[dubir]

how can i make light like this ? glowing spot light

[JTB]

It looks like what we call volumetric light and as everything else it should be somehow modeled in Maxwell...However there have been some tricks and workarounds with some strange materials. I think you should try and search the 1.x forums or wait for another answer...

[Bubbaloo]

For now, the easiest way to get the volumetric effect is post render, like Photoshop. Maxwell doesn't support volumetric lights for now, so if you want that effect inside the render, you will have to use some creative trickery to achieve the effect. These tricks (SSS, dust particle planes, etc.) are very calculation intensive and will increase your render times dramatically.

[dubir]

thanks Brian ,it is hard to belive that so advanced program like MR don't have such light .

[Half Life]

It's not the "light" you are seeing but rather the fog/smoke/dust illuminated by the light... any solution that doesn't create the fog/smoke/dust particles in the atmosphere will be a fake.

You can use SSS to create a similar effect but it will be so slow and take so many sample levels to clear as to be impractical to render for most people.

Biased render engines can do this sometimes because they are not looking for unbiased realism and so they can use whatever computational "trick" they need to get it to work.

Part of the problem here is smoke machines (how the photo was created) don't just fill the air with a homogeneous white haze -- rather the smoke tends to gather close to the ground and stay together in a tendril-y mass unless disturbed... this would be very hard to achieve without bringing particle simulation software into the mix.

Best,
Jason.