# Auto focus V. Manual focus (why)



## thiscityizdead (Aug 26, 2015)

Okay, so for years I've been shooting in manual mode setting for both camera and lens. I feel like I have more control in this setting; however, I was watching videos on Ai-servo, which I never use because I mostly shoot portraits and nothing in high speed. In these videos they talked about Auto focus. I decided to play around with my camera, 5D M3, and attached lens were 85mm 1.8. I really enjoyed playing with the auto focus setting on my lens. The focus points were fast and pretty accurate. Plus, Ai-servo was neat to play with too. I tested these settings on my fish. 

My question is, is it best to continue shooting in manual focus for portraits? I just hate that the focus points can't be used in manual focus.


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## TreeofLifeStairs (Aug 26, 2015)

For portraits I don't see much of a down side to manually focusing if this what you're used to. You generally have the time to focus and it's nice to have that control. The only time I could see AF being beneficial would be for kids since they can be so squirrelly.


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## thiscityizdead (Aug 26, 2015)

TreeofLifeStairs said:


> For portraits I don't see much of a down side to manually focusing if this what you're used to. You generally have the time to focus and it's nice to have that control. The only time I could see AF being beneficial would be for kids since they can be so squirrelly.




That's so true! So, do you believe the best option would to just stick to M all the way including manual focus on lens. 

What about AV. To be honest, I remember when I first started I would use av to get the settings for an aperture I wanted to shoot while using M focus. I used this a cheating method to set my speed with the f stop.


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## KmH (Aug 26, 2015)

thiscityizdead said:


> I just hate that the focus points can't be used in manual focus.


Look at page 111 of the 5D MKIII user manual.

The focus points can indeed be used to focus manually.

You select the focus point, manually focus while holding the shutter button 1/2 way down, and the focus confirmation light in the viewfinder lights up when focus has been achieved.
If the camera is set up to automatically select focus points but you focus manually the focus confirmation light only comes on when focus has been achieved _at the center focus point_.


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## thiscityizdead (Aug 26, 2015)

KmH said:


> thiscityizdead said:
> 
> 
> > I just hate that the focus points can't be used in manual focus.
> ...




Oh yeah, I knew that. Lol. What I meant was its harder to tell what's really being focused. Sometimes when I am on manual focus the lights/squares blink read and make the beep noise, but what I actually want to be focus is not. Example, I set the squares to be focusing on the eyes, but the squares blink red and the actual focus might be on the eyebrows. The eyes are still slightly focused but the brows are crisp. That's just one of the examples I can think of at the top of my head. 


One thing I struggle with is family portraits where I have several people in the frame. Would it be best to switch from spot focus to maybe using 9point focus.


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## TreeofLifeStairs (Aug 27, 2015)

You can always choose a smaller aperture to give you a greater focusing distance. It would just decrease you're chance of error.


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## thiscityizdead (Aug 27, 2015)

TreeofLifeStairs said:


> You can always choose a smaller aperture to give you a greater focusing distance. It would just decrease you're chance of error.


Oh! Okay! Thanks so much for the advice!

One last question, I found this tip setting. I just don't remember how I got there. 

It was something like holding the * button (AE lock) then holding the lightbulb button and it would lock hold the focus points. Or something like that. I just don't remember what video tutorial I saw. Do you happen to know what I'm talking about?


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## Braineack (Aug 27, 2015)

thiscityizdead said:


> My question is, is it best to continue shooting in manual focus for portraits?



if you want your shoots to be more difficult, take longer, and have less keepers, sure continue to use manual focus for portraits...


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## wyogirl (Aug 27, 2015)

With Auto Focus...especially on the 5dmkiii... I have no idea why you would use manual focus at all except for maybe astrophotography or something equally specialized.  AF is just so accurate these days.


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## thiscityizdead (Aug 27, 2015)

wyogirl said:


> With Auto Focus...especially on the 5dmkiii... I have no idea why you would use manual focus at all except for maybe astrophotography or something equally specialized.  AF is just so accurate these days.


Yeah. It seemed so crisp I'll have to try it out on my next shoot! It's just something I have to get used to now. Hehe.


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## JustJazzie (Aug 27, 2015)

Even for portraits, I think the only time I would consider using MF would be if shooting at f1.8 or >. 

MF for macro. AF for everything else.


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## thiscityizdead (Aug 27, 2015)

JustJazzie said:


> Even for portraits, I think the only time I would consider using MF would be if shooting at f1.8 or >.
> 
> MF for macro. AF for everything else.


Okay. I like shooting at a shallow depth of field, but my lens don't go anything below 1.8. For the most part, I think I can get away with it here and there. Thanks for the feedback!. Oh, that's a great point at shooting M for macro.


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## KmH (Aug 27, 2015)

The squares in the viewfinder surround the actual focus sensor which is smaller than the square.

There are regular focus points and cross-type focus points.
Regular focus points can detect horizontal or vertical lines of contrast, but not both, depending on the orientation of the sensor.
Cross-type sensors can detect both vertical and horizontal lines of contrast.
See page 78 of the user manual.


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## davisphotos (Sep 4, 2015)

The AF on the MK3 is amazing, if you aren't using it, you really aren't using the camera to its full potential. AI Servo is awesome, if your subject moves back and forth a little, or you move the camera even a little, your MF could be off, servo will keep focus locked on, with a great deal of accuracy. Also, with a USM lens and back button focus, you can fine tune the focus after auto focusing, or choose to manually focus for a photo or two.


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