ANDRO Save EXR

A PNG can't carry what a float32 decode produces - the values above 1.0 and below 0.0, the hundreds of thousands of distinct levels instead of 256. That's what EXR is for, and Save EXR (float32) is the node that writes a proper float32 EXR sequence from your image batch. It's the end of the pipeline this pack is really aimed at: decode in float32 without the clamp, save it as something that can survive a grade in Resolve or a Nuke comp.

There's a genuinely interesting trap hidden in the implementation, and it's worth knowing because it explains why this node exists at all. OpenCV compiles the EXR codec in but leaves it disabled unless OPENCV_IO_ENABLE_OPENEXR=1 is set before cv2 is imported. No ComfyUI launcher sets that, so any node writing EXR through cv2.imwrite silently writes nothing - no error, no file, you find out later. The pack's README documents it bit ComfyUI-OCIO too. This node sidesteps the whole mess by writing through the OpenEXR module instead, and it verifies the file actually landed before reporting success. If it can't find OpenEXR, it falls back to cv2 (only if that env var happens to be set), then to a 32-bit float TIFF as last resort.

Inputs

• images - the IMAGE batch. Wire it off VAEDecodeFloat32; every frame in the batch becomes one .exr file in the sequence.
• filename_prefix (default float32/frame) - a folder-and-stem template, same spirit as stock SaveImage. float32/frame produces float32/frame.00001.exr, frame.00002.exr, and so on. Give a long sequence its own subfolder - 121 frames of 1280×704 float32 EXR is roughly 1.2 GB.
• half_float (default off) - 16f vs 32f. Half still carries the out-of-range values, just with less precision. If you only need to survive one grade pass, half at half the disk space is a defensible trade; if you're keeping masters, leave it off.
• output_folder - absolute path, or empty for the ComfyUI output/ directory. For 1.2 GB sequences, point it somewhere you control.

Output

Just one: folder, a STRING with where the sequence landed. The node also prints a report to the console with the frame count, the backend used (OpenEXR, cv2, or tifffile(.tif)), and the carried value range with the out-of-bounds percentages.

Install

The one node in this pack with a real dependency:

cd ComfyUI/custom_nodes
git clone https://github.com/AndreiOrehov/comfyui-vae-float32
pip install "OpenEXR>=3.3"

Restart ComfyUI. Or install via ComfyUI Manager and let it handle the requirements. Without OpenEXR the node still works - you just get float TIFF files instead, which are every bit as correct value-wise but annoy your compositor, who will ask why you didn't send EXR.

Where people get burned

• Forgetting the decode side. An EXR faithfully records whatever you feed it. Feed it the stock bf16 decode and you've got a beautiful float32 file carrying 77 levels - this is exactly the "10-bit output" trap the README calls out, where the container is right and the content is wrong. The complementary pair is VAEDecodeFloat32 → SaveEXRFloat32; one fixes what goes in, this fixes what it goes into.
• Untagged output. Like ComfyUI's 10-bit video, these EXRs write with color_primaries/transfer/space unknown. The values are scene-ish linear float, but a color-managed pipeline needs the tags or a transform declared. The pack is honest that a colour-managed writer is the missing piece for a fully clean VFX handoff.
• The ▶ button. Same gotcha as the other output nodes in this pack - selecting the node and hitting the canvas-toolbar play button can queue only that node's branch. If your EXR folder is empty after a "successful" run, use a full Run first.