|A CreativeCOW Product Comparison
Auckland, New Zealand
©2008 Andrew Shanks and Creativecow.net. All rights reserved.
In this article Creative Cow Leader Andrew Shanks plans to go through some of the software options for checking greenscreens on set (Lensfeed, Veescope and Conduit Live).
As an on set VFX Supervisor, one of your jobs is to make sure the greenscreens/bluescreens on a shoot get lit evenly and that spill is controlled as much as possible (thankfully most gaffers and DoPs these days are pretty well versed in what is required which means our job is easier). Traditional tools to get the screen evenly lit and exposed are light meters (one of the most important tools a DP or Gaffer has in their toolbox), as well as using a waveform monitor sometimes on studio shoots (having it just pointed at a green/bluescreen you can see where unevenly lit patches can be). An easier technique DoPs often use is to switch on zebra patterns in the cameras viewfinder then rock the exposure up and down (overexposing the image) until you find a point where you can see hotspots or darker patches that need the lighting tweaked to correct them.
The above is fine for getting the screen evenly lit, but everyone on set usually wants to get a sense, even if its just rough, of what they’re about to shoot in regards to how it will look in the final scene (not just from a logistics point of view but also it can help motivate actors or solidify in their minds exactly what they are meant to be doing (e.g. “ah, so that ball on a stick is a dragon and we’re on a clifftop, riiiiiight”). In the past people have used vision mixers, but these setups are a pain when moving round to various locations (as playback VCR, mixer and power supply have to be lugged round). A popular method in the past 5 years or so has been capturing shots with a digital still camera to produce a test key on the laptop (which is a good way to go as you can load it into a compositing app on your laptop, pull a rough key (I like to keep it almost a one click key, as it then shows up the bad areas we might want to re-light), then display the greyscale matte it produces (a great visual guide to see where problems of spill are on the foreground, or where patches of potentially problematic uneven light might be on the background). The downside with the still image option is just that, it is still, you can’t see things update as you swing the light round (you can keep taking photos and transferring them, but it isn't a very quick interactive workflow).
In recent years applications for using your laptop as a monitor for your camera (especially for use with HD cameras) have started to come out (e.g. Scopebox (mac) and Adobe On Location (PC)). Most of the early options don't have keying capability unfortunately.
I came across this plug-in for After Effects a couple of years back and realized its potential for checking keys on set. Its main features are:
- ability to use a live video feed as a layer in After Effects
- multiple live layers supported (although performance would take a hit)
- pretty much anything you can do to a normal After Effects layer you can do to a lensfeed treated layer.
The way it works is you create a new solid in an after effects composition then apply the lensfeed filter to this layer (as you would any other filter in after effects, under the Frischluft filters submenu are 5 lensfeed filters, these correspond to 5 possible separate video feeds). If you have a single video source plugged in it should automatically see it and start updating the screen with that video feed (if not, you can click the ‘next cam’ setting until your source is displayed). Instead of a solid color layer you now have a continually updating video feed that you can manipulate and add filters to as you would any normal video clip, image, sequence, etc. What I tended to do was apply keylight to the layer, do a basic key (I prefer to do a very basic key in order to show up potential problems, so if you get an okay key even from a cruddy DV feed, you know when you do your proper keying work in post you’ll have no problems), and I then set it to display just the alpha channel of the the key (in the keylight filter) to look for problems).
Once that is sorted out, I set it to view the final key and drop the background plate (a still is all that is needed, even a temporary stand-in still) in behind. This means the gaffer can light to match the background plate (if one has been shot already).
I used to use this frequently, I have a composite/svideo to firewire converter box (Canopus ADVC-100) and used to just take a feed from whatever we were running into my laptop. It worked well, I found it handy having all the abilities of After Effects available to me to do rough comps (such as keying, resizing, rotating, scaling, masking, etc), but its downsides were it had a lag time of about half a second (things happening on screen might be a second delayed behind what was happening on the set) as well as only giving me what seems like around 10 to 15 frames a second (due to all the processing involved this is not surprising). This is a PC only option, it works with After Effects 6.5, 7 (way faster under v7), and also CS3 (I have not tested it under it yet though).
This little application appeared late 2007, and actually managed to sneak under my radar for a few months, but now I have found it I am a bit of a fan. The features it has are roughly as follows:
- it is a self contained Mac application that has full monitoring abilities (i.e. you can use the whole display on your macbook pro effectively like a 15.5inch or 17inch monitor for your camera).
- It has the option to display vectorscope, waveform monitor, waveform parade, overscan/title safe markers, and audio metering, --the scopes appear over a black and white version of your video source which is handy.
- It has Zebra pattern overlays (which you can control the level at which they kick in, --another good tool for finding hotspots on an unevenly lit screen without getting the DP to alter the exposure to do the same thing).
- It has the ability to flip (and flop) the video image, which is handy when you are using a 35mm lens adaptor which flips the image as standard (this allow you to see the image right way up with a simple click of a checkbox).
- It can handle 16:9 and 4:3 feeds
- Has the ability to move the background around (x and y offset adjustments)
- It will take feeds from any video device you have attached, from isight camera to firewire converter box, to DV camera, to USB camera, to HD/SDI card inputs (i.e. ability to connect to anything highend such as Kona HD feeds as well as low end DV or composite feeds). For example if you have a Mac Pro with a HD-SDI card and a feed from an HD camera you can monitor HD feeds directly on your laptop and do full frame-rate keys!! In theory using a MacBook Pro and an AJA IO-HD should give you realtime functionality at HD too, which would make for a sweet on set setup. The latest version has support for HDV cameras.
- can monitor as many video feeds as your computer can handle
- It can key any color you like (you have the ability to use an eyedropper style picker and click on a background colour on the screen), and it has many settings to help you pull a key (indeed it can be a little daunting at first, but you get used to how to set up the various sliders quickly for a good base result). Note in the examples here I have done a very rough key, which is good at showing there is a lighting issue on the right side of the screen.
- You can play a quicktime video clip under your keyed foreground
- It can capture video feed to your harddrive (handy for review or doing rough composites in Shake/After Effects between setups or in a break).
- The ability to display just the alpha channel of the key (this was a suggestion I made to fit with the way I’d been working previously, the creator of the application didn’t just take my feedback onboard he quickly integrated it into the new version within a day, -- talk about service,
- has aspect ratio correction
- Has a great online manual with plenty of illustrations.
- It deinterlaces interlaced footage by default which makes things easier on the eye.
- It is cheap, half the price of either Lensfeed or Conduit Suite
I got to give Veescope a bit of a work-out the other week and thought I would share my results here. We were shooting some pickup shots for a short film that had been shot on 35mm. For the pickup shoot we were using a RED camera at 4k, -- fun and games there, but that’s a whole different story, nice images at the end of the day and that is all that matters. Unfortunately there was an incompatibility with our downconverting to SD firewire (we run in PAL and didn’t realize RED only outputs a monitor feed in NTSC at this point in time). Despite not having a feed from the RED, I decided to just do a low-end test with a DV camera setup on a tripod. Even this rather hokey setup worked well for sussing out where lighting errors were, and at one point we had to replicate an earlier shot (which had been filmed on wires) but with the actor around the opposite way (in post the plan was to flip and flop him), so it was very handy to have the quicktime of the original shot sitting on one half of the screen and veescope sitting on the other side with the live feed being flipped and flopped on the fly so we could match things roughly (would have rocked if we’d had the direct feed).
After that night I put veescope through some more tests using a playback feed through the Canopus ADVC-100 into my Macbook Pro (and for reference I put it head to head with the other two pieces of software in this article) . Keying is as simple as running the software, choosing an input device, going to the patterns tab, clicking the chroma-key preview checkbox, selecting a screen color with the sample color tool, then slide the sliders until the required key is achieved (it also has other controls for spill, edge, etc, but again, I kept it a rough key).
With this setup (as with having it hooked up to a DV camera), when you are keying in the default veescope interface, everything seems to run at full speed (no dropped frames). There is a lag between what is in front of you and what is being displayed, but it’s probably around 7 to 10 frames and for setting shots up this really isn’t an issue. When you switch to full-screen display (command-F) with either no background or the matte view displayed, it again seemed to be at full frame rate (or close to it). The frame rate of the DV feed seemed to drop a bit when you are playing back a quicktime movie as a background (maybe to between 15 and 20fps, from the 25fps native I was running, the background movie played full speed however), this may seem bad, but it was completely usable, and it apparently runs full speed on the mac pros when running kona (or similar cards) at even HD resolution. Having veescope in full screen matte mode was perfect for swinging a light while looking at the result on the laptop screen, --quick way to get rid of bad patches on the screen, the DoP and gaffer can just look at the screen directly while moving the lights, which is great for me as I can just leave them to it and go graze at the unit food table ;-), certainly a lot more interactive than my old lensfeed technique. It also has zebra patterns you can set the levels for, which you can use the check the screen with in the traditional manner (without needing the DoP to rock the exposure on the camera).
I captured some video from the feed to test whether veescope dropped any frames with its capture, the quicktime clip it saved was full interlaced frame-rate and DV quality. The beauty of the capture is that it grabs the source footage, not what you are monitoring (so if you have title safe markers, zebras and are doing a test key in veescope while you are capturing, the file it will save is the un-effected original source feed). It was nice to load this capture into shake and do a quick test key there (with rough masks, rescaling, etc).
This is a new addition to the conduit package, a nodal plug-in system that has been available for the past couple of years from DV Garage. It has all the abilities of veescope, in that it takes a live feed from any video source that is plugged into your mac, can do a key, has various scopes (vectorscope, waveform monitor, etc), can capture footage on the fly, etc. It’s main features (apart from what it shares with veescope) are as follows:
- it is a stand alone nodal compositing system (akin to a lite version of shake, nuke, fusion) so has a lot of power in what you can do with it (including things like colourgrading, moving the image, basic cropping, scaling)
- like veescope it has multiple inputs (its maximum is set to 9, although your fps playback milage may very depending on how much work your cpu has to do).
- It comes with plug in versions of conduit for Photoshop (Mac/PC), After Effects (Mac/PC), Motion (Mac) and Final Cut (Mac)
- If you do a basic key on set, you can save that conduit project and then load it in any of the other conduit plug-in versions (e.g. into final cut pro).
- You get 3 month subscription to Pixelcorps, which is an online community where you can view many video tutorials, participate in challenges as part of a team and they also have vpn versions of software that you can use to work your way through their tutorials (usually 3⁄4 the cost of the software itself).
Conduit is built on the same quicktime base as lensfeed so performance is similar. By default it treats everything as being progressive, but you can switch it to de-interlace easy enough (interestingly it seemed to stay realtime when full screen with a background keyed in when I first tried it, but as soon as I got it to de-interlace, it seemed to drop to about 20 or so frames per second (a smidge faster than veescope under the same test). Again my tests here are just on a basic DV feed, I believe it would have the same realtime performance as veescope on kona cards, etc.
If you like working in a nodal compositing system, you’ll feel right at home here. If you haven’t used one before it will not be as intuitive to pick up and run with as veescope, you will have to watch the introductory videos and maybe glance at the reference pdf (there is not really a proper manual for the product which is a shame, but the author has a good blog with examples and the videos get you going quick, plus if you post on their forum you get prompt replies). Support for HDV cameras is on the way.
I used Lensfeed for a good number of years, and if you use after effects user and want to be able to use pretty much everything that after effects offers, on a live feed, then this is probably still a good option for you. The best PC option at the moment but you do need After Effects in order to run it. It is let down by speed compared to the other two offerings.
Out of the test, Veescope is my favorite on set piece of software, it is simple, elegant and powerful. It may lack the bells and whistles of conduit, but it has everything you require in an onset keying/monitoring application. It is a piece of software I could show a non-computer person how to use quickly (handy if it is going to be used by a camera assist who has better things to do than learn nodal compositing or after effects). I am also impressed with the feedback from the developer, having suggested one feature to him in an email, I got an email the next day to say he’d coded it in and then gave me a link to a beta, and talk about speedy! At half the price of the other two applications, and one of the cheapest pro video utilities on the market, it offers serious bang for not much buck. In my opinion every mac owning DoP, camera operator and on set vfx supervisor should have this handy app on their macbooks.
Conduit is also a good option as it does everything you could want to do, the only reason it doesn't take top spot is because not everyone has the need for the compositing features it has on set, and it would take slightly longer for someone to pick it up (if they haven't used nodal compositing before). Also you have to ask yourself can you justify twice the price for the features you'll actually need. It has a good interface, great scopes, good grading and comping nodes, the bundle of different versions is great for the price and the included guest membership to pixelcorps is good if you want to check out some training videos.
There are other options out there such as Adobe’s Ultra (which I cannot comment on as I haven’t tried it) and I’m sure more will arrive in the future. All the above applications fill a niche that for too long as been vacant, choose any and they will help give you confidence on set, in turn making the quality of your greenscreen/bluescreen keys better. All the applications listed have demo versions, so if you are in the market for one, take them all for a test spin and see which one will suit your workflow.