Light scattering / diffusion for southern window

[AnonYMouse]

If you put anything on the window, you are going to lose intensity. Reflective materials around the plants are not going to give 100% either but will give you photons that aren't being absorbed elsewhere. You could surround your growing area with a white screen (even covered in mylar).

You don't mention what plants you have in this window. I live in the south bay and my western facing window would cook my intermediate plants in Summer, I'm thinking southern would get even hotter. Berkeley is considerably cooler but something to consider when trying extend exposure.

I grow in a eastern window with a patterned privacy film and have burned patterns onto the leaves (mid to low light plants). So, depending on your plants, you might not want more light intensity.

[Ray]

No mirrors. All they do is directly reflect the light, coming through a window at a downward angle, straight to the floor. The same will be true of a sliver film, unless it is crinkly, so it's surfaces face in every direction.

A flat, bright white wall absorbs and reradiates the light in all directions.

A fine, dense sheer curtain will diffuse the light quite well, albeit reducing the intensity a bit. As the light passes through-, and between the fibers of the weave, it is diffracted and refracted in all directions.

What that primarily achieves is a more uniform distribution of light over time, as well as space, rather than having a beam that travels across the room as the earth rotates.

Keep in mind that to the plants, that window, or sheer in this case, becomes the source of the light, so the inverse-square rule still applies, so those plants closer will get more light than those farther away.

[Mountaineer370]

I'll share another reason to be very cautious in using mirrors. My cousin had installed a swing-arm makeup mirror in a small powder room. She was in there one day and noticed what she first thought was steam rising from the windowsill. Looking closer, what was happening was the sunlight coming in the window was hitting the mirror just right and reflecting toward the wood windowsill. It was heating up the wood enough to cause smoke. It had clearly been happening over time, since there was already a four-inch-by-one-inch section of charred wood. Very scary! Be careful with the positioning of mirrors in your house!

[dakotablue]

Thanks for your replies everyone. I have about 60 different species and am in the process of rearranging(mostly because I'm running out of space for new additions).

Can't really do mirrors, and I think panda film would be better anyways. It sounds like a very sheer curtain is likely the best option, if it was sheer enough I would still be able to see through just enough to see the trees outside maybe....

Trying to have the best of both worlds here! See outside, not cook the orchids, and have as many as possible in the window. Or I could just try and stop buying new orchids.... Hah

[Ray]

...or purchase supplemental lighting.