How to increase the length of distance that a light source emits?

[Anonymous]

I have placed some lighting fixtures at the base of the columns facing upwards, as shown in the image. The light from those fixtures only reaches 1/4th of the height of the columns.

1.I want to increase the length of the distance that the light is emitted so that the entire column will be illuminated from the fixtures placed at the base of each column.

2.I also want the light to be dim consistently throughout the whole area of emission, rather than very bright at the start and dimmer at the end.

Any ideas how to achieve this?

[rudi.roux]

Hi @Anonymous, 

To Answer Question 1: 

If your light fitting is using an actual IES file to drive the light intensity, you'll then be left with the rendering as shown as the IES file might be incorrect for the actual up-light being used. (The Projects Electrical Engineer will spec the correct light fitting for the areas which you mentioned to achieve the result which your looking for as per your final render). There is a workaround if the result which you're looking for is purely from a Visualization Perspective. 

Firstly, click on the light fitting, then click on Edit Type in your Properties Pallet, this will open the dialogue as shown below: (I just used a generic light fitting, but the principal stays the same).

Scroll down to your Initial Intensity and change your Efficacy to a higher value from what you currently have. OR you can simply change the Luminous Flux value to about double of what you have now. (Generally, play around with higher values until your happy with the rendered output). 

Secondly, you can click on the family and open it in the family editor / edit family. Once opened, click on the Light Source, this will then prompt you with an option in your ribbon to change the "Light Source Definition", I would change it to emit the shape of a spotlight as shown below. You can play around with the Light Distribution settings, but the once indicated below should do the trick. Then apply the changes as save and load the family back into your project, overwriting the existing family. 

Thirdly, click on the light fitting, then click on edit type to open your family type properties again, scroll down to the Dimensions and change the Light Source Symbol Length to your desired Length. (Again, you'll have to play around with this until your happy). 

Lastly, below is a scale of Initial Color or Kelvin Color Temperatures which can be used or changed under your family type settings, under your Photometric data as per my first image. 

To Answer Question 2:

Generally, the default dimming of your light families will all be 1 or 100%, but this can be changed prior to rendering. When your Rendering Dialog is open, go down to the Lighting section and click on Artificial Lights... Have a look at the image below, the dimming should be on 1 for everything, or simply play around with it until your happy with the end result. 

 

I hope this helps! 

[L.Maas]

I tend to use ligthing fixtures with IES sources. Often I look for lights (e.g seek.autodesk.com) that approach what I need to use. This often gives a better representation of the real life situation. Also several light manufacturer websites (e.g. http://www.lighting.philips.com/main/support/support/revit-library.html) have files Revit families available

[rudi.roux]

I agree with you @L.Maas that the best way is to use IES files which will result in a close to accurate representation when rendering. @Anonymous, my previous post is a way to "manipulate the outputs" which will result in a rendered image which you desire, which can then be handed to the Electrical Engineer to ask for assistance in specifying the correct fitting for the project which will leave you with the desired outside lighting.

Another great resource is Cooper Lighting - they have hundreds of lights and IES files for all of them and Revit Families for about 95% of their Products. 

I hope this helps! 

[Anonymous · Accepted solution]

1.I want to increase the length of the distance that the light is emitted so that the entire column will be illuminated from the fixtures placed at the base of each column.

Use the .ies file for the actual fixture you'll be using.

2.I also want the light to be dim consistently throughout the whole area of emission, rather than very bright at the start and dimmer at the end.

You might be able to achieve this in your rendering, but it will absolutely never happen in real life.  It's called the inverse square law.  If you want even illumination the entire height of the column, you'll have to use a continuous linear fixture on the column.

[rudi.roux]

Hi @Anonymous, 

Hope you're well. I would just like to follow-up regarding your original post and find out if your problem is resolved or if you require additional help? 

[Anonymous]

Finding a light source with the correct beam spread and intensity is what you need.  The higher you want to throw the light the narrower you want your beam spread and higher the intensity.  It will not be an even light effect over the entire distance but it will light from bottom to top.  If you want to light a round column more evenly you might put two fixtures at the base of the column to light one side.  Now the trick is to find such a Revit family from a light fixture manufacturer that you can use to give yourself more realistic results.  I haven't done any light rendering in Revit so I am not much help there.