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

I think the use of s16 lenses and the upcoming center crop feature are exciting.

I'm going after a Canon 2/3" lens and will be putting it on the F55 with pure mechanical adapter and using the built in 2x doubler in the lens. The MTF version adapter uses a magnifer in the mount PLUS the lens 2x doubler so I should be somewhat better off by shooting 4k full sensor and cropping in post and down-scaling to fit 2k or HD. At least I won't have light loss and less artifcats going through magnifiers.
 
After years of shooting with a Canon HD HJ21x7.5 I'm not convinced about using a doubler in this situation. To my eye the EFP doubler always deteriorates the image with reduced contrast, sharpness and distortion. I await your beta testing results!
 
Well Nate, so far from what I gather most of the folks who don't think there is an issue with the HFR are judging it after its been transcoded into another format, and/or uploaded online. I guess that's a good/bad thing. Converting the video into another format seems to help hide the artifacts but that's doesn't really make me happy about it.

I know if more people were to actually compare the HFR footage to the same scene shot in 24fps and look at original XAVC MXF file they would definitely see the difference - but most people capture footage, transcode, edit, render, upload/recompress and by then the footage has gone through 3-4 generations of processing. Any aliasing turns into tiny detailed noise "jumpies" and no one will be any the wiser.
 
Hi all, not to chime into the conversation late, but the 240fps short we shot for the firmware 2.0 launch has been given the okay to download. I'm not sure that this will necessarily add too much to the debate as some of Dennis' caveats still apply but for reference you can download the 20MBps 1080P MP4 file to have a look and pixel peep.

This was shot with the OLPF in all the time with the Sony primes (and a Canon 200mm T1.8). Remember that this was Beta firmware so bear that in mind. I did do a quick test without the filter against some test charts and very quickly decided that we needed it in.

https://vimeo.com/74338401

Cheers

Martin
 
Hi Martin thanks for providing the download and great work by the way. I love some of the natural elements like the fire and water sprays.

In general I definitely find the images a little on the soft side compared to what I know the F55 can do in regular HD mode or 4k downscaled to HD in post. It is missing that "cripsness" and detail, and of course we know this is the OLPF at work in order to smoothen out the image from a 4k sensor to HD.

With an entirely HFR edited piece nothing will seem to look out of place. My concern however would be for example if I was mixing regular frame rate footage (without OLPF) with footage shot HFR with the OLPF. I don't think the two would mix very well and would give quite an inconsistent look, almost as if it were shot with two different cameras or one was shot with 1/8 classic soft and the other was not. I know on the Sony boards the suggested solution was to insert the OLPF and use it even for the regular frame rate footage, but I find the image resolution seems overly reduced for my liking and I would not decide to impact all my footage in such a way just to make up for a deficiency when shooting HFR. ie. A normal project might only have a small portion of it in HFR versus the overall footage.

I see a hard time to explain to producers that I can do HFR but it will look soft when mixed with regular shot footage, so I'd probaly opt for the alisiasing/moire issues on HFR footage knowing it will at least look more consistent with what else was shot in regular frame rates.
 
I'm not sure it's going to be such a problem to be honest. The amount of HFR work shot on Epics/Scarlet/R1 in crop modes (which do significantly soften the overall image) and then intercut unobtrusively with regular 4K footage would suggest that it isn't the end of the world to take a sharpness hit on HFR - HFR work is meant to look dreamy anyway, so I think you get away with it.

Plus it's not like anyone's really delivering 4K content anyway for the time being, so it's even less of an issue when the 4K footage is being scaled down to 2K for display anyway.

Thanks for pixel peeping material Martin. Looks great.
 
I know I'm mostly pixel peeping, but its a let down when you shoot the same thing in regular HD and it looks clean and artifact free then switch to HFR and get a different ball game. Then to have to add the OLPF and soften it all up to hide the first issue just seems wrong to me.

Anyway I will can it for now.
 
Grug said:
The amount of HFR work shot on Epics/Scarlet/R1 in crop modes (which do significantly soften the overall image)
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Okay, I have to try this one more time... of course the crop mode softens the footage, but the alternative (the way Sony's currently implemented it) will equally soften the footage, and ALSO add the aliasing artifacts. I'm having a hard time understanding why folks think the crop-mode footage would be inferior (speaking of image fidelity, ignoring field-of-view and DOF considerations).

Let's look at potential workflows:
1) Shoot at 4K, finish at 4K: yes the 2K mode will be softer and noisier. Because the 2K footage will have to be blown up (magnified) to 4K for the finish, it will be softer, and the noise will be magnified too. But that applies equally to whether your 2K was filmed in a center-crop, or from a pixel-skipped extraction across the full field of view. Those concerns will be equal. The only substantial difference will be that there won't be a bunch of aliasing artifacts (caused by the pixel skipping) that not only will be present in the pixel-skipped version, but will also be magnified in the pixel-skipped version. And, the crop-mode version can (and should) use the same OLPF as the 4K version, whereas the pixel-skip 2K would need the different OLPF.

2) Shoot at 4K, finish at HD: here, still, the 2K stuff will be softer and noisier. Because the 4K will result in oversampling which, when downsampled, will provide maximum image resolution, but the 2K will be coming from a single-sensor Bayer pattern, and that means a maximum resolved image detail of slightly more than 720p. Assuming 75% image detail retention (which is pretty standard, and pretty good), your 2048x1152-pixel image will resolve about 1536x864. Mixing that in with 1920x1080 is obviously going to result in the 2K footage looking softer. And noisier, because the oversampling->downconverting process of the 4K footage will result in the noise being averaged together across downsampled pixels and thus smoothed out and minimized, whereas the 2K footage won't receive that benefit.

So in either case, you're inescapably going to have noisier, softer footage when shooting in either of the 2K modes. That's just the way it works. If you want full-res footage to intercut, you'd have to shoot it at full res, there's no other way. Without a doubt and without any alternative, 2K footage is going to be noisier and softer than 4K footage -- period.

So your choice is: do you want aliasing artifacts in exchange for field of view? That's the difference. The crop mode should provide at least 100% the resolution of the pixel-skip mode, and probably more because it won't be compromised by aliasing artifacts. And the crop mode will avoid having to use an alternative OLPF. However, the crop mode means you'd need to change lenses to get a comparable field of view, and you will never have the same DOF (unless adding appropriate ND filtration to equalize the DOF through f-stop).

The pixel-skip version, on the other hand, is going to have aliasing artifacts due to the pixel-skip. It'll maintain the same field of view and DOF of the 4K footage, but it's going to be aliased, on top of having the same softness and noise issues as the center-crop footage. The OLPF they're adding may smooth out some of that aliasing, but I would bet it will result in footage that's noticeably softer than center-crop would be.

That's just the nature of the game, when using a sensor that's designed for 4K to instead shoot 2K. No two ways about it, it's going to be compromised. You just have to pick which compromises you prefer.
 
starcentral said:
I know I'm mostly pixel peeping, but its a let down when you shoot the same thing in regular HD and it looks clean and artifact free then switch to HFR and get a different ball game. Then to have to add the OLPF and soften it all up to hide the first issue just seems wrong to me.
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Then I would suggest that your expectations were out of line. There's no free lunch. The only way to get clean/artifact-free regular HD and also simultaneously get clean/artifact-free HFR, is to shoot on a camera that delivers clean/artifact-free HFR in the first place. Like a Phantom. You'd need to be using a high-speed camera that's engineered and designed to pull off the entire image off the sensor, at high speeds. The Red Dragon could do it to a degree (full 4K at up to 150 fps) assuming 150fps is all you need.
 
Barry_Green said:
Then I would suggest that your expectations were out of line. There's no free lunch. The only way to get clean/artifact-free regular HD and also simultaneously get clean/artifact-free HFR, is to shoot on a camera that delivers clean/artifact-free HFR in the first place. ]
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Or an Alexa. Or even an Epic, which does 120 without crop. I thought it was very reasonable expectation, since the F55 clearly has those two cameras within it's sights.

Clearly this is the one facet where there is a shortcoming, and given size, weight, and power consumption I can understand somewhat. But at a $38K+ system price it's within spitting distance of an a used Alexa/Alexa HD/Amira and I didn't and still don't think it's an out-of-line expectation.
 
All I hope is Sony do the right thing and give us that S16 mode.

I guess it would produce excellent HD, also I think the extra DOF and Tele-ness of lenses will suit HFR shooting

Also the cam in 2kraw (any speed from 24-240) with something like a canon 8-64 will be a very fine doco cam

in 4k it is a wonderful narative cam
 
Sorry, let me clarify -- you are within your rights to expect it FOR THE PRICE, but it is unreasonable to expect clean footage FROM THEIR METHOD. Now, if you think that for the price they should be using a better method (such as the Epic does) then sure, I'll agree with that.

What I'm trying to clarify is that since we now know what the method is that they use, you can't expect pristine results from it. It is inherently going to be softer, noisier, and (depending on whether you go full-field-of-view or not) riddled with aliasing artifacts, which an added OLPF may reduce somewhat but will bring its own set of compromises. I think the best results you can expect from the technology used in the FS700/F5/F55 will be delivered by the windowed crop mode.
 
Barry_Green said:
What I'm trying to clarify is that since we now know what the method is that they use, you can't expect pristine results from it.
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I get that. Fair enough.

Alister's trying to make the same argument on the Sony board, and I'm like, I don't care how they get there, just get there. This camera aspires to play with the big boys. This is what the big boys do.

As time came to actually move my money for this camera, it was becoming clear that used Alexas were falling in price to meet the 55, and I had a moment where I realized for about 3-4K more, I could have an Alexa (this was late Feb).

I jumped on a little bit of faith that Sony understood where the target was, and would get there. It's been pretty slow getting there, and now there's this one thing that will never get there most likely. It's a bit brow furrowing.
 
Barry_Green said:
Then I would suggest that your expectations were out of line. There's no free lunch. The only way to get clean/artifact-free regular HD and also simultaneously get clean/artifact-free HFR, is to shoot on a camera that delivers clean/artifact-free HFR in the first place. Like a Phantom. You'd need to be using a high-speed camera that's engineered and designed to pull off the entire image off the sensor, at high speeds. The Red Dragon could do it to a degree (full 4K at up to 150 fps) assuming 150fps is all you need.
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I'm not asking for free lunch or expecting something from nothing or that isn't possible. I'm also not asking to defy physics, so I don't see how my expectations are out of line.

My expectation would have been for Sony to read the entire sensor then down-scale it. It would still look better than the artifacts in HFR mode and if it turns out Sony can't do it due to limited processing power I would rather take the FOV hit then butter up my image all creamy and organic like the good old days of shooting 35mm focusing screens with 1/3" CCD cameras from back in the 35mm adapter days. :huh:
 
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Expecting to be able to read the entire sensor and then down-scale it, is exactly the no-free-lunch scenario I was talking about. Sensors have maximum read rates. Apparently the sensor in the F5/F55 is limited, at full res, to 60fps (or so it seems from what I've gathered). Which is why they resort to pixel-skipping to get faster read rates out of it.

If you want full-res reading and downscaling, then you'd need a camera that's engineered to do that -- such as the Epic. The current version of the Sony (apparently) isn't capable of that.

Alister's trying to make the same argument on the Sony board, and I'm like, I don't care how they get there, just get there. This camera aspires to play with the big boys. This is what the big boys do.
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Totally understood. I'm not trying to be an apologist (I think that's the last thing anyone would accuse me of); just trying to explain it as I see it, because I figure the sooner someone understands the implications and ramifications, the better off they are in making an informed decision. Unfortunately for those who have already spent their money, it's a tad late for that!

I have a tremendous amount of interest in high-speed right now, so I've taken a higher interest in the Sony lineup than before, and have spent more time thinking about and examining this than I bet a lot of folks have. I think their compromise is reasonable for the FS700 at its price point, but I don't think high-speed should be considered a major selling point for the F5/F55. As a standard-speed cinema camera I think they are highly competitive, but the high-speed is compromised.
 
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.
 
With the trade offs the engineers have made, they have made these as extra features available to you, not the main purpose of the camera. At this point in time I think the F55 is one of the most versitile cameras out there, but it can't do everything perfectly. A little noise, hey Neat Video is a wonder. I'm still putting my nickels together for the F55.
 
Hi Andrew, good article and thanks for posting it. Definitely helps to confirm the difference between HFR with and without OLPF (as seen at the very bottom end of the article).
 
I did more tests this morning and this time shot Benjamin Franklin with 1250 ISO in slog2 and the difference in quality compared to my first test using STD 5 4000 ISO is literally night and day.

The micro-aliasing or tiny artifacting on highly detailed aresas or very thin lines do not appear with as much noise, jumpy blocks and line jumping as in my first test. (If anyone had actually downloaded my original example MXF file you would have seen what I was talking about.)

Looks like the main issue I was seeing at least was attributed to the higher ISO and possibly gamma curve I was using. This is a huge sigh of relief and I'm pretty confident I would be able to stick to shooting HFR without the added OLPF which softens up the image too much for my liking. (Can also try using 1/8 or 1/4 diffusion filter)

The OLPF however would be needed to reduce aliasing on diagonal lines going through any portion of the frame, but this in itself was not what I was worried about originally. You really needed to watch the original file to see what was going on.
 
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