[RobG]

I can't find a thread about this subject exactly - have any of the DFA 150-450 users made extensive use of the focus buttons on the lens? I'm curious about the utility of presetting the focus and jumping to that focus point with the buttons. I tried the lens in Japan and by default the buttons just behaved like extra AF triggers.

[tduell]

I've not used the focus buttons on the lens, nor set a focus preset, but it has been one of those 'Pa Kettle' things "...I'll get around to it one of these days".
I do make use of the focus range settings, always selecting 6-inf for anything over 6m as it focusses faster, and as soon as it's likely that a subject will be within 6m (birds) I switch to 2-6 to be sure I don't get caught not being able to focus.

Cheers,
Terry

[biz-engineer]

I tried the lens in Japan and by default the buttons just behaved like extra AF triggers.

The is a mode selection, AF, AF preset, and AF cancel. Memorization of the current AF position is done by pressing the AF Preset button for a few seconds, once done, the lens remember the AF position. Pressing one of the buttons around the lens move AF back to that preset position. That is useful in context. For example, when shooting small birds, the range is pretty much known in advance, something like 4 to 6 meters, in that case AF preset at 5 meters (middle of the range) makes auto-focus instant. When shooting larger wildlife, the distance range between 10 and 30 meters, again, focus preset at 20 meters allow very fast focusing. When AF preset is set in the middle of the range, the AF motor has to spin for half of that range, worst case. For any other shooting, AF preset at 30 meter (something like 1/3rd of the way from infinity), produces faster focusing operation. It took me some time to get used to AF preset and range settings on that lens, since I had the DA300 before, but I got used to it , and I'm very happy with AF so far. Except the DFA150-450 with the K1 and battery grip is a rather heavy combo.

[rawr]

FWIW, I have used a Nikon lens that also has 3 AF buttons around the lens barrel, just like the 150-450. The only thing they do is focus lock, which has once or twice been handy. But it's kind of fiddly to use in the field when you are also trying to drive the zoom, keep an eye on the subject etc. Need three hands.

Looks like the 150-450 can also do focus lock, when the switch is set to AF Cancel and an AF button is pressed:


The utility of all those AF buttons and switches very much depends on the type of shooting you do, I guess.

[RobG]

I've not used the focus buttons on the lens, nor set a focus preset, but it has been one of those 'Pa Kettle' things "...I'll get around to it one of these days".
I do make use of the focus range settings, always selecting 6-inf for anything over 6m as it focusses faster, and as soon as it's likely that a subject will be within 6m (birds) I switch to 2-6 to be sure I don't get caught not being able to focus.

Having focus limiting would be wonderful - thanks for the real life examples!

The is a mode selection, AF, AF preset, and AF cancel. Memorization of the current AF position is done by pressing the AF Preset button for a few seconds, once done, the lens remember the AF position. Pressing one of the buttons around the lens move AF back to that preset position. That is useful in context. For example, when shooting small birds, the range is pretty much known in advance, something like 4 to 6 meters, in that case AF preset at 5 meters (middle of the range) makes auto-focus instant. When shooting larger wildlife, the distance range between 10 and 30 meters, again, focus preset at 20 meters allow very fast focusing. When AF preset is set in the middle of the range, the AF motor has to spin for half of that range, worst case. For any other shooting, AF preset at 30 meter (something like 1/3rd of the way from infinity), produces faster focusing operation. It took me some time to get used to AF preset and range settings on that lens, since I had the DA300 before, but I got used to it , and I'm very happy with AF so far. Except the DFA150-450 with the K1 and battery grip is a rather heavy combo.

Great! This gives me a much better understanding of how it works. Thank you!

[geomez]

I only press the lens AF buttons by accident. I've attempted to use them in real world scenarios, but I don't find them any more useful than the rear AF button on the camera. If anything, they're more physically cumbersome and thought intensive. Also I've never used the AF preset function. I never got around to learning how it worked, and on the surface, didn't seam like a function that I would find useful in my photography. After owning the lens for about 9 months, I still feel that way about it.
On the other hand, I do use the focus limiter switch quite frequently.

[RobG]

FWIW, I have used a Nikon lens that also has 3 AF buttons around the lens barrel, just like the 150-450. The only thing they do is focus lock, which has once or twice been handy. But it's kind of fiddly to use in the field when you are also trying to drive the zoom, keep an eye on the subject etc. Need three hands. Looks like the 150-450 can also do focus lock, when the switch is set to AF Cancel and an AF button is pressed.

Interesting! I think the focus preset could be very handy at an airshow or a sporting event if there's a particular spot you come back to during the event. For example at one airshow I was near the point where the aircraft landed, and a focus point close to that would be a handy point to return to. For sports I can think of lots of situations where it would be handy, but I don't photograph sports.

I only press the lens AF buttons by accident. I've attempted to use them in real world scenarios, but I don't find them any more useful than the rear AF button on the camera. If anything, they're more physically cumbersome and thought intensive. Also I've never used the AF preset function. I never got around to learning how it worked, and on the surface, didn't seam like a function that I would find useful in my photography. After owning the lens for about 9 months, I still feel that way about it. On the other hand, I do use the focus limiter switch quite frequently.

Fair enough, YMMV. I suspect that I would use the focus limiter a lot also.

[ffking]

Pressing one of the buttons around the lens move AF back to that preset position.

that's actually the more useful feature of the old 'power zoom lenses of the 1990s - power zoom itself was just an unnecessary battery drain - but I remember they advertised presets using tennis players, where you could preset the zoom for either end of the court.

[RobG]

that's actually the more useful feature of the old 'power zoom lenses of the 1990s - power zoom itself was just an unnecessary battery drain - but I remember they advertised presets using tennis players, where you could preset the zoom for either end of the court.

Exactly, or if you had a cricket or baseball game - to return to focus on the batter for example.