I covered open gate pretty extensively in a previous video, but just a quick refresher of open Gate on the GH6…Camera sensors are typically 4:3 or 3:2 ratio, yet most cameras shoot video only using a 16:9 or 17:9 portion of their sensors, whereas the the LUMIX GH6 can shoot using the entire sensor in a 4:3 aspect ratio, capturing much more of your scene at once, and at a much higher resolution. Open Gate on the GH6 is 5760 pixels wide by 4320 pixels tall, where all you need for ultra HD is 2160 by 3840. This of course gives you a ton of options for reframing in post, and the nearly- square 4:3 aspect ratio is ideal for cropping both landscape and vertical video from the same footage — in fact vertical video at 1080 x 1920 means you have over double the vertical resolution you need for any social posts.
This is important for a lot of professional work now, as many clients are requesting vertical video for social in addition to the wide video, and shooting Open Gate means you don't have to shoot the same thing twice. Anyway this was covered extensively in the last Open Gate video, including how to edit that footage.
But now I want to talk about anamorphic, including a wild idea of shootingwith a 90˚ rotated anamorphic lens to get vertical flares and a slightly TALLER than square starting point for your crop. But we’ll get to that later. For now, let’s talk about shooting anamorphic, and deciding between shooting in open gate or in 16:9.
If you’re shooting with a high end anamorphic cinema lens like an Atlas Orion, those typically have up to a 2x squeeze factor, meaning the footage you capture can be stretched or squished by a factor of two. For these lenses, shooting open gate is expected. From a micro four thirds sensor at a 4:3 ratio (that's 1.33:1) or a full frame sensor at a 3:2 ratio (that's 1.5:1), once squeezed you get a 2.67:1 or 3:1 final shot — which you’d probably crop a bit out of for whatever final aspect ratio you wanted. What you WOULDN'T likely do is shoot at 16:9 (or 1.78:1), as the final stretch would be a massive 32:9 (that's a 3.56:1) ratio, which really isn’t effective.
But the kinds of anamorphic lenses that are approachable to folks like you and me, are the new generation of lenses like those from SIRUI and the relatively new LAOWA Namomorph lenses, which are impossibly small and really fun to shoot with. So… should you shoot with these in open gate, or in 16:9, or even 17:9? Well let's start by looking at the numbers. And I'm going to calculate all the anamorphic squeeze adjustments as compressing footage vertically instead of expanding it horizontally, to maximize quality. I'm going to throw a lot of numbers up here, but don't worry if you get lost, I'll summarize it at the end in a single chart.
On the GH6, Open Gate in 4:3 means 5760 x 4320 pixels. When correcting for anamorphic, you can stretch horizontally or squish vertically. For this video I'll talk about a vertical squish but if you need massive resolution, you can stretch as well – you'll see a chart with those numbers at the end. If you use a 1.5x anamorphic lens like the LAOWA Nanomorph, then that gives you a 5760 x 2880 image after the 66.67% vertical scale – that's 1 divided by 1.5 – which is a 2:1 aspect ratio, and actually a very popular aspect ratio on Netflix today. So, wider than native 16:9 at 1.78:1, but not quite Cinemascope at 2.35:1. However, you have way more pixels than you need, and can punch in and reframe for even a full 4K delivery. Here's some samples of anamorphic shot in 4:3 Open Gate.
Now let's compare to shooting 16:9, which is what usually is recommended when shooting with these smaller, less squeezed anamorphic lenses, like the Nanomorphs with a 1.5x squeeze, or the SIRUI with their 1.33x squeeze.
16:9 Ultra HD is 3840 x 2160 pixels, which if you vertically compress gives you 3840 x 1440, which is 2.67:1 aspect ratio, which is a little wider than Cinemascope. BUT if you crop the sides to get a 2.35:1 Cinemascope aspect ratio, then you're actually scaling the footage up a little bit to get back to Ultra HD. You could shoot at 17:9 DCI 4K just to get a little more horizontal resolution at 4096 x 2160, but then once squeezed your aspect ratio is even wider at 2.84:1, but you still scale your clip up to get to Cinemascope at UHD or 4K — and all you've really done is cropped some of your scene off the top and bottom of the shot, since 16:9 and 17:9 are actually the same field of view wide… just slightly less tall. Unless of course you shoot in internal ProRes 5.7K mode, which is also 17:9, however is 5728 pixels wide and once squeezed, 2016 pixels tall. Now if you crop for CinemaScope, you still have 4740 pixels wide, so more than enough for full 4K delivery. So many options. Here's some footage shot in 16:9 at a 1.5x squeeze.
Of course if you aren't trying to get a specific aspect ratio like Cinemascope, then who cares — just shoot at whatever looks good to you, and let's be honest; 16:9 with a 1.5x squeeze does look really cool. But if you DO want to be specific, and you DO want to maximize quality and flexibility, then let's put Open Gate and 16:9 side by side.
Comparing squeezed 4:3 Open Gate to squeezed 16:9, Open Gate has a clear advantage as you have a LOT more pixels to work with, can reframe all day long, and can even cut a vertical crop out of the footage at a full 1080 x 1920 resolution. But there must be a trade-off, right? Well, there is. Open Gate 4:3 internal recording is 10-bit 420 Long Gop up to 30p, while 16:9 UHD is 10-bit 422 All Intra and can go up to 60p. So you definitely have extra color information and higher framerate options in the 16:9 clip. But that's not the whole story. With the LUMIX GH6, you can also shoot internally in 5.7K 17:9 ProRes! This is almost as wide as Open Gate, just not as tall. It is still big enough though to even get a full HD vertical crop, and of course it's a higher bitrate and 422 color. SO right now you're thinking “oh man, I want full Open Gate but I want full quality, too! Why can't I have both?” Actually… you can. If you add an ATOMOS Ninja V, you can record 5.8K 4:3 Open Gate in 12-bit ProRes RAW at 24 or 25p, or with the Ninja V+, up to 30p.
One of the really cool capabilities of the LAOWA Nanomorph lenses is their ability to change mounts. I have both Micro Four Thirds and L mounts for these lenses and while the Nanomorphs don't cover the entire full frame sensor, they do cover the APS-C crop, so you can shoot anamorphic with these lenses on a full frame LUMIX in APS-C mode – which is in fact what I'm doing for this shot here, on a LUMIX S1H. But because the mounts can be removed, that means they can be put back on… incorrectly. And I found if you rotate the lens 90˚ – which will look a little funny on your camera – you can shoot open gate 4:3, then squeeze horizontally to get a nearly square 3840 x 4320 image, which you can still totally pull a full ultra HD 3840 x 2160 image from, or do an HD or even 4K vertical cut — and get vertical flares! Maybe you could actually then rotate the camera 90˚ to get back to horizontal flares, and eliminate rolling shutter… hmm. Anyway, it's somethig different… here's some samples.
You might be wondering how much of a difference the 1.33x squeeze of the SIRUI anamorphic lenses is compared to the 1.5x squeeze of the Nanomorphs.
Here's the same shot, made with both lenses, both in Open Gate and in 16:9. They aren't the exact same focal lengths to start; the Nanomorph is a 27mm lens and the SIRUI is 24mm, but they're close.
Calculating the effective focal length of an anamorphic lens gets a bit complicated, but Tito Ferradans over at Anamorphic on a Budget has a great calculator on his website, which I'll link to down below.
Where does this leave us? Well, there's no one answer to how to shoot anamorphic – open gate or 16:9; there's advantages to each. Fortunately the LUMIX GH6 is the perfect camera to shoot either with, and adding a Ninja V really does give you the best of all worlds. Next, watch this video to learn more about Open Gate in general, and watch this one to learn more about Anamorphic shooting and editing.