Focus settings for birds at sea.

[woodturner]

I was recently on a ship crossing the North Atlantic. as it was January it was a little rough. There were a few birds flying round the ship, which I tried to photograph with low success rate. I would like any suggestions on autofocus settings/MF to improve matters next time.... Using a A77ii.

I was located on deck at a height of about 16 metres above the sea level. The ship was doing 20 knots, mostly in Force 7 to 9, fortunately on the aft quarter. Rise and fall where I was = about 4 metres every 10-15 sec.

The birds insisted on gliding at low level in the lee of the ship, so were well below my position, meaning I was looking down on them against the background of the waves. This seemed to mean the AF (even if it initially acquired them) tended to lock on the waves rather than the bird. Hence I have a lot of great pics of the North Atlantic seawater only spoiled by an out of focus bird in the way. (also I have lots of seawater pics without the bird, where I missed it completely.

Later in the trip the weather abated, and the birds few higher, so the AF worked fine with them against the sky. So not a camera/lens problem...

Any suggestions how to shoot a moving target against a moving background? The combo seems unsurprisingly to fox the AF, which seems to want a target against something more static. Or shoot lots with MF and hope the bird cooperates and flies into focus??

I will be doing the same trip at the end of the year so would like to learn/do better.
thanks,
Eric

 

[stig]

Which lens were you using Eric? I would suggest using C-AF combined with Center Focus only and adjusting E/V values accordingly. Keep the speed over 1000/sec.

 

[woodturner]

Hmm, thanks for your reply. A quick review of my photos seems to show the problem is worse at lower speeds, so perhaps I was not allowing for motion of the ship enough - quite a lot were at 1/500 area, Next time I will set a speed a lot higher. I think I saw the birds gliding, and assumed I did not need higher speeds. I still see failure to lock/track on a lot of them, but it is difficult to pan from a ship. Just the operator as usual....
I'll try harder next time.

Thanks for the suggestion.

eric

 

[stig]

Hmm, thanks for your reply. A quick review of my photos seems to show the problem is worse at lower speeds, so perhaps I was not allowing for motion of the ship enough - quite a lot were at 1/500 area, Next time I will set a speed a lot higher. I think I saw the birds gliding, and assumed I did not need higher speeds. I still see failure to lock/track on a lot of them, but it is difficult to pan from a ship. Just the operator as usual....
I'll try harder next time.

Thanks for the suggestion.

eric

A lot depends on a steady hand of course, and I'm assuming you are bracing yourself, but even then, I find 1000/sec up to 2000/sec appropriate. What lens were you using?
Happy Easter holiday [or will I be banned for saying that these days]
-Stig

 

[woodturner]

I was mostly jammed in a corner next to the rail, sigma 400, sony 500, sigma 18-250. I could get reasonable panning shots horizontally from there against the sky, but pointing down at the sea seemed to be less successful. Initially I tried only shooting when the ship was mostly still, i.e., at the top and bottom of the wave, but getting the birds to cooperate with that proved difficult. I had vertical movement of the ship, panning, and the sea moving in the background. However, I think as I hadn't fixed the speed, against the sky and surroundings the speed was higher than looking down at the rather dark water. My BIF setting that I was recommended years ago uses aperture setting not speed.

I still feel the A/F lock didn't work so well with the sea in the background......

Perhaps the real message should be not to cross the North Atlantic in a January storm....

thanks and regards,

Eric

 

[stig]

I was mostly jammed in a corner next to the rail, sigma 400, sony 500, sigma 18-250. I could get reasonable panning shots horizontally from there against the sky, but pointing down at the sea seemed to be less successful. Initially I tried only shooting when the ship was mostly still, i.e., at the top and bottom of the wave, but getting the birds to cooperate with that proved difficult. I had vertical movement of the ship, panning, and the sea moving in the background. However, I think as I hadn't fixed the speed, against the sky and surroundings the speed was higher than looking down at the rather dark water. My BIF setting that I was recommended years ago uses aperture setting not speed.

I still feel the A/F lock didn't work so well with the sea in the background......

Perhaps the real message should be not to cross the North Atlantic in a January storm....

thanks and regards,

Eric

It's all fun and games until you need that sick bag...lol
Consider it good practise.

 

[TomV]

Your observation of sky vrs rough water as a background is the correct. The sky is rather homogeneous compared to the water. It is also much farther away. The focusing system will have more problems with the water as a result. With the sky, your target is much easier to differentiate, both by distance and texture. I have shot a lot of birds and dolphins at the ocean and on land and that is tough enough because of the low angle. I have shot a few times from a boat and the waves make a huge difference, Unless the targets are close it is a real challenge to keep the focus spot on the bird. When expanding it a bit then the water gets involved.
You could try closing down the aperture a bit to increase your depth of field and then increase the ISO accordingly to maintain some modicum of shutter speed.

 

[woodturner]

Thanks for the comments. Next time I will spend time doing experimenting to try to optimise things, I hadn't thought it would be quite so tricky. Next trip will be in the winter again so the challenge will still be there.

Interestingly I got a better results shooting down on a day when the sea was an oily calm. the a/f had an easier time perhaps.