New A6400- first time use - awful results!

[mi000ke]

I’m an experienced land photographer who decided to try underwater photography a couple of years ago. To keep it simple I started with an old Canon S110 P&S and Canon housing, shooting RAW with ambient light. The image quality was very good, but never great (see a couple of examples below), so I recently decided to upgrade to a Sony A6400 with 16-50 mm kit lens and SeaFrogs (Meikon) housing with a 4” dome. I dove with it yesterday for the first time (30’-50’, sunny day, 80’ vis) and the results were abysmal. Almost every shot was a blurry, grainy, out-of-focus mess for both moving and stationary objects. No part of those photos was in focus, so it was not a matter of focus capturing the wrong spot.

I shot ambient light at f8, 1/125, auto ISO. Highest ISO on any shot was only 400. The camera indicated focus (well, it would not obtain focus when lens > 40mm so I kept it around 25-30mm) but almost every one of the 70 shots was way out of focus. I’ve attached a couple of typical shots below. I then shot on land with the camera in the housing as a test and the images were fine. I’ve seen posted on the web some ambient light u/w photos taken with this camera and they look great – very crisp and nice color. Would appreciate any thoughts about what I’m doing wrong, or not doing that I should.

Examples (all went through a similar process of white balance/color adjustment and sharpening.):

Canon S110/ambient light:

A6400/ambient light:

 

[Nemrod]

Out of curiosity, what is the focus setting you are using? Since the Sony cameras all share the basic software and engine and autofocus system, which is known to be exceptional I agree you have an issue. I just bought one myself. Some lenses will not focus behind a dome without a diopter. The lens has to be capable of focusing on the dome, so that is a very close focus. Yes, the lens focuses on the image projected by the dome and dome ports usually have focus from right on the dome to infinity or nearly so for practical purposes underwater. But the camera lens must be able to focus on that image. I had to use diopters on several lenses behind domes on my old Nikon (film) SLRs.

Underwater photography can be challenging and frustrating and without strobes, well, B&W is your friend. Your focus issue is the dome. I bet it will focus in the air? But not in the water? Frankly, having shot several Nikonos cameras, several Nikon SLRs and several digital cameras, wet lenses are a lot easier to deal with (an opinion) than domes. But that said, despite owning several nice wet lenses, I will invest at some point in a dome but carefully match the lens.

Edit, I did a little looking around and I think you need a +2 diopter.

James

 

[Barmaglot]

The 4" dome is too small for the 16-50mm lens; you need to use either a flat port (the bundled flat port will do, and there is a short macro port that will allow you to attach wet lenses), or one of the larger domes (6" or 8", although the 8" is closer to 180mm in practice). The 4" dome is meant to be used with fisheye lenses, such as Sony 16mm with fisheye converter or Samyang 8mm f/2.8 manual fisheye.

 

[mi000ke]

Out of curiosity, what is the focus setting you are using?

AF-A - which automatically switches between still/single and moving/continuous focus. I'm going to try using standard single focus and set up back button focus to eliminate problems I may have caused with camera movement. It focuses fine on land, even when in the housing.

Yes, the lens focuses on the image projected by the dome and dome ports usually have focus from right on the dome to infinity or nearly so for practical purposes underwater. But the camera lens must be able to focus on that image.

Interesting - hadn't realized that. Thought it would focus on the actual object (my last housing used a flat port).

The 4" dome is too small for the 16-50mm lens; you need to use either a flat port (the bundled flat port will do,

I will switch it out with the flat port (unfortunately left it back in Boston, so not until next season).

Thanks for the info!

 

[gstrek]

I'm going to try using standard single focus and set up back button focus to eliminate problems I may have caused with camera movement.

I like BBF and will set it to C1 when using the A6XXX Salted Line housing. Using your index finger on the C1 housing button and middle finger on the shutter feels very natural and stable. Although my older A6000 is slower to focus than the newest generation of A6xxx cameras, I find it is acceptable when using AF-S and center focus point along with BBF.

 

[Barmaglot]

I will switch it out with the flat port (unfortunately left it back in Boston, so not until next season).

If you don't have any other ports with you, keeping the lens at its widest setting (16mm, maybe 20mm) should produce acceptable images.

 

[CanadaDan]

If you happen to have a small macro lens like the SEL30M35 with you it might do the trick. It's not listed for the 4" dome but it's worth a shot.

 

[mi000ke]

If you don't have any other ports with you, keeping the lens at its widest setting (16mm, maybe 20mm) shouleahd produce acceptable images.

Yeah, was thinking the same thing. I'll give it a try.
Todah

 

[mi000ke]

I did a little looking around and I think you need a +2 diopter.

James

The +2 diopter did the trick! Focusing fine now. Thanks for the advice.

 

[Nemrod]

The +2 diopter did the trick! Focusing fine now. Thanks for the advice.

Good news, I am glad that solves the focus issue. Now hopefully you can get some better than awful results !