Sharp Mantas in Hanifaru?

Many of my UW pics are sharp. 

I use the A7IV, 28-60, WACP-C.

But today in Hanifaru-Bay where there‘s a lot of krill (that‘s why the mantas are there) success was only 50%. 

Does anyone have a good idea which AF-mode to use? AF-C or AF-S? Subject tracking? Animal recognition on or off?
Currently AF was set to AF-C, small field center, subject tracking, animal recognition. 

The problem of course is the backscatter, right? And if I was able to tell the cam not to focus close I would be happy…

Maybe even, shock, horror, switch to Manual focus? 

If you had the aperture at, say f11, use AF to get close then flip to M. As long as the distance doesn't vary too much you should be good - and the Manual focus will of course ignore any turbidity or participant in the water.  

I would suggest getting closer. They seem far from you

This will help AF and reduce the amount of water and particles between subject and your camera

@TimG the distance varies very much. This is only snorkeling and Freediving so no way of keeping the distance. But it’s worth a try… setting to 4-5m and f11. 
 

@waterpixel the closer ones suffer from similar problems. If the AF recognizes the manta as goal then the pictures are tack sharp… 

Tomorrow I hopefully will try again. 

The biggest thing is to get closer. 

Once that's sorted, for mantas, I'd suggest AF-C with the tracking wide or zone setting, with the animal detection turned off

Mike

8 hours ago, fruehaufsteher2 said:

@TimG the distance varies very much. This is only snorkeling and Freediving so no way of keeping the distance. But it’s worth a try… setting to 4-5m and f11. 
 

@waterpixel the closer ones suffer from similar problems. If the AF recognizes the manta as goal then the pictures are tack sharp… 

Tomorrow I hopefully will try again. 

You will be dealing with virtual images so the distance the lens is focused at is much smaller, presumably you mean focus on something 4-5m away.  If you are set up for back button focus that is effectively the same as as switching to MF, without having to find that setting.  So you would focus with your thumb then once you are happy leave it at that setting and shoot.

What AF mode to use will depend on the camera you are using.  If you are going for back button you may find AF-S works better as AF-C is usually contrast detect and AF-S Phase which is again camera specific.  The Sony AF system is quite complex and not that well documented. 

Some things to consider Phase detect AF may work better than contrast detect particularly UW,  in some situations with AF-c at least the lens stops down when focusing and on some cameras the aperture at which Phase detect AF works is limited (limit is f9 on A7-II for example).

Have you adjusted AF tracking sensitivity?  making this slower will help prevent the camera refocusing on krill once it has focused on the Manta.  There are quite a few videos about on setting up the A7C you may be able to get some tips from them as well.

I don't know your camera, but on a Nikon I would use 3D Tracking.  Basically a small focus box I manually move around, but which can then track what I tell it to. 

No subject detection.

AF-C (continuous), with back button focusing.   I'd get focus on part of a creature, and keep the focus point on it if moving.  Otherwise I'd let off the back button and just shoot, using depth of field to cover small movements.   If I'm shooting wide angle at 14 to 30mm, F8-F10 works well.  Lots of depth of field, until something comes close.

Dear all, great thanks for your help.

I tried today again, first with MF. No way… The distance varies between 1m and 15m - and the Mantas are coming out of the blue and disappear again in less than 30 sec. In this interval I have to take a deep breath, go down, and use the camera. So no time for adjusting. 

I have to accept that only the pictures where the Mantas are close will be good enough to keep them. But anyway, as the rate of missed focus is less than 50% the ones with correct focus are >50%. Enough for me.

It feels like taking pictures in massive fog.

Maybe Lightroom's Dehaze is your friend?

1 hour ago, TimG said:

Maybe Lightroom's Dehaze is your friend?

Already done. You don’t want to see the original…. 

Ahhhh……. Hey, some ya win, some, ya don’t. 

Keep getting closer, and if you are prepared to do a few minutes in photoshop with the soft removal tool and maybe some hue/saturation work there is plenty more to be had - keep at it.

Difficult to work on a small jpeg, and I could go further with the backscatter on the manta, but here's an idea

Mike

2 hours ago, pooley said:

Keep getting closer, and if you are prepared to do a few minutes in photoshop with the soft removal tool and maybe some hue/saturation work there is plenty more to be had - keep at it.

Difficult to work on a small jpeg, and I could go further with the backscatter on the manta, but here's an idea

 

Mike

Agree, my choice would be levels first setting the black point properly and an "s" curve to bring up contrast. Could probably do a lot more with a RAW file but here's another:

Not sure if you’re using strobes or just natural lighting, but if the latter, have you tried using one of the orange filters for shallow water? 

While it won’t remove the haze per se, it’ll tone down the blues and greens and add a bit of warmth back in to the manta, which will aid in pop and contrast enough to make it feel sharper or clearer. Almost like an orange/teal Hollywood color grade. 
 

Definitely tough to fight the back scatter, especially while snorkeling or free diving. A lot of the dives I’ve done here in Japan have had really poor visibility until about 15-20 feet deep. 

Strobes are not allowed to not disturb the mantas more than necessary. 
filters might help but I don’t have any with me. So maybe I will overexpose a little to have more options to filter out green and blue..? 
 

I didn’t repair with photoshop but that’s the next step. Maybe today another approach. in this plankton soup the visibility will never be good. But mantas have to feed and it’s great being able to watch them open and close the mouth. 
 

https://www.instagram.com/p/Cu1rE8zP9CV/?img_index=1
 

43 minutes ago, fruehaufsteher2 said:

Strobes are not allowed to not disturb the mantas more than necessary. 
filters might help but I don’t have any with me. So maybe I will overexpose a little to have more options to filter out green and blue..? 
 

I didn’t repair with photoshop but that’s the next step. Maybe today another approach. in this plankton soup the visibility will never be good. But mantas have to feed and it’s great being able to watch them open and close the mouth. 
 

https://www.instagram.com/p/Cu1rE8zP9CV/?img_index=1
 

I would check your images for headroom to over expose first, the bright whites look like they are blowing in these shots.  I don't know how much flexibility you have in positioning but having the sun behind and maybe up to 45° either side you might help.  Also shooting up should help keep the background lighter which may make floating particles less visible.