View Full Version : nano


Ian Thomas
October 14th, 2011, 01:04 AM
Iam filmming my local semi-pro football teams matches on the EX3 and putting it on to DVD would i see any benefit by using the nano at 50mbps or higher

thanks

Dan Keaton
October 14th, 2011, 09:31 AM
Dear Ian,

One of the less know advantages of using a nanoFlash is the ability to record in ".MPG".

For SD, if you provide a SD signal to the nanoFlash, then you can record in ".MPG", and obtain pre-rendered DVD files.

Then one only needs to use a DVD burrning software that recognizes that the file has already been pre-rendered.

Thus, creating the DVD's from the footage can be very easy and very quick.

(If you are going to edit the video, then recording to ".MOV" or ".MXF" may be preferred.


For HD, you may also use ".MPG" and you will obtain a pre-rendered file for BluRay.

Rendering for BluRay is typically a very lenghty process. The nanoFlash does it in real-time.

And there are other advantages to using a nanoFlash, such as long record times, and your choice of quality options.

Ian Thomas
October 14th, 2011, 10:01 AM
Thanks Dan for that info, Iam Recording HD and then is going out on DVD just wondered if the quailty would be an inprovment comming from the nano or just record to the SXS cards


For HD, you may also use ".MPG" and you will obtain a pre-rendered file for BluRay.

Rendering for BluRay is typically a very lenghty process. The nanoFlash does it in real-time.

And there are other advantages to using a nanoFlash, such as long record times, and your choice of quality options.

Will the above option be better for SD DVDs

Thanks
Ian

Dan Keaton
October 14th, 2011, 10:35 AM
Dear Ian,

Since you are recording HD, then wanting to create SD DVD's, you will have to edit the video.

The nanoFlash can record the higher quality 4:2:2 video out of your camera's HD-SDI output.

But, you will have to downconvert to SD, thus some of the quality will be lost.

If you do use the nanoFlash, I would recommend recording in ".MXF" or ".MOV" depending on (generally) whether or not you will be editing on a Mac.

Garrett Low
October 14th, 2011, 08:41 PM
Hi Ian,

I don't shoot football games, but I do use a nanoFlash with my EX3 to shoot theatrical shows. I would imagine for the fast movement in Football you would see an improvement if you could use the I-frame only mode. It does mean you have to have some pretty big media but there is a noticeable improvement in the motion and color. I shoot everything in HD and downres for DVD's as well as offer BR's.

-Garrett

Ian Thomas
October 15th, 2011, 03:40 PM
Thanks Garrett

What mbps do you sett the nano in iframe for the best results

thanks
Ian

Dan Keaton
October 15th, 2011, 05:30 PM
Dear Ian,

Here are the nanoFlash bit-rates that I recommend, in order of increasing quality.

50-Mbps Long-GOP
80-Mbps Long-GOP*
100-Mbps Long-GOP*
140-Mbps I-Frame Only
180-Mbps I-Frame Only
220-Mbps I-Frame Only
280-Mbps I-Frame Only

* Note: Not recommended for older versions of Avid.
The current version of Avid supports all of the above.

Please note that 100 Mbps I-Frame Only is an option that I do not recomment using.

All of the above are 4:2:2.

18 and 35 Mbps Long-GOP are 4:2:0.

For Broadcast 50 Mbps Long-GOP is prefered by many networks.

100 Mbps Long-GOP is superior and a great choice for high quality footage.

For the ultimate in quality, use 280 Mbps - I-Frame Only, but you need a card that supports this high bit-rate.

Billy Steinberg
October 15th, 2011, 06:50 PM
Hi Dan,

Have you done any evaluating on what I-Frame only bit rate compares favorably with the quality of the 100Mb Long GOP? Is 140MB or 180Mb I-Frame enough?

Billy

Dan Keaton
October 15th, 2011, 07:04 PM
Dear Billy,

We used the Visual Clarity system to test all of our bit-rate / codec options.

If I remember correctly, 140 I-Frame was just slightly higher in quality than 100 Mbps Long-GOP.

The difference was very minor.

I am getting ready for a trip. I am sorry by I do not have time to research the numbers.

Billy Steinberg
October 15th, 2011, 08:59 PM
Thanks Dan, have a nice time in Boston.

Your mention of "Visual Clarity" rang a bell, and a forum search turned up the info (and chart) you were thinking of. For others that are interested, click here (http://www.dvinfo.net/forum/convergent-design-nanoflash/476796-video-quality-vs-bit-rate.html) to open a new tab with the thread (from a year and a half ago).


Billy

Dan Keaton
October 16th, 2011, 06:01 AM
Dear Billy,

Thank you for finding that post.

Adam Letch
October 16th, 2011, 06:19 PM
Hi Dan,

I note you stated 80mbps, and I remember probably at least 6mths ago people were requesting a bit rate between the 50 and 100mpbs long gop. Does that asterix mean its not implemented yet? Or has it been included.
Would be great to extend record time over the 100mpbs, but still have higher quality over the 50mpbs. Does a odd bitrate confuse NLE's? Or do they just handle it in the same way as 50 or 100?

Thanks

Kind Regards

Adam

Garrett Low
October 18th, 2011, 10:08 PM
Hi Ian,

The best results are definitely 280Mbps. But to gain just a little more time from my 64GB cards when shooting I-Frame I use 220Mbps. The loss in quality is very small and for most types of shots it is almost not even noticeable. I've also shot I-Frame only as low as 180 but there the loss is pretty noticeable.

-Garrett

Dan Keaton
October 19th, 2011, 08:15 AM
Dear Adam,

Yes, we implemented 80 Mbps some time ago.

It is included in our current release, 1.6.248.

The "*" indicated that it may not be supported in older Avid releases.

Ian Thomas
October 19th, 2011, 02:13 PM
thanks everybody
Garrett how long does your 64mbs card last at 220mps I-frame

Dan Keaton
October 19th, 2011, 08:45 PM
Dear Ian,

This link should help:

Media for nanoFlash | Convergent Design (http://www.convergent-design.com/Products/nanoFlash/nanoFlashMedia/tabid/1842/Default.aspx)

Garrett Low
October 20th, 2011, 01:07 AM
Ian,

The listing that Dan linked to is pretty accurate. I usually don't let the cards fill completely up, not because that would be a problem but because I usually want to start offloading at an opportune time. But, I usually go just a little over 30 minutes on my 64GB cards and they are just about full.

-Garrett

Ian Thomas
October 20th, 2011, 02:21 PM
Thanks Dan +Garrett

Garrett is it the better pic you get 220mps or what other reason do you use this high bitrate for

Garrett Low
October 21st, 2011, 01:44 PM
Ian, it could be psychosomatic but I think there is a quality improvement at 220 over 180. I have no hard testing data to prove it but I suppose a few quick shots of charts would prove it one way or the other.

-Garrett