Lumi is a computational photography tweak designed to take better and brighter photos in low light. Lumi makes use of LONG exposures by capturing several images to reduce noise and smartly merging them to enhance your low light images. All these operations are done on device itself, completely offline thereby protecting your privacy.

NOT COMPATIBLE WITH IOS 15/16

What devices does Lumi support?

All iPhones as from 6S (iPads are not supported). Full list:

iPhone 6S
iPhone 6S+
iPhone SE
iPhone 7
iPhone 7+
iPhone 8
iPhone 8+
iPhone X
iPhone Xr
iPhone Xs
iPhone Xs Max
iPhone 11
iPhone 11 Pro
iPhone 11 Pro Max
iPhone SE 2

Does not support iphone 12 which already has night mode

What iOS version can i use Lumi on?

As from iOS 13. iOS 12 is not and will not be supported.

Does Lumi work on all cameras?

Lumi works on back wide (main) camera and front camera. Using telephoto lens (2x) is not supported because that lens has very small aperture and is completely useless for low light photography. On iPhone 11 series, Lumi only supports ultra wide and front camera. On main camera, you can use stock night mode. On iPhone 6s/6s+ only back camera is supported.

How does this compare to iPhone 11 night mode?

Contrary to popular beliefs that night mode is only software, the truth is that the software can only do as much as the hardware can provide. If you put a hardcore software on a cheap phone with a crappy camera, you cannot expect it to produce an image as a higher end camera found on a premium phone with same software. The camera hardware differs a lot going from iPhone 6s to iPhone 11. A12 devices will have better results in extreme low light due to longer exposure duration support on main camera.

The iPhone 6s and iPhone SE will only be good in dim to moderate low light environment and quickly deteriorating in dark places. This is due to the following reasons:

Small aperture of f/2.2 (compared to f/1.8 of newer iPhones)
No OIS (optical image stabilisation) hence preventing longer handheld exposures (iPhone 6S+ does have a stabiliser and will perform slightly better in dark environments)
Noisy camera sensor
Mediocre maximum ISO of 1700
Slow processor which prevents the ability to process large number of frames in a reasonable amount of time

iPhone 11 camera is a beast in low light photography due to the high ISO of 3072 and low noise sensor supporting to 1 second of exposure time. Lumi is a cheaper alternative to better low light photos for phones that do not have any kind of night mode and cannot compete with Apple night mode in very low light environments. But in moderate to dim light, the tweak can result in decent photos.

In short, Lumi will not give you mind blowing photos like google pixel or iPhone 11 as they do in extreme low light.

I am an iPhone 11 owner. Why do i need it?

Apple night mode is awesome until you realise that it does not work on other cameras except the main one. Lumi bridges the gap by providing night mode on the selfie and ultra wide camera. Telephoto camera is not supported because it cannot capture enough light in dark situations due to small aperture. Unfortunately the ultra wide camera has a smaller aperture compared to the main camera and lack OIS, hence it cannot produce results as you get on main camera with stock night mode. That said, it will still give you way better images than before.

Does it require internet connection?

Lumi works completely offline. Your photos are processed locally on your device , hence protecting your privacy.

Can i take pictures of moving subjects in low light using this tweak?

Lumi is designed to capture static scenes with no motion. Attempts to capture landscape with windy flowers/tress or pet photos or moving cars will mostly likely end up having blurry parts. Regarding human portraits or selfies, it can be done provided that the subject holds still for about 5 seconds.

Does it require a Tripod?

While Lumi can work handheld, a tripod will yield sharper photos. To minimise handshake during capture, lean against a surface and hold your phone with two hands. Holding your breath helps too, reducing the minor body vibrations!

Can Lumi do astrophotography?

No, Lumi is for general low light photography and does not support shooting starry skies. Astrophotography requires a lot more complex operations.

When i enable Lumi, my camera preview appears laggy. Why?

This happens because Lumi increases exposure time, rather than using the stock frame rate. Doing so enables brighter preview thereby allowing focussing in darker environments. Without this, the camera would see very dark scene and focus would fail resulting in blurry images.

Why does the camera preview looks blown out in day light when Lumi is on?

Lumi is a low light camera tweak and hence is meant to be used in places where the luminosity ranges from moderate to low. Any attempt to use use it in daylight or in bright scenes will results in overexposed previews.

Why does Lumi take so much time to take a photo when stock camera can do it in a blink of an eye?

Stock camera uses a faster shutter speed to produce a sharp image. This works great in bright environment but as the amount of light gets down, a longer shutter speed is need to capture more luminosity. In technical terms, this is called long exposure photography. The keyword here being "long", meaning the shutter will have to remain open for longer periods of time. Since iPhones have pretty small sensors, they produce a lot of noise even at longer exposures. To combat noise, Lumi uses image averaging techniques to taking multiple exposures pictures and smartly merging them. This operation of capturing many long pictures is what makes the process much longer that stock camera app.

How do i save the original stock image?

Lumi uses its own exposure metering and does not work at all with the stock image. The "stock image" is the result of the camera auto exposure and computed iso/shutter speed settings. Since Lumi uses its own settings, there is no way to know what exposure settings the camera app would have chosen and hence it is not possible to save the original image during a Lumi capture. But you can toggle Lumi off and capture a normal image should you wish to.

I don't understand anything about the technical terms you are throwing. Can i still use Lumi?

Yes. Lumi was designed for amateur mobile photographers. All you need to do is:

Tap to focus on your subject (wait for focussing to be slow. Note: Focussing can be very slow in very dark)
Hold still for 5 seconds until Lumi captures multiple images
It will smartly merge them and you can get see your photo from roll

How do i take awesome night pictures?

Choose a moderate/dim scene with uniform lighting (avoid harsh light source like lamps/street lights)
Use a tripod or rest your hands/phone on a surface for maximum sharpness
Always tap to focus before taking each photo and wait for focus to stabilises (Focussing can take 1-3 seconds to lock in dark scenes)
Hold your phone using two hands as it reduces hand motion
Hold your breath if you are doing handheld shot (Yes, this helps!!)
For selfies, do not blink your eyes and try to stay still with minimal head motion
For human portraits, make sure your subjects hold very still for up to 5 seconds
Avoid scenes having any kind of motion like cars, persons, crowds, pets, windy trees