wordfool
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 Re: A1 to get firmware update in February? | |
TGPhotography wrote:
wordfool wrote:
Thought I'd post a few examples straight from camera (jpgs from RAWs, no editing or cropping or artistic intent!) to illustrate the problems I'm having with BEAF. It'll be interesting to hear from folks whether my expectations for BEAF are in the right ballpark, but my opinion is that BEAF is not working as well as it used to with these sort of shots that I've been taking for years.
First three are with the 200-600 a few days ago. Second three are with the 100-400 today in slightly worse light. The 200-600 was terrible with BEAF and I barely got it to activate at all over the course of an hour's shooting. Overall, the 100-400 seemed to work more as I'd expect -- a bit sporadic with its BEAF activation, probably due to the low light, but I saw it working often enough to feel a little reassured. Focus modes I variously used were AF-C small spot (my usual default), medium spot, and zone, both in tracking and non-tracking modes. Lenses wide open at 600mm and 400mm, respectively.
Screech owl, pretty small in the frame, BEAF box was bouncing all over its body:
Red-tailed hawk, in good lighting, BEAF did not activate at all (excuse the minor file corruption... having issues with my card reader). I had about 5 minutes taking shots of this bird and despite trying multiple focus modes I never got BEAF to activate:
Nuthatch in decent but not great light. BEAF did not activate at all as I followed it:
Northern Cardinal brightening up a dull day. BEAF worked as expected for this shot:
But a few seconds later BEAF failed to activate at all as he bobbed his head around, which was more typical of this outing:
Despite having a black eye in a black mask, BEAF used to have no problem with Cardinals. But here's another in which BEAF did not activate at all. Yes, it's a busy background, but how can an algorithm not see there's a bright red bird at the center of the frame?!
I assume none of these were shot in crop mode?
My opinion:
The only one of those I would expect BEAF to work reliably is the red tailed hawk. Maybe the last cardinal. I don't have experience with cardinals. I am just judging by size in the frame and profile.
Most of those the birds are too far away and too small in the frame. Sure, BEAF may or may not work in the far away instances. The bird is so small it doesn't matter all that much. A normal AFC mode like zone or small/med flex spot would work.
BEAF is most needed when the bird is close enough the whole animal won't be in focus so you want the eye sharp. The other benefit to BEAF is when there are other things in the frame the camera might grab onto while the bird is close.
Far away shots normal AFC is so good at picking up movement that wide, zone, or small/med flex spot should work. Plus at greater distances the whole thing will be in focus anyway. Basically A9 focus at that point.
I think that once BEAF activates for the first time in a situation, it seems more likely to work again. So in the red tail hawk shot if BEAF isn't working in zone, I would use small flex spot since it is perched and easy to drop it on the head. That usually gets BEAF to work, even if you switch back to zone. Don't know if I am imagining this, but it is my impression after hundreds of hours of use.
Just my opinions.
I shoot in AFC wide/zone non tracking generally. I have custom recall holds for small flex spot with tracking on the AEL and AFON buttons. One recall custom hold keeps the same shutter speed/A/ISO and just uses small flex spot with tracking. The other hold is for a 1/500 shutter, wide open A, auto ISO for perched birds. All focus modes wide/zone/small flex spot are with subject recognition on.
Correct, none were shot in crop mode.
The hawk is the weirdest of them and I had the bird closer and farther in many other perched shots, but in none of them could I get BEAF to work. Tried four different focus modes (S and M spot, flex spot, zone) both tracking and non-tracking and spent a total of about five minutes taking dozens of shots at three different perches. Nada. The nuthatch should have activated BEAF, too, based on my past experience with birds that size at that distance, regardless of its usefulness in terms of overall focus/DoF. I was surprised I got no flicker of life from BEAF at all as the bird moved around. And, as you say, the last cardinal also should have worked, but light was low in that case so I'll give BEAF a pass because of that.
With smaller subjects BEAF has indeed always been a bit of a crapshoot, especially in low light. The owl is a perfect example -- I'd not expect BEAF to have worked on that, yet it did activate and tried to find the eye. Shooting today, however, it seemed more random than usual -- the same group of birds (mainly cardinals) at the same distances, often on the same branches, showed no rhyme or reason as to when BEAF worked. The shots I posted were the extreme distances I tried. Many were closer, on the ground, and still seemed very random.
My limited testing has shown the main problem to be with the 200-600. When I least expected BEAF to activate, it did. When I most expected it to activate it didn't. The 100-400 at least gave me some recognizable BEAF behavior.
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