F55: XAVC vs XAVC-S

Duke M.

Duke M.

Veteran
I'm looking for a new, light, portable camera for a documentary. In the old days I would have used my EX-1. It would be nice to have it usable for future projects so 4k is desirable.

I looked at the Z100 as the successor to the EX-1, but the 1/3" has little DOF control and poor low light ability.

Then I became excited about the FDR-AX100. The 1" sensor has good DOF control (better than a 2/3" sensor), great low light sensativity, Ultra HD type 4k and its very backpack friendly. The Zeiss lens has manual zoom and focus controls which is unusual for a handicam. In regular HD it will shoot a broadcast compatable 50mbps and 4.2.2. and up to 60fps. In 4k mode its 4.2.0.

However, its XAVC-S. There's not a separate forum for the AX100 so my searches have been scattered. How compatable is XAVC-S with regular XAVC such as the F55 produces? Any idea if the footage would intercut well?

This clip is actually comparing two small 4k cameras. The sharper images are the AX100.

 
Thanks for the links.

starcentral said:
Mainly XAVC-S uses MP4 as the container instead of MXF like XAVC, and it will only go up to 3840 x 2160 (4K UHD)
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Yep, an MP4 wrapper. The limitation to UHD doesn't bother me since that's all the camera will do anyway.

starcentral said:
The 420 in 4K mode reminds me of the whole "can 8-bit 420 be graded" debate.
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The whole 8 bit being gradable discussion has always struck me as silly. 8 bit files have been graded for years. You just can't push them to the outer limits. And if I want 4.2.2 for green screen I'll shoot HD 50mbps and 422 then up rez. The stuff that really stands out in 4k are the details in a panoramic vista. I don't really want to see the details of the pores in the talent's face. I remember the latest Hobbit movie trailer where the Epic made the makeup and prosthetics obvious.

I did find this one:
http://www.xavc-info.org/xavc/share/data/XAVC_SpecificationOverview_Rev2_1.pdf
 
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It was interesting to see where Sony said that home displays will be limited to the UHD format instead of the Cinema 4k format.
 
Well Duke, Ill speak on the AX100 a bit. The only things really holding back the camera is the rolling shutter and the lack of image controls. If you keep the camera stabilized and aren't shooting too fast of movement the AX100 produces some really great images. The lack of image controls is the other issue. You basically have two camera profiles. Standard and cinema gamma. Thats it. No contrast control, no sharpening control. You an adjust the hue of the color though. But I'll say this. The camera easily captures 11 stops DR. The image is sharp as a tack and is essentially moire free. You get some aliasing on high frequency patters but the camera really does well with moire and aliasing.

Some people are a bit worried about the 60Mbit/sec XAVC-S. It holds it's own and grades pretty well. Yes, UHD is the maximum res for the S variant. I just got in today the Gh4 which I'm loving due to the image controls. But the AX100 is staying in the bag as well. Its a great run and gun shooter with having built in ND and zebras. The built in mic is pretty darn good too. In the palm of your hand you have most of what you need to make images. If they only would have included a couple image tweaks like contrast and sharpening the camera would have been all that much better. I also have the BMC4K. That camera is getting no love. FNP and dead pixels keeps the camera sidelined. In strong light the camera is nice and obviously the codec is beefy, but other than that the camera is a fail. Barely has 12 stops of DR and obviously you HAVE to rig it out (the screen is just unusable).

Out if the but $3k 4k's, the Gh4 is the strongest camera (especially when the Atomos 4k recorder hits). But the AX100 is no slouch. The week after next I have a stills shoot in Hawaii but have booked 5 days vacation there and will be using both the Gh4 and the AX100. I'll make sure to share when something is edited together.
 
I think most of us have used several cameras with rolling shutter as most cameras have it. I don't really put the GH4 in the same class. The body is about the price of the AX100 and then you have to buy lenses.

I had also thought of using the AX100 as a B roll camera and had a completely sacrilegious epiphany last night. I COULD SHOOT A FEATURE FILM IN 48-36 HOURS BY USING TWO AX100s at the same time.

I'm thinking a romantic comedy (which is mostly two people talking to each other). Shoot everything wide at 4k. All the dolly in and dolly out, wide angle, panning, slider and close ups can be done in post so you only need one take.

Pan and scan on the 4k images and release at 2k! (Yes there would be a few scenes that would require more and there will be times the talent can't remember their lines, but generally it would work.

People are goint to hate me for this but man, I just cut my budget to 15% of what it was. I think I'm going to change my whole business model if these work out.
 
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I don't fall for the wide two-shot turning into singles later in post, the problem is you won't get over the shoulder type shots unless you cheat in the wide shot drastically enough that both subjects are faced more towards camera in which the wide shot it wouldn't look right and be usable.

Regardless, the AX100 looks great and the price is even better. It will grade fine for most things, people are far too caught up on grading when all they are really doing is adding a vignette in post and adding some contrast.

1" is also a really great size. I am going to have to put one of these on my Christmas list. Has so many practical uses.
 
Duke M. said:
I think most of us have used several cameras with rolling shutter as most cameras have it. I don't really put the GH4 in the same class. The body is about the price of the AX100 and then you have to buy lenses.

I had also thought of using the AX100 as a B roll camera and had a completely sacrilegious epiphany last night. I COULD SHOOT A FEATURE FILM IN 48-36 HOURS BY USING TWO AX100s at the same time.

I'm thinking a romantic comedy (which is mostly two people talking to each other). Shoot everything wide at 4k. All the dolly in and dolly out, wide angle, panning, slider and close ups can be done in post so you only need one take.

Pan and scan on the 4k images and release at 2k! (Yes there would be a few scenes that would require more and there will be times the talent can't remember their lines, but generally it would work.

People are goint to hate me for this but man, I just cut my budget to 15% of what it was. I think I'm going to change my whole business model if these work out.
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You can punch in about 30-40% on 4K

I don't think this is enough to make that much of a difference.

Plus, if you did it every other shot, it would totally look dookie, just because you could tell the camera never moved.

Duke, you're delirious. :-)

Duke M. said:
All the dolly in and dolly out, wide angle, panning, slider
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Parallax man, parallax. You can't dolly in and out in post, nor slide sideways.
 
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Typically on a narrative film shoot I'd do a couple of takes wide, one or two medium takes and then close up over the shoulder shots of each person averaging about 5 takes per person. That's about 14 takes.

I've been taking images calculating how much I could push in, aspect ratios, etc.

I think I'd have to do one take wide, that I could push in to medium in post with one camera straight in front and the talent mostly facing each other.

Then I'd cheat the talent out a bit and set the two cameras about 45 degrees apart and I could start out medium and push in in post to close up like a traditional over the shoulder shot. I'd then run it continous because if the talent messes up you can always cut to the other person for reaction, then cut back (justifying the removal of the bad portion).

So your right, it would take two set ups and two takes. But the trade off from 14 takes in three set ups is still a big savings in time and money. Not really much harder on editing either, maybe even easier to edit. Any dolly move would be done in post except a zolly.
 
Nate Weaver said:
Parallax man, parallax. You can't dolly in and out in post, nor slide sideways.
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Parallax in a slider or sideways dolly of a street, buildings or railroad wouldn't work because the infinity point would move. But in a room, nobody would really notice. Dolly in and dolly out wouldn't be affected unless you're using something near a fisheye because the infinity point would remain the same (though you might need to make sure the center point is the same.

Also, since UHD is Quad HD you could go in 50% (enlarge the image 200%) and still have true HD. You can go in a bit past that (another 20%) and not really notice it in HD.

people could tell the camera never moved.
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Beyond cropping in, you also reframe the shot so the person is in a slightly different portion of the frame. A little farther left, a little down, etc.
 
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I use to blow up 720p from the F3 to match 1080p and it wasnt overly discernable, especially on youtube. That was a pretty big blow up.

On the F55 I did these post blow up tests a year ago. First half shows a blow up, the second half is way more exciting and shows a post zoom and pan.

https://vimeo.com/61298885
 
starcentral said:
I use to blow up 720p from the F3 to match 1080p and it wasnt overly discernable, especially on youtube. That was a pretty big blow up.

On the F55 I did these post blow up tests a year ago. First half shows a blow up, the second half is way more exciting and shows a post zoom and pan.
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Exactly Dennis. I've done similar things and no one's noticed. Now imagine starting at UHD and going down to HD. No loss in definition and you can get some motion in it if you want.
 
I don't think you can approximate a dolly move in post because of what Nate said - parallax. You can reframe certainly, punch in, and even push in but it's tantamount to a zoom, not a dolly push in. If you want to save money on takes, imagine your cuts sufficiently, overlap with the cut in mind and you'll save plenty. Planning your shoot will save way more shooting time than trying to spoof it in post.
 
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