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Jim Neiger
01-13-2008, 02:04 PM
I specialize in photographing birds in flight and I make a living teaching others how to do the same. One of the techniques I use I call bumping the focus. This technique is often mis-understood and I get alot of questions about it. I just finished a lengthy answer to a question in another thread, so I thought it would be usefull to post my answer here as well where it would be easier for folks to find in the future. Here it is:

There are three different uses for the bump focus technique. I will try to explain each of them below. By bumping I simply mean letting off the focus and then refocusing quickly.

1. The first reason to bump the focus is to prefocus. The first task when photographing a BIF is to aquire it in the viewfinder and focus on it. It is beneficial to be able to do this as quickly as possible. When using long focal lengths, the bird may be so out of focus that you can't see it in the viewfinder even if it's there. Then when you do get it in the viewfinder it may take much longer to focus on it if the foicus is set to a drastically different distance. To overcome these issues, I will prefocus at the approximate distance that I anticipate for my subject. Then when the subject arrives, I can find it and focus on it quickly. I prefocus the camera by pointing the camera at something at the desired distance and then I focus on it. Now I'm ready for a BIF at a similar distance. If I need to switch the distance I will simply point the camera at something at the new distance and bump the focus. This will prefocus the camera at the new distance. Photogs that use a tripod will often prefocus manualy. Since manual focus is difficult hand held with big glass, I use the bump to prefocus.

2. When I am tracking a BIF against a varied bg and I miss and focus on the bg I will bump the focus to quickly return focus to the bird. Bumping the focus overrides the delay set by the tracking sensitivity custom function. Iset this tracking sensitivity to slow to get thelongest delay possible. This heelps when you are focused on the bird and want to avoid focusing on the bg, but it hurts when focussed onm the bg and you wantg to return focus to the bird. Bumping the focus overrides the delay.

3. This is the most important use of the bump technique. Most photogs will aquire focus on a bif and then try to continously maintain foucs while they are tracking and watching the bif in the viewfinder. They tend to focus continuosly waiting for the moment they wish to make a photograph. Often while watching, tracking, and waiting for the moment, the photographer will miss and focus on the bg. This is extremely easy to do when the bif is flying against a varied bg. This is the reason it is so much more difficult to photograph BIF against a varied bg as opposed to smooth sky bg. When the focus grabs the bg, then the photographer needs to re-aquire focus on the bif. This may take too much time causing the photog to miss the critical moment. I try to avoid this by only focusing on the BIF when I'm sure I'm on target and during the critical moments when I'm acualy making images. So, what I will typicaly do is aquire the bif initial and focus on it. Then I will let off the focus and just watch it in the viewfinder while tracking it visualy only. As the distance changes, the BIF will start to go out of focus. When that happens I bring it back in focus by quickly making sure the AF point is on the biurd and then I bump the focus to get it in focus again. I do this repeatedly as I'm visualy tracking the bird. When the BIF gets to the spot I want to start making pictures, I wil focus and shoot all at once. I shoot in short controlled bursts trying to time the critical moments with the best wing positions, etc. Because I have bumped the focus along, the focus is very close to where it needs to be when the moment to make pictures arrives. Then when I focus and trip the shutter it happens very quickly. If I tried to focus constantly while the bif approached I would likely miss, focus on the bg, and miss the critical moment. My goal is to keep the bird close to in focus and in the viewfinder without focusing on the bg and to do this up until the critical moment arrives. Then I try to maintain the focus while making great pictures. Bumping takes lots of practice, but if you develop this skill, it will make your keeper rate go way up.<!-- / message --><!-- sig -->

Fabs Forns
01-13-2008, 02:17 PM
Thanks for sharing this with us, Jim :)

Alfred Forns
01-13-2008, 02:26 PM
Thanks Jim !!!! Remember when you got the 10D and started this technique !!! Sure worked for me !!! Great Tip MUST READ !!!

Jim Neiger
01-13-2008, 02:42 PM
Thanks Jim !!!! Remember when you got the 10D and started this technique !!! Sure worked for me !!! Great Tip MUST READ !!!

I sure do remember the 10D. It didn't do AI servo very well, but I was determined to photograph bif. I ended up using one shot mode and constantly bumping the focus. Without going thru that I may not have figured out the benefits of the bump. Talk about learning things the hard way. ;)

James Prudente
01-14-2008, 11:40 PM
Jim do you use the shutter button to focus or do you set up the AE Lock Button for focus?

Jim

Josh O'Donnell
01-15-2008, 07:38 AM
Jim, thanks for the EXCELLENT read here... Great way to start off my morning!

Jim Neiger
01-15-2008, 09:10 AM
Jim do you use the shutter button to focus or do you set up the AE Lock Button for focus?

Jim

Hi Jim,

I use the shutter button to focus and I set the * button to AF lock. I use the AF lock button when photographing still subjects. This allows me to stay in AI Servo, but still be able to compose still subject images in camera. I don't use my thumb to focus becuase my index finger is much more coordinated than my thumb and the coordination is needed to bump the focus.

Jeff Nadler
01-15-2008, 09:32 AM
Jim,

Since you making a living teaching such techniques, you have been extremely generous with us in sharing this technique here. Thank you sincerely. I have not used this technique but will print this and try it soon. Best wishes.

Nonda Surratt
01-15-2008, 09:50 AM
Thanks Jim!

I just need to get to Florida:(

Peter Hawrylyshyn
01-15-2008, 12:59 PM
Jim -
When "bumping" to prefocus (Use # 1 above) , do you always rely on the camera AF or do you ever focus manually?

Jim Neiger
01-15-2008, 01:45 PM
Peter,

I use the camera Af because I almost always shoot hand held, and manual focusing while hand holding is very awkward. If I'm on a tripod, I tend to still use the camera. It's faster than manual focus. The prefocus is simply to get the AF close to the right distance so when you acquire the subject it happens very quickly.

Andrew McCullough
01-15-2008, 08:16 PM
Thanks for sharing this.

Kenn Christensen
01-15-2008, 08:58 PM
wow... thanks Jim it was quite thrilling and revealing to read your techniques.. .. I learned to do something very similar with my 20D.. the ai servo was very weak and my only hope was doing what your saying here.. when I switched to the 1d Mk III I of course did things the same way.. and maybe thats why Ive not had major focus issues.... because for SURE with the 20D.. if you got the center point off the bird you lost focus while using ai servo and I was never able to reacquire it quickly enough.. though I did use the trick with finding an outside focus point at the same distance I hoped to be shooting at.. it would hopefully be a nice strong focus point that would consistantly be acquired quickly by the AF.... but by the time I did that.. and got back on the bird.. it was often too late... I always capture bif handheld.. I didnt like the confinement of a tripod.. I heard of the bumping technique.. but really had no idea what was meant by it.... thanks again...

Jeff Parker
01-19-2008, 03:53 PM
Hi Jim,

I use the shutter button to focus and I set the * button to AF lock. I use the AF lock button when photographing still subjects. This allows me to stay in AI Servo, but still be able to compose still subject images in camera. I don't use my thumb to focus becuase my index finger is much more coordinated than my thumb and the coordination is needed to bump the focus.

This sounds like a good technique. Is it only available on pro bodies? I can't figure out how to do this on my 40D.

JH Tugs
01-19-2008, 04:17 PM
I've just been trying this, funnily enough. If I'm doing it right, on my 350D it's Custom Function #4 (Shutter Button / AE lock). By default, this would be set to "AF/AE Lock". Setting this to "AF/AF Lock" means that the * button, instead of locking the exposure, locks the focus. I have to keep the button pressed to maintain the focus, but this was working nicely for me in AI Servo mode just now.

George DeCamp
01-20-2008, 05:21 PM
Hey Jim,

Thanks so much for the tip. Looking at your impressive work, as I have done over the years, and reading something like this is the kind of thing that makes places like BPN worth their weight in gold. Thanks Jim for spending the time to put this together for all of us.

Maxis Gamez
01-20-2008, 07:41 PM
Excellent info. I tried this several times and it works for me, especially if i know where the bird is going!

Buck Ward
01-20-2008, 09:00 PM
Thanks for the explanation, Jim.

Is this technique more successful, or more necessary, with some camera bodies than with others? I shoot BIF only occasionally, but with my old Canon 10D, I found that I often needed to resort to an unrefined version of your technique. The 1D3, AF infamy notwithstanding, does a pretty good job of follow focusing, so I haven't been bumping it. What cameras are you using?

Jim Neiger
01-21-2008, 10:16 AM
Thanks for the explanation, Jim.

Is this technique more successful, or more necessary, with some camera bodies than with others? I shoot BIF only occasionally, but with my old Canon 10D, I found that I often needed to resort to an unrefined version of your technique. The 1D3, AF infamy notwithstanding, does a pretty good job of follow focusing, so I haven't been bumping it. What cameras are you using?

Hi Buck,

There are four main factors that impact the need for bumping the focus. They are AF speed, focal length, size of subject in frame, and bg.

AF speed: The slower the AF speed the more need there is for bumping the focus. Slower AF means longer recovery time if you miss, so it's more important to bump the focus if the AF is slower. Camera bodies with slower AF need bump focus more than faster AF cameras. Adding teleconverters slows down AF and increases the need for bump focus. I think this one answers your first question.

Focal length: Longer focal length makes it more difficult to focus accurately on a moving target. This is because the longer focal lengths magnify the effect of your movement. This makes it harder to focus on a specific target increasing the likely hood of missing and therefore increasing the need for bump focus.

Size in frame: The smaller the subject is in the frame the harder it is to focus on it, so this too increases the need for bump focus.

BG: A varied bg increases the need for bump focus. Having a varied bg causes the mian need for using bump focus. If the bg is varied the camera is much more likely to lose focus on the subject and focus on the bg. Most of the time the camera will maintain focus when you miss a subject and the subject is moving accross a smooth sky bg. So varied bgs increase the need for bumping focus and is the main reason for the technique in the first place. The closer the subject is to the varied bg, the more likely the camera is to focus on it when you miss.

If you combine all of these factors then bumping the focus is almost mandatory. For example, I sometimes will photograph BIF with a 500mm + stacked 1.4x and 2.x TCs. This causes the AF to be extremely slow, the focal length to be extremely long. Combine this with a varied bg and a small in frame subject, and you have an almost impossible shot. Using the bump focus technique brings this back to the realm of possibility.

I have used the bump focus with all of the cameras I own. This includes the 10D, 20D, 1D2N, and now, the 1D3. I think this answers your second question.

Dave Stewart
01-21-2008, 06:10 PM
Jim,

I an intrigued - how do you get AF with stacked TCs?

Great info BTW

Regards

Dave

Jim Neiger
01-21-2008, 06:43 PM
Jim,

I an intrigued - how do you get AF with stacked TCs?

Great info BTW

Regards

Dave

The pro body Canon cameras will AF with stacked TCs. The camera doesn't see the second TC. The AF is very slow, but it works. For BIF prefocus and bump focus become critical because if you miss you are usualy done.

Here is an example of a BIF image made with my 1D2N, 500mm and stacked TCs hand held.

Peter Hawrylyshyn
01-21-2008, 08:49 PM
Jim -
best instructional thread so far in BPN
thanks for all the details, plus time and effort onyour part
will definitely test it out on my next trip to Florida

Buck Ward
01-22-2008, 08:19 PM
Jim

I wonder what your setting is, on the 1D3, for the custom function that controls focus sensitivity. Conventional wisdom seems to be to it set to slow, and that makes sense to me for normal focus tracking, so that's where mine is set. But when I think about it, it seems that bump focusing might benefit from it being set faster. What's your advice?

Peter Hawrylyshyn
01-22-2008, 08:45 PM
Buck -
jim answered this in the other thread about BIF

Tracking sensitivity is misunderstood by many. It does not speed up Af or make the af track better. What it is is a delay when the camera switches focus from one subject to another subject. For example; if you are tracking a BIF against a varied bg and you miss and the af point hits the bg, there will be a short delay beffore the camera focuses on the BG. The delay in this case is a good thing. It may allow you to get back on the bird without losing focus. If you do mistakenly focus on the bg, the same delay will cost you time when trying to return focus to the BIF. In thiscase the delay is a bad thing. The delay is really a double edged sword. Sometimes it works for you and other times against you. I used to balnce this by setting the tracking sensitivity to STANDARD, but then I discovered a way to use the delay when it helps me and override (get rid of) the delay when it doesn't. I override the delay by bumping the focus. By bumping, I mean let off and refocus. This will override the delay. Now I have the best of both worlds and I can maximize the benefits of the delay by setting tracking sensitivity to SLOW. So SLOW is the way to go if you learn how to bump the focus to override the delay when needed.

Hope this helps

Peter Hawrylyshyn
01-22-2008, 08:52 PM
Jim -
For answering a question , maybe i can ask one more about your 1D Mk 3 settings and telephoto lenses:
C Fn III - 5 Lens drive when AF impossible : Artie has always recommended "1" - focus search off . Others on various web blogs have disagreed with this . What do you use and does it make a difference?

Are there any other C Fn III AF settings which you've changed from defaults on the 1D Mk3 for your BIF

Thanks again
Peter

Jim Neiger
01-23-2008, 01:00 PM
Jim -
For answering a question , maybe i can ask one more about your 1D Mk 3 settings and telephoto lenses:
C Fn III - 5 Lens drive when AF impossible : Artie has always recommended "1" - focus search off . Others on various web blogs have disagreed with this . What do you use and does it make a difference?

Are there any other C Fn III AF settings which you've changed from defaults on the 1D Mk3 for your BIF

Thanks again
Peter

I tried the focus search OFF for a while, but I had problems with the camera not focusing when I wanted it to, so I switched it back to ON. The only CFIII setting I modified was the tracking sensitivity which I set to slow.

Buck Ward
01-23-2008, 07:26 PM
Thanks Peter and Jim. That answers my question.

Jay Gould
03-24-2011, 02:56 AM
Hey Kissimmee, this is such a wonderful way to do BIF, at least for me since I spent a few days with you that I thought I would bring this back to the beginning 1) because I have a question, 2) for those that have not read and considered this method I think you should, and 3) if you find yourself in the Florida area and love to shoot BIF, spend a couple of days with Jim on his boat and you will be very happy you did so.

Now, I have been rereading Artie's 7D Manual, gosh his manuals/books are good, and he indicates that he has gone to using rear focus by programing the AF-ON button to turn on AF, and using the shutter button for EXP and to take the image.

Question - not just for Jim: for those that like and use the AF-ON button for rear focus, do you also use/can you also use the AF-ON button to use Jim's "bump" method?

While I do believe in not reinventing the wheel and I will always use Jim's method, do you have more control using the AF-ON button?

Daniel Cadieux
03-24-2011, 04:49 AM
Yes, the bump method works just as well using the rear button focus. I would not say you have more control...its just a matter of preference and comfort. I prefer the rear focus method (I use the "*" button on the 40D), it just feels more natural to me, but for others using the shutter button for focus is still the way to go.

Alan Lillich
03-24-2011, 06:45 PM
Jay,

A slightly different spin from Daniel's answer. Yes, the AF-ON button turns on focusing just like a shutter half press, and could be used for Jim's flight techniques. But there are some coordination issues doing that for me.

I am normally an exclusive back button focus shooter. I vastly prefer the flexibility it provides, and the fully separate control of focus and shutter. I took the BIF class from Jim and Doug last July, and found there that it was actually a little easier for me to use the bumping technique with shutter button focus.

The issue for me was that when hand holding with a heavyish lens (D700 with 200-400, 10 plus lbs total) I did not have enough coordination in my thumb. I had too much tension in my hand holding the weight to make wiggling my thumb comfortable. I suspect I could get over that with practice, but have not put the time into it yet to know for sure.

I'm still a back button focuser in all other situations.

Alan

Alan Lillich
03-24-2011, 06:47 PM
I should add the other side of the coordination - when using shutter button focus I tend to accidentally push too far sometimes - so I shoot instead of bump. tradeoffs ...

Jay Gould
03-24-2011, 06:52 PM
Can you expand upon what you have found as the benefit of back button focus. Frankly, no one has sufficiently explained the benefits.

Especially since you would have to go and switch the focus changes each time you switched from HH bump techniques to other methods.

I guess you could set one C Mode Dial choice for back focus and one for BIF.

I am always in AI Servo when shooting moving subjects and I use the AF-ON button to lock AF for a stationary subject shot.

Daniel Cadieux
03-24-2011, 07:22 PM
Jay, apart from the fact that focus and shutter are manipulated independently (which I love), the biggest benefit of using the back button for focus is having "AI Servo" AND "One Shot" available all the time at once...without ever changing the setting ever again in-camera. Just put it in AI Servo and leave it there forever. Keeping that back button pressed keeps focus active for as long as the button is pressed (as in AI Servo), and as soon as you let go of that button focus is locked. Like Magic:S3:

Alan Lillich
03-24-2011, 07:36 PM
Jay,

Here are usage examples of why I prefer back button focus. This is all personal preference, you may feel differently.

1. Leave the body in AI Servo all the time. No need to remember to switch for different situations.

2. Other than the HH-heavy-gear-BIF case mentioned above, it is a lot easier for me to "mash" the back button than gently half press the shutter button. I know when I'm focusing and when I'm not. I don't have problems accidentally shooting too early. This is true also on a tripod with even the heaviest gear.

2.1. My goal for HH-heavy-gear-BIF is to improve my thumb coordination. It isn't massively bad, just slightly less comfortable and more tiring to use my thumb for several hours. Note that a 70-200 is light enough to use my thumb, as is a 400 DO, and probably a 300 f/2.8. The Nikon 200-400 is 7.4 lbs, 1.4 lbs more than the current (not v II) Canon 300 f/2.8, 3.1 lbs more than a 400 DO.

3. When I want to focus and recompose I simply press the back button, let go, recompose, shoot. This uses 1 button to focus, press it again to change focus. Using shutter plus AF lock you have to press 2 buttons each time, and you have to press AF lock while holding the shutter at half press and not accidentally shooting. And then all the confusion/accidents when the AF lock releases when you don't expect it.

Alan

Jay Gould
03-24-2011, 08:41 PM
Jay,

Here are usage examples of why I prefer back button focus. This is all personal preference, you may feel differently.

An interesting discussion; I have made my comments within the quote; I am intentionally playing devil's advocate.

1. Leave the body in AI Servo all the time. No need to remember to switch for different situations.

When you say leave it in AIS all of the time, don't you really mean for subjects are that are either moving or have the potential to move during the shoot?

You would not use AIS for landscape or people photos, would you? Wouldn't you change to One Shot?



2. Other than the HH-heavy-gear-BIF case mentioned above, it is a lot easier for me to "mash" the back button than gently half press the shutter button. I know when I'm focusing and when I'm not. I don't have problems accidentally shooting too early. This is true also on a tripod with even the heaviest gear.

I do not "work" on a tripod for moving subjects; only HH either with 70-200 or 300.

When you do HH you have to go into the various menus and make the changes to cancel back button; then you have to do it again to go back to rear focus. Have you programed C1, C2, etc?

If you use the bump method I do not believe you really "mash" the back button because it too needs to be tapped gently to "bump". I haven't tried it but I am guessing bumping the larger shutter button might be easier than bumping the small back button.

2.1. My goal for HH-heavy-gear-BIF is to improve my thumb coordination. It isn't massively bad, just slightly less comfortable and more tiring to use my thumb for several hours. Note that a 70-200 is light enough to use my thumb, as is a 400 DO, and probably a 300 f/2.8. The Nikon 200-400 is 7.4 lbs, 1.4 lbs more than the current (not v II) Canon 300 f/2.8, 3.1 lbs more than a 400 DO.

3. When I want to focus and recompose I simply press the back button, let go, recompose, shoot. This uses 1 button to focus, press it again to change focus. Using shutter plus AF lock you have to press 2 buttons each time, and you have to press AF lock while holding the shutter at half press and not accidentally shooting. And then all the confusion/accidents when the AF lock releases when you don't expect it.

Yes, you do use two buttons when using AF-ON as AF-OFF. However, if I am shooting a bird that has stopped for a moment, it is my understanding that when you push the AF-OFF button the focus at the moment you push the button is locked and you simply recompose and shoot. If the bird starts to fly away you simply let up on the AF-ON button and AIS automatically starts.


Alan

At the end of the day it is horses for courses and what is most comfortable.

Charles Glatzer
03-24-2011, 08:48 PM
You can set the AF/ON button to work as an AF off button and lock and hold on a point of focus when using AIS. I switch back and forth from using the shutter and back button for AF depending on what I am shooting. The key with either method is to be able to stop the lens from focusing when desired. Moreover, in order to be able to tweak the focus manually you need to be able to stop the camera from focusing as per the above methods.

Best,

Chas

Jay Gould
03-24-2011, 08:51 PM
Chas, when you raise the issue MF, probably you are on a tripod, and you are not dealing with a quickly moving subject that has stopped momentarily on a stick or to sniff something :eek: so you have a bit more time. Yes?

Alan Lillich
03-24-2011, 09:28 PM
Jay,

1. Daniel and I both really truly mean leave the camera in AI Servo all the time. When shooting a still subject I often, but not always, press the back button to focus, let go of the back button, then shoot. Even if the subject is still, I might not be. If I'm doing hand held macro work (yes, I do that), then I'll hold the focus button to deal with my motion.

2. I often use a 13 lb Sigma 300-800. Handholding is not an option for me with that. With a 300 f/2.8 or lighter I would always use back button, even for HH BIF. The "mash the back button" comment was comparing that simple push fully motion to the precise control of a half shutter press. Even Jim Neiger holds the focus down sometimes, he does not always bump.

3. I'm more experienced with Nikon bodies than Canon. The comment about AF lock releasing unexpectedly comes from that, maybe it is less of an issue with Canon. With Nikon, if the metering shuts off before you shoot, then when you do shoot and metering starts again the AF system also starts again. With back button this is a non-issue - focusing happens always and only when I want it to happen.

I'm happy to converse, but don't understand the need for a Devil's Advocate. Some like back button, some don't. I'm not out to convince anyone, only explaining my preferences to the curious.

Alan

Charles Glatzer
03-24-2011, 10:18 PM
Chas, when you raise the issue MF, probably you are on a tripod, and you are not dealing with a quickly moving subject that has stopped momentarily on a stick or to sniff something :eek: so you have a bit more time. Yes?

Yes, but I will also manually AF at times to maintain comp with wildlife subjects moving parrallel to the frame, especially when I cannot get an AF point positioned properly on the subject.
This is more problematic with full frame cameras as the focusing points do not extend as far into the frame.

Chas

Jim Neiger
03-24-2011, 11:45 PM
Using the * button to focus, or using the * or AF-ON button to lock focus and the shutter button to focus, both allow you to remain in AI Servo all of the time so you are always ready for action, but can also shoot still subjects without sacrificing anything. I prefer to focus with the shutter button for two reasons: 1. My index finger is more coordinated than my thumb (particularly in cold weather). This allows me to bump the focus, as I've described above, more precisely. I also find it easier to foucs and shoot with one motion of the index finger than trying to coordinate my index finger AND my thumb. That said, I've always considered choice of method to be a personal preference.

I avoid using manual focus because I'm almost always shooting hand held and I find manual to be akward when not on a tripod. Instead, I use a combination of bumping and locking the focus to achieve the correct focal plane while also achieving the desired composition.

Jay Gould
03-24-2011, 11:47 PM
Jay,

1. Daniel and I both really truly mean leave the camera in AI Servo all the time. When shooting a still subject I often, but not always, press the back button to focus, let go of the back button, then shoot. Even if the subject is still, I might not be. If I'm doing hand held macro work (yes, I do that), then I'll hold the focus button to deal with my motion.

Alan, if you are going out specifically to do landscapes at sunrise, for example, do you still shoot in AIS?


2. I often use a 13 lb Sigma 300-800. Handholding is not an option for me with that. With a 300 f/2.8 or lighter I would always use back button, even for HH BIF. The "mash the back button" comment was comparing that simple push fully motion to the precise control of a half shutter press. Even Jim Neiger holds the focus down sometimes, he does not always bump.

I too hold done the focus until it is necessary to bump.


3. I'm more experienced with Nikon bodies than Canon. The comment about AF lock releasing unexpectedly comes from that, maybe it is less of an issue with Canon. With Nikon, if the metering shuts off before you shoot, then when you do shoot and metering starts again the AF system also starts again. With back button this is a non-issue - focusing happens always and only when I want it to happen.

I'm happy to converse, but don't understand the need for a Devil's Advocate. Some like back button, some don't. I'm not out to convince anyone, only explaining my preferences to the curious.

The DA comment was simply to indicate that I like to cover an issue in depth.

Alan



I appreciate your answers; Thanks

Desmond Chan
03-24-2011, 11:57 PM
3. I'm more experienced with Nikon bodies than Canon. The comment about AF lock releasing unexpectedly comes from that, maybe it is less of an issue with Canon. With Nikon, if the metering shuts off before you shoot, then when you do shoot and metering starts again the AF system also starts again. With back button this is a non-issue - focusing happens always and only when I want it to happen.



Alan, if I understand you correctly, basically you're saying that if we use the shutter button instead of the AF lock, then when we press the shutter button down, the metering starts, and the AF also start. Have I understood you correctly? If so, my question then is: what is bad about it that you see?

Also, wouldn't the use of the shutter button also allow "focusing happens always and only when I want it to happen"?

By the way, when you press down the shutter button, the VR also starts (if you have it on). This is not the case when you use the AF button on the back of the camera.

And, if you are using any of the auto-exposure modes, the metering is on and active all the time whether you have your finger on the shutter button (or any button for that matter) or not. Try that if you are inclined: turn the camera on, use any of the auto-exposure mode, look at the exposure readings at the bottom of the viewfinder and you should see they keep changing when you point and move your camera around.

Daniel Cadieux
03-25-2011, 05:25 AM
Alan, if I understand you correctly, basically you're saying that if we use the shutter button instead of the AF lock, then when we press the shutter button down, the metering starts, and the AF also start. Have I understood you correctly? If so, my question then is: what is bad about it that you see?

Nothing wrong, just a matter of preference.

Also, wouldn't the use of the shutter button also allow "focusing happens always and only when I want it to happen"?

Yes, but when using the compose/focus/re-compose method the focus falls off the subject wjen recomposing (unless using the AF Lock button). Or always switching between One Shot and AI Servo depending on the need. When using the back button to focus, simply let go of that button and focus is locked EVEN WHILE IN AI SERVO! No need to ever go in-camera to switch focus method.

By the way, when you press down the shutter button, the VR also starts (if you have it on). This is not the case when you use the AF button on the back of the camera.

With Canon IS does start when pressing the back button, just as it would when using the shutter button.

And, if you are using any of the auto-exposure modes, the metering is on and active all the time whether you have your finger on the shutter button (or any button for that matter) or not. Try that if you are inclined: turn the camera on, use any of the auto-exposure mode, look at the exposure readings at the bottom of the viewfinder and you should see they keep changing when you point and move your camera around.

When the camera is set to focus using the back button, the shutter button is setup as the exposure lock when half pressed so that takes care of that issue. Perhaps it is an additional CF (can't remember) but very convinient.



Again, simply a matter of preference, but fun to at least try. When I did try it 5-6 years ago I immediately loved it and never looked back.

Alan Lillich
03-25-2011, 08:14 AM
Jay: Yes I really truly mean AI Servo all the time. I don't even think about changing it unless my thumb gets tired in HH BIF with the 200-400. The fewer settings that I change, the fewer settings I will forget to change back later.

Desmond: I think Daniel provided all the answers that I would. Yes it is a bit annoying that Nikon VR does not start when using the back button to focus.

Desmond Chan
03-25-2011, 05:44 PM
Yes it is a bit annoying that Nikon VR does not start when using the back button to focus.

Hmmm...I thought that was one of the advantages of using AF-L/On button, i.e., to get a faster AF lock? My experiences seem to suggest that with VR off, I can get a AF lock faster. I think Doug and others also have mentioned that little fact in some of the threads. It might be a good thing then to leave the VR alone at that point.

Desmond Chan
03-25-2011, 06:15 PM
Again, simply a matter of preference, but fun to at least try. When I did try it 5-6 years ago I immediately loved it and never looked back.

To me, since many of you stated that once you'd tried it you "...never looked back" in your replies about the use of AF-L/On, it seems to suggest that it is more than just a personal preference, as in whether one prefers to use the thumb or the index finger, but that there're factual benefits in using that little button.

My question is: is that so?

So far, I've found that:

1. If you want to lock the AF, just don't press the buttons, i.e. the AF button or the shutter release button. That's the only way to lock the AF regardless of which button to use is my finding. In that regard, neither button has the advantage I'd say.

2. If you use any of the auto exposure mode, the exposure meter is active and on with or without you pressing any button. To lock the exposure reading, and if you choose to use the AF button, you have to program the shutter release button for exposure lock purpose. But if you use manual exposure mode (like I do :S3:), the exposure reading is locked, by default, regardless of any button you touch or do not touch. So neither AF nor shutter release button has any advantage here is my opinion.

3. Focus and recompose (people still do this?:t3). This is the aspect I think the use of AF button definitely helps as the pressing down of the shutter release button will not change the locked AF. Without the use of the AF button, well, given the cameras of today, we can always just move the focus point to where the subject is in the frame and get rid of the recompose step all together :S3: The other way is to use manual focusing.

4. With the use of the AF-button, in the case of Nikon, the VR is not activated and so a AF lock could be obtained a bit faster than when the VR is on. I don't know if in Canon case whether the AF button will activate the IS but, based on what I read, without the IS on, AF lock can also be obtained faster. And if you choose not to use the AF button but use the shutter release button instead, well, you can simply turn the VR/IS off and get the same benefit especially when the shutter speed is already fast enough (1/500s or faster). Then again, even with the use of the AF button, I think the VR/IS (if it's on) will still be activated when you press the shutter release button. I'll leave you to judge if that is going to delay you from obtaining your shot much :S3:

5. In the situation where you need to react fast, say, a bird suddenly fly out from the bush, I tend to thing the use of the shutter release button alone could give you a better chance to get the shot. Then again, with practice, I think it can also be done just as effectively with the use of two fingers/buttons.

I have tried using the AF button. I just don't find it better than simply using the shutter release button alone. My reasoning for for not using the AF button is pretty much the same as Jim's.

Charles Glatzer
03-25-2011, 06:28 PM
Yes, but I will also manually AF at times to maintain comp with wildlife subjects moving parrallel to the frame, especially when I cannot get an AF point positioned properly on the subject.
This is more problematic with full frame cameras as the focusing points do not extend as far into the frame.

Chas

AIS can often lend itself to focus chatter when trying to lock on static images. This equates to in and out of focus images. I will at times lock focus by taking my finger off the back button, or holding in the AF/OFF button...thereafter tweaking the focus manually. Yet, another crayon in the box.

THERE ARE NO DEFINITIVES!

Chas

Jim Neiger
03-26-2011, 10:46 AM
AIS can often lend itself to focus chatter when trying to lock on static images. This equates to in and out of focus images. I will at times lock focus by taking my finger off the back button, or holding in the AF/OFF button...thereafter tweaking the focus manually. Yet, another crayon in the box.

THERE ARE NO DEFINITIVES!

Chas

I agree that there are no definitives, but usually I want to use settings that are effective in any situation. I don't want to miss dramatic action images because I was busy changing my camera settings. The settings I use are designed to let me shoot effectively in any situation without making any sacrifices and without changing camera settings other than exposure.

Charles Glatzer
03-26-2011, 11:43 AM
I agree that there are no definitives, but usually I want to use settings that are effective in any situation. I don't want to miss dramatic action images because I was busy changing my camera settings. The settings I use are designed to let me shoot effectively in any situation without making any sacrifices and without changing camera settings other than exposure.

Jim,

We are in agreement. 99% of the time the AF is in AIS. Change is always made prior to shooting conditions, not during. It is that Pro Active thing again :-) Both methods described allow for similar control, with the major difference being the photog's comfort level and dexterity.

Best Amigo,

Chas

Roger Clark
03-26-2011, 02:00 PM
To add to the discussion, I'll tell my preferences. I do bump focus was well, before joining BPN, so it was nice to hear Jim describing it. I will also hold the button down and follow a bird, unless it (or my tracking) is erratic, then I'll do the bump method. Also if a subject is moving against a complex bright background, I'll definitely use the bump method. I also use the shutter button half press to AF. The reason is that I use my thumb and index finger to move the AF point around when following a subject (thumb only on non 1D cameras). I'll move the AF point to the eye of the subject and the composition I want. For me, assigning another button to do something on the back of the camera during tracking is just too much. Perhaps if I got out and away from computers more....

Roger

Jay Gould
03-26-2011, 05:31 PM
Roger, you have added an interesting dimension for me: use of thumb and index finger - why both? - for movement of the AF point.

Please expand what you do in this regard: which wheels/buttons, how programmed (7D) for me, and which finger/thumb for which wheel/button.

Thanks!!

Roger Clark
03-26-2011, 05:54 PM
Roger, you have added an interesting dimension for me: use of thumb and index finger - why both? - for movement of the AF point.

Please expand what you do in this regard: which wheels/buttons, how programmed (7D) for me, and which finger/thumb for which wheel/button.

Thanks!!

Jay,
on 1D cameras, one uses the big wheel on the back of the camera and the small wheel by the shutter button to move the AF points around. So one uses thumb and finger to move AF points (after hitting the button to select AF points) one wheel in the x-direction, the other in y.

On recent canon consumer cameras, there is a joystick. So one just uses a thumb to move AF point with the joystick. Or you can move the AF point around with either the large wheel on the back, or the small wheel by the shutter button, but the selection goes sequentially (no x-y movement).

I find the x-y movement on the !D series faster with two fingers, even with 45-points to choose from. I'l learned to change AF points while panning following a subject, never taking my eye off the viewfinder. If the subject turns in a different direction, I switch AF points to maintain the composition I want with the changed direction.

Now, of course, with really fast action, there is no time to change AF points. E.g. cheetah running. Gee I have a hard enough time time keeping the cheetah in the frame, let alone change AF points. I need more practice. Gotta go back....

Roger

shane shacaluga
01-29-2013, 12:00 PM
I have just been pointed at this thread. Thanks a lot for sharing and I will be trying this out over the weekend. Where do you slow down the tracking sensitivity of the AF? Is it possible on a D7000?

Jim Neiger
01-29-2013, 12:41 PM
Shane,

Not exactly sure for the D7000, but Nikon refers to the same function as "Tracking". The possible settings range from long to short, you want long.

shane shacaluga
01-29-2013, 05:07 PM
Perfect will look for it in the manual

thanks