Pros and Cons of Solid-State and the EX1
I have recently been planning the introduction of my students at the
International film School Sydney to Solid-State workflow with the Sony EX1.
One issue fundementally driving the contemporary cinema industry of late is its diversity - diversity of acquistion, diversity of process, diversity of delivery. And in this evolution we are at last beginning to shake off hierachical perceptions in favour of parralel ones. In simple terms, there's no Best choice, only the Best choice for the project. The idea of developing a Workflow for the project is now a crucial creative process because the diverse array of options can all impact upon creative outcomes.
So it's in this light that we have introduced solid-state workflows and have to teach to our students to make informed and considered decisions about their workflow in concert with its creative imperatives. What follows are some of the notes Ive been putting together on the basic Pros and Cons of solid-state.
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Overview:The digital recording of moving images to memory cards rather than traditional digital tape represents the future of digital cinema for great many forms of production. This type of recording is known as 'solid-state' as it involves no moving parts and the 'footage' is written directly as digital files immediately readable by a computer.
Solid-State is not just a different way to record cinematic media but rather it represents an entirely new way of conceiving and managing the production process.
There are many advantages to Solid-State recording but there are also significant drawbacks. The resistive impact of these Pros and Cons will be determined by the needs and demands of the particular production in question.
There is no 'best' format, only the best for the needs of your particular production. So it is important to weigh up carefully what your production requires before deciding on a format. Solid-State may be the prefect format or it may bring significant obstacles
The XDCAM EX Format:XDCAM EX is a new variation of Sony's long standing XDCAM format. Where as XDCAM records to optical disc media (known as ProDiscs which are effectively BluRay discs in a hard case) XDCAM EX is designed specifically for Solid State memory.
XDCAM EX is recorded to special memory cards known as 'SxS'. These cards use the ?Xpress Card 3/4' slot which is common on most higher-end laptops such as MacBookPros.
XDCAM EX is capable of supporting a range of HD resolutions and frame rates:
1280x720 - 24p, 25p, 50p
1920x1080 - 24p, 25p, 50i
What is most significant about XDCAM EX is that it shoots 'full raster HD' 1920x1080. This means there is No anamorphic stretch on the pixels unlike HDV which shoots 1440x1080 and stretches the Pixels by a Pixel Aspect Ratio (PAR) - of 1.333:1. The advantage of this is an image with greater fidelity and sharpness.
XDCAM EX uses the same Mpeg2 codec as HDV but at a much higher bitrate of up to 35mbps to HDV's 25mbps. This results in a much richer and sharper image that is more robust for post production manipulation.
PROS of Solid State on the EX1:- Non-Linear file access
Each individual shot can be accessed, reviewed and played back in camera. Likewise individual shots can be deleted without effecting any others. There is no continuous timecode as there is with tape so there is no such thing as broken timecode often cased by in-camera reviewing. Shots can also be individually tagged and managed in camera.
- Fast Transfer
The SxS memory cards have very fast transfer speeds meaning footage can be copied from card to computer in 1/4 time (1 hour of footage takes approx 15mins to transfer)
- XDCAM Browser
A dedicated piece of software for XDCAM formats allows for individual shots to be efficiently tagged, logged, annotated, and managed much more effectively than traditional tape logging.
- No tape Problems
No tape wear, no spooling issues. No mis-aligned recording heads. No timecode breaks.
- Immediate recording
Solid State recording starts immediately the moment you press the REC button. No delay as the tape spools or the recording head is engaged; recording starts immediately with almost zero delay.
CONS of Solid State on the EX1:- There is no source master
With XDCAM EX there is no tape to put on the shelf as a backup of your footage. SxS cards are too expensive and not designed as a long-term storage media. After shooting all footage must be copied to hard drive and the cards erased to be used again. This means the only copy of the footage is on hard drive which is more fragile than a tape. It is crucial that you engage careful and thorough back-up procedures of your footage to guard against data loss.
- Short Record Times
Where as digital tape is cheap and plentiful, SxS memory cards are expensive and limited in number and capacity. The EX1 can take 2 memory cards at a time. At 8gb per card this will allow for approx 50mins of record time together. However having two cards means one can be removed and its footage transferred to a laptop computer on location whist continuing to shoot with the other card.
- NLE compatibility
Currently not all editing software systems are compatible with XDCAM EX. Final Cut Pro is fully compliant but Premiere Pro is not; you will not be able to import or work with XDCAM EX footage in Premiere. This should only be short term and it is expected Premiere will be XDCAM EX compatible in the coming year.
Posted at 01:00AM Apr 09, 2008
by Mike Jones in video |
I don't know that id use the phrase "much higher data rate" when comparing 35mpbs to 25 mbps. In fact considering that it is actually doing 1920 instead of 1440, there's a lot more resolution to cover which effectively soaks up that increased headroom.
I haven't shot with the camera, but I detest the HDV format. It's great only as long as you don't want to do something with the footage. As soon as you'd want to key it, grade it or layer it, you'll find it's limitations. I remain sceptical that this will be much of an improvement on the pretty mediocre HDV format. (not the camera, the codec)
It's such a shame that Sony insist on segmenting the market in the way they do.
The camera looks good otherwise, and I think you've covered the pro's and cons of data based capture.
It is worth reminding them that hard drives fail and that although it may seem to be faster to shoot this way because of reduced digitising time, you still need to actually watch your rushes generally before an edit anyway.
Meanwhile, you should be backing them up in a safe and redundant way. Anyone do that ?
Right now I am shooting a cooking show that is shooting with 2 cameras using P2. We take a WD RAID with us and backup every night off our cards. We can't always do this because of power limitations. And it's extra time for ME every night that I don't get paid for.
2 days ago I was 6 hours sailing up the Franklin river in Tasmania on a boat with no 240V. So I have to resort to a laptop with a USB powered drive. Not ideal for me and I always get a sort of sick feeling every time I format the cards.
jb
Posted by John Brawley on April 10, 2008 at 02:56 PM EST #
To criticize HDV is to criticize any production format that isnt 422 - XDCAM, DV, DV50, IMX, even HDCAMSR is 3:1:1. So is anything less than 422 or Uncompressed somehow not worthy or detestable?
The idea that you cant key HDV, grade or do stuff with it in post is simply not true and a very narrow perspective. shot well and handled well you can pull very respectable keys on HDV and you can do very effective colour grading. Sure its not 444 uncompressed but its highly effective and can produce excellent results. Use a lossless intermediate such as Cineform or ProRes and the end result can be even better.
28days later colour graded from DV. Gabriel colour graded from a HDV source. Both films look great. Sequences of Letters from Iwojima were shot with HDV and colour graded into 35mm seamlessly. Parts of hi-end TV dramas JAG, CSI and 24 all shot HDV and excessively colour graded. The argument that HDv cant be pushed around in post just doesn't hold up. It might not be a first choice or a best quality choice but it is a very viable professional choice pending budget and production needs.
As for the Ex1 it is far and away the best camera under $15000 ive ever used. 1/2" sensors and full raster HD more than make up for any drawbacks of 420 long gop. Its a Cinealta camera supplanted into a small form body but carrying all the pedigree.
This where ive always found the dvcprohd format of p2 so mis guided. sure is 422 intra but the native sensor is just 960x540 and uprezing and the anamorphic stretch is horrendous. Not to mention the absurd file sizes and short record times. I would argue that larger resolution and higher compression produces a more functional and flexible image than much lower native resolution and less compression.
As for XDCAM) it is a massive step up from HDV, not in the same league. It would be a major mistake to put HDv and XDCAM in the same category, worse still to dismiss them as somehow unworthy. XDCAM has been a great production format for a long time (and now has a 422 variant) XDCAMEX goes a step further than XDCAM by removing pixel aspect ratio stretch and producing a full raster 1920. Its a rich, robust codec structure with a great deal of visual fidelity. The detail it can retain right through post is astounding. Go and shoot with it and i feel confident you will be astounded.
When the Ex1 and the XDCAMEX format is compared side by side DVCPROHD from a HVX there is no comparison - clarity, fidelity and detail all go to Sony (not to mention record times and transfer speed -1hr/16gb and 1/4 real time transfer)). I think Panasonic have to seriously re-think their approach to solid-state because the gross inefficiency of P2/DVCPROHD along with the huge up-resing required to meet 1080 is more than apparent when compared side by side.
Now of course comparing XDCAM with Uncompressed or 35mm film is not apples to apples. But right now for low cost production I dont believe there is any better option. Big step up from HDV (which of itself I would argue is very good and very viable) and far superior to Panasonic's antiquated DVCPROHD. Panasonic are now in the scrambling process getting away from DVCPROHD, moving to AVCHD Intra and ditching the obsolete and slow p2 in favor of more generic memory cards. As they complete that process it will be interesting what they evolve into on the other side. But at the moment I really think its very hard to justify shooting any other solid state format. And given the choice between HDV and XDCAM EX the choice is obvious.
There may well be something better but nothing on the market right now.
Posted by Mike Jones on April 11, 2008 at 11:58 AM EST #
DV(50?) DVCPRO 50 is 4:2:2. IMX is 4:2:2. XDCAM can be 4:2:2. And none of those video formats are uncompressed. HDCAM SR is 4:2:2 or 4:4:4. Perhaps you're thinking of regular HDCAM 3:1:1 ? HDV and HDCAM and DV25/DVCPRO are the chroma challenged formats.
I have to disagree with you with regard to getting good key's and colour correction from HDV. While the keyer or grader *itself* may be able to operate more effectively with an intermediate format, how can you argue that there can be a better result when there is no additional data to source from ? My personal experience is that it is extremely limiting in terms of colour correction and relies on you getting it looking right at acquisition. Keying is something that general requires high precision. You may be able to get a reasonable key that many would be happy with within a few minutes. But to make it seamless takes a lot longer and is almost impossible with HDV. The same goes for colour correction. You can execute very basic correction, but to grab a secondary hue and separate it without it all turning to blocks is very very difficult.
I'd also say the same thing about HDCAM. It is a terrible format to grade from or work with in post. It looks good as long as you bake in the look and are happy to do that on set. Just because you *can* grade from chroma deprived formats doesn't mean you should. Listing a slew of productions that have used the format doesn't change the fact that it's a compromised format that is less than ideal.
I have no personal experience with the EX1 but by all accounts the camera itself is good. I also think you're linking P2 to the HVX 200/202 which has a lesser resolution chip, but there are other camera platforms that are P2 based which address the issue if native 1920 is required. Of course it's easy to trash P2 as being antiquated but it's been with us reliably since it's release in 2004.
As you say, the *native* resolution of the camera is not 1920, so I usually record in 720 25PN mode which gives good record times with the additional bonus of variable frame rate. And has done so for the last 2 years.
As a cinematographer my personal preference would be for less resolution with more colour depth. Sharpness and res isn't everything.
I wasn't trashing XDCAM EX, but questioning how much of am improvement it was over HDV. XDCAM / XDCAM HD of course is something else altogether.
I think all of these cameras deliver great results considering their cost. Obviously a production needs to be viable and costs vs quality is an important part of that equation. They are great for certain situations and I'm interested in seeing how the EX1 compares. But looking at the specs, it's hard to see how it can be a significant improvement over HDV.
jb
Posted by John Brawley on April 11, 2008 at 03:04 PM EST #
I stand corrected on IMX and Dv50. I was confusing DVCPRO which is 411 and I had thought IMX was based on 420 but have now been set straight. XDCAM 422 is brand new - havnt used it yet)
I wasnt suggesting any of these were uncompressed, in fact the opposite - I find it hard to buy into criticism of HDV and XDCAM because this is to effectively argue that anything less than 422 or Uncompressed is somehow not worthy?
Again with colour grading I point to those movies and TV shows mentioned - all engaged complex and stylized colour grading on 420 sources.
A 422 or 444 lossless intermediate does indeed give much improved results in grading and effects. Obviously you dont add in visual data that wasnt there in the shot but you do gain enormous headroom and colour space to process the grade and fx.
In the same way that grading in 32bit floating point space gives better results than traditional 8bit on the same material because the changes are processed in greater headroom its the same for shooting 420 as an aquistion format and grading in lossless intermediate 422 or 444 allows for smoother gradations, reduced banding and artifacts, smother and sharper results.
Everything you say is true about the limitations of compressed sources but only when compared to uncompressed or 35mm film sources. To dismiss HDV and XDCAM as detestable seems to me a rather verbose statement. Dare i say even 'snobbish' :)
HDV and XDCAM should be compared to peer formats and on a bang-for-buck basis. Because on that playing field the fact that they can also, when production demands, be spliced seemlessly into other higher end formats (as numerous films and Tv shows attest) shows them as a highly viable format.
On the basis of Quality, Bang for Buck and Efficiency no other format on the market is as good as XDCAM right now. So to view it as just another detestable variant of HDv is kinda wrong headed thinking to my mind.
You're dead right about 720p on the HVX, thats the much better way to go. And yes I was specifically referring to the HVX camera re P2 not larger more expensive P2 ENG cameras. The HVX is the only comparable camera to the Ex1 and there is no question in my mind that side by side and in any other test XDCAM on the Ex1 is a big leap forward. ANd this is both the camera AND the format.
I do find it very interesting your preference for colour depth over resolution (which is the very basis of Panasonics perspective for DVCroHD/P2/AVC Intra). An absolutely valid position that im sure you share with many other professionals - but I'd argue that both physiologically and aesthetically audiences respond to resolution more than colour. But i could be wrong.
Thanks for your thoughts.
Posted by Mike Jones on April 11, 2008 at 06:24 PM EST #
Well I guess that's what I am arguing. That generally speaking, 4:2:2 or better provides a minimum to be able to have enough room to manipulate the image in post. I have shot on way less, and i think it's a bit simplistic to describe my view as snobbish. I've shot films with a mobile phone despite pleading from post production supervisors to shoot with a more robust format that could be later degraded. We tested it out to 35mm and nothing looked as *true* as the stuff that was ACTUALLY shot with a mobile. I believe i shot one of the first TVC's to go to air on the Z1. It was a spot for C.U.B and the rental company had just taken delivery of their first camera. It hadn't even been cased and was still in it's cardboard box with it's batteries uncharged. Of course when it comes to visual performance, wouldn't you expect a cinematographer to be snobbish ?
I also only said that I found HDV detestable, not XDCAM.
The EX1 is a leap forward and it probably trumps the HVX in many ways. However it's 2 years behind so I hardly think of it as a quantum leap forward.
resolution is an easy way to compare numbers when you don't trust your eyes. One number's higher than another so it must be better. The truth of course is more complex. Have you ever seen how soft a video image looks once you turn off detail and coring ? Arguably, that's as close as you would get to shooting RAW with some of these cameras.
Detail is an artificial edge enhancement that is applied before the image is recorded. This artificial sharpening helps to improve the *perception* of image sharpness and improves he apparent resolution. To me it makes everything look processed and electronic. They have been using it on larger LCD and plasma TV's for a while now too and I think it looks dreadful.
And guess what ? If i want a video camera image to look more filmic, the first thing I'll do is turn down or even turn off the detail.
So by turning off the detail and visibly softening the image, it suddenly becomes less electronic and processed looking and more subtle and sympathetic.
Colour correction is such a vital part of the image processing chain. I find it much easier to light and expose for a grade than for a finished result at he point of capture. I expose and light my images totally differently if they will not be receiving a grade. And so i want all the information I can have so as to be able to manipulate this later on. All the resolution in the world won't help remove a green cast from someone's skin if they're under mixed lighting.
There are so many other things that also affect resolution or rather, the perception of resolution. Optics, shutter speed, aperture, lighting and that's all before any signal processing and compression ! Then the exhibition formats of course. Film, digital projection, HDTV, SDTV, Computer screen...
Maybe we should set up an experiment. Shall we shoot some tests ?
jb
Posted by John Brawley on April 11, 2008 at 11:07 PM EST #