Brightness

A plain brightness slider just multiplies pixel values, which is why it so often looks wrong - it blows out highlights or crushes shadows while your midtones barely move. LF_Brightness is the LF Nodes take that understands exposure, and it's worth reaching for over a naive adjustment because it separates brightness from gamma and lets you pick the tonal midpoint.

The two main controls are:

• brightness_strength - −1 to 1. Negative darkens, positive brightens. Combined with midpoint, it does this around a chosen tonal anchor instead of brute-forcing the whole range.
• gamma - 0.1 to 3, default 1. Values below 1 brighten the shadows, values above 1 darken the highlights. This is the control that actually rescues an underexposed image without nuking the sky.

There's also a localized_brightness boolean, which "enhances brightness locally in darker regions" - a smarter shadow-lift that doesn't touch the already-bright areas. That's the hidden hero for fixing faces that fell into shadow in a render.

How it fits

Like the rest of the LF filter family, it takes a batch (single tensor or list), returns image and image_list, and shows a KUL_COMPARE before/after widget on the node. Pair it with LF_LoadImages to grade a whole set of renders in one pass, or drop it post-sampling for a quick exposure fix before saving.

The workflow where people really feel this one: a prompt that rendered too dark (models love to do this with "night" or "candlelight" keywords). A quick pass - gamma 0.8, a touch of localized brightness - brings the subject back without the flat, washed look a plain brightness bump gives you.

Installing it

Standard LF Nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/lucafoscili/comfyui-lf

or ComfyUI Manager → LF Nodes → install → restart. No dependencies, no models. The pack is the frozen legacy repo (the author moved on to lf-nodes), so this node is stable and finished.

Where people get burned

• midpoint defaults to 0.5, which is a mid-gray anchor. If your image is mostly dark, leave it - but if you're adjusting a highlight-heavy image, moving the midpoint up makes the adjustment act on the brighter end.
• Gamma and brightness stack. Set brightness_strength first, then fine-tune with gamma; doing both at max just makes a hazy mess.
• It's a per-frame correction, not a scene-referred exposure tool. For heavy color-grading you want a real color node (the pack also has LF_ColorAnalysis for matching); this is for the quick, visible fix.

If "it came out too dark" is a recurring sentence in your life, this is the node that fixes it properly.