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Expert
Posts: 414
Registered: ‎04-03-2013
Message 11 of 17 (959 Views)

Re: Version 8 firmware VF display glitch

A different experience... could the difference be that Nez and Alister have F5s, and Doug and I have F55s?

 

I do remember, in the early days, in the days before the time, before the existence of the CBKZ-55FX, there were only two modes of scan for 2K/HD recording, full and centre. I was never clear whether the 2K full scan was derived by "binning", or by subsampling.

 

Now, we have three modes, 4K, 2KF and 2KC which appear to be available in the 1-60fps range for 2K/HD recordings.  My earlier question was to inquire whether there was indeed a difference in this case between the 4K and 2KF, whether it related to binning vs subsampling, and whether, as per discussions years ago, the moiré was the result or one or the other of methods of derivation of the 2K/HD image.  Intuitively, I can understand how the binning method might create the artefacts, and the subsampling could avoid them.

 

However, the difference between Doug's and Alister's experiences gives rise to the question as to whether the differences in the F55 and F5 image sensors may relate to the aliasing and moiré artefacts.  Could there be a image processing advantage to the output from the global shutter imager over the rolling shutter imager that becomes evident in these artefacts?

 

Have any F55 owner/operators ever actually observed the aliasing and moiré artefacts in their footage?

 

It may be that the F5 sensor requires the 2K OLPF, and the F55 sensor does not.

 

Comments, please?

 

Best regards,
Will

 

 

Expert
Posts: 2,403
Registered: ‎11-21-2012
Message 12 of 17 (940 Views)

Re: Version 8 firmware VF display glitch

The F5 has had "Normal" (4K) scan all along, it was there for the CBKZ-55FX upgrade.
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Nez
http://www.videosoul.co.uk/
http://twitter.com/watchvideosoul
Expert
Posts: 2,266
Registered: ‎11-23-2012
Message 13 of 17 (938 Views)

Re: Version 8 firmware VF display glitch

The bottom line is the F55 and F5 both have 4K sensors with a 4K OLPF (Optical low pass filter) optimised for 4K capture.

 

When the sensor is operating at Normal 4K all is good, even if recording to HD or 2K as the sensor is operating at 4K so there is no aliasing at the sensor level. Down conversion to HD/2K includes anti-aliasing.

 

But if you operate the sensor at 2K Full Scan then you have in effect a 2K sensor behind a 4K optical filter. There is a miss-match and aliasing will occur. Whether it will cause you a problem depends on what you are shooting. This is the way light behaves and optics/sensors work.

 

Sony were aware of this so they allowed the ability to change the OLPF and have a 2K OLPF available for those that wish to shoot using the 2K Full Scan mode without aliasing problems. They didn't do this just for kicks and grins, they did this because it's a very real problem.

 

The pixel pitch on both the F5 and F55 is exactly the same so both wil exhibit similar amounts of aliasing and this has been my experience shooting with both cameras. We did a number of tests at Bristol University with both cameras and aliasing was obvious during 2K full scan. I've also seen it many other times from both F5's and F55's.

 

Will it ruin every shot? Probably not. Will you always see it? No, it depends on what you are shooting. Can it totally ruin a shot? Oh yes!

Expert
Posts: 2,403
Registered: ‎11-21-2012
Message 14 of 17 (936 Views)

Re: Version 8 firmware VF display glitch

Also, it depends how you are monitoring. Down conversion for displays can demonstrate aliasing/moire that won't be seen when the recorded material is viewed on a display at it's native resolution. So, in your EVF you might see it... but on a true 1080p display (if recording 1080p with Normal (4K) Scan), you won't.
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Nez
http://www.videosoul.co.uk/
http://twitter.com/watchvideosoul
Expert
Posts: 77
Registered: ‎11-08-2013
Message 15 of 17 (611 Views)

Re: Version 8 firmware VF display glitch

[ Edited ]

A very interesting discussion.

 

Am I alone in being sceptical here when I very clearly remember buying a 1080/2k camera, and subsequently having to pay a substantial amount of money to UPGRADE it to capture 4k?

 

Now I'm being told that actually, to get good 2K from my camera, I have to pay again for a 2k filter (that surely should have been ******ed to the 2k camera from day 1)?

 

Once again Sony appear to have got themselves confused, at the customer's expense?

 

 

Please Note: I wrote  F  I T  T ED - the forum seems to interpret this as an offensive comment?!?

Expert
Posts: 2,403
Registered: ‎11-21-2012
Message 16 of 17 (581 Views)

Re: Version 8 firmware VF display glitch

What you're missing Nick is that the camera had a 4K sensor from day one.

The 1080/2K images it (originally) produces(d) are derived from that 4K sensor. That's how it was always intended, that is super sampling, that is what "Normal Scan" in the menu is.

You don't need the 2K filter to shoot 2K if you are using Normal Scan (as you should, to get the best 2K image.

Yes, the F5 can now shoot 4K, although it's not a super-sampled image anymore. You'd need an 8K sensor to do that. So actually, the 4K image is, in some respects, compromised.

The additional 2K filter isn't needed for general 2K shooting, it's only if you are shooting 1080/2K in "2K Full" scan mode... and the only time you should be doing that is if you are shooting over 66fps and don't want to use centre scan.

So, I don't think there is anything wrong here.
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Nez
http://www.videosoul.co.uk/
http://twitter.com/watchvideosoul
Expert
Posts: 77
Registered: ‎11-08-2013
Message 17 of 17 (570 Views)

Re: Version 8 firmware VF display glitch

[ Edited ]

I'm not missing the 4k sensor - the F5 was a 2k camera, the F55 a 4K camera, from day 1. With benefits of 4k in more recent times we forget how this camera began its life. We all suspected the F5 could shoot 4k, but Sony would neither 'confirm nor deny' the fact.

 

What I am missing is why the F5 had a filter optimised for 4k   f  i  t  t  e  d from day 1, when it was marketed as a 2k camera. It was effectively compromised for HFR capture in 2k, yet the big selling point was / is that it can capture beautiful 2k images, upto 240 fps. It explains why some of my early 2k shots at 120 / 150 fps looked horrible.

 

We all complained that we had to pay for a 4k upgrade. Had that upgrade been slightly more expensive, but included a filter optimised for 4k in the package, we would have probably been a happier bunch of people and felt that we had better value for our money?

 

As I said before in a polite way, Sony have got this '****** about face' and are charging us for it.

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