Making GIFs from 35mm film photography

如何用 35mm 胶片制作 GIF 动图

Everyone loves a good GIF, and my favourite (of all time) is this one (circa 2015): Let’s make a GIF in the hardest way possible. Why? It’s pointless, but some pointless things are just fun to do. 人人都喜欢有趣的 GIF 动图，而我个人最喜欢的一张（大约制作于 2015 年）是这样的：让我们用最困难的方式来制作一个 GIF 吧。为什么？虽然这毫无意义，但有些无意义的事情做起来就是很有趣。

Step 1: Acquire photons

第一步：捕捉光子

For this step I’ll be using the Lomo ActionSampler, a plastic camera made in China by a series of anonymous unknown factories. It’s been branded as many different things over the years, including as the Revolver Selby in 1991, so it’s a design that’s at least 35 years old. The camera uses a unique clockwork spring-powered mechanism to rotate a circular shutter over 4 different lenses, at a speed of around 1/250s per frame. This means, if you’re lucky, you can capture 1 second of action at a glorious 4 frames per second. Because you never really know how the photos will turn out, I’ll shoot a 36 exposure roll of Lucky SHD 400 film, and we’ll see what we get. Now that our photos are captured on China’s finest cheapest black and white film, we need to make them visible. 在这一步中，我将使用 Lomo ActionSampler，这是一款由中国一系列不知名工厂制造的塑料相机。多年来它被冠以各种不同的品牌名称，包括 1991 年的 Revolver Selby，因此这款设计至少已有 35 年的历史。该相机使用独特的发条弹簧驱动机制，带动圆形快门在 4 个不同的镜头前旋转，每帧速度约为 1/250 秒。这意味着，如果你运气够好，就能以每秒 4 帧的华丽速度捕捉到 1 秒钟的动作。因为你永远不知道照片最终会是什么样，我决定拍摄一卷 36 张的乐凯 SHD 400 黑白胶卷，看看能得到什么。现在照片已经记录在这些中国最优质（也最便宜）的黑白胶卷上了，我们需要让它们显影。

Step 2: Develop film

第二步：冲洗胶卷

I could send the film off to a lab for developing and scanning, but this is the hardest way to make a GIF. I develop film at home so luckily I have all the requisite parts: Developer tank and reel, Ilford Ilfosol 3 developer, Ilford Rapidfix fixer, a dark bag, jugs, thermometer and other assorted accessories. By a combination of luck and limited skill, it worked! We have developed film, each frame containing 4 images captured at 4 frames per second. 我本可以将胶卷送到实验室进行冲洗和扫描，但这可不是“最困难的 GIF 制作方式”。我平时就在家冲洗胶卷，所以幸运的是，我拥有所有必需的器材：显影罐和卷片轴、伊尔福（Ilford）Ilfosol 3 显影液、伊尔福 Rapidfix 定影液、暗袋、量杯、温度计以及其他各种配件。靠着运气和有限的技术，成功了！我们得到了冲洗好的胶卷，每一帧都包含了以每秒 4 帧速度捕捉到的 4 张图像。

Step 3: Scan images

第三步：扫描图像

I don’t have a fancy film scanner, so for this I’ll be mounting each frame on an LED light panel then taking a photo with a digital camera on a tripod, with lots of light and a small aperture to try to get the best detail possible. I’ll shoot the frames in RAW which will give me some flexibility in the software later to expose them more correctly. This is similar to the digital intermediary phase in “real” filmmaking. I loaded the RAW files into Affinity and eyeballed the exposure to hopefully get useful images back. They’re inverted of course, so a quick cmd+i inverts them the right way round. 我没有高级的胶片扫描仪，所以我把每一帧胶片固定在 LED 灯板上，然后用架在三脚架上的数码相机进行翻拍。通过充足的光线和小光圈，尽可能获得最佳细节。我使用 RAW 格式拍摄，这能让我在后期的软件处理中更灵活地调整曝光。这类似于“真正”电影制作中的数字中间片阶段。我将 RAW 文件导入 Affinity 软件，凭经验调整曝光，希望能得到可用的图像。当然，它们现在是底片效果，所以用 cmd+i 快速反转颜色，就能得到正常的正片图像。

Step 4: Crop frames

第四步：裁剪画面

The alignment of each 4 frames within the 35mm frame is not exact (this is a plastic camera from the 1990s after all). In fact frames 1 and 2 are a different width to frames 3 and 4, so I’ll need to crop each frame, then align them as layers manually in Affinity. Making the frames 50% transparency helps as a rudimentary form of onion skinning. Now we export the frames as PNGs, and number them by frame order. 35mm 胶片上这 4 个画面的对齐并不精确（毕竟这是 90 年代的塑料相机）。事实上，第 1、2 帧的宽度与第 3、4 帧不同，所以我需要裁剪每一帧，然后在 Affinity 中手动将它们作为图层对齐。将图层透明度设置为 50% 有助于实现类似“洋葱皮”（onion skinning）的简易对齐效果。现在我们将这些画面导出为 PNG，并按顺序编号。

Step 5: Align frames and Gif-ify

第五步：对齐画面并生成 GIF

Using imagemagick on the command line I was able to combine the images into a GIF. I went for a “ping pong” animation style, just to make the GIF last a little longer and give a better sense of the motion. magick -delay 25 -loop 0 1.png 2.png 3.png 4.png 3.png 2.png animated.gif 通过命令行使用 ImageMagick，我成功将这些图像合并成了 GIF。我选择了“乒乓”（往复式）动画风格，这样可以让 GIF 播放时间更长，并带来更好的动态感。

Delay 25 means 25/100ths of a second, or 4fps - making it more lifelike to the real world it was captured from. Naturally with 4fps this isn’t exactly like watching a Pixar movie, so I created some tweens by blending frames at 50% opacity each using: magick 1.png 2.png -define compose:args=50,50 -compose blend -composite 1-2-tween.png Delay 25 代表 25/100 秒，即 4fps，这使其更接近于它所捕捉的真实世界。当然，4fps 的效果肯定不像看皮克斯电影那样流畅，所以我通过将两帧画面以 50% 的不透明度混合，创建了一些中间帧（补帧）：

With these tween frames as part of the animation it appears much smoother. And there you have it! A looping animated GIF, acquired from the real world on 35mm film. Next project: do it with IMAX. ;) 有了这些中间帧，动画看起来流畅多了。大功告成！一个从现实世界中通过 35mm 胶片获取的循环 GIF 动图就完成了。下一个项目：用 IMAX 试试看。;)