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Convergent Design Gemini, one month on.

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I’ve been testing and using a Gemini with my S-log equipped PMW-F3 for a month now and I have to say that every time I use the combo the image quality amazes me.

The Gemini firmware has been updated many times in that month, but I can report that the latest release is nice and stable and delivering the goods. The gemini is remarkable easy to use, the on screen menus are clear and concise. Talking of the screen the LCD is very good indeed. It is clearly visible even in bright direct sunlight. I’ve also been using some other external recorders with screens and the Gemini stands out as a clear winner in this regard.

Power consumption is very good. I’m using Swit 86U batteries with a D-tap to power both the F3 and the Gemini and I get around 2 hours from a fully charged battery. This keeps the size and weight of the rig very manageable, no need to upgrade my tripod or use special mounts for the Gemini, it sits very nicely on the F3’s handle. You can still use the full kit handheld without needing to use a shoulder mount or wear the recorder in a rucksack or similar.

Now.. there are some important things to consider with the Gemini. It is a high end production tool at a low end price. You do get high end, beautiful image quality and you get the same kind of files as you’d use for high end movies and commercials. These DPX files are basically sequences of uncompressed still frames. If you are considering the Gemini you do need to think about your workflow. You will be generating some damn big files, 750GB per hour and that presents a few issues.

Don’t expect to transfer your material to a laptop hard drive in real time. The Gemini uses ultra fast SSD’s because regular hard drives are not fast enough for 444 uncompressed data, so you just won’t get real time uncompressed copies to a laptop drive. It’s taken me up to 3 hours to copy an hour of footage to a fast single hard drive. If you want real time or faster transfers of uncompressed 444 (from ANY device) then your going to want a nice big, fast, raid array, that’s just a fact of uncompressed life.
One option with the Gemini is to convert your files to a compressed codec as you transfer from the SSD’s. This can actually end up faster than doing a straight copy as with a fast computer the material can be pulled of the SSD quickly, encoded and then the more compact file written to a conventional hard drive. For this to be effective I recommend at the very least a dual core i5 2.3Ghz machine. For current model MacBook and iMac users you will be able to use the Sonnet Echo Express thunderbolt to express card adapter along with a Sonnet Express34 to dual eSata adapter to get fast transfers (available December).
I’ve been transcoding to ProRes 4444 and the results are superb. Avid Media Composer 6 now includes a 444 codec but I have not tested this yet. My i7 iMac will encode from uncompressed to ProRes 444 at around realtime speeds.
Another thing you must consider is that because DPX is a stills sequence, there is no audio. At the moment the Gemini does not record audio, so I record both in camera with audio plus the DPX files on the Gemini. It’s pretty straight forward to sync them up in post. There will be a firmware update in the future to add audio recording to the Gemini, so this is just a temporary issue.

So, being realistic about things. The Gemini 444 is a great device. It’s uncompressed so the image quality is fantastic. But you must consider that this is a very high end uncompressed recorder and with any uncompressed HD recorder you will end up with big files. I won’t be using the Gemini for everything I do, the workflow doesn’t suit fast turnaround productions and frankly it’s overkill for web videos etc. But when quality is paramount the Gemini truly excels, performing as well as devices costing many times more, yet offering one of the best LCD’s, very low power and it is a featherweight in comparison to some of the other external brick recorders.

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Can you see the difference between a 8 bit and 10 bit camera output?

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The question is can you see a difference between a camera with a 10 bit output and one with an 8 bit output? This is being asked a lot right now, in particular in relation to the Sony FS100 and the Sony F3. The FS100 has an 8 bit output and the F3 is 10 bit.

If your looking at the raw camera output then you will find it just about impossible to see a difference with normal monitoring equipment. This is because internally the cameras process the images using more than 8 bits (probably at least 10 on the FS100, the EX3 is 12 bit) and then convert to 8 or 10 bit for output so you should have nice smooth mapping of graduations to the full 8 bit output. Then consider that most LCD monitors are not able to display even 8 bits. The vast majority of monitors have a 6 bit panel and even a rare 8 bit monitor wont display all 8 bits as it has to do a gamma correction at 8 bits and this results in less than 8 bits being displayed. 10 bit monitors are very rare and again as gamma correction is normally required there is rarely a 1:1 bit for bit mapping of the 10 bit signal, so even these don’t show the full 10 bits of the input signal.  So it becomes apparent that when you view the original material the differences will not normally be visible and often the only way to determine what the output signal actually is is with a data analyser that can decode the HDSDi stream and tell you whether the 2 extra bits actually contain useful image data or are just padding.
Where the 8 bit, 10 bit difference will become apparent is after grading and post production. I wrote a more in depth article here: Why rendering form 8 bit to 8 bit can be a bad thing to do. But basically when you start manipulating an 8 bit image you will see banding issues a lot sooner than with 10 bit due to the reduced number of luma/color shades in 8 bit. Stretch out or compress 8 bit and some of those shades get removed or shifted and when the number of steps/shades is borderline to start with if you start throwing more away you will get issues.

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Updated notes for FS100 – F3 Video Review.

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To see the video scroll down to the next blog entry.

The main aim of the shoot was to see how the FS100 held up against the F3. We shot on a bright sunny day by the River Thames and again in the evening in a typically lit living room. There were no big surprises. The FS100 is remarkably close to the F3. You would have no problems cutting between the two of them in a project.
I did find that the FS100 LCD appeared less sharp and not quite as good as the F3’s even though they both use the same underlying panel. This is probably down to the additional layers required for touch screen operation on the FS100. I also did not like the 18-200mm f5.6 kit lens. There was too much lag in the focus and iris controls, but the beauty of this camera is that you can use a multitude of lenses. For the evening shoot I used a Nikon 50mm f1.8 which was so much nicer to use. On reviewing the footage I did find that we were tending to over expose the FS100 by half a stop to a stop, this does make making accurate comparisons difficult and I apologise for this. I believe this was down to the slightly different images we were seeing on the LCD’s. I did use the histograms on both cameras to try to ensure even exposure, but even so there is a difference. A small part of this is also likely down to the very slightly different contrast ranges of the two cameras.
Oe thing we discovered, not mentioned in the video is that when you use a full frame lens, like the Nikon 50mm. You must ensure that the E-Mount adapter you use has an internal baffle or choke. If it doesn’t you will suffer from excessive flare. The adapter I had did not have a baffle and some shots (not used) were spoilt by flare. The adapter I have from MTF for the F3 has a baffle as do MTF’s E-Mount adapters, so these should not suffer from this issue.
The FS100 performance is so very close to that of the F3’s (at 8 bit 4:2:0, 35Mb/s) that it is hard to tell the two apart. I believe the F3’s images are just a tiny bit richer, with about half a stop more dynamic range, in most cases it takes a direct side by side comparison to show up the differences.
The range of camera settings and adjustments on the FS100 is not quite as extensive as on the F3, nor do the adjustments have such a broad range. However there is plenty of flexibility for most productions.
If you don’t need 10 bit 4:2:2 then it is hard to justify the additional cost of the F3, both cameras really are very good. Despite some other reports else where I felt the build quality to be very good and the buttons, while small, are big enough and well placed. If you do want autofocus then you will be pleased to know that it actually works pretty well on the FS100 with only minimal hunting (of course you must use an AF compatible lens).
I did also record the HDMI output to one of my NanoFlashes at 100Mb/s. Comparing these side by side it is extremely hard to see any difference. It is only when you start to heavily grade the material that the advantage of the higher bit rate Nanoflash material becomes apparent. There is less mosquito noise in the NanoFlash material. I was really impressed by the AVCHD material. The lack of noise in the images really helps.
The FS100 really is the F3’s little brother. The pictures are remarkably close, which they should be as they share the same sensor. The FS100 packs down into a remarkably small size for transport. The loan camera from Sony was actually packed in a case designed for the MC1P mini-cam, about 15″x10″x5″ so very compact indeed. The F3 is considerably larger and bulkier, in part due to the extra space taken up by the built in ND filters.
The lack of ND filters does need to be considered. There are some clever solutions in the pipelines from various manufacturers as well as existing solutions such as vari ND’s, screw on ND’s and a Matte Box with ND’s, so it’s not a deal breaker
I think there is every chance that the FS100 will be the first NXCAM camera that I will purchase. It will be a good companion to my F3. It’s modular design will allow me to get shots that are not possible with the F3. I felt that the FS100 (with the 18-200mm lens that I don’t like) was better suited to “run and gun” than my F3 with either manual DSLR lenses or PL glass. You can, with the FS100 simply point the camera at your subject and hit the one push auto focus and auto iris and have an in-focus, correctly exposed shot. This is much more like a traditional small sensor camcorder in this respect. The long zoom range also makes this more like a conventional camcorder, although there is no servo for the zoom.

In conclusion, in my opinion, for “run and gun” or quick and dirty setups the FS100 with the 18-200mm lens has an edge over the F3 due to the fast auto focus and auto iris one-push controls. For more precise work and shallow DoF your going to want a different lens, something with manual control and calibrated focus and iris scales. For more demanding shoots then the F3 is probably the better choice with it’s slightly improved dynamic range and the ability to use S-Log and 4:4:4. In either case these cameras can produce highly cinematic pictures and I see no reason why you could not shoot a great looking feature with either.

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Sunrise Over The Hudson

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Well, I’m now in New York preparing to introduce some of our potential dealers to the Genus Hurricane Rig. I’m going to be spending some time with the guys at ZGC and Abel Cine showing them how the 3D rig works and what it can do before heading down to LA for ShowBiz Expo later in the week. Our hotel overlooks the Hudson river and Manhattan so I could not resist the opportunity to shoot the sunrise this morning. Apart from anything else I’m jet lagged so was up at 4am!! The video was shot with my trusty EX3 at 1 frame every second, sped up to x400 in FCP. I used the TLCS controls to limit the maximum gain to +6db and to introduce shuttering when the iris gets to f11. This helps deal with the huge changes in light levels. Now I know where the sun appears I might re do this later in the week, centered on the sun. Hope you like it.

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Vapour: The Sky in motion.

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The last couple of days provided some really spectacular skies with amazing vapor trails and fluffy clouds. So I grabbed a selection of cameras and shot a bunch of timelapse which you can see cobbled together in this clip. I used a Sony PMW-350 and a Canon 350D and 550D. Amazing how well they match after a quick grade. I also included an previously un-used Aurora shot from Iceland at the end. The name of the clip comes from the fact that clouds are made of water vapor and ice crystals.

You can also watch it in HD on Exposure Room.

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How I shoot the Northern Lights

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Well I have just returned from Iceland where I held a couple of 3D stereoscopic master classes and a workshop on video for the internet. They went well and we all had fun despite almost a foot of snow fall the morning of the classes. On the last day of my trip I decided to try and get some more Northern Lights footage. As I am often asked how I do this I put together the clip below which explains what settings I use for the Aurora and also gives a brief description of S&Q on an XDCAM EX. Basically what I do is use the EX Slow Shutter at 32 or 64 frames to increase the sensitivity of the camera. For a dim Northern Lights display I use 64 frames but for a bright display I drop down to 32 frames. The slow shutter acts like a long exposure on a stills camera. I then combine this with interval record shooting at 1 frame every second. I did also have a Canon DSLR with me and tried to shoot the Aurora with that. I found I needed a 10 second exposure at 800 asa to get a similar result to that achieved with the EX. The 10 second exposure means that it would take longer to get a decent length video sequence and most of the motion of the Aurora would be lost. Some of the exposure difference was I admit to the slower F4 lens on the Canon compared to the Sony EX’s F1.8, so perhaps with a faster lens you could bring the exposure down to around 5 seconds and this is something I hope to try when I go Aurora chasing next winter.

If you watch the video make sure you stay to the end to check out my attempt to record a piece to camera in 60 mph blowing snow! Don’t know why I even thought it would work. What I will say is that my new Vinten 5AS did a great job of keeping the camera steady in some pretty extreme conditions.