This is an updated version of the HDR Light Studio 1.0 review. Updated information about the 1.5 version is located (mostly) at the end.
Have you ever spent hours searching for the perfect studio HDRI for your product shot, and still ended up with something that is not quite as good as you wanted. Maybe part of the image looks good, but there is that one annoying light that creates a really bad reflection and you end up spending half your day repainting that part of the HDRI in Photoshop. What if you could just select that light and move it, almost as easily as you would move a light inside your 3D application?
HDR Light Studio is like a virtual studio lighting tool that allows you to create just the studio HDRI you need from scratch. You select a light type from a toolbar and place it in the virtual studio. You can then change the light properties, such as watt, falloff, color, size and position. When you are done you render an EXR or HDRI to use in your 3D application. And if you need to change anything, its just a matter of going back into HDR Light Studio, making the change, and re-rendering. To aid you in placing the lights HDR Light Studio lets you render a grid overlay in a low resolution preview HDR file. This will show up in the reflections in your rendering, and can be used as a visual aid in placing your lights.
The main hdr light studio interface (click to zoom)
HDR Light Studio is very easy to use, and you can just jump in and use it without really having to read the manual first. Lights deform correctly in the Lat/Long space as you move them around. You can easily preview different exposures, and easily change the properties of all the lights. Everything can also be controlled precisely by numerical input if needed. HDR Light Studio also has a powerful background synthesis tool that lets you create a background gradient. This tool lets you control the color and luminosity of the background along the vertical axis of your HDRI.
Overall the user interface is great to work with, however there are two minor annoyances. First the application is fixed size, meaning you cannot resize the window. This is not a big deal, bit it would be nice to have the ability to fill a 24" wide screen monitor. The second annoyance is that you can't select lights in the main work area. Until you get used to this behavior you will be using CTRL-Z a lot, since instead of selecting the light you wanted to modify you will instead move the light currently selected in the light list to the position you clicked. You have to select a light in the light list before moving it or changing its properties. However, you do have the ability to scroll through the lights using the Up and Down arrow keys to get to the one you want very fast. This way of working is very different to what you might be used to from other applications, so it could seem a bit strange at first. Once you get used to it, it should not be a problem though.
Main UI A different screenshot of the main UI. (click to zoom).
Render dialog File path, file format and render resolution. (click to zoom)
Background synthesis Flexible background gradient creation. (click to zoom)
Versions and resolutions
HDR Light Studio comes in three different version: Basic, Standard and Pro. Basic only supports three light sources, and can render at a maximum resolution of 3000×1500. Standard supports unlimited light sources and has a maximum resolution of 5000×2500 pixels. Both Basic and Standard can only render certain preset resolutions. Pro also supports unlimited light sources, and also lets you render unlimited custom resolutions.
Using HDR Light Studio with V-Ray
In V-Ray you load the HDRI files generated by HDR Light Studio just like you would any other HDRI. In the VRayHDRI map you set the type to spherical environment, and apply it to the environment overrides of your choice in V-Ray. You can chose to use the environment as both the light source and for reflection/refraction, or you can use it for just one of them. You can also map the HDRI to a dome light. A typical workflow would be to first render a quick preview render with guides, rendering an image in V-Ray, and then using the guidelines in the reflections here to fine tune the lighting in HDR Light Studio. Then repeat this in an iterative process until you are satisfied with the result. Finally you would render a hires HDRI from HDR Light Studio, and use that to make the final render. The workflow is straightforward, and you can get great results.
Workflow in V-Ray RT
You are all probably drooling at the possibility of having interactive rendered feedback while creating custom HDRIs. Unfortunately currently using HDR Light Studio with V-Ray RT has some workflow bottlenecks. The main problem is that V-Ray RT currently does not recognize that an HDR file has changed and keeps using the version of the file that it originally loaded. Even if you make changes and quick render new versions from HDR Light Studio, V-Ray RT will keep using the same version until you close the active shade render and start a new one. All other aspects of using HDRIs from HDR Light Studio in V-Ray RT work just as they do with any other HDRI file.
Chaos Group are working on adding support for recognizing HDR file changes in an update to V-Ray RT, so hopefully this situation will improve in the near future.
New features in HDR Light Studio 1.5:
The Standard and Pro version let you work with a library of real and synthetic lights: HDRI Light Packs.
A new synthetic light system that lets you alter the bulb position, shape and falloff in the standard light types.
Dark Lights - add darkness instead of light in areas
Half Lights - cuts the light in half for when you need a visible horizon line
Solid Lights - are not blended additively. Especially useful for the new real lights which have darker areas along the edges that should not blend with the background.
The user interface has also been updated, among other things improving on the light list scrolling issue that version 1.0 suffered from.
The HDRI Light Packs is a great new addition that takes version 1.5 to a whole new level. The light types in the seven included HDRI Light Packs are Soft Boxes, Spot Lights, Windows, Synthetic Arrays, Window Gobos, Rounded and Guides. The real lights contain lots of little subtle details that show up in reflections and helps increase the realism of your rendering. The synthetic arrays, gobos and rounded shapes can all be useful for various creative effects.
Lights are selected from the HDR Light Studio Warehouse:
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The HDRI files produced by HDR Light Studio can produce some great renderings, and the program is very easy to use. The price is also very sensible for professional use and the program should pay for itself on the first job. The 1.5 release has taken an already great application and made it even better. The negative point of minor UI annoyances is not enough to stop us from recommending this software strongly. Any professional CG artist with a need for studio lighting setups should add HDR Light Studio to the toolbox.