Luxi turns your iPhone into an incident light meter.
What is Luxi?
Luxi is a small diffusion dome that fits securely over your iPhone’s front-facing camera. When attached and used with a light meter app, Luxi will help you determine the best settings for your DSLR or other camera so that you can take perfectly exposed pictures.
What does it do?
With Luxi, your iPhone becomes a convenient and easy to use incident light meter. Professional light meters with the same features can cost several hundred dollars and require you to carry a whole separate device.
Incident light meters, like Luxi, measure the amount of light falling on the subject you are photographing, not the light reflected by the subject. Incident light meter readings are independent of the subject's reflectance and cannot be fooled by tricky lighting situations like back-lit subjects (e.g. sunset portraits).
Why do I need this?
"I already have a light meter built into my camera; why do I need a separate device?"
The light meter built into all cameras measures reflected light. A reflected light meter shows an appropriate setting for an average of the whole scene. If you are taking a picture of a scene that does not have an average lighting situation, your camera's built-in light meter will not be accurate. Usually, that causes an overexposed or underexposed picture.
Sunset portraits and other pictures with strong back-lighting are common situations, and can be aided by using an incident light meter like Luxi.
"My light meter app already has an incident mode. Why would I need Luxi?"
It is important to capture all of the light falling on your subject. Luxi is designed to work just like a professional incident light meter which can capture light from a 180° angle. When using a light meter app without Luxi, the iPhone camera only receives light from a limited angle which means it doesn't capture all the light. This will produce readings that are both inconsistent and inaccurate.
How to use Luxi with your camera
Readings taken with Luxi can be entered directly into your DSLR or any camera with manual override capability.
We have tested the Luxi and compared its performance against professional handheld light meters and got comparable results. The following picture shows a Luxi side-by-side with a relatively low-end Sekonic L-308 handheld light meter under even lighting conditions.
Why we need your help
We need your help to make Luxi available to everyone because we think everyone should have the tools to take great photos. The initial costs needed to produce Luxi in quantity are high.
With your support, Luxi can begin production and start shipping to Kickstarter backers by late May. Please spread the word and share our project with your friends. Everyone knows at least one photographer!
Note: Luxi is patent pending and will retail for $24.95 (iPhone not included). iPhone, Apple, and Apple logo are registered trademarks of Apple Inc. Sekonic is a registered trademark of Sekonic Corporation.
Luxi in the news!
Emily Price - Mashable
Erin Lodi - DPReview
Michael Zhang - PetaPixel
Dave LeClair - GizMag
Tim Barribeau - Popular Photography
Charlie Sorrel - Cult of Mac
Camillo Miller - The Apple Lounge - From Italy!
Bárbara Pavan - ALTFoto - From Spain!
"Well done, interesting and simple design" -- Dr. Vlad Vyshemirsky, Developer of the Pocket Light Meter app
"I love the idea" -- Mark Meyers, Professional movie camera operator/ steadicam operator. Credits include: Mission Impossible III , Pirates of the Caribbean. IMDB
"Professional photography on your keychain" -- David Weber, Professional Photographer
Luxi web page: www.luximeter.com
Facebook Page: http://www.facebook.com/esdevices
Sparkfactor Design: www.sparkfactordesign.com
Find us on Twitter: @LuxiMeter
See our progress: http://www.esdevices.com/blogs/news
Risks and challenges Learn about accountability on Kickstarter
I collaborated with Sparkfactor Design on this project and they have done a ton of great work designing, prototyping and testing Luxi. I have lined up the same qualified manufacturer who also helped me on my previous Kickstarter project and they are ready to go.
We designed Luxi to work with iPhones without cases. There are too many cases on the market to create a solution that works with them all. Luxi needs to lie flat against the iPhone because it needs a flat surface to seal out any stray light that might interfere with light meter readings. However, Luxi accommodates most protective skins/screen protectors.
Luxi works with any light meter app that can use the front-facing camera and can be calibrated with an offset. We have tested Luxi with many of the light meter apps available for the iPhone.
We're excited to tell you that we have been working with the developer who created Pocket Light Meter to create a Luxi mode which is specifically designed to be used with Luxi. Stay tuned for updates on this. We may also work with additional app developers in the future to create more exciting ways to use Luxi.
Unfortunately not. While Luxi itself has no limitations on this, iPhone light meter apps are unable to detect light coming from flashes due to iPhone hardware limitations.
Update: You spoke and we heard. Due to an abundance of support from backers for iPhone 4/4S compatibility, we have decided to make Luxi available for both the iPhone 4/4S and 5.
We know that there are many photographers with Android phones who would like to use Luxi. However, Luxi works well because it is designed to snugly fit onto the iPhone 5, and it would simply be too daunting to create a different version to custom fit every available brand and model of Android phone.
Yes, it's possible with apps which include this feature. However, we recommend using Luxi for reference purposes only.