

With those two aspects in mind, I think I have chosen to invest in a Sony a6000 camera to pair with the Meikon salted line. I like the handle with trigger button for freediving, it has a vacuum option, and it is cheap. Choosing a port and lens for this has been problematic, however and I'd love some insight. My subject will almost always be a freediver and the rays of light or cave features that come with a cenote. Sometimes animals in the ocean, but I spend way more time in cenotes. Basically, I am saying I will almost exclusively shoot wide angle. Here are some options I have come up with based on my research.

1. Sony 16mm F2.8 with fisheye converter - cheap, but do I need a fisheye if I'm in a cenote with clear water? Could I just be further away with a nicer wide angle lens?

2. Sony 10-18mm F4 - more expensive but looks nicer. Again, do I need a fisheye?

3. Sony FE 16-35mm F4 - I really like the idea that I will fall in love and one day upgrade to a Sony a7r camera

4. Sony FE 28mm F2 - If I don't need a fisheye would this lens make sense since it is F2 and should gather more light in a dark cenote? Again, I like the idea of one day upgrading to a full frame a7r. I know there is a fisheye conversion for this lens, but sea frogs doesnt have a port that will fit it.

5. Sony E 20mm F2.8 with a wide angle wet lens - Sea frogs has a port with 67mm screw on that this lens fits into. It says macro, but wouldn't a wide angle wet lens also work?

Any insights here? Could I get away without using strobes in any of these set ups? It would be nice to not have that extra bulk.

Also, I am a beginner. Am I completely off base here? Would a different/cheaper camera option provide better value? I was thinking about one of the nice compacts (tg-5, rx100v, gx 2) with a wide wet lens until I saw how cheap a used sony a6000 is and really liked the trigger handle on the sea frogs salted line.

Thanks for taking the time to read/respond!

There are some basic things in your notes that are not correct.

First the 10-18mm f4 is not a fisheye lens, it's a rectilinear and is equivalent to 15-27mm lens on a full frame and has a field of view of 110°-75° across the diagonal. A fisheye provides a 180° angle of view across the frame.

the 16-35 will be 24- 52mm equivalent. (84° - 46°) which is getting a little narrow for underwater.

The 28mm f2 on the A6000 would be equivalent to 42mm and if you have it in a flat port it would be more like a 55mm lens as a flat port will magnify the image about 1.3x. That's a 42° angle of view with the flat port which is way too narrow.

On the Salted line housing do your homework, the early models had no ability to zoom, the newer models provide zoom, but not for every lens. A lot of people love them on this forum, but personally I think you get what you pay for and I'd rather pay more for a housing to get features like zoom gears for a wide range of lenses and proper extension for the domes etc. You could look at Fantasea or perhaps Ikelite or look in the classifieds. Fanatsea have a full range of ports and gears to suit most lenses you would want to use.

Based on what you want to do, I believe you are in wide angle territory and will need a dome. This means you MUST stop down or the corners will be mushy , more so at the widest settings. Even though the water is clear it still absorbs light and colour and if you decide you want strobes you still must be very close! If you are shooting into the light - i.e. the light beams you'll be recording something more akin to silhouettes without strobes unless you place your model in the beam and the light will be coming from above, not much from the side unless you have light from another opening coming over your shoulder- if that's what you want fine, just understand your limitations. You can use flat ports but again corner quality will be an issue and you can only go so wide with a flat port before the light rays just do not enter the port. I would suggest surfing round the internet to see what other people are using in the way of lenses, for the type of shot you want to do.

It seems to me I would want to use a fisheye and a native fisheye lens at that which means something other Sony. Maybe a m43 camera with the panasonic fisheye lens?, the cheapest option is likely to be a 1" sensor compact with a wet wide lens or again look in the classifieds to see what is on offer if budget is a concern. Look at the overall system, not just "this is a good camera so I want use it UW."

It also seems like corner quality is less important if the corners are black cave, which relaxes your needs a little - you can open the aperture a bit more, but I'm talking f8, maybe f5.6, definitely not f2 and maybe get away with smaller domes.

I would want a vacuum system regardless of what type of diving I was doing!

 

On the Salted line housing do your homework, the early models had no ability to zoom, the newer models provide zoom, but not for every lens.

That's not quite correct - there is only one 'Salted Line' model (unless you count black and white SKUs separately), and it has always shipped with zoom rings for 16-50mm and 10-18mm lenses. The earlier models of housings for A6000, A6300, and universal A6xxx had built-in zoom gears for 16-50mm lens, but no interchangeable ports - the fixed port is usable with 16-50mm, 30mm macro, Sigma 19mm and a few other lenses of similar size and focal length. As for zoom gears, they cover 16-50mm and 10-18mm, plus they've recently shown a new gear for 16-70mm and 18-105mm that's supposed to go on sale soon - this covers the most commonly used lenses.

Regarding corner performance, here are some pool samples of 16-50mm and 10-18mm with bundled flat port and 6" and 8" domes at various apertures and focal lengths. As far as fisheyes go, I have a 7Artisans 7.5mm f/2.8 manual lens, and it works okay, but 180 degrees diagonal FoV is just way too broad for most situations. I might get a Tokina 10-17mm with a Sigma MC-11 or Metabones at some point, if I have some extra cash burning a hole in my pocket, but overall, 10-18mm serves me pretty well for wide-angle.

That said, keep in mind that this housing, while much smaller than, say, an Ikelite DSLR setup, is still quite bulky and has about 1kg of positive buoyancy with a 6" dome and an A6300 with 10-18mm inside. It also tries to float dome-up, as the dome is light and has a lot of air trapped inside. With a tray, four 8" arms (no floats), clamps and strobes (all negatively buoyant), I still had to mount about half a kilo of weights on the back of the 8" port to get it neutral in salt water. Since you're freediving, size, weight and buoyancy are probably a more important consideration for you than for scuba divers, so while an A6000 might provide better image quality, I suspect that a waterproof camera that doesn't require a housing (Olympus TG-5, or maybe a SeaLife DC2000 or Nikon AW1 if you want a larger sensor) may prove to be a better option.

Yes, it was the A7 Meikon that didn't allow access to zoom, but your point about the positive buoyancy is an issue, I dived one time with a new configuration of lfoat arms, it can't have been more than 250 gr positive, it was terrible to shoot with.

I disagree though about the fisheye being too wide, you just need to get closer, I went and looked at a few sites showing images from cenotes and many are using fisheyes Like this one: http://www.brandoncole.com/IFPro/scripts/imageFolio.pl?img=0&search=cenote&cat=all&bool=and which are mosltly shot with the 15mm fisheye. I used a fisheye for the first time on a recent trip, this shot is form Halmahera Indonesia and I'm about 1m away :

If you're shooting people and you want flash to reach them and also for them not to fill the frame you have need to be close and shoot very wide. Shot with Oly EM-1 MkII and Panasonic 8mm f3.5 fisheye 1/250 @ f8 ISO400.

7.5mm on APS-C is a good deal wider than 8mm on m4/3 though; you'd need a 5mm fisheye rather than 8mm to get the same field of view, and situations where you need to go this wide are just not very common. Lighting them is also a challenge. I'm guessing that a less wide fisheye such as SEL16F28+VCL-ECF1 combination, or an adapted Tokina 10-17mm would be easier to use in this regard, but I'm pretty happy with my 10-18mm as it is.

By the way, the original Meikon A7 housing did have zoom control, it's the A7 II housing that doesn't have it - but they've announced a new housing for A7 II series that has zoom control, vacuum port, pistol grip, etc, basically their new A7 III housing adapted to an A7 II body.

Regarding buoyancy - I think that positive buoyancy is easier to deal with than negative, as additional weights can be mounted in very small increments to fine-tune it. I bought a box of adhesive weights meant for car wheel balancing; they weigh 7 grams apiece allowing for excellent precision, and the adhesive holds up fine in salt water. Negative buoyancy is countered with floats, but they are typically much larger, and if you're diving a bare housing rather than a handled rig, there might not be any place to actually mount them.

Thank you both for your insights so far - I'll take a closer look at some images and ask around to see what other divers are using in cenotes. I think I will end up with either a compact with wet lens (any suggestions here that include a pistol grip?) or the salted line set up as described above with either a 10-18 in a 4 or 6 inch dome or the SEL16F28+VCL-ECF1 combination, or an adapted Tokina 10-17mm, though I will also look into other brands with native fisheyes per Chris.

My only hesitation with that is I see sony a7r as top of the line non-dslr. I will never take a dslr underwater (size), so I figure I should get used to sony cameras? Is this a bad way of thinking? Thanks again to both of you for the insights.

Oh and as far as the compacts that don't require a case eg. tg-5, - I'll be diving much deeper than the recommended limit, so a camera + housing is definitely necessary!

If you're going to go deep, keep in mind that Meikon's pistol grip is rated only to 20 meters. Pistol grips are generally a feature of surf housings rather than scuba diving ones, as underwater we frequently want to bring the camera down to the bottom and a pistol grip would get in the way there. You also can't mount it simultaneously with a tray, which limits your light attachment points to just the cold shoe. Also, 10-18mm won't work with a 4" dome; that dome is tiny - here's a picture of the housing with macro port, flat port, 4", 6" and 8" domes:

Likewise, 16mm+VCL-ECF won't work in the 6" dome, as that dome's barrel is too long, and the tiny lens won't clear it. Tokina 10-17mm should work in the 6" dome, but you'll have to DIY a gear and there are reports that it doesn't AF very well in poor light. Note that this test was done with an A6300, which has much better AF capabilities with adapted lenses than A6000 and the reviewer still wasn't impressed. Other reviewers have posted different opinions though, so your mileage may vary.

Sony isn't the only game in town when it comes to mirrorless - there's Fujifilm, and more recently Nikon Z6/Z7, Canon EOS R/RP, Panasonic S1/S1R, not to mention the extensive micro four-thirds lineup from Olympus and Panasonic. Not all mirrorless cameras are small either; bodies like Olympus E-M1 and Panasonic GH5 are pretty much DSLR-sized.

I hadn't realized other companies were getting into full frame mirrorless, I'll take a look at sizes and housings. Thanks again for all this info - super helpful.

Note that Sony is the only mirrorless vendor where you can share native lenses between full-frame and crop bodies. Fujifilm does APS-C and medium-format with completely different mounts, Nikon mirrorless are full-frame only, Canon has full-frame and APS-C mirrorless (EOS R and EOS M respectively) but they have different mounts although both can adapt EF-mount SLR lenses, while Panasonic S1/S1R uses Leica's L mount.

Housings are already available for Canon EOS R and Nikon Z, but only from the usual suspects (Nauticam, Ikelite) which means high cost. Meikon and to a lesser degree Fantasea offer much better value for money, provided you're willing to live with some missing features, but Meikon's offerings for Sony cameras stand head and shoulders above their own efforts for other systems; I have no idea why, but that's what it looks like.

Recognize though that while mirrorless bodies are smaller, the lens size is set by the sensor as is the dome size, you can use smaller domes but you tend to undo the benefits of the big sensor image quality wise so you might as well use the smaller sensor.

If you are looking at a compact the main choices are Sony RX100, G7X MkII and Panasonic LX-10 Here's a review from last year on the best compacts underwater: https://www.backscatter.com/reviews/post/Backscatter-Best-Underwater-Compact-Cameras

There are varying compromises between the models among other things relating to how they deal with wet lenses to go wide. Lenses that change length as they zoom can be a problem as they are too far away from the port at the wide end. You can click through to see recommended wide lenses to add on to the camera, which vary according to both the camera and chosen housing. Click the housing first to see what wide lenses are offered.. You may wish to add a single handle tray and some models have shutter extensions available as well. You can see the options change depending on the limitations of the base camera and also the housing style.

On fisheye lenses I wasn't suggesting the 7.5mm quoted, rather the standard 180° fisheye, which is 8mm in m43, 10mm in APS-C and 15/16mm full frame and provides a 180° field of view on the diagonal of the sensor. You can use these lenses with Fantasea on Sony or various others on m43 cameras. These are systems with domes and variable extensions to accommodate different lenses and focus gears available for many UW suitable lenses. This for example is the Port chart for the Fantasea A6000: http://www.fantasea.com/downloads/FMLLensPortChart.pdf They provide zoom gears for some of the lenses you might be interested in. The problem of course once you get away from Sea frogs, prices are steeper. To use any lens you are getting into expensive housings.

Remember, that because of the need to stop down heavily for most underwater photography the gains of FF are smaller than on land. For most wide angle lenses you have to stop down to F16 on FF, but only to F8 on micro 43. This means that the two stop low-light advantage is already gone. DR on mu43 is fairly competitive with FF bodies (especially compared to Canon). This means that the only real benefit is resolution. 20mp are enough for fairly large prints already so unless you want to do ridiculously large prints you will be fine.

If you are only free diving I would seriously consider skipping the FF dreams. In fact you could probably get superior results with a one inch compact and wet wide for your shooting scenario as you don't have to stop down nearly as much, as far as I know. I'm not sure which aperture is recommended for a Sony RX100 with WWL1 but probably no higher than f5,6, once again negating all the low light/ISO advantages of FF.

For what it's worth, I'm not a big fan of fisheye lenses. I don't like the field curvature a fisheye lens creates. While I have a fisheye, I don't use it much. Curvature of the rays of light you mention in your initial post would drive me crazy.

-AZTinman

Great to know about FF vs not while underwater. I think I will keep thinking and decide either on a compact with wet wide angle lens or the bulkier/more expensive a6000 and 10-18 or 16mm with fisheye converter. I still like the idea of the pistol grip above 20m, but the cost savings and convenience of a compact are appealing. I need to think more about the kind of shooting I'll do. Thanks to all

If you're going to go deep, keep in mind that Meikon's pistol grip is rated only to 20 meters. Pistol grips are generally a feature of surf housings rather than scuba diving ones, as underwater we frequently want to bring the camera down to the bottom and a pistol grip would get in the way there. You also can't mount it simultaneously with a tray, which limits your light attachment points to just the cold shoe. Also, 10-18mm won't work with a 4" dome; that dome is tiny - here's a picture of the housing with macro port, flat port, 4", 6" and 8" domes:

 

 

Likewise, 16mm+VCL-ECF won't work in the 6" dome, as that dome's barrel is too long, and the tiny lens won't clear it. Tokina 10-17mm should work in the 6" dome, but you'll have to DIY a gear and there are reports that it doesn't AF very well in poor light. Note that this test was done with an A6300, which has much better AF capabilities with adapted lenses than A6000 and the reviewer still wasn't impressed. Other reviewers have posted different opinions though, so your mileage may vary.

 

Sony isn't the only game in town when it comes to mirrorless - there's Fujifilm, and more recently Nikon Z6/Z7, Canon EOS R/RP, Panasonic S1/S1R, not to mention the extensive micro four-thirds lineup from Olympus and Panasonic. Not all mirrorless cameras are small either; bodies like Olympus E-M1 and Panasonic GH5 are pretty much DSLR-sized.

Just out of curiosity, does the 16mm+VCL-ECF work in their 8" dome?

Just out of curiosity, does the 16mm+VCL-ECF work in their 8" dome?

I'm almost certain it doesn't. SEL16F28 is really short, and the built-in extension is sized for the considerably longer SEL1018, so the shorter fisheye will vignette heavily. You need the 4" dome, which has no extension at all.

On 3/15/2019 at 11:34 AM, hyp said:

Remember, that because of the need to stop down heavily for most underwater photography the gains of FF are smaller than on land. For most wide angle lenses you have to stop down to F16 on FF, but only to F8 on micro 43. This means that the two stop low-light advantage is already gone. DR on mu43 is fairly competitive with FF bodies (especially compared to Canon). This means that the only real benefit is resolution. 20mp are enough for fairly large prints already so unless you want to do ridiculously large prints you will be fine.

 

If you are only free diving I would seriously consider skipping the FF dreams. In fact you could probably get superior results with a one inch compact and wet wide for your shooting scenario as you don't have to stop down nearly as much, as far as I know. I'm not sure which aperture is recommended for a Sony RX100 with WWL1 but probably no higher than f5,6, once again negating all the low light/ISO advantages of FF.

Why do you need to stop down underwater? I keep reading this but don’t understand why. Is it because the AF is not good enough on most cameras underwater so a deeper depth of field allows for more in focus footage?

24 minutes ago, bubbagump00 said:

Why do you need to stop down underwater? I keep reading this but don’t understand why. Is it because the AF is not good enough on most cameras underwater so a deeper depth of field allows for more in focus footage?

This is due to the curvature of the virtual image generated by a dome port. Basically you are trying to focus on the inside surface of a large bowl. Stopping a lens down increases depth of field increasing the chance of getting the sides of the bowl in focus.

33 minutes ago, bubbagump00 said:

Why do you need to stop down underwater? I keep reading this but don’t understand why. Is it because the AF is not good enough on most cameras underwater so a deeper depth of field allows for more in focus footage?

No, it's not the AF, it's the amount of Depth of Field (DOF) that you can achieve. Wide-angle imagery usually needs a good bit of DOF to allow for the lens having to focus on a virtual image created by the domeport - not the actual image. The virtual image is very close to the   dome and for the lens to be able to capture reasonably sharply the whole range of the curve of the image, you need a smaller aperture and therefore greater DOF.

Then for macro, subjects are so small and the lens magnification so great that DOF is very small - hence using small apertures to increase DOF as much as possible - or at least until refraction becomes an issue and sharpness begins to deteriorate.

The amount of DOF create depend to a large extent on the sensor size as well as lens aperture. The smaller the sensor the greater the DOF. Hence hype's comment that you might be better with a 1" compact sensor rather than FF.

2 hours ago, Tom_Kline said:

This is due to the curvature of the virtual image generated by a dome port. Basically you are trying to focus on the inside surface of a large bowl. Stopping a lens down increases depth of field increasing the chance of getting the sides of the bowl in focus.

So will an image be focused in the center and unfocused on the edges if your depth of field is too shallow when using a dome?

7 minutes ago, bubbagump00 said:

So will an image be focused in the center and unfocused on the edges if your depth of field is too shallow when using a dome?

Correct. If the subject is centered and has just water as a background one can use a larger aperture. Out of focus blue is not so noticeable.