Sony FDR-AX100

[Ken Ross]

Originally Posted by Noa Put

Ken; does the autofocus not pump in normal light conditions? I think I have seen some reports about the autofocus pumping but that very well could have been under less then ideal light conditions where you can't expect a autofocus to function right. I also remember from shooting back in my xh-a1 days that 25p as opposed to 50i also showed bigger difference in how accurate the autofocus was, an explanation given then was that in 50i there are more frames per second the camera could use to judge focus from and since in 4K we all are shooting either 24,25 or 30p that might be a reason why the autofocus gets fooled easier compared to shooting in 1080p 50p, maybe Alister knows if this is the case?

I know my cx730 holds autofocus pretty well but if it looses it it can go lost completely and has a hard time recovering, I use manual focus whenever I can but during run and gun I often let the camera decide, what matters most to me is that under normal light and when you are shooting wider the autofocus doesn't hunt or starts pumping, does the ax100 perform well under such conditions?

Noa, no, I really haven't noticed any tendency for the autofocus to pump or hunt under typical lighting conditions. I've had a number of Sony cameras and I actually find this to be one of the more stable AF systems. It also seems quite able to hold focus once it's locked on.

It's not lightning quick, but it's quick enough and not visually distracting as it goes from one focal point to another. Do you get an occasional miss? Sure, I've yet to use a videocamera's AF system that didn't. But I do think I get less misses with this than most other cams I've used. For me, it's behavior is very nice for run n gun.

As for low light focusing, it seems pretty average in that respect. As expected, the lower the light the more you can expect some hunting. But at that point we should be using MF anyway. ;)

[Alister Chapman]

The AX100 autofocus is contrast based, so low contrast (low light, high gain, longer focal lengths) will give the AF problems. Generally the faster the frame rate the quicker the AF can operate, but there is a trade off in low light of slower shutter speed giving a brighter image and a higher frame rate with shorter shutter giving more samples but maybe with less light.

However a camera manufacturer sets the AF speed there will always be someone that's unhappy. Some people want snappy, rapid AF that will quickly find focus, others may want sluggish AF as they don't like quick focus changes. Hunting is normally caused by the camera simply struggling to find an object with enough contrast or texture to provide an accurate focus point or nothing staying at the same place within the frame from frame to frame. After all the camera must compare the previous and next frame to decide whether the focus result is getting better or worse to determine the best focus point. Contrast based cameras must hunt and go through focus to determine the best focus point. Camera gain and noise is also a real AF killer.

Low light sports is probably just about the worst possible scenario for AF. Add the large sensor and shallow DoF that make accurate AF even tougher and it's no surprise that the AX100 has a tougher time of it than cameras with much smaller sensors. I would suggest that the AX100 is probably just about the worst camera you could get for shooting sports with AF. What's the point shooting in 4K when most of it's going to be out of focus anyway, you really are going to need to learn to focus manually, 4K needs incredibly precise focus to be of any real benefit. Better to use a small sensor where the deeper DoF will hide focus inaccuracy if you want to rely on AF in anything less that good light and high contrast.

It takes Sony a long time to write a firmware update. Weeks, if not months as it must go through Sony's tough QA process before release. I expect the V2 update was being prepared even before the first cameras had shipped. This is common these day. Get a basic set of firmware working so you can bring the camera to market asap, then work on improved firmware with those small subtle tweaks that can take a long time to get just right and release this later on.

I have not notice any difference in AF between V1 and V2 (but then I don't use AF very often, it's too unpredictable).

[Noa Put]

Thx for the info, I was only worried the camera focus would start hunting when the lens was wider and when light conditions where about average, like in a church. As soon as I start zooming in more I switch to manual but I need the camera to refocus first for me, I usually use the touch focus feature for that on my cx730 as I don't trust my own eyes for critical focus, it's is pretty reliable but not always.

I do find it very difficult to focus manually when shooting 4K and just being slightly off sticks out like a sore thumb when you view it on a large screen. It will take me some time to build up the necessary funds to get the ax100 but having shot at 4K on my GH4 has me sold on the cropping ability which is really awesome, if used the right way, once you cop all other artifacts get magnified as well, like noise or microshakes. But I really need a more video oriented camera that can replace my cx730's, the GH4 requires hard work to get good footage out of it when running and gunning, it looks great if used right but slaps you in the face if you use it wrong. :) 4K can be very unforgiving.

[Mark Rosenzweig]

I have posted these before. Talk is cheap. Video shows you what works, and what does not.

Here is a test of the autofocus speed and accuracy in good light:

Sony FDR AX100 4K Video: Auto Focus Test Outdoors on Vimeo

Here is a test of purposeful focus tracking - when the camera is asked to track, again in good light:

Sony FDR AX100 4K Video: Focus Tracking and Auto-focus Test on Vimeo

Both tests were carried out after the firmware upgrade. You can *see* what the camera does, and like it or not - too fast? not fast enough? miss the bounce you get with other cameras?

I may post similar tests in low light, but people appear to prefer to argue rather than look.

[Noa Put]

I have posted these before. Talk is cheap. Video shows you what works, and what does not.

With over 1500 replies it's hard to keep track about what has been posted about the camera, if it doesn't work that can also be up to a operator error and that's a part the video will not show, but thx for posting the videos again as they do show that under ideal situations it does work as advertised.

[Aaron Holmes]

Originally Posted by Noa Put

Are you sure it was not a wrong setting in camera before? I saw in Alistar's review he says the HD images are one of the best he has seen and I don't have seen any other complaints about this so could it be you had it in a manual setting where the iris was completely closed causing diffraction and a softer image?

Yes, pretty sure. My mention of incorrect settings before was largely rhetorical; I tried everything, including various apertures, as diffraction was one of my concerns. Didn't make much of a difference in terms of apparent sharpness/detail.

Pre-upgrade, I noticed that the firmware version was not available anywhere in the camera menus, though the update instructions said that it should be. A bit of Googling suggested that this was a sign of pre-1.0 firmware, so perhaps that's the cause? *shrug* The updater software said I had 1.0, but perhaps that's simply the smallest number it ever displays.

Whatever the cause, I'm very pleased with the 1080p60 out of the camera now.

[Anthony Lelli]

Originally Posted by Mark Rosenzweig

I have posted these before. Talk is cheap. Video shows you what works, and what does not.

Here is a test of the autofocus speed and accuracy in good light:

Sony FDR AX100 4K Video: Auto Focus Test Outdoors on Vimeo

Here is a test of purposeful focus tracking - when the camera is asked to track, again in good light:

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Both tests were carried out after the firmware upgrade. You can *see* what the camera does, and like it or not - too fast? not fast enough? miss the bounce you get with other cameras?

I may post similar tests in low light, but people appear to prefer to argue rather than look.

@Mark
Very good. You made a great presentation of the AF . Well done


@Noa
well, you made a very good point that I will follow. Even if you don't have the camera I appreciate a contribution like that. Staying wide(r) is the key. You too well done


@the forum
I'm sorry for coming out like that, it was a stressing experience yesterday, I was a bit frustrated and I moved "stuff" that didn't help at all. I had to find something to blame, it was a childish reaction and for that I again apologize.

Reviewing the clip again this morning (1hr long) I can see first of all that AF and 4K are a difficult mix, in particular in low light, sports, soccer where the players move fast, when pan and zoom are often used at the same time, and sudden changes happen often.
Like Noa said the key is to stay wide(r) than when I shoot 1080. Is it workable? (the AF of the AX100 in 4K I mean): yes it is.

Guys please understand that I am a cameraman, that's what I do: I don't go deep in technical stuff but I look for a way to make it work, which is sometimes a very different approach. I wanted to produce in 4K because it's beautiful . I was ready to do anything to achieve that. And I sill am.

The debut of the AX100 in 4K doing an entire soccer game is a week away now, Still trying to figure it out, I want to make this 4K at night happen and rest assured that I'll do whatever it takes to make it happen.

@Mark again : you made it easy to see for everybody in just 1 post while I was struggling pointing out that a camcorder doesn't have to jump between targets too quickly : every time I hear that the AF of the AX100 is slow I jump off my chair: it's the way video cameras work , and again and for the last time this is a camcorder, not a still camera.

The AF MUST keep the last target until a new target comes in. If not the old target will be lost and nothing will be in focus. Also the transition should be gentle, no jumping from there to there, Mark made it very clear in his video.

So for now we have the following:

lanc with 8 constant zoom speeds solved (usung a vivitar 8-button via multiport with 10-pin adapter)
30p is fine for 4K in night soccer at least. speed of 1/125 is also working great. (extremely high definition with no ghosts around the players) it looks quite good actually, no I mean it looks unbelievably good!
AF is a challenge, stay wider, don't zoom too much as I usually do. It should be fine
Panning : the less is better. I'll have to be extremely careful with the panning. It's workable, definitely

[Noa Put]

Originally Posted by Aaron Holmes

Whatever the cause, I'm very pleased with the 1080p60 out of the camera now.

I have experienced some weird things with my Sony camera's as well, not with the image but with functionality, a menu button stopped working on my nex-ea50 and after one year started working again, same for my rx10, the lens would automatically return to it's last position when I turned the camera on which disappeared again after a few days. :) Probably there was something electronically interfering with a function that caused the softness, as it had not been reported by others you probably just had a faulty camera in the beginning but the firmware fixed it so good to see it does work like it should now.

[Bruce Dempsey]

Really shouldn't move the camera much at all .(A famous director cliche once said "let the world walk through your frame" or something like that.
.however that will require a mutli-camera live -switched production which is much easier to do than it sounds especially for something like soccer 2 or 3 almost locked down cameras covering the centre of the field and endzone cams behind the the nets.Would make for a network like production.
It can all be handled by 1 cameraman

[Peter Siamidis]

Originally Posted by Noa Put

Thx for the info, I was only worried the camera focus would start hunting when the lens was wider and when light conditions where about average, like in a church.

There's basically two possible issues with AF on this camera, focus hunting and locking onto the wrong target. Previously I put hundreds of production hours on an NX30 (which I loved) and so far I've put about ~20 production hours on the AX100 (firmware 1.0). I think my lighting will most closely match what you have in mind because I film almost entirely indoors with two Nova LED light panels, which puts the sensor typically at about 9 to 12db. So this is not what people would consider ideal lighting but nor is it low light, it's somewhere in the middle and what may be considered typical lighting for a run and gun situation where you can't have complete control of the situation.

Overall I haven't noticed that much issue with focus hunting although I think much of that is because of how slow they have the focus speed set at. If focus speed were set as lighting fast I'd be willing to bet that there would be focus hunting present sometimes, but as it stands it's not something I have noticed much in my real world use of this camera. Personally I like the focus speed because it makes for nice transitions, but everyone will have their preference there. What is more of an issue is focusing on the wrong target. This of course happens when I get into situations where the sensor dips into 15db but what can I do, that can happen with run and gun type situations. But even with better lighting I have noticed that sometimes it will focus on the wrong target. For example I had a face in the middle of the display with both eyes visible, but instead the camera was locking onto a small patch of wood grain in the background presumably because either face detection failed or because the wood grain pattern had more contrast. Or I'll have cases where 80% of what is visible is all at a certain distance and where I want focus to be, but it will grab a small contrasty pattern far away and lock onto that. This only happens sometimes and under my "normal' lighting conditions so I need to start using the touch-to-focus feature on future shoots to help the camera out when that happens. Overall I am still happy with how the AF performs because I realize my lighting isn't optimal and that's just how contrast AF works, and ultimately for the most part the AF is correct. I had similar issues with the NX30 but it was less noticeable of course because of it's small sensor size. I'll probably switch to 3 Nova lights on future shoots rather than just 2, that should help out somewhat.

[Anthony Lelli]

Originally Posted by Aaron Holmes

Yes, pretty sure. My mention of incorrect settings before was largely rhetorical; I tried everything, including various apertures, as diffraction was one of my concerns. Didn't make much of a difference in terms of apparent sharpness/detail.

Pre-upgrade, I noticed that the firmware version was not available anywhere in the camera menus, though the update instructions said that it should be. A bit of Googling suggested that this was a sign of pre-1.0 firmware, so perhaps that's the cause? *shrug* The updater software said I had 1.0, but perhaps that's simply the smallest number it ever displays.

Whatever the cause, I'm very pleased with the 1080p60 out of the camera now.

Oh yes,
the 1080 on the AX100 is now almost as good as 4K (almost) and better than anything I saw before IN 1080. The AF in 1080 is also solid , rarely lost the target like it does in 4K .
The new firmware did it, no questions.
But I am concentrating on 4K at the moment. Shot 1080 only to compare with another 1080 camera and the AX100 came out literally like it was 4K in comparison. I had to double check if it was actually set @1080 (seriously) when I saw the difference.

[Noa Put]

Peter; the nx30 should be comparable to my cx730 in the way it operates, I also have some older sony xr versions (a xr500 and a xr520) and the touch focus f.i. locks on much quicker and is also much more reliable then my cx730, I always need to double check with a loupe, it has happened more then once that the touch focus refused to lock on a person while I was zoomed in if there was a higher contrast background and I really need a camera that at least can focus right when use the touch focus feature.

Is it easy to use the focus ring and focus manually with peaking enabled? in 4K there is hardly any room for error.

[Anthony Lelli]

Originally Posted by Peter Siamidis

T I think much of that is because of how slow they have the focus speed set at. If focus speed were set as lighting fast I'd be willing to bet that there would be focus hunting present sometimes,

This AX100 is my first camera in years without a focus speed adjustment, actually. There must be a reason why other cameras have it, no? Even the XA10 and XA20 to be honest have it.

[Peter Siamidis]

Originally Posted by Noa Put

Is it easy to use the focus ring and focus manually with peaking enabled? in 4K there is hardly any room for error.

Honestly the only time I use manual focus is for certain projects where I film a stationary subject and the camera is on a tripod, so I focus, record and walk away. I've never filmed run&gun type content with manual focus, and haven't even gotten around to even using manual focus at all yet on the AX100. It seems like it would be easy to do given how nice the focus ring is on the AX100, but as you say to get it locked on correctly in 4k with the default viewfinder would be a challenge. What might work better for you is using an external display like this one:

Amazon.com : Sony CLM-V55 5-Inch Portable LCD Monitor for DSLR cameras : Camera & Photo

I used one briefly for a while when I had a VG900, from what I recall you could leave the on camera lcd as normal and set that external 5' lcd to magnification mode with peaking, so it could be purely a focus assist tool where you use the camera lcd just for general framing and then the large lcd for focus. I presume this would also work fine with the AX100.

[Noa Put]

Having an external monitor would not work for me as I would like to keep it all as small as possible but would ofcourse be much better for accurate focussing which is important in 4K, I had one soft image during the photoshoot from last wedding with my GH4 when I shot at 4K and I didn't notice during recording, only afterwards in post and that shot was not usable. Having a separate focusring and being able to use peaking on the ax100 does give at least the option to easily go manual when needed. I read that both the lcd screen and viewfinder are very sharp so that should help as well. Anyways, will find out once I get the camera, hopefully prizes have gone done a bit by then :) Thx for your helpful responses.