F55: Looking for 2K 240fps raw MXF to look at

Not to derail the thread - but yes alexa's going for 40k used and the red epic is now like 20-30k with all the parts going - and without a need for a rocket soon - Sony has a lot of competition coming up - I do indeed hope they resolve their slo motion issues. I still think the f55 gives an image almost as nice as the alexa and its lighter and more run and gun - but it's getting nutty out there!
 
Andrew Stone said:
Thanks for the detailed breakdown Barry. Finallly beginning to understand the math & methodology behind resolving.

Just read Adam Wilt's article "Sony F5 / F55 Optical Low-Pass Filters". It will confirm suspicions and hopefully allow people to get back to shooting rather than pixel peeping.
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Hadn't seen that before; glad Adam broke it down like that.

Yes, that all lays it out exactly like I would expect. The nasty aliasing that's evident in the "pixel-for-pixel crop of an HDR image shot with the 4K OLPF" shows exactly what Nate was complaining about, and exactly what I would expect from a pixel-skipping method of reading the sensor.

Once you install the 2K/HD OLPF, you get the results he shows in "Pixel-for-pixel crop of an HD HFR image shot with the HD/HFR OLPF". Vastly better, in that the artifacts are largely eliminated. However, as Dennis has been concerned about, there's a huge drop in overall sharpness. Look at the point where the lines blur to mush, it's about halfway between 750 and 1000 lines (so, 875 lines?) Now compare that to the downconverted 2K from a 4K source (Pixel-for-pixel crop of a 2K image shot with the 4K OLPF) and you'll see just how much is lost due to the pixel-skipping and new OLPF. Yes you get rid of the aliasing artifacts, but you pay a pretty steep price in sharpness to get it.

All things added together and once it's all said and done, if I was using a Sony F5 or F55 for high frame rates and I wanted the sharpest pictures and best quality, there's not a question in my mind that that will be accomplished best by the new/forthcoming window crop mode. It won't be perfect, and it won't be super-sharp, as previously said it'll be around halfway between 720p and 1080p, but it'll be as sharp as you can get from this given technology. Second place, if for some reason I couldn't use the center-crop or absolutely had to preserve the field of view or DOF, I'd vote for the 2K with the new 2K OLPF.

Sorry to be the bearer of bad news, but for those who thought that they'd be getting sharp/crisp 2K slow-mo, that's just not in the cards for the F5/F55, the sensor technology appears to not allow it. I am disappointed by that, as much if not most of my interest in the new Sonys was in the high frame rate capability, but I am also somewhat encouraged that they are at least actively trying to address the situation by giving options (the sensor crop/window mode and the new 2K OLPF).
 
Center scan mode to me at least would appear to mean reading the center only, and thus not resorting to the line-skipping/pixel-binning method in v2.

http://community.sony.com/t5/F5-F55...information-September-12th/m-p/181017#U181017

New announced function for v3.0 (formerly v1.4).....


HFR Full Scan Mode, and Center Scan Mode
In v2.0, we are going to support Full Scan Mode for HFR, no windowing of the imager sensor.

In addition, we will support Center Scan Mode on the CMOS sensor in v3.0. Maximum frame rate is the same as Full Scan mode.

2K RAW Center Scan Mode for S16mm lens
We decided to support Center Scan Mode on the CMOS sensor with Audio for S16mm lens users. Worldwide, there are a lot of S16mm lenses hence we were asked by many to support. By using S16mm lenses you can record MPEG50, XAVC HD, HDCAM SR File and 2K RAW (w/R5) with audio.
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Sony Wrote;

"We decided to support Center Scan Mode on the CMOS sensor with Audio for S16mm lens users. Worldwide, there are a lot of S16mm lenses hence we were asked by many to support. By using S16mm lenses you can record MPEG50, XAVC HD, HDCAM SR File and 2K RAW (w/R5) with audio....2K RAW on 50p and 59.94p TC base"

not sure where that mentions HFR?

​
 
Good to see. Indeed I hope they are right :)

I think this will be brilliant low mass S16 zoom any speed (FPS) from 24-240 raw at a manageable size. ND/XLR

Seems to be king of the hill for HD target doco work used like that

S
 
eddavid said:
Not to derail the thread - but yes alexa's going for 40k used and the red epic is now like 20-30k with all the parts going - and without a need for a rocket soon - Sony has a lot of competition coming up - I do indeed hope they resolve their slo motion issues. I still think the f55 gives an image almost as nice as the alexa and its lighter and more run and gun - but it's getting nutty out there!
Click to expand...

The only thing keeping me from an Alexa then and now for most part is my lack of beast mode to go run-and-gunning with it.

Every time I start to think I could hang with it, I'll do another shoot with one and get reminded just how brutal it can be if you have to get it on and off your shoulder 40 times in one day by yourself.
 
What I can tell you from my own tests and watching Tom's video is that:

- By using very low apertures where a lot of your frame might be out of focus, ie. f2.8, or long lenses where again you will be shooting with a more narrow depth of field you are not going to see the artifacting as being so prominent. If you were to shoot a forest or some other scene at f22 the results would be different.

- Shooting in RAW or slog2 with the lowest ISO setting possible reduces the effect of micro-aliasing ( this is where very tiny fine lines "dance" around through the frame as the object or camera moves). As mentioned in the past, this effect is largely visible and seen on the original files, but not as visible once uploaded to Vimeo or YouTube where the compression tends to help smoothing things out. You are probably not going to see it on a leaf taking up 1/4 of your frame. You are going to see it more with a highly detailed scene.

- Traditional aliasing of diagonal lines will ALWAYS be visible in the full scan HFR mode on the F5/F55. There is no two ways about it. You shoot a diagonal line across your frame and you will have some aspect of jaggies there. Its 100% unavoidable unless you purchase and install the new OLPF optimized for HD HFR (softening your image plenty). In Tom's forest shoot there are no real straight edge lines so aliasing does not poke its ugly head out here.
 
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Backfocus92 said:
Here is some footage that Tom Guilmette shot and his write up.

What do you think?
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I downloaded the MXFs. He underexposed so badly he has not done the noise combined with aliasing any favors.

In my opinion if you're going to have aliasing, taking care to expose correctly and not add any noise to the situation is paramount to hiding the aliasing.
 
I missed this thread but in Filippos short he kindly uploaded some source frames, the aliasing is very obvious (hair, edges etc,.). What was also odd was that there was what looked like mosquito style compression noise in there too (but these was 'RAW' source frames). Even watching the 1080p vimeo version of it there are some scenes where it's quite clear and obvious (around her shoulders and high contrast areas). There's a wide shot with trees and you can see the aliasing movement in there. So firstly there's a chance this stuff isn't being debayered properly yet. In resolve the RAW settings allowed a very soft version which hides the problem (the BMW log look).

I simply don't see how you can get around scanning alternative lines and expect a good result. It's like looking at the world through half closed venetian blinds. An OLPF would have to basically blur the heck out of everything. If you shoot incredibly shallow DOF then you'd get away with it but you're back to the days of dSLR my-first-video.

The centre crop idea is nice but you could just crop a 4K original.

Does the F5/F55 have a burst 4K mode?

The 700 can burst at 120fps 4K, taking that and downsampling to 2K should give much better results by comparison to the RAW 2K mode.

cheers
Paul
 
paulcurtis said:
The centre crop idea is nice but you could just crop a 4K original.

Does the F5/F55 have a burst 4K mode?

The 700 can burst at 120fps 4K, taking that and downsampling to 2K should give much better results by comparison to the RAW 2K mode.
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Crop from 4k - one assumes that the 'engine' cannot process enough data flow for 4k at HFR,

A crop mode would stress the 'engine' less and allow full frame monitoring

Burst could be a solution (assuming the 'engine' ca do 'high revs' for a short time) and no the 5/55 dont have it

I vote crop.

S
 
I'm hoping for a 10-20 second burst mode using full 4k sensor, debayered and downscaled to HD XAVC and that will be the end of that.

I don't think I would use the OLPF for free.
 
paulcurtis said:
The centre crop idea is nice but you could just crop a 4K original.
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If shooting at "normal" frame rates, yes, you certainly could. But isn't the whole point of scanning less of the sensor, to get increased frame rates? Windowing the sensor lets you read it faster, and that's how you get high-speed frame rates.
 
Barry_Green said:
If shooting at "normal" frame rates, yes, you certainly could. But isn't the whole point of scanning less of the sensor, to get increased frame rates? Windowing the sensor lets you read it faster, and that's how you get high-speed frame rates.
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Yes of course i totally missed that, thanks for correcting me!

From a personal perspective i've only ever used or wanted that kind of slow mo in small bursts, hence my thinking orientated to caching 4K and then outputting it (with the ability to crop or scale or reframe as needed in post) but i appreciate other application where long running slow mo might be a benefit.

cheers
Paul
 
From where I'm sitting Sony has opened a can of worms with these new cams in many more ways than one. I'm curious to see when Sony will fix real issues (or how) and when they will start taking real requests with more priority over the features that don't matter.
 
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