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Sony NEX-EA50 (all variants)
Including NEX-EA50UH / EA50EH / EA50H / EA50UK / EA50EK / EA50K


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Old March 6th, 2013, 01:48 PM   #1
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Auto Focus With Face Detection = Very Good

My first shoot with the EA50 was a disaster, mostly due to focus issues I was not expecting. My lack of use of a large sensor camera was obviously the curl-pit to the success of the shoot. So last week was my second shot at it. This time I used auto focus on all three cameras with face detection and my results were excellent . The camera held focus very well even when my subject would step back and forth. I think this is a great solution if you are shooting a live event with one subject in the shot. I am sure the EA50 would get confused if there were multiple subjects in the shot.

BTW = Abelcine PP2 worked out fantastic. Thanks for all who share here!

JC
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Old March 7th, 2013, 08:01 AM   #2
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Re: Auto Focus With Face Detection = Very Good

If its like the other small Sony's with face detection it will alter the parameters to get as many of the faces correctly in focus, exposure and WB. I think my little Sony can track up to 8 faces and then alter depth of field to get as many correctly captured as is possible. I think you can indicate by touching the major face which one is important to you and this will then have a double box around it showing its priority.

Ron Evans
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Old March 7th, 2013, 08:39 AM   #3
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Re: Auto Focus With Face Detection = Very Good

That is quite nice to know..My Panasonic AC-130's had face detection but I never trusted it!! So far I haven't used FD on the EA-50 as yet ...What has impressed is to spot focus for weddings so at least I know the camera has been told to focus on the bride and even if they move a little the DOF range at something like F4.5 is sufficient to keep everything in focus ... My last wedding I had a tight shot of the couple and the celebrant in shot and, of course, used spot focus and the image stayed razor sharp ..the celebrant then jumped up and moved away to the left so I had no option but to do a quick zoom out to reframe and completely forgot to do another spot focus touch but despite the reframing focus still remained sharp so the lens must be quite close to parafocal between say a zoom up to about 1/3rd of the range and then back to wide which is nice to know...If I had been really tight at 200mm I doubt whether a zoom back to 18mm would have stayed in focus but I might be wrong?

I wonder whether face detection would have been as good (or better) than using spot focus? What I should have done, of course, is good wide and then touched the LCD to check focus again..I had the time but the brain never engaged!!

Chris
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Old March 7th, 2013, 08:55 AM   #4
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Re: Auto Focus With Face Detection = Very Good

I prefer to use spot focus when I shoot as then no light changes or such will throw off the auto focus. When you zoom back from telephoto to wide the apparent depth of field gets deeper so all will stay in focus. The problem comes when it has been focused at wide angle and then zoom in closer. It will almost certainly be out of focus then. I mainly use the face detection when shooting family events as then there is no way I could focus as fast on 2 grandkids running around or expose for that situation like the iAuto does.

Ron Evans
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Old March 8th, 2013, 12:32 AM   #5
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Re: Auto Focus With Face Detection = Very Good

Joe,

So far I have not been impressed with face detection. A single subject, in stage lite, with a dark background, and little movement my be the perfect set up for it. That would make sense out of you getting the result you did. I am glad to know it is working for you but I will have to become super familiar with it before I would ever consider using it on a gig. I don't use AF of any type on stage shots. I prefer manual with spot focus.

Did you hook up big external monitors to each camera to aid your operators with focus? This camera is pretty good at locking focus and does not seem to go into search loops easily but becareful, it can happen. If all your monitoring with is the LCD you may not see it until your in post and by then your up a creek.

Steve
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Old March 8th, 2013, 07:14 AM   #6
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Re: Auto Focus With Face Detection = Very Good

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Originally Posted by Steven Digges View Post
Joe,

.... A single subject, in stage lite, with a dark background, and little movement my be the perfect set up for it. .......
Steve
I do not have an EA50 but with the CX700 for example it does not work well for stage lighting and I always use spot focus. Seems to work best with lots of faces around like a family party or crowd. Locks on to many faces and with the EA50 like my NX30 one can then be assigned to be the prime face that it will track ( likely has the same algorithm Bionz processor). If light changes etc it will sometimes loose lock but will regain quickly. That is the advantage of spot focus as once locked the lighting or exposure used is not important within reason as the spot focus will still try to maximize the depth of field when it is set. Change the exposure and it will change the focus point since it uses edge detection just like peaking to get the focus. Get the exposure right then spot focus is the way to do it for best results I have found with the little Sony's over several years now. I think that is one of the reasons that face detection is only available in auto.

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Old March 8th, 2013, 11:46 AM   #7
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Re: Auto Focus With Face Detection = Very Good

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Originally Posted by Steven Digges View Post
Joe,

Did you hook up big external monitors to each camera to aid your operators with focus? This camera is pretty good at locking focus and does not seem to go into search loops easily but becareful, it can happen. If all your monitoring with is the LCD you may not see it until your in post and by then your up a creek.

Steve
Its Joel not Joe! :) I hate Joe! LOL..

Actually no, I did not hook up to external monitor. However I did do extensive testing at the venue. (I get access there anytime it is a weekly project.) The stage lighting is possibly not as one would think for a live event. Meaning there is ample ambient light and also 6 750 watt mole Richardson soft lights on the area where the subject would be standing along with other cans that you find typically on stages. In my tests I did find that the subject needs to have enough light/proper exposure to enable the auto focus/face detection to work properly. In post I did find some "hunting" when the subject would move out of range but not like the camera operators wouldn't lose focus for a split sec anyways. When the camera hunted for focus, focus was quickly, almost instantly (maybe >1 sec) locked. Also 1 subject only i don't think having say; 4 people on stage in a wide shot with different lighting stops, would have good results. For my project and the lack of real quality camera operators that can do a great job pulling focus, this is really the best most consistent option for me.

Also isn't spot focus generally the same as face detection? I mean instead of relying on the software to focus and detect, your relying on a general area from the tiny LCD screen to lock focus. I don't know about you but i have fat clumsy fingers i think spot focus would be a nightmare for me and my eyes.....

JC
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Old March 8th, 2013, 06:42 PM   #8
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Re: Auto Focus With Face Detection = Very Good

Hi Joel

Actually even with my fat fingers I can get pretty accurate with touching the screen....You are not trying to focus on a body part of a person but rather a "zone" My fear which actually happpened with my Pansonic AC-130's is that the camera will "choose" the background as opposed to my subject...(It actually focussed on the bride and groom and then after 10 minutes decided the trees behind them were a better bet...that of course ruined my footage..!!

Even with fat fingers I'm sure we can get a "touch" in the general area that we want in focus and then check it with expanded focus (I also leave peaking on)

Doesn't anyone know if the Sony LCD screen would respond to a "stylus" rather than a finger?? That would be a very accurate way to do it!!

Chris
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Old March 8th, 2013, 07:02 PM   #9
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Re: Auto Focus With Face Detection = Very Good

Not that it is needed but I just happen to have an ink pen sitting here with a stylus on it. It works great on the LCD screen so I put it in my camera bag. Maybe it will come in handy if my hands are dirty or gloved.

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Old March 9th, 2013, 08:41 AM   #10
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Re: Auto Focus With Face Detection = Very Good

Thanks Steve

My first Tablet came in a case with a keyboard and we accidentally dropped it on the floor one day (slid out the case and smashed the screen) I kept the case/keyboard and has discovered in the case is indeed a stylus meant for the tablet screen so yes, I'll keep that handy as well. I wonder how much of an area the spot focus actually looks at when you touch the screen with a stylus ? Would anyone have a wild guess?? With weddings I tend to favour the bride in the shot anyway and keep aperture small enough so the DOF covers the couple and the celebrant/priest behind them but it might be really cool to do a focus shift between a priest and the couple as well.

Chris
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Old March 9th, 2013, 09:03 AM   #11
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Re: Auto Focus With Face Detection = Very Good

Spot focus only works in manual so the operator controls the exposure and WB. Face detection only works in auto so that the camera can control WB and depth of field in focusing on the face. I think the EA50 is like my NX30 and CX700 in that identifing the major face ( by touching it when the box is around it ) the camera will track that one face as it moves as the priority fous point.

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Old March 9th, 2013, 08:03 PM   #12
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Re: Auto Focus With Face Detection = Very Good

Hi Ron

The really nice thing about the EA-50 is the fact that in Manual you can also control what stays in auto and what stays in manual including aperture, shutter, iso/gain, WB and focus so the camera can stay in manual but have everything in auto except focus so all you need worry about is touching the screen and the rest of the parameters look after themselves.

Not that I will use face detection but does face detection require that everything is in full auto or does only focus need to be in auto .... ?

Chris
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Old March 9th, 2013, 08:16 PM   #13
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Re: Auto Focus With Face Detection = Very Good

Camera can be in full manual mode and face detection can be used but AF will need to be on.
JC
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Old March 10th, 2013, 04:07 AM   #14
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Re: Auto Focus With Face Detection = Very Good

Hey Chris,

The stylus does not pinpoint a focus point anymore than a finger does. The same size box shows up. But maybe it will allow you to aim the center of the box a little bit.

Steve
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Old March 10th, 2013, 02:51 PM   #15
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Re: Auto Focus With Face Detection = Very Good

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Originally Posted by Joel Corral View Post
Camera can be in full manual mode and face detection can be used but AF will need to be on.
JC
I do not have a EA50 so my comments are just from the manual and how it works on my other camers. But on page 41 of the AE50 manual it notes that shutter speed etc cannot be changed when face detection ON. I think for the reasons I noted in my other post. Would be nice to know if it does work differently. Sony manual do not always describe the functions correctly.

Ron Evans
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