Oh yes it is, Gints. The general rule in this discussion should be that we all examine and compare clips and stills on really big displays - watching them on a 20" (even professional and calibrated, but small) monitor will never show what we're talking about. And after all, we're delivering for big screen (often much bigger than my 50") - aren't we?

This is the most rudimentary question, and it took me a long time experimenting before I was able to define it first, and answer it then. The noise is there, because it's in the source camera in the first place (for various reason - irrelevant to this discussion). But it's the excessive fluctuation of detail (and hence the noise) in the high bitrate nanoFlash files what makes it come to live of its own, and seriously jeopardize the obvious advantages of the nano recording!

This was also my original impression. But, this thread has got me wondering otherwise. However, I've noticed that a lot of this discussion revolves around use of the Nano with the EX3, a camera that I've always considered to be relatively noisy to begin with.

I'd love to hear if any others are experiencing this issue with alternative cameras. Or aren't having issues, for that matter. I know there are some on this list using some pretty sophisticated cameras in conjunction with the Nano...if you're out there, what settings are you capturing to and are there some that you avoid?

I shoot primarily with an HDW 730 and canon glass. No question, in my opinion, that the highest bit rate I-fame settings look the best and get me closest to an HDCAM recording. But, I typically (for storage reasons) shoot 180 or 140 Long GOP. When I see noise, it's usually in the shadows or underlit portions of the image--which I believe is more a result of my camera settings and chip set. On a 50" consumer set (I only have a 20 inch production monitor) the results look pretty good. But the consumer set has all sorts of scaling and noise reduction, and de-interlacing algorithms going on, so I'd expect it to look good and I'm not sure it's a fair judge.

I use the Nano because it allows me to work in difficult conditions where tape storage and maintenance is a real burden, and it delivers high quality results. As soon as I can afford to work with all 64GB CF cards and bus powered FW drives double in capacity (but not physical size) I'll shoot everything at 220 or 280. Until then, I'll hop back to HDCAM tape when the situation allows and shoot high bit rate Long GOP when it doesn't.

Cheers,
Eric

Gints,

I see much more color information comparing the two. Most of the time I'm shooting with the PMW-350, a quieter camera than the EX-3. Inherent noise is reduced and so is probably not an apples to apples comparison. Even when shooting the Nano with our EX-3 the benefits far outweighed any noise issues. I'll admit it would be nice to A/B each source to see a scope comparison. Additionally, most of my viewing is done on Sony 24" LCD monitors. I don't have access to anything larger.

Best,

Dave

I'm still counting this will happen, Mike - but we need a more technical input from you and Dan...

Dear Piotr,

Our best technical advice is based on the very thorough and objective results that we obtained by testing all of our modes on the Video Clarity System.

Summary:

At 100 Mbps and Below, please use Long-GOP for the best images.

Above 100 Mbps, please use I-Frame Only.


(In a post above, I explained why you may see the difference in "frame by frame" quality, when you have an image with lots of detail, or a very noisy image, and use Long-GOP above 100 Mbps.)


With that said, how may I help you?

What technical detail would you like us to provide?

Dear Dan,

Let me answer with the above excerpt from one of my previous posts (I bolded out the most relevant parts).

Now, I'm not an expert in advanced L-GoP settings, but (even before acquiring my nanoFlash) I have played with various settings when rendering out both HDV and the XDCAM EX into MPEG-2. Below are the two relevant tabs of the MPEG-2 Vegas template.

I can tell you that even though the impact of tweaking these parameters is quite subtle, I have found that for 1080/25p, I achieve best results (including the most consistent frame quality within a GoP) when using the exact settings as shown in the attached template pages.

May we know whether or not the nanoFlash L-GoP encoder uses similar settings?

Thanks

Piotr

PS In the below sheets, please disregard the Template, Notes, and Format fields' contents - these haven't been updated to reflect the real settings (in this case, for nanoFlash L-GoP 50 Mbps/422 t/l).

Dear Piotr,

We use the commonly accepted standard of 12 frames per Long-GOP for 720p and 15 frames for 1080.

Sorry, but I do not currently have the level of detail that you are requesting.

I hope you understand that we have to create files that are usable with a wide range of Non-Linear Editors. Tweaking codec parameters, and then testing them against every possible editor, with all of the frame rates and options can be a very lengthy process.

Dear Dan,

The settings I'm talking are by no means tied to a single encode (MainConcept), or NLE (Vegas).

They're general MPEG-2 settings that all encoders (software and hardware) use, and their purpose is getting the best compromise of quality vs. the required encoding speed, storage etc.

If you *know* otherwise, I'm all ears.

"Our best technical advice is based on the very thorough and objective results that we obtained by testing all of our modes on the Video Clarity System.

Summary:
At 100 Mbps and Below, please use Long-GOP for the best images.
Above 100 Mbps, please use I-Frame Only."


Hi Dan,

Are you telling us to avoid using Long-GOP above 100mbps? Are we talking about a point of diminishing returns or "deteriorating" returns? That's not how I interpreted the chart that was distributed with the VCS test results. I'll go back and check that thread.

However, if this is the case (that our video will actually suffer as a result of using 140 or 180 Long GOP), why would you even include these as optional settings?

Eric

Hi Dan,

Just FYI, here was a quote from the thread following the VCS test:

"Our current feeling is that at 180 Mbps I-Frame Only and Long Gop are about equal in quality."

Have you changed your opinion on this?

Just to be clear, my understanding was that 180mbps was a little bit starved for creating high quality I-frames... Whereas180 would be more than adequate when taking advantage of the more efficient Long-GOP structure.

Thanks,
Eric

Dear Eric,

Based on the Video Clarity Test alone, the I-Frame Only mode beats Long-GOP, but please read the following.

We tested the nanoFlash with a Video Clarity System. I will provide the raw numbers below.

In our testing, we used a representive, high-quality video stream, with lots of motion and detail, video from a football game. This video is feed into the nanoFlash, then recorded, then played back into Video Clarity, which then analyzes the video.

A numeric score is then obtained. Lower numeric scores are better.


While the Video Clarity system is very good, it can not duplicate your actual shooting conditions. For example, not everyone shoots football games. In order to keep out testing time to a reaonable level, we did not test with each and very one of the various video test streams that the Video Clarity system provides.

For example, you use an entirely different camera than Piotr and the noise level in your images would be different.

With the nanoFlash, you can easily run a test using the two modes, and determine what is best for your shooting conditions.

We do feel that if one is providing excessively detailed, or very noisy images, to the nanoFlash, that I-Frame Only will provide a better image than Long-GOP at 140 Mbps or higher. At 100 Mbps is it very close, and one should run their own tests.


Here are the raw numbers from Mike Schell, for the Football video test. Mike ran the tests.

Here’s the I-Frame vs Long-GOP comparison for the Luma data
Note: the chroma is always so much better than luma in the video clarity system.
This may seem counter-intuitive, but the Video Clarity system is based on Human Visual Perception and our eyes are better with luma than with chroma, so we are showing the results of Luma.

Lower numbers = better quality:

50I = 3.40
50L = 2.97 Long-GOP Better

100I = 1.953 I-Frame slightly better
100L = 2.043

140I = 1.536 I-Frame slightly better
140L = 1.686

180I = 1.277 I-Frame better
180L = 1.448

For the absolute best results, for your camera, for your type of shooting, we recommend running a quick test for yourself, using the bit-rate that you want to use.

Since you will probably only use a few bit rates, then testing the difference between the two modes is not a lengthy process.

Dan,

Based on your numbers why do you recommend L-GOP at 100Mbs? If I-frame is a more compatible format (in MXF for example at 100) and slightly better quality why would you use L-GOP.

Also this information seems contrary to what CD has long advised. I had been led to believe that 100 L-GOP was definitely better quality than I-frame at that bit rate. I-frame was supposedly a less efficient approach, and maybe it is at 50.

Mike Schell said this last year:

"Long-GOP is typically 2X to 3X more efficient than I-Frame only. So 100 Mbps Long-GOP = 200 to 300 Mbps I-Frame only. There is a significant improvement with Long-GOP recording."

Can you clarify this information?

Jeff

Dear Jeff,

This is the first time I had actually seen the raw numbers.

For 100 Mbps, the difference is 0.09, which is a very small difference.

Our earlier testing had shown Long-GOP to be better.

I have never recommended I-Frame Only at 100 Mbps. I have recommended 140 Mbps I-Frame Only before.

I was also surprised.

Before I would switch from 100 Mbps Long-GOP to 100 Mbps I-Frame Only, I would run some tests.

It could be that if we had run all of the different video test suites (different videos), then we may have found some more differences.

I think it would be great if some of our users, run some tests and show some real world examples.

They may either confirm the Video Clarity tests, or not. The results may be very subjective.

I collected a number of bit-rate/MPEG format clips of natural subjects such as water streams and evergreen branches which are generally lower in contrast than football games. 220 MBps I-Frame compared to LongGOP140 in noise levels, and there was a visible reduction in macroblock artifacts between 100 and 140 LongGOP. I-Frame140 was visibly noisier (fine grain) than LongGP140. That is not to say that there is anything wrong with the Nanoflash - only that the bitrate, high as it may seem, is inadequate for the detail in the scene.

SxS is crunchy in high motion areas, and I don't think that increase in noise at higher bitrates for Nanos I-Frame and LongGOP is worse than the decrease in blocky artifacts. For my tests, LongGOP140 had about the same level of noise as I-Frame100. This noise/detail modulation is easy to see on a 24" 1920x1200 Apple Cinema display.

I just hooked up my Nano to my 52" Sony Bravia and looped the files until I became familiar with them. Also, I watched frame grabs from each. It is difficult to see the difference between the files or frame grabs in these examples on an Apple 24", but the Bravia easily reveals the blocky artifact. I'm viewing the 24" display from 6" and the 52" display at about 24" .

If anyone is interested in a set of 5-10 second clips and frame grabs, I'll post them.

Here are a few of my tests shot at f/5.6 with shutter around 1/125 and gain=0dB with Sony EX1. Bark was chosen because of the undulating sun reflected from nearby water. Evergreen was chosen for complexity under slight movement. Wide fountain was a compression buster with moving tall grass, several water patterns and background grass. The compression type is in the file name as well as in the (crappy) audio of most files. My Nanoflash started recording with a latency of a few seconds with the latest firmware.

Clips (Nano IFrame100, I-Frame140, I-Frame220, LongGOP100, LongGOP140, SxS ) and Frame grabs here :
Index of /Videos/Nanoflash/Test_July11

Although it is difficult to see the difference on a 24" 1920x1200 monitor, a ~52" 1080p TV will make the differences very obvious. I use the Playlist feature of VLC media player for fast switching between clips.

Evaluating the nano codec
 

As long as this thread has sort of morphed into evaluating the Sony MPEG-2 hardware codec used in the nano, I wanted to add my 2¢ again. (Even though my earlier comments were not received well...).

First, I think this is really where the discussion belongs, not where it started, and I'm happy about that. With the exception of reliability, the effects of starving the codec used are probably the most important decision about whether the nano is suitable for ones needs. Personally, I find the Sony MPEG-2 hardware codec truly outstanding, particularly due to CD allowing us to set whatever bit rate and compression mode we feel appropriate.

Instead of comparing nano clips to pristine uncompressed clips, (almost) everyone is comparing the nano clips to the native Sony EX1 clips. While this test is very meaningful to those of you who only shoot with Sony EX1 cameras, it barely begins to tell the story about the good and bad parts of the Sony MPEG-2 hardware codec used in the nano. While I believe that the Sony EX1 gives a tremendous bang for the buck, and would recommend it (when used with a nano!) without hesitation to those that ask me about a camera in that price range, the camera section of the EX1 is by no means a source of pristine video. I've wondered all along if those making comparison tests are mostly coming to wrong conclusions, and making the wrong tests. It seems to me that most of the testing just reveals that the EX1's built in codec sucks. It would be really useful (and revealing) if someone with an EX1 could record a little video to an SRW or uncompressed to a computer/drive, and compare THAT to the nano's recording of the same thing.

If all you want is to figure out what nano codec settings to use when you're shooting with a Sony EX1, then fine; your observations are relevant to your needs. If you want to figure out what the strengths and limitations of the nano and its codec are, then you really need to (1) evaluate the nano output compared to an uncompressed signal (or at least a signal from a top of the line Sony SRW video tape recorder), and (2) you need to use source material from a MUCH better camera than the Sony EX1. I'm not saying you shouldn't evaluate the nano using an EX1, just that you shouldn't evaluate the nano using ONLY an EX1.

[begin part that always pisses everyone off]
I wish I could upload a few clips of stuff I've shot and recorded with the nano (at 100Mb-Long GOP mostly), to show how utterly transparent the recording is, but they're not mine to upload. The video comes out of $100,000+ cameras, via fiber, as HD-SDI, and each camera has been extensively setup before and during the shooting, including gamma tables and noise reduction, to make the best pictures possible under the shooting conditions. The monitoring is done in a dark room, at a 12" viewing distance, using the very best 20" Sony CRT broadcast monitors, which are also calibrated before the shoot. (At home, I watch the files using an Apple 30" Cinema Display, which is pretty good, but not in the same league as the CRT monitor I use at work). You also need to make sure the monitor you're using to evaluate the pictures is not negatively effecting what you see. Is that 50" LCD displaying pixel for pixel, for example, or is it scaling the picture before it displays it? Is it adding edge detail to the picture, and the noise in the picture, which won't show up in the mushy 35/4:2:0 EX1 codec, but will show up in the nano codec or uncompressed video?
[end part that pisses everyone off]

So I reiterate; if you really want to evaluate the nano codec, you have to compare it's output to its input, and you have to use more than just a Sony EX1 as the source. Comparing the nano codec and the Sony EX1's (relatively crappy) built in codec is a misleading and fruitless endeavor, unless all you're looking for is to decide whether to buy a nano for your EX1.

(And lest you feel otherwise, I have no illusions that the nano set to 100Mb-Long GOP puts out the same picture as I'm feeding it. It is VERY close though. I have yet to see a real macroblock, just a bit more noise (probably due to the 8-bit reduction). I have some concert footage with strobes going off and saturated lights shining through smoke that holds up just fine. There is no tearing or macroblocking when the strobes go off, and the moving light beams show full gradation of color and intensity with no banding at all. If I get a chance, I'll make some 180Mb-I Frame recordings and see how much apparent difference there is when shooting with ridiculously expensive cameras, but I'm pretty sure that any improvements I see won't be worth the reduction in recording time.)

Billy

Billy Steinberg wrote "unless all you're looking for is to decide whether to buy a nano for your EX1."

That, and which Nano settings improve my video footage that is submitted for broadcast. CD is probably very happy about their low-end market and may comment on the percentage of their sales to EX1-class users. I bought the Nanoflash on faith-in-concept because there were nearly no clips or frame grabs available to view. To my knowledge, there are *zero* clips or framegrabs comparing uncompressed data from any camera made available to the Nano/XDR community. If you have the gear, please consider uploading some of that video or at least a pair of grabs of the same frame for our education.

" just a bit more noise (probably due to the 8-bit reduction)"

No, the noise is more significant than the least significant bit. Surely, you will be convinced if you step through your footage frame by frame and notice spatial detail modulation in the mid-tones.

You make a good point about monitor display capabilities, but the answer is simple in this case : it is very easy to see clusters of 16x16 pixel macroblocking artifacts in 1080p video or stills on the 52" 1080p LCD TV and harder to see them on a smaller LCD unless they cover large screen areas. These blocky artifacts are much easier to find if a frame is viewed at 200% magnification on the smaller 24" Apple Cinema monitor. The changes in noise levels among clips of different bitrates are also obvious and seem to scale inversely to the bitrate. This noise appears to be mostly detail modulation rather than sensor noise in most cases.

"I'll make some 180Mb-I Frame recordings"

This thread, Piotr made a point that additional noise was noticed for Long GOP at 140 MBps and higher. 100MBps didn't show a great fluctuation of detail between the I-Frame and the successive P-frame. Please let us know what you see.

"I have yet to see a real macroblock, just a bit more noise (probably due to the 8-bit reduction)."

I'm inclined to agree with Billy on this one...I've not yet seen a macro-block artifact with the nano, even at 100mbps. Even when I've accidentally left the unit recording while a swing the camera around or walk to a different set up--I get totally clean garbage :-).

I do think there might be an increase in noise, but I can't confirm without further testing...and I'll stick to opinion that 220-I frame is noticeably better than any bit rate beneath it (assuming the material calls for it).

In response to Dan's reply...thanks for providing those numbers. While I understand the confusion surrounding whether or not to use Long-GOP or I-frame, I'm glad to see that there are advantages to using increasingly higher bit rate Long-GOP modes (i.e. 180 is better than 100). Your early posts read as though you were suggesting otherwise.

Bottom line (IMHO) is you can't get something for nothing. If you want the highest possible quality from the Nano you need to be prepared to invest in larger, faster cards and larger storage so that you can record 220 and above. If you want to have the highest quality from your camera, you need to invest in a better camera and lenses.

Cheers,

I have been capturing uncompressed 8 bit 422 with a blacmagic decklink hd extreme, from the EX1, if certainly there is a difference in quality I am not impressed with the results, now for sure it´s not the capturing card, but the camera, the EX´s are great cameras for the price, but they are noisy cameras. This weekend will be using my recently arrived nano, so I can make comparision with uncompressed from the same camera. but I am sure that the achilles heel is the camera head and not the codec.

There is additional confusion as to whether detail modulation due to I-Frame and P-Frame quality differences worsens as the bitrate for LongGOP increases above 100 MBps. When played at the correct speed, this noise appears to be at the mid-tone level but the cause is not obvious until time is spent stepping through the material frame by frame. I can pick out better frames usually every 6 frames (sometimes 7) and am wondering why I see this for group length = 15 for an NTSC system. Camera is Sony EX1. Frame Grabber is Sony Vegas 9e .

1.) When it's said that noise levels seem to scale inversely to the bitrate, that means as bitrate goes up, noise goes down. That's what I would expect but Piotr's point is the opposite.

2.) Kind of hate to jump into the fire with this, but I don't trust Vegas for viewing noise levels on any size monitor. Has it been tried to view stills on the 52 inch monitor just connected to the Nanoflash itself via it's HDMI connector?

3.) I understand my comments at this stage may be unwelcome, particularly since I don't have the EX1 anymore since I use the PMW350 instead. But my recollections from the EX1 were that it was a lot less noisy than is being assumed now. And I can't offer any more than that, since I have used 100 mbps Nanoflash setting exclusively, the videos have been very clean and noiseless, but I don't think it's just because I don't use the EX1. Again, I'm suspicious of Vegas. $0.02

Tom, we could suspect Vegas. However, I see the same type of artifacts when playing the clips in VLC Media Player and the Nano to the large TV via HDMI. I'll spend some time with Sony ClipBrowser.

conclusion?
 

Tom, Gints, Dan at al.

Thank you all very much for your input to this thread.

I have not posted for quite a long time, but believe me I have taken every opportunity between my jobs (that couldn't afford experimenting) to see into the issue even deeper, and have come to the conclusion that:

- as far as the noise is considered (and especially those noise fluctuations between frames), the Long-GoP format is inferior to I-frame at anything above 100 Mbps.

At 140 Mbps and up, I-frame is much quieter than Long-GoP.

And believe me, I made sure that neither Vegas, nor my particularly monitoring device, influence this conclusion.

Disclaimer: all this thread of mine, as well as this (hopefully final) conclusion, applies to the 1/2" EX series cameras which unfortunately suffer from quite an excessive noise in the first place. Anyone using the nanoFlash on cameras with less inherent noise (read: larger S/N ratio, usually achieved with larger imagers), may find their results differ.

Thank you for starting this thread, Piotr. As a result of your instigation and my successive anecdotal experiments, I'm upgrading from 140 MBps LongGOP to 220 MBps I-Frame only. It is a shock that nearly 7x the native Sony EX1 35 MBps data rate is needed for adequate results in mostly handheld shooting, but so be it.

For tripod shooting, I was surprised that 140 MBps LongGOP showed a different and higher noise modulation than 100 MBps LongGOP. Now that I'm over the data rate shock, the Nano has proven to be a great path for ~$6000 camera owners to significantly improve video and frame grabs.

Also, I have since learned that my consumer TV (Sony Bravia 52" , 1st gen) unfairly amplifies macro-block edges even with all menu sharpening/noise reduction set to neutral or off. Still, that has been a a valuable viewing tool to quickly which parts of the video are compressed inadequately. Thanks to Eric Liner for asking that I pay attention to that.

Piotr wrote "1/2" EX series cameras which unfortunately suffer from quite an excessive noise in the first place. "

We need to examine uncompressed video from the EX1 HD-SDI stream to conclude that this is the root of the problem.

You will probably think I'm out of my mind, but I cannot just hide from the public what I have just find out. I only hope I will receive a constructive answer from Convergent Design.

So far, what I have been looking for in the images generated by my nanoFlash at various settings has been the noise. Typically, on the EX cameras it's most prominent in low light, or on shaded areas (generally, on large uniform color areas exposed below some 40 IRE) - this is what I was inspecting.

After settling with the conclusion the 140 Mbps I-Frame format is the best compromise for my camera, typical usage etc. from the viewpoint of noise, today I discovered - much to my shock - that the WHOLE picture is buzzing with somewhat I would not call noise (as it occurs even on very bright areas), but a sort of grain. When this shimmering grain's magnitude is comparable with very fine detail (like tree foliage in a distance), the grain is spoiling the detail definition and is very disturbing.

This is true of all my I-frame clips of up to 140 Mbps, and makes them much lower quality than my EX1's internal encoding (L-GoP, 35 Mbps).

Dan and Mike, I really am shocked and disappointed. I'm back in the point where I have to question my nanoFlash and/or my camera's HD-SDI working up to specs!

Please explain the nature of what I'm seeing. If this is how recording to the nanoFlash is actually supposed to look like, I must say - with a deep and sincere disappointment - that this $3,000 device is reduced now to just a backup device, the simultaneous recording to the broadcast-accepted, 50 Mbps 4:2:2 L-GoP being the only format where the advantages outweigh the shortcomings, when compared to my EX1's internal recording...

Tomorrow I will run another series of tests to compare the camera codec with the nanoFlash I-frame at higher bitrates. Hopefully, the grain is not as disturbing as it is at 140 Mbps.

Dear Piotr,

I welcome others to comment on your situation.

I believe that the key will be to attempt to reduce the noise originating with the camera.

Could you please post your camera settings and what type of scene you are shooting.

What is the gain?

What is the Shutter Speed?

What is the Aperature (F-Stop)?

Are you using a Custom Preset or Profile?

Does this problem occur when you have adequate light, such as on a bright sunny day and the entire scene is bright?

Dear Dan,

C'mon, please - you know better than ask me all those questions again. Therefore, let me only answer the last one:

- yes, the problem is also present when I have adequate light, such as on a bright sunny day and the entire scene is bright.

I will not post any screen grabs, as the grain is only visible on the moving picture.

There *Was* a similar Problem with the Flash XDR
 

Hi Piotr:
There was a similar problem of poor quality playback of clips when playing back the clips inside of the Flash XDR SSDR. I and Aaron complained about this and this problem was fixed with firmware release 1.5.55. This was a recorder based problem and NOT a camera HD-SDI stream output issue.

*Here's a way to find out what's going on: Remove the recorded clips on your CF card from the Nano Flash and import them into your NLE completer editing system. Look at the clips inside your editing system, or with VLC video player and see if the same noise discrepancies you are seeing from the Nano Flash in playback are also visible from inside your computer when playing back RAW CF Card footage.

I hope this helps.

Unfortunately Mark the grain is still there - no matter whether I play the clips from the nano, inside my NLE, or with VLC.

It's similar to the noise - that I was discussing for the most part of this thread - in that it's shimmering, thus most visible in the moving video. Unlike the noise, the grain is almost "translucent", and present everywhere in the picture (the noise being random darkish pixels, only present in low-light/shaded areas).

Another fact that makes it similar to the noise in L-GoP clips is that when I render such a grainy I-Frame 140 Mbps clip to 35 Mbps 4:2:0 (or even 50Mbps 4:2:2) in Vegas, the grain is filtered out and the picture becomes as clean as that originally recorded with the EX1, or nanoFlash at 50 Mbps.

This again makes me feel the latter format (L-Gop 4:2:2 50 Mbps) is the only nanoFlash format where advantages over the native EX recording are more readily visible than the artifacts nanoFlash introduces - but that is certainly not worth the extra hassle of external recorder with the price tag like this. Especially now that budget cameras become available recording 4:2:2 50 Mbps natively.

Very, very disappointing indeed.

Translucent Noise & Such
 

Hi Piotr:
OK. Understood. I must therefore, conclude the malfunction can only be the result of two possibilities.

A) Non-Spec HD-SDI camera output from EX-1 Sony.

B) Busted Nano Flash.

Let us proceed to a secondary procedure to determine the source of your malfunction: Can you get your hands on another Nano Flash ? Perhaps there is a rental house in Poland which may have the Nano Flash in its inventory. Try your setup with a secondary Nano recorder.

OR

Locate PC or MAC with an HD-SDI video capture card. Capture some test shots live out to the computer and check on broadcast HD monitor.

Mark,

If you keep in mind what I said about 50 Mbps L-GoP (which is the only format on my nanoFlash that doesn't introduce any artifacts over the native SxS recording), it becomes apparent that nothing is wrong with my camera's HD-SDI output.

This is, unfortunately, how the nanoFlash encoder chips perform. When - after my long testing of noise in Long-GoP - some other people came up and confirmed my observations, Mike & Dan offered the conclusion that L-GoP is only better with data rates of up to 100-140 Mbps (even though before, they kept saying L-GoP is preferable to I-Frame only with speeds of up to 180 Mbps).

I wonder what they say now. Last time I uploaded samples onto CD's ftp for them to analyze and comment on my findings, which they never did. Since the new kind of artifact that I now find with I-Frame only is not visible in a still frame grab, I wonder if somebody would spare some time and assess them this time, if I uploaded a couple of files again?

Hi Piotr, i have recently purchased nanoflash for my EX3 but not tried it yet. It's still in a box. I'll be flying to Poland soon and if you happen to live fairly close to me (SE Poland) i don't mind meeting up with you to compare our NF.

Dear Piotr,

1. We have been extremely busy.

2. We posted the results of the objective Video Clarity system.

However, the results from the Video Clarity system apply to the specific type of video that we tested, which was a football game. This test uses very clean footage.

One can use this as a guideline to select a bit-rate/mode, but the results will not apply under certain conditions, such as a completely different type of footage, or sending noisy images to the nanoFlash.

The Video Clarity system is a wonderful system, and it provides a wide variety of professionally recorded images to use to perform the tests. We used only one of the test scenarios in our testing.

3. Your camera in 35 Mbps 4:2:0 mode will reduce the noise in your images as opposed to what comes over the the HD-SDI output.

4. The nanoFlash in 35 Mbps 4:2:0 mode will reduce the noise in your images in exactly the same way.

5. If you camera sends noisy images to the nanoFlash, the nanoFlash will not distinguish the noise from detail and do its best to reproduce both.

Thus, the nanoFlash should not be expected to reduce the noise in your images.

6. One can easily setup a camera, or pick a scene in which the images will be noisy.

7. The Sony EX1 series is a very nice camera but is very capable of producing noisy images depending on the scene, the lighting, and the camera setup.

The nanoFlash is an extemely versatile device in which one can pick and choose the File Type, Bit-Rate, I-Frame Only or Long-GOP.

8. We have in the past, and still do, recommend 100 Mbps Long-GOP as the best, general purpose, option taking file size and recording time into consideration.

9. There are conditions were we recommend other modes.

If you are shooing a movie, and file size is not a consideration, we recommend 280 or 220 Mbps.

If you are wanting the nanoFlash to reduce the noise in your image, you could choose 35 Mbps.

However, we highly recommend that you first take all reasonable efforts to reduce the noise in your images by using appropriate lighting and setting up your camera to reduce noise.

10. The best way to test if the nanoFlash is doing it's job,
the best way to test if your camera is putting out a clean image,
and the best way to test various nanoFlash modes,
is to test your camera and nanoFlash in A-B fashion using a high-quality professional monitor.

If one is expecting
1) Excessive Camera Motion,
2) Excessive Motion in the image,
3) Excessive Detail in the image, or
4) Excessive Noise in the image, then other modes may give better results.

9. We really want to help you get the most of your camera and your nanoFlash.

Where's the noise ?
 

.....Which leads me to consider strongly the possibility you have a busted Nano Flash my friend. Perhaps the encoder circuit in your Nano is on the way out, or some other internal component, such as, a transistor or a resistor is coloring the input signal slightly ? The fact that you wrote the noise is "translucent" makes me wonder about something electronic in your Nano going bad. You need to test another Nano to confirm and eliminate any further variable.

...Well, this is how your Nano Flash chips are performing, and you could be right, only, I would have thought other Nano Flash users would also be reporting this kind of anomaly.

I do not get any of the kind of translucent noise issues with my Flash XDR. The higher I go in Long GOP or I-Frame (Intra) the way cleaner things look. Here's a thought - and again, I'm not trying to be dogmatic about this either, but would it be possible that Sony has a special super DSP chip inside it's in camera encoder which is ultra-tweaked to do away with a great deal of in camera noise and optimizes everything to go onto the SxS cards ? With my Canon XL H1, it has this great big fat DSP chip called a Digic II, which creates the most incredible 4:2:0 HDV MPEG 2 m2t files on HDV cassette I have ever seen (Even tops all of Sony's HDV camcorders). Canon states in its literature that this chip removes noise and optimizes the image for a cleaner MPEG 2 compression. What got my attention was how you said all is well with Long GOP 50 Mbps setting. - Hmmmm ! Sony's in camera encoders are optimized for two settings -

1. 35 Mbps 4:2:0
2. XDCAM HD 4:2:2 Long GOP 50 Mbps.

The higher up you go with the Nano Flash or Flash XDR in encoding data rates, then the more faithful the built in Sony XDCAM HD 4:2:2 encoder will be at reproducing the signal, and this *may* be your problem here.


...This is interesting. Personally, I think Long GOP is useless above 50 Mbps because the industry doesn't allow for it, however, I-Frame 220 or 280 Mbps in particular is utterly astounding and I-frame can be edited on any "A" list NLE. Long GOP 180 is wonderful, but you're limited to FCP to post it, or go ahead and shoot in Long GOP 180 and play it out in realtime into your NLE via HD-SDI from the box - Now that's a BIG winning way to go.

...Perhaps these products reach the very limits of MPEG 2 8 Bit Video technology ? Maybe your combination of camera and Nano Flash exposes this ? I'm not sure you don't have a busted Nano however.

Hello Piotr and thank you for your efforts and posting your findings!
I've not seeing anything disturbing in my NF material, not that I've looked anything as thorough as you have, but, the fact and the matter is that all of my material has no problem passing the Broadcast requirements in Canada and in the USA.
To come in rescue to your problem, you got an offer from other NF owner in Poland and that could help you relize that your NF is good or bad. Until then, the only think that I could suggest to you is to rent other EX1 (borrow if you can) or simply get any other camera with HD-SDI out and look for the same problem. I know, different camera, different things, but, if the NF is faulty with your EX1 records it would be faulty with other camera too. It very well could be your EX1 or the HD-SDI on it. Doing that would give you the idea that is your camera or is really the NF.
Just as Dan have said, the NF would record and reproduce everything that is given to it - gain, shadows and so on...
Also Dan, asked about the PP settings. That is a very good question. If you are using PP setting made on your own not calibrated by a vector scope, some or all of you colours could be trowing out a lot of noise.
I am not an expert on this, but, I've seen it on my EX3 just by playing with PP settings and testing. If you have the time and consider that option, please go to a camera center/ rental/post facilities and calibrate your EX1 PP settings and that would clear a lot of your troubles, I hope , if your HD-SDI and NF are working properly.
Just my 2c.
Hope you find out what the problem is and start enjoying your camera with NF very soon!
Luben

Guys,

Thank you very much for your advice. Of course I hope you realize I'm talking subtleties here - just like with the (dark area) noise, the shimmering fine detail ("translucent" grain) can only be seen on a fairly large display, like my 50" plasma.

Kris,

Could you please send me a PM? I tried emailing you, but for some reason I can't. It so happens I do live in the SE of Poland, so I'd be more than happy to meet and share experience.

Piotr, I'm willing to look at your files again. I've concluded that my Sony 52" Bravia (2007 model) unfairly amplifies noise and macro-block edges with sharpening that can not be reduced with user controls. The clincher was using the Nanoflash to record MPEG LongGOP at 18 MBps.

Have you considered trying a card that can record the uncompressed video signal and experimenting with another software video compressor such as VirtualDub/ffmpeg for comparison ? It appears that you are pleased with the severe high frequency reduction of SxS 35 MBps LongGOP and less so with the compression between that and very high bitrates. We've talked about the LongGOP shimmering noise in which the I-Frame is signficantly better than the preceded or following P-frame, but I'm not sure that all of your comments relate to that.

Piotr, sure, I'll take a look at your files. Please include more action in your scenes so that it's easier to match the Nano frames with the SxS. The very wide views of your house shots make it difficult to compare detail, so some close-ups would be preferred.

email sent

The EX is not the quietest of cameras. The noise it produces is across the entire luma range it is not restricted to just shadow and dark areas. The reason it is less obvious in brighter part of the image is that noise has a fixed amplitude relative to the brightness, so a dark part of the image at say 100mV with 10mV of noise is being modulated by 10% while a 500mV (brighter) signal with 10mV of noise is modulated by only 2% so the noise is much less obvious visually, but the same amount of noise is still actually present.

The higher the bit rate that you record at the better any such subtle image differences will be recorded. A low bit rate codec will often ignore such very fine image changes as part of the data reduction process. I often observe more visible noise in my NanoFlash footage. This is perfectly normal. The 35Mb/s coded from the EX turns noise into blocky artefacts. This is most noticeable in dark foliage where the image can become a little "muddy" for want of a better word. Put the same footage through the NanoFlash and the fine, subtle detail is restored, along with the image noise. There is a good example of this in the sky frame grabs in the review I did of the NanoFlash last year. XDCAM-USER.com Convergent Design NanoFlash
If you consider that the grain in the NanoFlash sky is moving from frame to frame it is easy to see that this could react with the detail enhancement circuits of a consumer TV to create "shimmer" while the blocky artefacts from the 35Mb/s EX would not have the same effect.

Large screen consumer TV's are never a good way to judge the true quality of footage. They have all kinds of processing circuits adding who knows what to the image making it very difficult to make any kind of objective conclusion.