Single point auto focus vs manual focus

[Brev00]

I don't typically worry about af precision shooting landscapes preferring to use my own version of hyperfocal focusing. When I do this, I stop down to f 11-13 and either af to a point in the scene (at a guesstimated distance) or switch entirely to manual and use the distance scale on the lens. At a wide enough mm, I find focus point precision just does not matter too much. It has an effect similar to using a compact camera in terms of dof.

[Mike Buckley]

OFF TOPIC

I just bought and infa red remote release for my D7000...The main problem is size - so small I might miss locate it.

My solution to that issue

[ajohnw]

OFF TOPIC


My solution to that issue

Thanks Mike cause I am very likely to loose it. Not much chance of that when they have a lead - unless I tuck it out of the way due to the lead and forget were. Also off topic but I have just bought a rather large Skeleton Case in the hope I can put all of my photo gear in it - take out what I want to use, put it in the bag and hopefully put it back in it when I need something else. Plucked foam insert though rather than a solid piece.

John
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[Brownbear]

Thank you! Not only for a great example of why one would do this, but also how to.

I do that sometimes, and here's why:
When using timed delay, the AF will focus at the chosen spot or multiple, when the shutter button is half pressed. Often when I shoot something that is not moving, a stationary setup, I don't want it to focus when I touch the button, as I use the self timer to make the camera release after a two second delay. Then I focus first, lock focus by switching to MF, but of course I don't touch the focusing ring of the lens. Then I can shoot a set of bracketed exposures without focus changing. This is also done for panoramas, when nothing shall be changed while reorienting the camera - MF and Manual exposure. Actual focusing is done with AF, and then locked by switching to MF.

The same raindance for actually making a selfie. There is no way to have the camera focus on your face if you don't have a remote release, but you put a stand-in there for focusing, and then you lock focus, so it will not change. MF is a way to lock focus. No change will be made by the camera when the button is pressed.

[Brownbear]

Thank you to all for your helpful replies. And Larry, John, Urban, Andre and Photo Nut for adding on and expanding.

Andre... I agree. The only reason I asked the question is because switching to Manual focus if I have focused on the subject just fine using Auto focus is something that I don't do. So of course I thought it was something that I should be doing for some reason or the other, ie; that perhaps switching to manual focus would allow for sharper focus.

Mike... I have misplaced my remote release and I'm hoping that it is not lost. Perhaps I will find someone to drill a hole in my next one.

Thank you to all!

[ajohnw]

As I should have done it already I have just looked at the D7000 manual - not much help and the menu's. Maybe the D7100 is the same.

The lock button can be programmed to lock just AF and it remains locked while that button is pressed. It looks to be fairly conveniently placed. So - set camera according to mode - 1/2 press shutter to focus where needed, press and hold the lock button, release shutter button, frame - shoot. The camera should remain at the same focus for as long as the lock button is held in.

Alternatively if the shutter release is set to lock exposure as well it's possible to meter off an entirely different area retaining the same focus with the lock button and then frame and shoot with the locked exposure. I often do this sort of thing to give the sky for instance more bias in a shot than standard metering will give on the actual scene. The same method can be useful in all sorts of situations, biasing to the dark end for instance - hdr sets etc.

Of course this will work at it's best in metering looks after itself modes.

Hope that doesn't sound too garbled. Easier to do than say.

John
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[Manfred M]

I picked up a CamRanger recently and this makes things even more interesting.

With it I can remotely control most key camera functions and either autofocus or manually focus, using either my laptop or tablet. A sharp manual focus is far more evident when using a large screen.

http://camranger.com/features/

[nimitzbenedicto]

Hi Christina,

Using our AF-On back button . Maybe this can help.

https://www.youtube.com/watch?v=FzqQskGoURE

https://www.youtube.com/watch?v=RVRjPjrQYkA

[Brownbear]

Thank you Victor. Very thoughtful of you to share.

The video is great for it's simplicity. And yes, I will try back button focus, one day soon.

Hi Christina,

Using our AF-On back button . Maybe this can help.

https://www.youtube.com/watch?v=FzqQskGoURE

https://www.youtube.com/watch?v=RVRjPjrQYkA

[ajohnw]

Thank you Victor. Very thoughtful of you to share.

The video is great for it's simplicity. And yes, I will try back button focus, one day soon.

AF ON is an option on the AE-L / AF-L button on the D7000. It works in single shot AF too and does just that when the button is pressed.

It just enables what ever AF mode is selected.

Sounds a pretty sensible way of running the camera to me other than for maybe opportunistic work.

John
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[Brownbear]

Thank you John. Also very thoughtful of you to share, and truly appreciated, as always.

AF ON is an option on the AE-L / AF-L button on the D7000. It works in single shot AF too and does just that when the button is pressed.

It just enables what ever AF mode is selected.

Sounds a pretty sensible way of running the camera to me other than for maybe opportunistic work.

John
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[rpcrowe]

I am always singing the praises of the AF capabilities of my 7D cameras. However, if you are using the camera in the default auto select 19 point mode you are not getting the fullest use of the amazing AF capabilities of this camera. Unless you do some customization, you have a very nice auto focus system but nothing to jump for joy about...

I like using auto-point expansion or zone auto focus on my Canon 7D.

AF POINT EXPANSION

What AF expansion does is allow you to choose a focus point (the middle) and the immediate surrounding points become active. This means if you’ve focusing on something that moves, the surrounding points will quickly pick up the slack and grab focus so focus is not lost. Which means that you can even track a moving subject in AI Servo and maintain the exact area of focus you decide.

Zone AF SELECTION

Simply put, it’s like using single point AF but you can choose a cluster instead of just one point. The camera will focus on whatever is closest in the zone you have chosen so watch your focus. When using any of these modes, I have turned on the option (in my setting menu) of having the camera display with a red square the point of focus on each image as I look at them on my camera’s screen.

I normally have my camera set up in Zone AF with the top cluster selected...

That way, I am usually focusing on the heads of my subjects. What happens when I switch from horizontal to vertical format? No problem... the camera automatically detects the change and shifts the zone focus to the top grouping in the vertical position. I have my cameras set up to do this but, if memory serves, that is not the default.

I met a Canon Representative at a shoot one day and he set my cameras to shift to the top cluster in either horizontal or vertical positioning.

However when shooting landscapes or cityscapes, I will most often use the center grouping.

There are so many-many ways to customize the 7D A/F system. If you are interested, here is a quickie tutorial..
https://www.youtube.com/watch?v=TDizJ_5EuWw

I like to shoot all types of photography and I also like working with a camera which provides the best chance to get my image in focus. The 1D (series), 5Diii and 7D are probably the best cameras in the Canon lineup for autofocus, especially on fast moving subjects. I cannot venture to say what models of other brand cameras are the best for Auto Focus...

Speaking about customization, the 7D Servo AF tracking sensitivity customization was something that I did not quite understand at first. It seemed counter-intuitive to slow down the tracking but, that is now a function that I use frequently when shooting sports...