Dual Link HD-SDI

[Douglas Call]

Originally Posted by Dan Keaton

Dear Douglas,

The Flash XDR is a wonderful recorder, we are just not currently manufacturing it.

Wow, I guess the Flash XDR just never quite took off or else you would have been manufacturing the new and and improved model b and c etc. It's probably because everyone is concerned about weight and size. Since you can mow buy 64GB CF cards and soon 128GB cards it sort of eliminates the need for 4 slots. I understand why videographers would want to keep the sound recording in their actual shooting camcorders viewfinder. it's important to be able to monitor both the sound levels and zebra's and other indications at all times. at least it was important to me. I did lots of interviews though.

[Dan Keaton]

Dear Douglas,

The Flash XDR has a two-channel analog audio output.

This allows one to take two-channels of XLR audio into the no-compromise audio circuits of the Flash XDR, process and record it ass 24-Bit / 48K, then send it to the camera inputs so that a redundant recording can be created simultaneously.

Thus you can monitor audio levels in your viewfinder.

To do this just requires a 5-Pin XLR to two 3-Pin XLR audio cable.

While the Flash XDR was the smallest, lightest, lowest power professisonal HD/SD recorder/player when we introduced it, many felt that it was too big for them.

Thus, we worked hard to build the second generation nanoFlash which is 40% the size of the Flash XDR, uses less power, and has HDMI inputs and outputs.

When the Flash XDR was designed, the maximum size CompactFlash card was 16 GB's.

Now, much faster 64 GB cards are available at lower prices and 128 GB cards are being promised soon.

With two 128 GB cards, the nanoFlash will be able to record Broadcast Quality (Sony PDW-F800 XDCAM 50 Mbps Long-GOP Quality) for 10.6 hours uninterrupted.

Or 14 Hours Sony XDCAM EX quality, or 2 hours using our 280 Mbps maximum quality mode.


The nanoFlash also offers analog audio inputs, one channel balanced mic/line, or two channels of unbalanced mic/line, which are processed as 24-Bit / 48K, and a two channel headphone/line output which can be used to feed manay cameras.

[Douglas Call]

I guess the uncompressed data rate for 1080p @ 60fps 4:2:2 color space is around 1.5Gbs/sec and the uncompressed data rate for 3G-SDI (1080p @ 60fps, color space 4:4:4) is around 3Gbs/sec. Will Convergent Design be coming out with a nanoflash unit capable of handling the 3G-SDI interface or dual-link SDI with a recording time of about 60 minutes at some point?

[Mark Job]

Originally Posted by Dan Keaton

Dear Douglas,

The Flash XDR has a two-channel analog audio output.

This allows one to take two-channels of XLR audio into the no-compromise audio circuits of the Flash XDR, process and record it ass 24-Bit / 48K, then send it to the camera inputs so that a redundant recording can be created simultaneously.

....Yup. When you say "no compromise," then you mean no compromise - The audio quality is beyond superb in the flash XDR from analogue sources. There is abundant headroom, which helps one obtain very hot voice signals for interviews without fears of digital audio distortion on the top end of voice inflexions.

Originally Posted by Dan Keaton

Thus you can monitor audio levels in your viewfinder.

To do this just requires a 5-Pin XLR to two 3-Pin XLR audio cable.

Dan I need to get this cable.

Originally Posted by Dan Keaton

While the Flash XDR was the smallest, lightest, lowest power professisonal HD/SD recorder/player when we introduced it, many felt that it was too big for them.

....The footprint is the only possible negative I can see with the XDR.

Originally Posted by Dan Keaton

Thus, we worked hard to build the second generation nanoFlash which is 40% the size of the Flash XDR, uses less power, and has HDMI inputs and outputs.

..I have not found the Flash XDR to be much of a power drainer in any way. I use it with the Anton Bauer Elipse battery, and this little battery powers the XDR without compromise for an entire working day on the set.

Originally Posted by Dan Keaton

When the Flash XDR was designed, the maximum size CompactFlash card was 16 GB's.

Now, much faster 64 GB cards are available at lower prices and 128 GB cards are being promised soon.

With two 128 GB cards, the nanoFlash will be able to record Broadcast Quality (Sony PDW-F800 XDCAM 50 Mbps Long-GOP Quality) for 10.6 hours uninterrupted.

....Surely, you folks at CD must have known the storage capacity of CF media would only gradually increase in size ? Now multiply your calculations times four and you have close to one day (As in 24 hours) of continuous recording time. In fact, with 4 x 64 GB cards now available, and with 128 GB cards sure to arrive shortly, why is there even a need to eject media ? (Or shall I say shoot them across the room or out the window as I did the other day ! ;-) Ha ! Ha ! He ! He ! It wasn't raining, I was on the first floor, and the sidewalk of the gallery where I was shooting was clean and dry) - Just leave the CF cards in the recorder and plug them in via FireWire and let the Nano/XDR emulate a hard drive. With Avid Media Composer or Avid News Cutter, this would allow you to directly AMA a Nano Flash to the workflow in the field for news gathering or doc download, then back on the camera and format and shoot again. Sorry, about the big programming that would take Tommy :-) Dan, could you imagine the selling point of a nano or an XDR if you could directly AMA the device to the workflow in the field via FW I/O and a freakin laptop !?!?!? Heck, you wouldn't even have to remove the Nano or the XDR from camera piggy back, just connect it in the field to a tablet sized laptop talking to the news van or micro wave via Bluetooth and you're in !

Originally Posted by Dan Keaton

Or 14 Hours Sony XDCAM EX quality, or 2 hours using our 280 Mbps maximum quality mode.

....Or 25 minutes with 4 x 64 GB CF cards in uncompressed mode in Raid 0 :-) Would think you might get close to 60 minutes with 4 x 128 GB Cf cards striped in Raid 0 (??)

[Dan Keaton]

Dear Mark,

Yes, we expected the CompactFlash cards to increase in size and get lower in cost.

At one point we were able to get a quality 300x Read Speed, 133x Write Speed, 32 GB card for under $70. This card worked up to 100 Mbps in the Flash XDR and nanoFlash.

But, if one steps back for a minute, it is quite a technological feat to have 64 GB or 128 GB CompactFlash cards for a few hundred dollars.

I am very happy that you are pleased with the audio quality of the Flash XDR. We did our absolute best to make the audio subsystem great.

The audio in the nanoFlash is also very good, but it does not have 65 dB of gain like that Flash XDR does, it only has 44 dB of gain. Of course, this is enough gain for most purposes.

I will check on our stock level for the cable you requested. We can certainly custom build one for you if we do not have it in stock.

[Dan Keaton]

Originally Posted by Douglas Call

I guess the uncompressed data rate for 1080p @ 60fps 4:2:2 color space is around 1.5Gbs/sec and the uncompressed data rate for 3G-SDI (1080p @ 60fps, color space 4:4:4) is around 3Gbs/sec. Will Convergent Design be coming out with a nanoflash unit capable of handling the 3G-SDI interface or dual-link SDI with a recording time of about 60 minutes at some point?

Dear Douglas,

The current nanoFlash is not designed to accept HD-SDI at 3G, nor is it designed to handle 4:4:4 or 60 fps, or dual-link HD-SDI.

I am sorry, but it would be inappropriate for me to speculate on what we might dream up in the future.

I can say that if we start work on such a product it would take us many months to bring it to market. The nanoFlash is a very complex product.

[Billy Steinberg]

Originally Posted by Douglas Call

I guess the uncompressed data rate for 1080p @ 60fps 4:2:2 color space is around 1.5Gbs/sec and the uncompressed data rate for 3G-SDI (1080p @ 60fps, color space 4:4:4) is around 3Gbs/sec.

Nope. 1080p 4:2:2 @60fps is 3Gb/s. 1080p 4:4:4 @60fps is 4.5Gb/s.

Note that just specifying 3G-SDI (or dual link SDI) doesn't tell you what the frame rate, frame size, or color space is, (and dual link or 3G SDI won't handle 4.5Gb/s).

Billy

[Douglas Call]

Originally Posted by Billy Steinberg

Nope. 1080p 4:2:2 @60fps is 3Gb/s. 1080p 4:4:4 @60fps is 4.5Gb/s.

Note that just specifying 3G-SDI (or dual link SDI) doesn't tell you what the frame rate, frame size, or color space is, (and dual link or 3G SDI won't handle 4.5Gb/s).

Billy

Yes I hear you on that. Although in calculating the approximate bandwidth required in MB/sec it appears that 3Gb/s is around 375MB/s. So are there any external portable (relatively light battery operated) recorders that will support the 3Gb/s rate?

[Douglas Call]

Originally Posted by Dan Keaton

Dear Douglas,

The current nanoFlash is not designed to accept HD-SDI at 3G, nor is it designed to handle 4:4:4 or 60 fps, or dual-link HD-SDI.

I am sorry, but it would be inappropriate for me to speculate on what we might dream up in the future.

that sounds reasonable. I'm sure the NanoFlash is a marvel of engineering. It's probably more than sufficient for my needs I guess testing will tell. 1080p @ 60fps will probably just give you sharper individual frame images (with less motion artifacts). I'm sure it's benefit will be in more action oriented sequences like water & snow skiing or intense fast movement dances and other action oriented sequences.

[Dan Keaton]

Dear Douglas,

The nanoFlash and Flash XDR are great, in my humble opinon, by not creating motion artifacts.

When you use 100 Mbps Long-GOP or above you can be very confident that there will not be too much detail or motion in the scene or camera motion which would result in artifacts.

If you have an exteme amount of detail, an extreme motion in a scene, and excessive camera motion, I would recommend 140 Mbps Long-GOP.

Of course or higher bit-rate I-Frame Only modes are good also.


Background: The Flash XDR which records the same as the nanoFlash was used in a carefully controlled test to check for artifacts.

One of our users shot the Houston Marathon using 100 Mbps Long-GOP.

25,000 runners, colorfully dressed, with lots of motion in the image, as runners tend to move up and down while running, were coming towards the camera.

This qualifies as lots of detail in the image and lots of motion in the image.

The camera was mounted on the back of a moving pickup truck.

The camera also had up and down motion as well as occassional side to side motion.

In normal playback speeds, no artifacts could be detected.

In detailed frame by frame analysis of the long recording, two artifacts were found.

Since that test, we added high bit-rates would have eliminated these two artifacts, in my opinion.

[Dan Keaton]

Originally Posted by Douglas Call

Yes I hear you on that. Although in calculating the approximate bandwidth required in MB/sec it appears that 3Gb/s is around 375MB/s. So are there any external portable (relatively light battery operated) recorders that will support the 3Gb/s rate?

Dear Douglas,

With todays solid-state recording media, allowing for some bandwidth headroom, I know of none that support 375 Megabytes per second, on a continuous basis.

If one needed to design such a recorder, it would have to be designed to write to multiple media devices in parallel, which is certainly possible.

And to answer your specific question, I am not aware of any device under $10,000 that does what you want. Of course, I am be overlooking some device.

[Douglas Call]

Originally Posted by Dan Keaton

Dear Douglas,

When you use 100 Mbps Long-GOP or above you can be very confident that there will not be too much detail or motion in the scene or camera motion which would result in artifacts.

If you have an exteme amount of detail, an extreme motion in a scene, and excessive camera motion, I would recommend 140 Mbps Long-GOP.
Of course or higher bit-rate I-Frame Only modes are good also.

Dan I guess when you were talking about the 100/140Mbps Long-GOP bit-rate you were referring to shooting at a 1080i @60fps? If so I'm not sure what class (vendors) camcorder I need for that bit-rate. I more familiar with the P2 doing I think up to 100Mbps but I'm not sure what camcorder does the upto 140Mbps bit-rate in the 1080i @60fps. It sounds like if you could put the 140Mbps camcorder with 4:2:2 color space in a hand holdable pro camcorder configuration then I would be able to handle any situation I might encounter on location. I would like to get away from on shoulder camcorders. I'm just to old to lug around a 17lb camera (sometimes more once you put your on camera light, IDX batterie(s) and wireless microphone receiver(s) on the unit :-) The other thing is finding one that does all this and can record to solid state media!

[Dan Keaton]

Dear Douglas,

With the nanoFlash and Flash XDR, when you select a certain bit-rate in our menu, then that is what you get, regardless of the frame rate.

Thus 1080i60, 1080i59.94, 1080p30, 1080p29.97, 1080p24, 1080p23.976, and 720p60, 720p59.94, etc. will give you 100 megabits per second if that is what you selected in the menu.

Most other recorders do not do this, and the effective bit-rate is reduced for certain frame rates.

There is one special case where we convert 720p60 to 720p30 or 720p50 to 720p25. We eliminate the duplicate frames after it has already been encoded, but this is easily compensated for by selecting a higher bit-rate in the menu.

The class of camera or camcoder is not an issue if it has HD-SDI or HDMI outputs.

The encoding to the desired bit-rate is done in the nanoFlash or Flash XDR, not in the camera.

Yes, if you put a nanoFlash on most any camera or camcorder with a HD-SDI or HDMI output you can successfully record almost any level of detail, or motion in the scene, or camera motion.

While you stated that you want to find a camcorder with this high level of functionality and high bit-rate built into a camcorder, I do not think you will find one. That is one of the reasons why we built the nanoFlash.

Of course if you want to spend a lot of money, you can find high-end cameras that have built-in high-bit rate recorders built in. The Sony SRW-9000 or SRW-9000PL come to mind. For these two specific cameras, while they can record internally, the nanoFlash is a Sony recommended accessory, as the nanoFlash makes an ideal Proxy recorder for these high-end cameras.

If you are familar with using a P2 camera with DVCPro HD, you are in for a very pleasant surprise.

The nanoFlash's 100 Mbps Long-GOP is superior to DVCPro HD and the workflow is easier.

[Aaron Newsome]

In addition to XDR, I also have a cinedeck extreme. It does support 3Gb/s HD-SDI. I bought it mostly because I wanted the option to do 4:4:4 uncompressed but I never do it. Too much data. I record mostly Cineform 4:4:4 maximum bit rate to SSD. Cinedeck also records uncompressed, ProRes 422 and 4444 as well as Avid DNxHD.

Dan hit the nail on the head though with the "under $10,000" comment. The cinedeck is at least twice the price of the XDR and near three times the price of the nano. These units should not even be compared, they're aimed at completely different markets.

There are only a handful of cameras that offer 4:4:4 output at all. They are all high end.

If you have a 4:2:2 10 or 8bit camera, you're probably not considering a cinedeck extreme which likely costs more than your camera did. A nano flash is probably a much more sensible choice.

[Douglas Call]

Originally Posted by Aaron Newsome

In addition to XDR, I also have a cinedeck extreme. It does support 3Gb/s HD-SDI. I bought it mostly because I wanted the option to do 4:4:4 uncompressed but I never do it. Too much data. I record mostly Cineform 4:4:4 maximum bit rate to SSD. Cinedeck also records uncompressed, ProRes 422 and 4444 as well as Avid DNxHD.

Dan hit the nail on the head though with the "under $10,000" comment. The cinedeck is at least twice the price of the XDR and near three times the price of the nano. These units should not even be compared, they're aimed at completely different markets.

There are only a handful of cameras that offer 4:4:4 output at all. They are all high end.

If you have a 4:2:2 10 or 8bit camera, you're probably not considering a cinedeck extreme which likely costs more than your camera did. A nano flash is probably a much more sensible choice.

We'll it definitely sounds like NanoFlash is the way to go. I can get a Nanoflash for around $3K and a couple of 64GB compact Flash cards for around $1K. So basically I can be recording high quality video directly from the cameras HDMI or SDI output for around $4K (approx.).

Although I do recall that some of the camcorders discussed in the various forums on this website (which include SDI & HDMI connectors) don't necessarily pump the 1080x1920 video across to the HDMI or SDI outputs. I also recall reading that some of them don't pump the sound across either. I know we have to be extremely specific now days and you can't be to careful. I was looking at the Canon XF305 as the right camera for my needs but I guess I'll have to read the specs carefully to make sure it or one of the new Sony camera's with SDI support what I need for the Nanoflash out of the SDI/HDMI connector.