Underwater photography strobes - the right and wrong choices?

[bradlys 0]

I am doing a trip here soon to French Polynesia (Tahiti and Moorea) where I will be snorkeling quite a bit. My partner is going to be scuba diving some but I don't think they'll bring the camera with them. We're mostly going for relaxation but photography is a fun hobby for us both. I'm looking at scuba diving in the future but not right now. We decided this would be a great time to get into underwater photography because we've used a gopro before when we were at some nice islands in Thailand. We just found the photography aspect of that experience to be lacking.

I ended up buying a Seafrogs A9 housing. Part of me regrets this because I thought *maybe* I could get away without buying strobes for our first underwater photography journey - especially since we'll be focused on snorkeling depths/areas but now I'm seeing lots of shots and regretting not having strobes. It also wildly inflates the price from the $700 for the housing, standard port, and 6" dome port. I ended up seeing a Seafrogs SF-01 strobe on Amazon for $200 - so I bought it. It seems to be some kind of Sea & Sea clone - and I am hoping it's not as bad as the ST-100-PRO that I saw horrible reviews floating around for... It doesn't come with a sync cable - so I'm thinking of buying the cable or just returning my impulse buy of a flash. It also means that we need to get a tray ($60) and some arms ($???? Can't find these for reasonable prices anywhere - it's just some aluminum brackets) and maybe some floaties of some kind. (I'd like to figure out a homebrewed solution that is cheaper than buying special $XXX foam)

What are your thoughts? Would a single flash be sufficient for an enjoyable experience? Should I just buy the sync cord now and own it? At this point - it's like... I can either get a flash setup and it'll cost $200 for flash + $150 for cable + $60 for tray + $100 in arms/floats/brackets (insane how much this stupid stuff costs) + $70 in batteries(18650)/charger for a total of $580. If I find another SF-01 for $200 - that'd be a nice deal but unlikely.

What are your thoughts? I feel like I'm in such a bind with so little time. Worst case scenario - I can return the flash and just go on my trip-flashless and have some batteries I can use in a flashlight or something later. (Charger works for other things too)

[hyp 115]

This once again shows that it's important to check out the full system cost before deciding on a camera. The A9 belongs to the highest range FF cameras and you want to put it into a cheap chinese housing with a 6" port that will give you really soft corners most likely. Strobes, arms and trays are one of the few things that you take with you when you upgrade systems and move housings. As the way you light your shots can make or break the image they are quite important too. 

If you can return the whole setup, I would highly recommend it. Going with a cheaper Camera (maybe Sony A7RIII) would give you enough budget to invest into a housing from a reputable brand with a port selection that is compatible to your lenses. Generally it's said that the camera only makes up about 1/3 of the total cost of bringing a camera underwater with decent lights etc. So if you have 6000$ to spend, buy a camera for 2000$. I'd guess that if the cheaper the camera becomes the lower that ratio gets so if you have 4000$ to spend, buy a camera for around 1000$.

On the matter of strobes, I have seen very few reports on the Seafrogs strobes, but those I have seen were largely positive (although I don't really trust the source here, but nvm). Maybe you can get away with them, but my experience generally says that if you buy cheap, you buy twice. On paper they should be powerful enough. 

Also, to save some money, check out the thread on the DIY strobe sync cables. 

[adamhanlon 0]

With big sensor high resolution cameras, you need big, wide, powerful strobes. Unfortunately, these are expensive!

A 6" dome port on a full frame camera is also not optimal.

It is hard to advise you as any decision will be personal, but I think if your current system is unused, I would not use it and investigate options on your return. 

Adam

[TimG 62]

Good advice form Adam and hyp.

I'd suggest these are decisions you should not make in a hurry especially if the budget is, understandably, an issue.

As hyp explains, some of the items that , perhaps, you see as peripheral (arms, strobes) are some of the few items which you can transfer from system to system: so chose them well and to last.

You do need to consider the system as a whole and not the sum of diverse parts. Not to do so will eventually - or maybe sooner! - lead to serious disappointment and frustration and significant extra cost.

 

[bradlys 0]

11 hours ago, hyp said:

This once again shows that it's important to check out the full system cost before deciding on a camera. The A9 belongs to the highest range FF cameras and you want to put it into a cheap chinese housing with a 6" port that will give you really soft corners most likely. Strobes, arms and trays are one of the few things that you take with you when you upgrade systems and move housings. As the way you light your shots can make or break the image they are quite important too. 

If you can return the whole setup, I would highly recommend it. Going with a cheaper Camera (maybe Sony A7RIII) would give you enough budget to invest into a housing from a reputable brand with a port selection that is compatible to your lenses. Generally it's said that the camera only makes up about 1/3 of the total cost of bringing a camera underwater with decent lights etc. So if you have 6000$ to spend, buy a camera for 2000$. I'd guess that if the cheaper the camera becomes the lower that ratio gets so if you have 4000$ to spend, buy a camera for around 1000$.

On the matter of strobes, I have seen very few reports on the Seafrogs strobes, but those I have seen were largely positive (although I don't really trust the source here, but nvm). Maybe you can get away with them, but my experience generally says that if you buy cheap, you buy twice. On paper they should be powerful enough. 

Also, to save some money, check out the thread on the DIY strobe sync cables. 

Hmm - didn't know about the dome port sizing influencing corner sharpness. I think the only other option for the seafrogs housing was an 8" dome but it's specifically not compatible with some of the lenses I'd be using. I'm not sure why - probably the tube is too long or something. Here's the compatibility list: https://docs.google.com/spreadsheets/d/1_UDOLZ1HnFoeIpTBHGcIwu4iN1s5n2LWzj1UXXrUnM8/edit?usp=sharing (I am using a Tamron 17-28 and 28-75 and a 50mm macro for UW photography)

As far as why I have the A9 - I've had it for a few years. I don't plan on buying a second camera to do underwater photography when I already have a very capable one. If I was going to buy another camera - I'd either buy an R5 or A1 at this point and then sell my A9. I don't need two bodies.

Unlikely to be able to return it at this point - they don't have a very lenient return policy. Even then, I'd lose out quite a bit on it I'm sure because of shipping costs and what not.

I was mostly trying to keep my entire budget for UW to be under $1000-1500 once I discovered the seafrogs housing. Before that - I was never planning on doing any UW photography because the housings I'm familiar with are usually $3000. (Which is about what I paid for my A9 - hard to justify)

I don't think the DIY strobe sync cable thing is for 5-pin connectors, is it? That's what the seafrogs SF-01 uses - it's not the fiber optical type.

Edited May 21, 2021 by bradlys

[troporobo 252]

Aside from the expense, adding strobes raises the technical and physical complexity of your system a lot.  If you’re new to all this, figuring out exposure and strobe settings and managing cables arms and clamps for the first time while on an exotic holiday may not add to your enjoyment!   
 

I would hesitate to snorkel with my complete system (two strobes with multiple arms and clamps).  It’s a lot to set up and manage, and while it’s OK doing all that at depth now that I’m experienced and the rig is neutrally buoyant, I would not want to try while bobbing at the surface.  If you’re a really strong swimmer then you can get to the subject, position the camera and strobe, and get the shot. It may take a few descents per image to get it figured out as you’ll need to change settings and try again. But if you’re shooting from the surface, with bright sunlight, the strobe will do nothing at distances beyond 1 m.  Keeping it simple and shooting ambient only would certainly be more relaxing.

[hyp 115]

1500$ is a really tight budget to bring a FF camera underwater. If you already own the A9 then obviously it makes sense to try and bring that camera underwater, but there is a reason the Seafrogs housings are much cheaper and the port selection will make things difficult. One way to make using smaller domes possible is using a fisheye lens as they are much more forgiving behind a domeport. Most people use a 230mm dome for rectilinear wides and even on micro four thirds I use a 7" dome for my wide angle lens. It doesn't sound like you're too ambitious with your UW photography, so maybe you can live with the 6" dome and soft corners. The further you zoom in the better they will be so at 24mm they might be ok already. The 28-75 should be fine. 

If you're really just snorkelling then I think you can get away with no lights and maybe a red filter. Up until about 5-6m the camera should have no trouble white balancing. Make sure that you shoot in RAW so that you have the best options of fixing colour in post. That way you don't have a complex system with arms and tray (although a handle is still recommended).

 

[bradlys 0]

Do you guys have example photos of using a 6" vs 9" dome with the same lens? I just want to get an idea of the type of sharpness loss one would expect. (Like obvious on Instagram viewing from a phone or just to pixel peepers)

The 2x strobe and what not definitely seems overkill for a first trip and especially with snorkeling. I've seen folks do it online but it does seem rather excessive.. That's why I haven't just bought it - obviously!  I worry about the weight stuff too - so that's why I'm also looking for cheap float ideas or improvisation for when I'm somewhere to just get a better feeling.

I'm really interested in trying out flash. If it doesn't work - I'm sure someone will buy some of it. I might be able to return *some* of the items if it's really bad since I bought through Amazon.

Obviously getting the $3000 housings with the largest dome possible in the clearest and finest glass in the world would be most optimal but I'm trying to compromise here and still take just 1 camera instead of having to have multiple bodies and what not. We really like using my A9 and I don't like having to adjust to different bodies/menus/performance/etc.

[TimG 62]

I'm travelling at the moment so can't post some examples.  But without doubt there is a huge and highly visible difference between the 6" and 9" domes for rectilinear. This is not pixel-peeping (I'm no pixel-peeper). Results, if you have coral reef at the edges, are horrible. Some pics can almost look as though you have hit the zoom as you pressed the shutter.  If you have "blue" at the edges then it's ok.

No doubt lights and their ancillary arms etc will make snorkelling tricky. It'd be worth trying hip's idea of a filter. Low cost, easy to travel with and no big loss if you decide it's not for you. And, yes, shoot in RAW which then gives you some flexibility in processing.

I can certainly appreciate your argument in your final para. The problem is though that a mix of physics and reality join uncomfortably together when using high end cameras. Compromises in add-on equipment impact far more on a camera like the A9 (similarly the D850).  Its high quality sensor becomes almost a liability if you want to go budget for everything else. It's an argument i've been making recently. Yep, high end cameras are fabulous but when you take them underwater, they produce a very high end additional price to make them perform in the way they should; and a significant gain in transportation issues. You can't really get away from this dilemma.

 

[ChrisRoss 150]

As others have said UW photography is a complete system and to get the sort fo quality you might be used to from high end land cameras takes significant investment of both $$$ and time and diving skills on your part.  Costs generally scale with sensor size and low end housings are cheap because they cut corners to reach a price point.  But you've jumped in now, so what to do ??

I would suggest if you are snorkeling, just go without a strobe and see how you like it , use the 28-75 lens as getting close to get the advantage of using the wider lens is probably not practical when snorkeling.  If you are on the surface or shallow, adjust your white balance using a custom white balance or correct the best images in post (shoot RAW!).  The Seafrogs strobes do not have a great reputation and I don't know if the new ones are any improvement _ I would return it

The other thing to be aware of is the housings from Sea frogs are often very buoyant so getting them below water may be a challenge.

you asked about an example of bad corners, here's an example shot with a 17mm lens in a 170mm dome:  https://uwaterphoto.com/?p=839

 

[adamhanlon 0]

I think the problem revolves around cost vs benefit. Given your budget, I would not chose to house the A9, but would go for a compact camera with housing. This would remove many of the optical/expense issues  inherent with your existing set up. I think a relatively cheap (possibly second hand) compact camera will probably provide you with better results, will be easier to use and will be more manageable for travel. 

To further complicate your dilemma, some lenses work behind dome ports, and some do not. This is not focal length dependent, but is a function of the lens's construction. That said, I don't know of any lens that will provide acceptable (for me) corner sharpness with a  6" dome port on a full frame camera.

I would love to see what Seafrogs are basing their lens chart on! My gut is that they have just looked at vignetting and physical fit as being the only criteria. If not, they seem to have somehow managed to solve all the optical problems that have plagued underwater photographers since people first took cameras underwater. 

I would love to see how a Sony FE 16-35mm f/2.8 GM works with a flat 6" port as they recommend. I suspect it will look horrible!

[Phil Rudin 485]

Bradlys, 

Rather than to dwell on all of the negatives surrounding your purchase let me suggest how you can make what you have work for you. 

First the lions share of folks doing underwater photography are spending the amount you have spent or far less. Most are using GoPro cameras, cell phones in inexpensive enclosures, compact cameras in small acrylic housings and more. Many of the photographers commenting here at some time started with just such a system. For those who have not actually used one of the Seafrogs housing and just assume they are "cheap" this is my experience. I ordered a Seafrogs housing for a student who was riding his motorcycle to Florida from NY and was unable to carry both the housing and the camera equipment. He housed the Sony A7R IV and the 24-70 F/2.8 along with a Sony FE 16-35mm F/4 he borrowed from me. For the 24-70 he used the flat port and for the 16-35 he added the eight inch port. His intent was as yours to only snorkel shooting in both pool and shallow areas in the Keys, these sessions involved models. For snorkeling he was able to get by without any flash and some of the results were quite good. Corner sharpness is subjective, shooting models you often want a shallow DOF where corners don't matter. 

Regarding the Seafrogs housing it was as well built as any of the housings I have used from Olympus, Fantasea and others. The housings are a clam shell design and have a dual O-ring seal on the main door and a single O-ring seal on the bayonet mount interchangeable ports. The housings ship with a builtin moisture alarm and they offer a vacuum system which works very well for the $107US price, the pump is a bit flimsey. The ports also lock into place with a positive locking device and a backup retaining lock. The housing also comes with a single sync cord (Nikonos type) point with the hotshoe cord included. The housing also has two fiber optic ports and they sell a manual flash trigger for $30US and fiber optic cords for $30US. My client paid an extra $12US for expedited shipping and I had the system on my doorstep from HK in four days. 

If you already own the Tamron 17-26mm F/2.8 this would be an excellent choice paired with an eight inch dome port or you can test it with the six inch dome in a pool and see if the results are good enough for your needs. Regarding the single flash unit if you place it above the center of the dome port using the pictured $55US accessory which attaches to the cold shoe on top of the housing you should be able to get by for your trip.

You could easily spend tens of thousands on better quality equipment but for those only doing U/W photography for a few days a year or for those wanting a system to use in the pool for shooting the kids the Seafrogs offerings are not a bad choice.

Also go to the BLOG section of the seafrogs wed site and watch all of the tutorial videos on setting up and using the housings. They cover everything will will need to know about how to keep the housing dry on the inside.

  

[bradlys 0]

14 hours ago, adamhanlon said:

I think the problem revolves around cost vs benefit. Given your budget, I would not chose to house the A9, but would go for a compact camera with housing. This would remove many of the optical/expense issues  inherent with your existing set up. I think a relatively cheap (possibly second hand) compact camera will probably provide you with better results, will be easier to use and will be more manageable for travel. 

The only issue for me is that I don't want to carry two cameras/systems or maintain that. I'd like to get a FF experience as well.

16 hours ago, ChrisRoss said:

As others have said UW photography is a complete system and to get the sort fo quality you might be used to from high end land cameras takes significant investment of both $$$ and time and diving skills on your part.  Costs generally scale with sensor size and low end housings are cheap because they cut corners to reach a price point.  But you've jumped in now, so what to do ??

I would suggest if you are snorkeling, just go without a strobe and see how you like it , use the 28-75 lens as getting close to get the advantage of using the wider lens is probably not practical when snorkeling.  If you are on the surface or shallow, adjust your white balance using a custom white balance or correct the best images in post (shoot RAW!).  The Seafrogs strobes do not have a great reputation and I don't know if the new ones are any improvement _ I would return it

The other thing to be aware of is the housings from Sea frogs are often very buoyant so getting them below water may be a challenge.

you asked about an example of bad corners, here's an example shot with a 17mm lens in a 170mm dome:  https://uwaterphoto.com/?p=839

 

It's interesting to see that 170mm dome shot. I tried shooting with my 6" dome with the 17-28 earlier today at some stuff - it demonstrated the effects you mentioned about soft corners. They are noticeably soft. I mean, definitely on my screen at 27" but I don't know if I'd notice on my phone - it'd depend on the subject. Coral is very detail oriented so I might notice. It's also not super predictable in terms of sharpness from my small tests. I need better subjects than my lawn and patio. (Probably should shoot a picture of some test papers on a wall or something) At what distance and aperture would one notice the corner sharpness being drastic? Probably the wider the aperture - the more noticeable?

10 hours ago, Phil Rudin said:

Bradlys, 

Rather than to dwell on all of the negatives surrounding your purchase let me suggest how you can make what you have work for you. 

First the lions share of folks doing underwater photography are spending the amount you have spent or far less. Most are using GoPro cameras, cell phones in inexpensive enclosures, compact cameras in small acrylic housings and more. Many of the photographers commenting here at some time started with just such a system. For those who have not actually used one of the Seafrogs housing and just assume they are "cheap" this is my experience. I ordered a Seafrogs housing for a student who was riding his motorcycle to Florida from NY and was unable to carry both the housing and the camera equipment. He housed the Sony A7R IV and the 24-70 F/2.8 along with a Sony FE 16-35mm F/4 he borrowed from me. For the 24-70 he used the flat port and for the 16-35 he added the eight inch port. His intent was as yours to only snorkel shooting in both pool and shallow areas in the Keys, these sessions involved models. For snorkeling he was able to get by without any flash and some of the results were quite good. Corner sharpness is subjective, shooting models you often want a shallow DOF where corners don't matter. 

Regarding the Seafrogs housing it was as well built as any of the housings I have used from Olympus, Fantasea and others. The housings are a clam shell design and have a dual O-ring seal on the main door and a single O-ring seal on the bayonet mount interchangeable ports. The housings ship with a builtin moisture alarm and they offer a vacuum system which works very well for the $107US price, the pump is a bit flimsey. The ports also lock into place with a positive locking device and a backup retaining lock. The housing also comes with a single sync cord (Nikonos type) point with the hotshoe cord included. The housing also has two fiber optic ports and they sell a manual flash trigger for $30US and fiber optic cords for $30US. My client paid an extra $12US for expedited shipping and I had the system on my doorstep from HK in four days. 

If you already own the Tamron 17-26mm F/2.8 this would be an excellent choice paired with an eight inch dome port or you can test it with the six inch dome in a pool and see if the results are good enough for your needs. Regarding the single flash unit if you place it above the center of the dome port using the pictured $55US accessory which attaches to the cold shoe on top of the housing you should be able to get by for your trip.

You could easily spend tens of thousands on better quality equipment but for those only doing U/W photography for a few days a year or for those wanting a system to use in the pool for shooting the kids the Seafrogs offerings are not a bad choice.

Also go to the BLOG section of the seafrogs wed site and watch all of the tutorial videos on setting up and using the housings. They cover everything will will need to know about how to keep the housing dry on the inside.  

Yeah, this will likely be a lot of my experience as well. Although we're excited to both shoot photographs of coral, rays, sharks, various fish, etc.. It's a lot more likely I'll be working with my "model" quite a lot to get the perfect shot for the gram... She gathered some 50+ inspiration shots for us to recreate - so I have my work cut out for me on this trip. If I'm not using the underwater housing - it'll be the drone. If it's not the drone - it'll be the gopro for videos. If it's not the underwater housing - I'll be on land with my tripod. If not that - then with the phone - etc. etc.

This is my setup - it doesn't have the fiber optic ports. https://seafrogs.com.hk/collections/sony/products/sony-a9-v-2-series-fe12-24mm-f4g-uw-camera-housing-kit-with-6-dome-port-including-standard-port-zoom-rings-for-fe12-24-f4-and-fe16-35-f4-included-white

Such a simple cable - it should only be $25-30 even though it's such a low volume seller.

Edited May 23, 2021 by bradlys

[Architeuthis 192]

Hi Bradly,

Is the vacuum system included in your set? If not, I strongly recommend you buy one: not all, but most floodings happen in housings that do not have one. My wife, e.g., flooded her Oly EPL5 in the original Olymus housing, that did not have a vacuum system and according to Phil is of similar quality to the Seafrog. In her case it was a 300 Euro camera with kitlens, but in your case it would be a Sony A9...

Maybe this would also be the time to look for a good insurance for your photographic equipment, in case you do not already have one - when the camera is soaked in saltwater you can throw it away afterwards...

Wolfgang

 

P.S. regarding the optical cable: when on budget (or also for reserve, we always have such cables with us in addition, in case a "good" cable breaks), you can buy the cable as meterware and stick the ends into plugs like this:

https://www.unterwasserkamera.at/shop/catalog/en/product_info.php?info=p4471_inon-double-hole-rubber-bush-for-fiber-optics.html

=> But be careful, these connections are not standardized and may well be different in your Seafrog housing and flash. I am sure that every UW photography shop has such simple connectors and can give you advise, which one will fit...

Edited May 23, 2021 by Architeuthis

[bradlys 0]

8 hours ago, Architeuthis said:

Hi Bradly,

Is the vacuum system included in your set? If not, I strongly recommend you buy one: not all, but most floodings happen in housings that do not have one. My wife, e.g., flooded her Oly EPL5 in the original Olymus housing, that did not have a vacuum system and according to Phil is of similar quality to the Seafrog. In her case it was a 300 Euro camera with kitlens, but in your case it would be a Sony A9...

Maybe this would also be the time to look for a good insurance for your photographic equipment, in case you do not already have one - when the camera is soaked in saltwater you can throw it away afterwards...

Wolfgang

 

P.S. regarding the optical cable: when on budget (or also for reserve, we always have such cables with us in addition, in case a "good" cable breaks), you can buy the cable as meterware and stick the ends into plugs like this:

https://www.unterwasserkamera.at/shop/catalog/en/product_info.php?info=p4471_inon-double-hole-rubber-bush-for-fiber-optics.html

=> But be careful, these connections are not standardized and may well be different in your Seafrog housing and flash. I am sure that every UW photography shop has such simple connectors and can give you advise, which one will fit...

I don't have the vacuum system (it's about $120 to buy the testing kit) - it comes with the port for it but I've submerged it for 2+ hours to test it. Only in a bucket of water but it was bone dry inside. (Obviously isn't a good test for sizeable depth testing) You can see the housing in the listing. It doesn't have fiber optic ports either. It just has a 5-pin sync port.

Edited May 23, 2021 by bradlys

[Barmaglot 262]

On 5/22/2021 at 10:20 AM, bradlys said:

Do you guys have example photos of using a 6" vs 9" dome with the same lens?

It's not exactly apples to apples comparison, but when I upgraded my SeaFrogs A6xxx housing from 6" to 8" dome, I took a series of comparison photos in a pool using 16-50mm and 10-18mm lenses (24-75mm and 15-27mm FF-equivalent). You can see them here.

 

38 minutes ago, bradlys said:

I don't have the vacuum system (it's about $120 to buy the testing kit) - it comes with the port for it but I've submerged it for 2+ hours to test it. Only in a bucket of water but it was bone dry inside.

I highly recommend getting the vacuum kit, it has saved my camera numerous times. One time, I was staying at a house with a bunch of cats, sealed my housing in the morning, pumped it out, went to have breakfast and saw it start to flash red. Opened the door and found a tiny white cat hair on between the white o-ring and white plastic... the thing was maybe 3-4mm long and almost transparent, but it would've been enough to kill $2k worth of gear.

40 minutes ago, bradlys said:

It doesn't have fiber optic ports either. It just has a 5-pin sync port. 

Pavel at UW-Technics makes a flash trigger board for SeaFrogs housings that comes with a replacement bulkhead that allows you to use optical triggering with strobes instead of the electrical sync cords, but it's a $450 expense.

[bradlys 0]

1 hour ago, Barmaglot said:

It's not exactly apples to apples comparison, but when I upgraded my SeaFrogs A6xxx housing from 6" to 8" dome, I took a series of comparison photos in a pool using 16-50mm and 10-18mm lenses (24-75mm and 15-27mm FF-equivalent). You can see them here.

 

I highly recommend getting the vacuum kit, it has saved my camera numerous times. One time, I was staying at a house with a bunch of cats, sealed my housing in the morning, pumped it out, went to have breakfast and saw it start to flash red. Opened the door and found a tiny white cat hair on between the white o-ring and white plastic... the thing was maybe 3-4mm long and almost transparent, but it would've been enough to kill $2k worth of gear.

Pavel at UW-Technics makes a flash trigger board for SeaFrogs housings that comes with a replacement bulkhead that allows you to use optical triggering with strobes instead of the electrical sync cords, but it's a $450 expense.

At that price - I almost may as well go with a different kit for the replacement bulkhead. Is there any reason to not use the 5-pin besides maybe some flashes out there not supporting it?

I'll look into the vacuum pump system then. That is frustrating that it seems mandatory then. It would be unpleasant to have a surprise - although I feel you're going to have these kinds of issues anytime you're opening the case at all... there will always be a risk a microscopic cat hair gets on there when you're putting your camera in. So... idk how I feel about it.

[Barmaglot 262]

24 minutes ago, bradlys said:

At that price - I almost may as well go with a different kit for the replacement bulkhead. Is there any reason to not use the 5-pin besides maybe some flashes out there not supporting it?

The electrical cords are somewhat bulky, expensive (the dual sync cord sold by SeaFrogs is $130, and that's as cheap as it gets), limit your strobe choices (for example, Retra flashes are optical-only) but most importantly, their connectors are sealed by o-rings and represent additional points where water can get in. The UWT board also gives you TTL capability, whereas direct connection via sync cord works only in manual mode. Specific to Sony full-frame cameras, UWT board also gives you higher maximum sync speed (1/250 vs 1/160) and if you use Retra flashes, you can do high-speed sync at speeds all the way up to 1/4000.

Keep in mind that the UWT optical bulkhead has the triggering LED built in and requires the UWT board to function; it will not work on its own. You could try a DIY mod with a simple piece of acrylic replacing the electrical connector and the SeaFrogs flash trigger behind it, but I have no idea how well that would work, if at all.

[ChrisRoss 150]

6 hours ago, bradlys said:

I don't have the vacuum system (it's about $120 to buy the testing kit) - it comes with the port for it but I've submerged it for 2+ hours to test it. Only in a bucket of water but it was bone dry inside. (Obviously isn't a good test for sizeable depth testing) You can see the housing in the listing. It doesn't have fiber optic ports either. It just has a 5-pin sync port.

Tests such as this are meaningless, it only tests that the housing is tight at that time.  Leaks are caused by grit or hairs laying on the o-ring, allowing a path for water to get through or twisted or damaged o-rings. Each time you use the housing and open it up,  there is a risk of getting material on the o-ring which will cause it to leak.

Leaks are actually most likely in shallow water such as a rinse tanks, o-rings need to be loaded to seal - the pressure deforms them and presses them onto the surface.  The vacuum actually pre-loads the o-rings which is arguably as big a benefit as the leak alarm the system provides. 

$120 is cheap insurance, I can't emphasize this enough - get the vacuum system!  Also note that while it is very useful, it is not a substitute for poor o-ring maintenance - look after you o-rings and clean them regularly.

[bradlys 0]

Ok - folks. I think I'm about set. I definitely went overboard on this whole thing but it's ok - it's within my "buy 1 lens per trip" quota.  I usually buy a new lens/something for every big trip we do. (So, once or twice a year)

This is what I have now - which is definitely a bit more than I had planned for but within my "1 lens" budget.

• $729 - Seafrogs A9 housing w/ flat port and 6" dome - https://seafrogs.com.hk/collections/sony/products/sony-a9-v-2-series-fe12-24mm-f4g-uw-camera-housing-kit-with-6-dome-port-including-standard-port-zoom-rings-for-fe12-24-f4-and-fe16-35-f4-included-white
• $218 - Seafrogs SF-01 strobe - https://www.amazon.com/gp/product/B07ZVFZWCZ/
• $123 - Seafrogs 5-pin dual sync cord (express shipping increased cost) - https://www.aliexpress.com/item/1005001429200373.html
• $87 - Seafrogs VPS-100 vacuum system - https://www.amazon.com/gp/product/B08CDPLH4F
• $56 - Seafrogs aluminum tray - https://www.amazon.com/gp/product/B07ZQJY9DL (I don't think I need anything fancier - if I do, I can return it after the trip)
• $20 - Kitdive 8" arm - https://www.amazon.com/gp/product/B019DL7VAS/
• $18 - Kitdive 5" arm - https://www.amazon.com/gp/product/B00Z59W97I/
• $40 - 4x ball clamps - https://www.amazon.com/gp/product/B083XP2183/ (doubt they'll be an issue - I don't need $50 ball clamps)
• $70 - 18650 batteries and charger from https://liionwholesale.com/ (These are multipurpose though - so I don't consider them just part of this purchase)

Total: $1,361.

If I had planned better - maybe I could've gotten a better setup for cheaper but I had very little notice on this trip. It's still cheaper than the most affordable Ikelite body-only housing for an A9 (not even including a port).

I bought a 50mm macro lens for $400 just for fun. It'll likely not be super useful for underwater macro but I'll give it a shot since I have the flat port that works with it. My SO and I have an interest in trying some macro photography out more (in general - not just UW) and $400 is very cheap to me. (It's also much smaller and more versatile than the 90mm and that was my main reason for choosing it)

Even if we just get a few good fun shots out of this setup and use it a few times - it'll be worth it to me. I can always sell it if I decide after this trip that it's not worth it to me and I'm sure someone will pick it up eventually. I've definitely gotten most of this stuff for relatively cheap.

Also - with this setup - my SO is looking at potentially taking it on one of her scuba dives. We'll have to test the buoyancy soon and see how lopsided it is. Hopefully it's not catastrophic and is slightly manageable. It'll definitely not be neutral like the pro-rigs out there.

[TimG 62]

Well done on finalising it! I hope you get some pics you love - and do post them here. And, most important, have a great time!

[Phil Rudin 485]

Will you have one flash or two?

[Barmaglot 262]

Small note on clamps - I have a number of clamps similar to the ones you linked, and a pair of Ultralight clamps that I got in a store when my luggage got delayed, and the difference is quite significant. The Ultralight clamps grip better when tightened, and slide smoothly when loosened, allowing easy and precise strobe positioning without the whole setup flopping around. Cheap arms are fine, but quality clamps are worth the extra investment - I'm planning to replace all my remaining clamps with Ultralight ones before next trip.

It's be nice to have a field report about the SF-01 strobe - I had a pair of ST-100 Pros and they were serviceable, but limited to TTL-only operation when triggered by fiber optics; I have since then sold them onwards. Hopefully the SF-01 is better in this regard.

[Phil Rudin 485]

The SF-01 flashes are out of stock and unlikely to return so I would be looking for an alternative. 

[bradlys 0]

I bought the last one on Amazon. I only have 1. I'd list if I purchased two.

They still sell them on Aliexpress and elsewhere. I bought the dual sync cord to future proof myself. No point to buy 1x.

Edited May 24, 2021 by bradlys