HDR timelapse ‘The Chapel’ is een korte film ter ere van een tempel in Zeliszów, Polen, ontworpen Karl Langhans en gebouwt in 1796-1797. Patryk Kizny maakte deze video en maakte een uitgebreid verslag van productie, shoot en postproductie.
HDR timelapse production workflow
De HDR timelapse video van The Chapel is gemaakt door Patryk Kizny, die een uitgebreid plan bij hield over de opname en postproductie van zijn HDR timelapse video. Patryk Kizny over zijn HDR timelapse productie:
HDR timelapse production workflow
If shooting in SDR and processing using the workflow above is not enough, you may try the HDR workflow. Be conscious however, that it is really time-consuming and processing power demanding.
The basic approach is mainly the same, however some other techniques and software are used to merge multiple exposures to HDR 32bpp images. To keep things simple, I’ll describe only these steps.
1. Shooting HDR timelapse
The same rules as in SDR workflow apply.
Additionally, you need to shoot stills using exposure bracketing. +2/-2 is fine, less demanding scenes might work with +1/-1 EV.Be sure to shoot with low ISO, on a 5D use native ISO settings (160/320/640/1250) to get as low noise as possible.
2. Quick preview HDR timelapse
Assuming you have the JPG files stored separately form RAW footage, you can generate the quick preview using Quick Time Pro or other software. Quick Time is really fast and is just right for this purpose, so simply import a sequence and render to any preview format you like at decreased resolution for a smooth playback.
3. Preprocessing HDR timelapse
The goal at this stage is to merge the subexposures into HDR frames at 32bpp, develop in the similar way as in SDR workflow, import them to to Adobe After Effects and render the master footage in high resolution.
2. Batch-merge using Photomatix Pro
Using the batch feature of Photomatix Pro (PMP), run a batch on a set of files to generate a sequence of HDR images. There’s an easy way to tell PMP to process files in group of 3 files to match your -2/0/+2 bracketing subexposures.
At this stage we get the set of 32 bpp HDR images that will be developed in the next steps. This will take time, so grab your kettle or play some music.
If you’re not heading for HDR tone-mapped look with a lot of local contrast enchancement, consider using exposure merging instead of generating HDRs.
3. Develop one frame of HDR sequence to find your settings
At this point we do the development of the source files in a similar way as described in SDR workflow, but we have HDR files instead of RAWs and use PMP’s tone mapping feature as a development tool.
Play with all settings that PMP provides you with and keep in mind that the more aggressive the development, the more time you’ll need to spend checking the settings on multiple frames.
Be sure to save your settings at the end in an XMP file.
4. Test your settings for other frames
This step is even more important than in SDR workflow. Since the HDR development might produce much more artifacts, so you need to carefully check further frames in different points of the sequence against the artifacts of the deveolpment recipe. Simply open a few files across the sequence and develop using the stored setting. If any artifacts appear you’ll probably need to apply less severe processing and re-test.
5. Batch-develop the sequence
This is the second batch you need to run. Basing on HDR files and your well-checked recipe, convert the HDR files to 16-bit TIFF files. Unfortunately this is storage consuming and PMP won’t offer you any other of convenient intermediate formats to keep your 16-bit data.
6. Import sequence in AE
This is pretty simple. All you need to do is create a new project in AE using 16 bit color depth, then drag the previously prepared folder to the file browser in AE and the software will recognize and import a sequence for you. If you add the stills sequence to render queue, AE will create a sequence with the right settings for you. Real time saver.
7. Apply initial effects
At this stage you may apply the GB Deflicker filter, motion blur or other filters of your choice to the footage and/or perform motion tracking to remove any camera shakes. At this stage apply only the basic effects for the initial processing of the footage. The final look will be created later, so don’t worry about that.
8. Render to a rich format at 100% color resolution.
Up to this point we’ve been working on a rich material. What I mean here is that at each of stages the original bit depth of the RAW files was preserved. Rendering to an intermediate format is the first step in the workflow where you lose information. It is essential to understand it and keep in mind.
Choose the format depending on the project you do and the processing power or storage available. I usually work with Apple Pro Res 422 here, but you can get the great results with Cineform codecs or Lossless Animation (which is storage consuming however). My recommendation is a Pro Res 422 (standard) or Pro Res 422 HQ format for more demanding projects. If you have enough computing and storage resources choose Pro Res 444. Be sure to render to 10 bit color resolution to preserve as much of the color space as possible.
9. Editing and grading HDR timelapse
At this stage you have the high resolution 10-bit footage ready to edit and grade. Although this workflow recommends Apple Final Cut Pro, you may do the edit in Premiere or Avid. Be sure to work with the rich format of the working sequence not to kill the information in the files. If working with FCP use the same codec as was used for the rendered master footage. Do your final processing applying effects and grading either in Magic Bullet Looks or Apple Color.
10. Exporting HDR timelapse
Export your final work to the delivery format of your choice.
HDR timelapse making of
Kijk voor meer informatie over The Chapel op thechapelfilm.com