Question on Shooting wide open


xjosephtbr

Member
Feb 3, 2014
267
1
18
Singapore
There isnt a problem with the focus but when i hold the shutter and move to the composition i want the focus always gets off is this natural? Im using a 6d and sigma 85f1.4
 

Should make like a way to track the object you set the focus, recompose and then auto refocus on the tracked object again before it fires off
 

Should make like a way to track the object you set the focus, recompose and then auto refocus on the tracked object again before it fires off

Nikons can do this with the combination of AF-C and 3D tracking, but it isn't very reliable. If you focus on the eyes and recompose, it will focus somewhere on the face but not necessarily the eyes. Canons can do this with AI servo and automatic af selection I believe, but it's even more unreliable.

Those 2 cases that I mentioned above are meant for tracking subjects that are actually moving across the frame, not static subjects that "move" because you move your camera. In general, cameras can't track stationary subjects (at least they don't do it very well)
 

Last edited:
camera can track stationary object provided its moving relative to camera view.

just swing your camera.
 

camera can track stationary object provided its moving relative to camera view.

just swing your camera.
 

camera can track stationary object provided its moving relative to camera view.

just swing your camera.

focusrecomposediagram.jpg
 

First can u tell us what u shoot n in what situation? If u think 1 method can suit all situations, u will not be getting optimal results, especially when yours is f1.4 lens shooting wide open without tripod or with moving subject.

For years, I'm mainly into event photography and I do shoot other genres too. In a single event, I will probably switch between different focusing modes to suit what I am shooting. Quite hard but after some practice and experience, u will get used to it.
 

Last edited:
camera can track stationary object provided its moving relative to camera view.

just swing your camera.
Depends on what camera you're using. My 60D will re-focus on whatever is at the AF point immediately, it will not track. 60D does not have an option to set the delay before AI servo picks another focus target, so it happens immediately. I believe 70D can, but it is still unreliable from my experience. Swinging the camera will make the camera switch the AF point to something nearby, but not exactly what you initially focused on.
 

Based on James Brandon's illustration on the dart board, he was shooting wide open at f1.4. The focus recompose method was off due to DOF much shallower. If we were to step down to f5.6, there will not have such issue, or at least not that obvious. Of course other factor is for the photographer to consider.

Does a camera with 51 focus point more accurate than the 39 pts if given the same wide opening setting?
 

I think the issue is that when you focus/recompose using f1.4 at 85mm, any slight movement of your camera away from the point where you focused on would cause the subject to be out of focus.

Suggestion is if you want to use focus/recompose method would be to stop down a bit more to f2.8, 4 or 5.6 depending on the subject you are shooting. You dont have to feel like you are sacrificing a lot of background separation since you are already getting a lot more separation by using a full frame camera.

Otherwise consider getting a camera with top notch AF system that can focus well even at the outer AF points such as the 7D, 5D3 or 1D series cameras.
 

Based on James Brandon's illustration on the dart board, he was shooting wide open at f1.4. The focus recompose method was off due to DOF much shallower. If we were to step down to f5.6, there will not have such issue, or at least not that obvious. Of course other factor is for the photographer to consider.

Does a camera with 51 focus point more accurate than the 39 pts if given the same wide opening setting?
Stopping down would of course make it not so much of an issue, but then you don't buy a f1.4 lens to shoot at f5.6 anyway.

As for your other point, more AF points will not help. It will help in focus tracking, but not for static subjects. Focus-recomposing uses only one AF point only anyway (if using the traditional method). If you use AF-C and 3D tracking (or AI servo and automatic AF point selection), I don't know if more AF points will help - it might, but a better metering system should help (at least in theory - 3D tracking and Canon's equivalent of it uses the metering system to report the subject movement and location to the AF system, so the camera will know which AF point to switch to)
 

Based on James Brandon's illustration on the dart board, he was shooting wide open at f1.4. The focus recompose method was off due to DOF much shallower. If we were to step down to f5.6, there will not have such issue, or at least not that obvious. Of course other factor is for the photographer to consider. Does a camera with 51 focus point more accurate than the 39 pts if given the same wide opening setting?
Accuracy is not related to the number of AF points a camera has. Sometimes each AF points performs differently from others. But the more AF points means u can get more precise at the point u want the focus to be.
 

Last edited:
Should make like a way to track the object you set the focus, recompose and then auto refocus on the tracked object again before it fires off

Tracking is usually used on moving subject.
It would be better to tell use what is your subject etc. otherwise my advise for u is to compose first then select the correct AF point before u activate the shutter.
 

install magic lantern
use focus masking
 

Stopping down would of course make it not so much of an issue, but then you don't buy a f1.4 lens to shoot at f5.6 anyway.
+1 You're buying an f1.4 lens to shoot at f1.4

Learn to use peripheral AF points to minimise the movement to recompose your shot. I assume you're choosing your own AF point and not letting the camera do it automatically?
Hence why many photographers keep wishing (in vain) for a wider spread of AF points across the frame. This is more an issue on FF DSLRs (like your 6D) and less so on APS-C DSLRs and mirrorless cameras.

I personally use the closest AF point to where I want to focus on in a given composition to lock focus before recomposing minimally and often I won't need to recompose at all.
This is especially important when shooting close wide open where the DOF can be razor thin.
 

Nikons can do this with the combination of AF-C and 3D tracking, but it isn't very reliable. If you focus on the eyes and recompose, it will focus somewhere on the face but not necessarily the eyes. Canons can do this with AI servo and automatic af selection I believe, but it's even more unreliable.

Those 2 cases that I mentioned above are meant for tracking subjects that are actually moving across the frame, not static subjects that "move" because you move your camera. In general, cameras can't track stationary subjects (at least they don't do it very well)

For the purpose you mentioned 3D tracking is not the af mode to use. you should be using dynamic tracking. You need to go back and understand what each tracking mode does and how they work. In the end it comes down to how well the photographer understands his/her equipment.

Hint: 3d tracking tracks by color...

And you are mistaken, cameras can track a stationary object quite well with the frame moving. Again it comes down to you understanding how your equipment works and react.
 

Last edited:
For the purpose you mentioned 3D tracking is not the af mode to use. you should be using dynamic tracking. You need to go back and understand what each tracking mode does and how they work. In the end it comes down to how well the photographer understands his/her equipment.
Sorry, my understanding was based on older Nikon cameras, like the D90. I'm using Canon system now so I don't know which AF area modes (on Nikons) are used for what purposes now.

From Nikon D90 manual:
3D-tracking AF:
In AF-A and AF-C autofocus modes, user selects focus point using multi selector. If user changes composition after focusing, camera uses 3D-tracking to select new focus point and keep focus locked on original subject while shutter-release button is pressed halfway. Use to recompose photographs while shooting relatively static subjects.
Dynamic area AF:
In AF-A and AF-C autofocus modes, user selects focus point manually, but camera will focus based on information from surrounding focus points if subject briefly leaves selected point. Use with erratically moving subjects.

And you are mistaken, cameras can track a stationary object quite well with the frame moving. Again it comes down to you understanding how your equipment works and react.
Maybe Nikons can, but my Canon 60D definitely cannot. I have tried both combinations of AF area modes (single point and automatic area) in conjunction with AI servo mode on my 60D. None of them are able to retain focus on the subject after recomposing. I can only do it (unreliably) by focusing (back button AF), snapping the camera very quickly to recompose, releasing the AF button immediately, and then shooting. If the AF button is held down after recomposing, the camera immediately switches to focusing on the selected AF point (or the middle AF point if automatic area AF is used)

From 60D manual (using AI servo in conjunction with automatic AF point selection):
When the AF point selection (p.78) is automatic, the camera first uses the center AF point to focus. During autofocusing, if the subject moves away from the center AF point, focus tracking continues as long as the subject is covered by another AF point.
However, in practice, this only works if the subject is actually moving. If the subject is stationary and I move my camera, the camera will re-focus at the centre AF point (where I normally have it on)
 

Sorry, my understanding was based on older Nikon cameras, like the D90. I'm using Canon system now so I don't know which AF area modes (on Nikons) are used for what purposes now.

From Nikon D90 manual:
3D-tracking AF:

Dynamic area AF:

Maybe Nikons can, but my Canon 60D definitely cannot. I have tried both combinations of AF area modes (single point and automatic area) in conjunction with AI servo mode on my 60D. None of them are able to retain focus on the subject after recomposing. I can only do it (unreliably) by focusing (back button AF), snapping the camera very quickly to recompose, releasing the AF button immediately, and then shooting. If the AF button is held down after recomposing, the camera immediately switches to focusing on the selected AF point (or the middle AF point if automatic area AF is used)

From 60D manual (using AI servo in conjunction with automatic AF point selection):

However, in practice, this only works if the subject is actually moving. If the subject is stationary and I move my camera, the camera will re-focus at the centre AF point (where I normally have it on)

3d tracking is based on rgb metering. Which means it tracks by color and metered value. If there are other elements in the 51 pt area that is similar in color, you will see the point jump around. So best situation is where your subject stands out in color and brightness, like a kid wearing red running in a green field. Or a blue color bird among green background. If you track on the eye balls or the whites, and there are also similarly light or dark colors in tge frame, you will see the af point hop around. Which is why you get the impression that it is nkt accurate.

Dynamic af reads movement based on the next point. It is more accurate if you want to track movement of a moving subject that does not stand out as much. The number of points determine the coverage, but the more points u choose the slower the af tracks.

D90 works the same way. Same as the d4, just that the d4 is way faster.

I know for sure nikon cam bodies are capable of tracking stationary subjects and so does canon cameras. You just have to figure out how it is done. And I know for sure auto af point selection is not something you should use in this situation.

cam tech has come a long way. In the end, the hardware is quite capable. It is more on the user to understand how his/her equipmemt work. Don't blame the equipment.
 

Last edited: