Noise comparison: 35/4:2:0 vs. 180/4:2:2

[Piotr Wozniacki]

Sorry David, but there is no "noise reduction" switch on the EX1 that I'm aware of.

Also, the issue in this thread is not so much the noise on the EX1, but its increase in high bitrate nanoFlash files.

[David Cherniack]

Picture Profiles / Details / Crispening

Adjusts noise suppression levels.

If you have it on the processed EX image could appear less noisy than the unprocessed nF image.

[Piotr Wozniacki]

Oh,, crispening is what you mean.

Yes, I do use it sometimes (dialed into negative or positive territories, depending on the quality of scene lighting and hence the anticipated level of noise vs. the high detail definition desired), but it was at zero in this particular test shoot.

But you must keep in mind, as well, that BOTH the EX1 original AND the nanoFlash recording ARE processed (the PP settings act on the SDI stream, as well). So even if the crispening was at some strange value, it would affect BOTH.

[Bob Grant]

All I can offer is that from my experience the EX1 hooked up to a 17" Panasonic monitor via HD SDI looks noiser than what it records. One question, how does the video recorded by the EX1 compare to that recorded by the NF at the same bitrate.

[Piotr Wozniacki]

Originally Posted by Bob Grant

All I can offer is that from my experience the EX1 hooked up to a 17" Panasonic monitor via HD SDI looks noiser than what it records.

Hi Bob,

Thanks for chiming into another of my measurebator threads. Do you recognize the picture from our V1E's "oil paint" discussion back in 2007? :)

Your above statement is very valuable as it would suggest there IS some moderate noise reduction going on the EX cameras just prior do the on-board compressing/encoding (as opposed to acting on the pre-compressed stream, that is subject to DSP according to the PP settings in power, and output from SDI)!

Originally Posted by Bob Grant

One question, how does the video recorded by the EX1 compare to that recorded by the NF at the same bitrate.

Will have to check in similar low-light situ, but if you take a look at the red flower close-up in another of my measurebating threads on this forum, where I was comparing color resolution of 35 Mbps 4:2:0 with that of the nanoFlash'es 50 Mbps 4:2:2, there is no such apparent noise increase in the nano picture.

[Peter Moretti]

"Your above statement is very valuable as it would suggest there IS some moderate noise reduction going on the EX cameras just prior do the on-board compressing/encoding (as opposed to acting on the pre-compressed stream, that is subject to DSP according to the PP settings in power, and output from SDI)!"

Or like you said earlier, the EX codec itself is providing some form of "noise reduction." I would like to hear CD take on all this. Hope they respond.

[Julio Veas P.]

Personally I don´t think the HD-SDI output is noisier, I have been using my EX-1 to capture uncompressed 8 bit 4:2:2 video with a BlackMagic Decklink HD Extreme 2, under Windows and using Adobe Production suite and the results are Great, I don´t see a noiser Image than the one in the cards. even with color corection applied the final noise level is far better.

now my nanoflash arrives next month so I can not compare the difference with my actual wokflow, but whatever is generating the noisier images we all see I don´t think is the HD-SDI output.

greetings

[Piotr Wozniacki]

Thanks Julio for this input.

Yes - definitely looking forward to some exhaustive explanation from Convergent Design!

[Garrett Low]

Piotr,

Did you try emailing CD directly? They seem to be pretty responsive.

I'd be interested in their insight too.

Garrett

[Piotr Wozniacki]

Yes Garrett - I did today morning, after having waited in vain for some response from Dan, who used to be so active in this forum.

I e-mailed both Dan and Tommy, but still no answer...

[Aaron Newsome]

I honestly don't see any issue here. The nanoFlash is recording a much more detailed image, that includes the noise information. The lower bitrate of the on-board Sony codec is smoothing those noise artifacts right out of the image.

I think these two images are showing me exactly what I would expect to see.

[Piotr Wozniacki]

This has been one of my *possible* explanations, as well - but a word from CD would be appropriate, none the less.

Also, Alister Chapman (whose knowledge can't be overestimated, and who is also using the EX/nanoFlash combo) stated on the EX forum he never noticed such increase in noise, so the issue is far from closed.

Last but not least: the increased noise at the highest nanoFlash encoding bitrate thwarts all advantages of "much more detailed image" - as you put it - by far. On my 50" plasma, the noise/grain in nanoFlash recordings is much more striking than any potential or factual benefits of using it (like the better color resolution, or lesser mosquito noise)...

Disclaimer:
On the other hand, I seem to be the only one complaining about it - so a possibility exists something might be wrong with my SDI connection or nano unit. Which calls for some comments by CD even more!

[Tom Roper]

Several things concern me conceptually about the methods in the test.

The screen grabs are jpg compressed, from different streams and codecs. One is sourced from 35 mbps compressed the other sourced from uncompressed and then compressed to 180 mbps by the nanoflash, but the jpg file size of the displayed grabs are roughly equivalent in size, meaning the latter jpg is about 4-5x more compressed for display.

In other words, the extra chroma samples responsible in part for the 180 mbps bit rate, what's happened to them in the conversion to roughly equivalent jpg file sizes?

The other thing is the second set of grabs that are 1920x1080, but have been magnified. When I looked at the full frame images (the first grabs) at 100%, I could hardly see what Piotr was talking about, but now I do, that's why he asked to view them at 1:1 on at least a 50 inch monitor. It is hard for me to see the noise at 1:1 on a 17 inch monitor.

I think what we're missing here as well, is the intention of nanoflash is the improvement in noise reduction in motion, yet we're looking at static images that arguably can be played at much lower bitrates 8-10 mbps on an HDTV monitor with people having a hard time to distinguish the difference from even 35 mbps unless there is motion.

What I am absolutely certain about, is I've never tried the 180 mbps setting, just the 100 mbps is what I use (looks good to me), and I also don't know if Piotr's native stream was interlaced or progressive..

[Gints Klimanis]

Thanks for posting the examples, Piotr and Luben. Appreciated. I posted a similar comparison with elephant seals at sunset and demonstrated an increase in noise recording in low-light as well.

So, what's the complaint? The Nanoflash is obviously recording more detail, including noise detail. The device is doing its job. If you're worried about noise, then software noise reduction will allow for a more selective.

I'm currently experimenting with shooting with shooting the EX1 at a higher gain level of +6dB to allow my lens to close to f/4 instead of the usual f/2.8 for my regular indoor sports shoot. This increases scene detail due to increased DOF, and I believe puts the lens at an aperture which delivers greater center sharpness. (Someone correct me if f/4 is not actually sharper than f/2.8) The higher bitrates of the Nanoflash would relax the stress on the video compressor. I'm shooting at 140 MBps LongGOP and will post images soon.

[Gints Klimanis]

Originally Posted by Tom Roper

The screen grabs are jpg compressed, from different streams and codecs.

Agreed. Piotr, aren't you able to grab frames as uncompressed PNG?

EDIT: Apologies, Piotr. I see that you posted uncompressed PNG of the red flowers in another thread.