Sony 6400 seafrog - extremaly poor quality after switch from Canon? Please help!

[mi000ke]

This is quite odd. I have tested the 16-50 with SeaFrogs 4", 6" and 8" dome and the only situation in which it had trouble focusing was the 4" dome at focal lengths longer than 30mm.

@Barmaglot , you are correct - sorry, I meant to type 4" not 6" (went back and corrected it).

 

[Barmaglot]

@Barmaglot , you are correct - sorry, I meant to type 4" not 6" (went back and corrected it).

Well, there's at least part of your problem - the four inch dome is really too small to work with anything but a fisheye lens. While the 16-50mm will physically fit in it, even when you get it to focus, the image outside of the immediate center will be very soft. If you want to get good image quality out of the 16-50mm lens, you need to use the 6", or preferably 8" dome. I have done some pool testing with the various lenses and SeaFrogs ports that I own; you can see the results here. The 16-50mm lens is absolutely capable of producing stunning images; these three were shot with the 8" dome, on the same dive, in the order of descending subject size:

Another point of note is that Meikon/SeaFrogs acrylic domes lack advanced optical coatings and thus are quite prone to flaring. Avoid bright lights, especially sunlight, hitting the dome edge-on - for best experience, keep the sun behind you.

Lastly, the images that you posted are suggestive of some sort of freshwater environment, perhaps a quarry? I have never dived in quarries, but with the water clarity that I can infer from your images, shooting wide-angle is a non-starter. I have successfully shot my A6300/SeaFrogs setup in water conditions where I had trouble seeing my own hands, but it was always on macro subjects. Here is a sample picture taken under those conditions, i.e. if you can't physically feel your buddy, you've lost them:

The little out of focus blobs are silt particles, and you can see sand grains liberally sprinkled over the sea moth itself. This was taken with a Sony 90mm f/2.8 G macro lens, at a distance of maybe 10-15cm from the port glass.

 

[CanadaDan]

A thought on the flare...

You never mentioned what lights and strobes you are using. I'm presuming a strobe or two triggered by the popup flash and fibreoptic cables.

Could it be flash flare from the popup? With the pancake lens is there possibly enough space for the flash to leak into the dome and cause the effect? I don't have a pancake to test the hypothesis but I can't think of anything else that would light up the inside of the dome unless you have a head mounted light on and it was pointing into the housing or at the dome.

edit: Maybe the flash diverter (shiny bit inside underneath the fibreoptic ports) is missing/misaligned?

 

[uwlunatic]

Hi !!
We have been using the Sony A6000 & A6500 in the Seafrogs UW-Housing, but have never encountered these problems.
Even when using it with a variety of Domes and Macro Diopters the quality of the images was always satisfying.
There might be a problem with your strobe positioning - or White Balance. Also the conditions you are diving in make the use of a strobe very difficult and we would advise to change to manual settings.

Try shooting without strobe and adjusting the White Balance manually.
Here I will link one of our recent articles on how to find the right White Balance underwater.

Finding the right White Balance

I hope this will help. https://lunatics-world.com/2021/03/25/finding-the-right-white-balance/

 

[Jon Underwater]

It looks for all the world like your internal pop-up flash has reflected around inside the housing onto the dome? It might be because that pancake lens is so shallow? You might consider folding over some black electric tape on itself by the pop-up or around your lens to reduce light leaking into the housing & port- I did have to do this a little with my previous seafrogs housing. Also, perhaps check any external strobes are positioned well back behind the dome?

I'm a very interested party as after a bit of homework I've taken a punt on the seafrogs 'salted line' housing with the Tokina 10-17mm on a sigma mc-11 in the "6 dome. About to try it in my local Dorset waters for the first time this week!

 

[Cavetecdiver]

It looks for all the world like your internal pop-up flash has reflected around inside the housing onto the dome? It might be because that pancake lens is so shallow? You might consider folding over some black electric tape on itself by the pop-up or around your lens to reduce light leaking into the housing & port- I did have to do this a little with my previous seafrogs housing. Also, perhaps check any external strobes are positioned well back behind the dome?

I'm a very interested party as after a bit of homework I've taken a punt on the seafrogs 'salted line' housing with the Tokina 10-17mm on a sigma mc-11 in the "6 dome. About to try it in my local Dorset waters for the first time this week!

Thanks that could be the case. I will try using some black tape.
Can you share how tokina with mc performed? Can you share any pics done with this setup?
Is tokina plus mc adapter not too lengthy to fit into 6'¿

 

[gstrek]

Thanks that could be the case. I will try using some black tape.
Can you share how tokina with mc performed? Can you share any pics done with this setup?
Is tokina plus mc adapter not too lengthy to fit into 6'¿

What if you used a zoom gear and fit the lens into it just to help block light from entering the port?

 

[stuartv]

It looks for all the world like your internal pop-up flash has reflected around inside the housing onto the dome?

I used to shoot an Olympus E-M10 in a Meikon housing. I had exactly that same kind of reflection showing up in my images and that is exactly what it was. The camera's popup flash firing and reflecting inside the housing all the way to the inside of the dome and then back into the lens.

I got some black foam weatherstripping of the right thickness and made a collar of it around the lens. That fixed it.

Fixing that might also help with the exposure issues. Though, the only really good answer for that is to learn how to shoot in Manual mode.

 

[stuartv]

Also, not sure why you are using a 20mm prime in that rig. I think the kit lens (16-50?) and a Nauticam WWL-1 wet wide angle dome would result in much better images.

Keep in mind that, for u/w shooting, it's the combo of lens, port, and wet optics (if any) that is important. A "cheap" lens with good wet optics will often significantly outperform an "expensive" lens with the wrong port/dome.

 

[Jon Underwater]

Thanks that could be the case. I will try using some black tape.
Can you share how tokina with mc performed? Can you share any pics done with this setup?
Is tokina plus mc adapter not too lengthy to fit into 6'¿

It fits fine with the 6" dome, I've spoken to a US based diver prior to adopting myself, but so far I've only pressure tested the housing, not yet taken the full rig out in it yet. Hopefully I should get a chance soon though.