Sony FDR-AX100

[Ken Ross]

Originally Posted by Noa Put

Not seeing any artifacts either but I also viewed it in a way anyone else would. Rolling otoh shutter seems quite severe though.

That definitely didn't look great at the end Noa, but that was a pretty severe test. I think the real test will come with more typical usage. I've had some cameras in the past that looked pretty bad with that wild back and forth panning test, but in real world usage showed few rolling shutter issues.

I'm guessing for typical panning speeds this won't be much of an issue. We shall see.

Paul, I am amazed at how good the down sampled video looks. I think this was another area that some were suspicious of in the Sony demo. I heard some conspiratorial explanations on other forums that ranged from 'it wasn't really shot with the AX100, but rather a higher end 4K camera' or 'it was shot with the AX100 but recorded to an external recorder' to 'it was doctored in post by Sony'.

This is probably testimony as to how good the output of this camera actually looks.

[Noa Put]

For my use that amount of rolling shutter wouldn't be an issue but I guess for anyone shooting sports or any other fast moving objects it would be.

[Ron Evans]

We have to remember that we are all looking at a downconverted file. What was used to downconvert ? There are big differences in downconvert algorithms that can introduce artifacts.

Ron Evans

[Rodman Bourne]

I have read (and forgot where) that the HDMI output format for 4k is specifically designed for the Sony Bravia 4K TV's... What does that mean? Can full 4k be played from the camera to a Samsung 4k TV?

[Ron Evans]

HDMI 1.4a can only send 30P to a TV but HDMI 2.0 can send the full 60P. Initially the Sony FDR-AX1 HDMI output was a special Sony protocol that would send 60P but only to Sony Bravia 4K TV's. The latest FDR-AX1 firmware updates this output to full HDMI 2.0. However a lot of the early 4K TV's only have HDMI 1.4 so can only receive a 30P signal unless their firmware can be updated. Some low cost displays may not be able to refresh 4K at 60P also. The FDR-AX100 is only 30P anyway so should not be a problem.

Ron Evans

[Ken Ross]

Originally Posted by Rodman Bourne

I have read (and forgot where) that the HDMI output format for 4k is specifically designed for the Sony Bravia 4K TV's... What does that mean? Can full 4k be played from the camera to a Samsung 4k TV?

I had asked the same question when they announced the AX100. FWIW, a couple of Magnolia stores have offered to let me play the AX100's output to their Samsung 4K TVs. I think it's an important question.

I'd like to think that the output is not proprietary. Ron is correct in that HDMI 2.0 should resolve any 60p issues, but that's not the issue here. Until we actually try it, I don't think we'll know for sure.

I plan on doing this shortly after I receive the camera and I'll report back. I'm also planning on getting a large screen 4K TV this year, so I'd like to think I'd have some flexibility in brand offerings. Samsung & Sony are on my short list.

[Ken Ross]

Originally Posted by Ron Evans

We have to remember that we are all looking at a downconverted file. What was used to downconvert ? There are big differences in downconvert algorithms that can introduce artifacts.

Ron Evans

Hopefully Sony's on-the-fly downconvert implementation in the camera is of high quality, as I suspect many will be connecting the AX100 to their HDTVs and watching 4K footage downconverted.

Questions questions, few answers yet. ;)

[Joey Atilano]

I downloaded the video from Vimeo and watched it a few times last night and even my wife said that the video was noticeably sharper/she said looked more HD and she usually can't tell between SD/HD.

I did notice that it had some weird movement on the static shots almost like he had it on a tripod with the OS on. Has anyone else noticed that? If it was handheld the stabilizer works great.

I want to say my old HV20 had the same amount of jello if you swung it back and fourth and it did fine on all the action I shot if you followed it.

[Ron Evans]

Focus is very critical for 4K as the image is so sharp. The normal hunting the autofocus does is noticeable when shooting grass or water etc and needs to be in manual focus. At least that is what I have found. The shallower depth of field with the larger sensor of the FDR-AX100 may make this more obvious too.

Ron Evans

[Ken Ross]

Originally Posted by Joey Atilano

I downloaded the video from Vimeo and watched it a few times last night and even my wife said that the video was noticeably sharper/she said looked more HD and she usually can't tell between SD/HD.

I did notice that it had some weird movement on the static shots almost like he had it on a tripod with the OS on. Has anyone else noticed that? If it was handheld the stabilizer works great.

I want to say my old HV20 had the same amount of jello if you swung it back and fourth and it did fine on all the action I shot if you followed it.

Joey, yes, I absolutely noticed this movement. In fact, it's my biggest concern about the camera. I say that because the biggest failing of my RX10 is the relatively poor implementation of the OIS. Without a tripod, it's virtually impossible to get steady shots anywhere near the end of the zoom range. To be honest, when Sony does OIS right, you can handhold those shots and it really looks almost tripod mounted. IMO, a couple of those clips were not giving me that kind of impression. Of course we don't know for sure how zoomed out he was.

With the RX10, I deliberately keep the zoom biased toward wide as a result of the inevitable shakiness at long focal lengths. So when I saw what I too would characterize as some unsteadiness on the part of the shooter, it got me concerned about the OIS. Now to be fair, I've never seen a poor implementation of OIS in recent years from a Sony Handicam camcorder, so it could be something else. In fact the thought I had was whether the guy was testing rolling shutter in a more realistic manner than he did at the end of the video.

I attribute the OIS behavior in the RX10, more to the relatively massive size of the lens which, if correct, would be less of an issue with the AX100.

BTW, one of the videos I once posted was from the Canon XA10. There were guys yelling about rolling shutter as the result of that same kind of wild panning back & forth. So I shot a clip as I was walking and doing normal pans. Nobody, except one guy, could see any evidence of rolling shutter in that clip. To me, that's a more realistic test. The one guy that said he saw it, just 'expected' to see it, and thus he saw it. :)

[Peter Siamidis]

Originally Posted by Paul Rickford

Found a link here for the AX100 manual

http://support.sony-asia.com.edgesui...4534651111.pdf

Hmm, it says on page 24 that on the AX100, a 64GB memory card can hold 2h 10min of XAVC S 4k footage. So if my math is right then it records at ~8.2MB/sec recording rate, or an average of ~65.6mbps.

[Dave Blackhurst]

Well, I'm sure the "I wanna swing my camera back and forth" crowd will be disappointed, but when that qualifies as proper camera operation, we're all in big trouble! It's a way to show that a sensor has "rolling shutter" or a sequential read sensor, so what? If there is a global shutter read option available, then there's something to talk about, otherwise, this is the available technology, be aware and shoot accordingly. Global shutter will no doubt come eventually, once there is a processor that can chomp data down at the required rates, but 'til then...

One thing I've noticed on the smaller cameras at long zoom is that WIND seems to be a particular challenge to the image stabilizers - I'm guessing it's an irregular movement or something, and I know it shows up with long extended lenses! It's an annoyance, but long zooms are always a challenge, simply because you're trying to fill a frame with an object some distance away... it's like a sniper shot! Notice how much effort is placed by a sniper to have EVERYTHING stable - bipod, sandbags, lying prone, breath control, special trigger mechanisms, etc... I actually think it's pretty impressive that cameras do as well as they do at stabilization!

One of the "tricks" with steadicam operation is to stick with a wide lens - it will minimize any shake that might get through the rig - you don't see long zoom steadi shots...

[Ron Evans]

Originally Posted by Peter Siamidis

Hmm, it says on page 24 that on the AX100, a 64GB memory card can hold 2h 10min of XAVC S 4k footage. So if my math is right then it records at ~8.2MB/sec recording rate, or an average of ~65.6mbps.

Not all the 64G is used for data. Some needs to be reserved for the file allocation tables, any directories that the camera creates etc.

Ron Evans

[Ken Ross]

Originally Posted by Peter Siamidis

Hmm, it says on page 24 that on the AX100, a 64GB memory card can hold 2h 10min of XAVC S 4k footage. So if my math is right then it records at ~8.2MB/sec recording rate, or an average of ~65.6mbps.

Pete, I'd bet they're allowing for peak bitrates during complex scenes. I'd be surprised if this records at a fixed bitrate.

[Ken Ross]

Originally Posted by Ron Evans

Not all the 64G is used for data. Some needs to be reserved for the file allocation tables, any directories that the camera creates etc.

Ron Evans

Ron, as I recall when looking at these files structures, they take up a really tiny amount of space.

Dave, I fully intend to swing my AX100 back and forth wildly for at least 50% of my shooting. Now why is that my wife refuses to watch my videos? :)

Seriously, these tests have always amused me. But I guess the shooter is trying to make a point.