Sunday, October 23, 2016

Huawei P9 monochrome camera - red filter

Having a "monochrome" camera, i.e. a camera that records luminosity only, rather than RGB colors, allows for the good old color filter tricks, without reducing image quality, just as in the days of B&W film. Personally, I would prefer to call the camera filterless, rather than monochrome.

There are a lot good articles what happens when using which filter on B&W film. Here is one of those, please have a look.

Now, what about the loss of quality I was indicating, which does not occur when using a filter-less imaging array?
A regular color image sensor has a filter array printed on it, letting pass red, green or blue light on a respective pixel. In a so called Bayer filter array, the distribution of filters is RGGB. Consequently, only every 4th pixel is sensitive to red light. When using a red filter, for high contrast B&W photography (see article above), the 12 Mpx color camera is turned in a camera having effectively 3Mpx only, since the green and blue pixels will contribute to noise only, potentially creating JPEG artefacts.
In the absence of the RGB filter array, every pixel will be sensitive to all wavelengths, therefore, using a red filter wont affect the resolution or noise levels of the image.

It happens to be the case, that I got some red (LEE Filters 164 Flame Red) gel for spots. Although not perfect, this is pretty good stuff for improvising filters. The filter cuts somewhere in yellow, so, it will result in a little less contrast than a pure red filter.
LEE Filters 164 Flame Red
Those gels are usually just cut to size. So, this is what happened to a small portion of my roll.
A small piece of Scotch tape and the filter gel sits in the P9's case. Mind you, the RGB camera should not be covered!
Small piece of filter gel attached to case

So, what can you expect?
As mentioned above, the filter is a low pass which cuts somewhere in the yellow wavelengths. So, the photographic effect to be expected is in the range between a red and a yellow filter.
To give you an idea, I shot the city hall building, once with the desaturated RGB camera and once with the red gelled filterless camera. As a reference, I added color images from the RGB camera.

Desaturated RGB camera
Red gelled  filterless camera
JPEG converted from RAW (DNG) file
A slightly different angle and one face the shopping mall in Rijswijk. Same test, the effect might be even more obvious here. I metered for the 'IN' sign.

RGB camera

Red gelled filterless camera

JPEG converted from RAW

For the time being, I will keep the Fire Red gel in my phone's case. Should I require all wavelengths, I can easily flip the filter gel away from the camera lens and still keep it inside the case.

Saturday, October 22, 2016

Huawei P9 monochrome camera

Did some comparative photographs today, comparing the desaturated JPEGs from the regular camera and the JPEGs created by the monochrome camera.
The files can be found on this flickr album.
Note that files from the regular camera are indicated by "cof" while files from the monochrome camera are indicated by "mon".

The EXIF data confirms what was to be expected, the monochrome camera is by a bit over 1 f-stop more light sensitive. The monochrome mode could therefore be pretty interesting for low light street-photography. Maybe with image contrast maxed out and image brightness reduced.

Stay tuned for more Huawei P9 imaging experiments, tips and tricks.

Friday, October 21, 2016

Huawei P9 - MONOCHROME mode

Please, HUAWEI, please release a new firmware in which the B&W-camera's data can be written to a DNG-file!

Why oh why would I commence a blog post like this? The hope is that HUAWEI, through a supposedly simple firmware-update, could make this a premium B&W shooter.

Very simple experimentation, i.e. moving a finger in front of the camera modules, reveals, the "MONOCHROME" mode (yes, capitals are used in the menu) indeed uses the camera next to the phone's edge. In a way, that is indeed good news.

In order to judge the quality of the 2 different cameras, I took 2 shots from a photo published by wired.co.uk (credits to Amy Davies) from my laptop's screen.

The first shot is taken with the regular "PRO" mode, desaturated JPEG + RAW(DNG). The second shot was taken with the "MONOCHROME" mode; and yes, I had correct for the parallax of the 2 cameras.

The following images are 100% crops of the same image portion, the pixelation reflects the pixels of my laptop's screen (no camera artefacts!). The DNG-file was opened in RawTherapee.

RAW (DNG) - desaturated JPEG

MONOCHROME JPEG - desaturated JPEG
RAW (DNG) - MONOCHROME JPEG

Clearly, the monochrome camera can pick up the black matrix of my laptop's screen a lot better than the Bayer filter camera, no surprise here.
Further, the dynamic range of the monochrome camera seems a lot better, just like expected.

HUAWEI, it is your hands to turn the P9 a superior camera by allowing to record RAW data from the monochrome sensor. Such a feature would turn that phone into my favourite camera ever easily.

Thursday, September 29, 2016

Huawei P9 / all digital cameras (blue sky trick)

Since digital cameras and white balance settings, there is a trick to turn a dull grey sky into something blue, while keeping you talent (in a close portrait situation) with a very natural appearance.

The images I shot, testing the technique with the P9, I cannot share on the interwebs, sorry for that.
Anyway, here is the technique:

  1. put the camera into the pro mode
  2. select the incandescent (light bulb) white balance (that should turn everything daylight into blue)
  3. force flash (this will fire the flash, which is daylight equivalent)
Should you be confused now, this is what it is all about:
  • the camera "thinks" that white surfaces are illuminated by warm light
  • the camera flash fires at daylight color temperature (usually used for fill-flash)
  • parts of a scene outside the range of the flash will be taken as incandescent
  • parts of a scene within the range of the flash will be illuminated by a daylight spectrum 
Therefore, you will get 2 different color profiles within a single image. 

As indicated before, I tried the method, and it works with the P9, however, I am unable to share the results online.

I wish to point out that this is, next to using polarised filters, a method that cannot be replicated in post-processing.

Wednesday, September 28, 2016

Huawei P9 vs. Wiko Jerry

This might be a somewhat unfair comparison, the Wiko Jerry is a very decent Android phone, no doubt. It sports dual SIM, one of which is full size (adapters provided), in addition to the possibility to add an SD-card.
When it comes to the Huawei P9, the only option are nano-SIMs, while one can choose between a single SIM + SD-card or dual SIM.
Anyway, we are talking photography here. Very obviously, the winner is the Huawei P9.

Below shots a certainly not side-by-side, obviously taken on different days, under distinct conditions.
Anyway, both are in-phone JPEG renderings.
Wiko Jerry
Huawei P9
There is a clear winner. However, the winner is more than 5 times more expensive than the runner up. 

Anyway, what we are looking at is a decent smartphone with a camera, versus a decent prosumer camera with smartphone functions. For a prosumer camera, the Huawei P9 might not be the cheapest, but in the lower segment. Figure that, the Huawei P9 offers a camera with almost full control (no real control over aperture though). 
The Wiko Jerry is a good smartphone, with a 5Mpix shooter that resembles nothing to call home about, although decent enough to take the occasional shot to document something.
In contrast to that, the much more expensive Huawei P9 might actually be the camera you might want to use for artisan work. 
For my next journey, I seriously consider to choose the P9, rather than a real camera, in particular since I get RAW files when using the P9.

The question is, 2 smartphones in the pocket vs 1 smartphone and 1 camera. Certainly 2 smartphones are easier to carry...




Sunday, September 25, 2016

Huawei P9 (long exposures)

The camera of the P9 sports to modes for which a stable mount, such as a tripod, is required: Night Shot and Time-Lapse. Manual shutter settings allow up to 30s exposure in the pro-mode.

How to hold the camera

Of course there are some tripod options available for smartphones. However, those would form an additional piece of kit, which probably will stay home for the most of the time. Also, the ones that are a bit lightweight are also considerably flimsy and might vibrate a while when used with a bigger phone like the P9.

Here is my solution, use a wallet-type case:
Mine cost me €15.  The good thing is, the case will always be with the phone, and so will be the function as a stand. Of course one will need a conveniently shaped handrail, wall, table, window sill, etc., with view. Obviously, this arrangement favours landscape type photographs.
Pro: no extra part to loose... if you lost the case, I guess, you lost the phone.

How to trip the shutter

The next challenge, trigger the shutter w/o introducing vibrations. The built-in camera app offers some interesting alternatives to touching the display.
  • timer
  • audio control
  • volume bottom
Timer delayed shutter release is a technique often used in absence of a remote shutter release. There are some pros and cons with that method. For long exposures, the cons are essentially absent, in particular with a 10s delay. Pro: no extra part to loose.

Audio control, in my view, is only useful in the "above certain dB level"-mode.  With the P9 a finger snip works just fine. Certainly, this method requires a relatively quiet environment. Pro: no extra part to loose.

The volume bottom is mounted on the phone itself, so, what the point, you might ask. Well, I much prefer this as a shutter release over the touch-screen, during regular photography. For long exposure, however, you don't want to touch the phone, right? Well, firstly, think of the timer mentioned above.
But even better: use the headset provided with the P9. Not only do the earbuds sound great, the headset comes with a volume bottom. Guess what, when the camera app is set to releasing the shutter by the volume bottom, you got yourself a real cable shutter release. Con: don't loose the headset!

Tip

The autofocus can be confused, so, I do advise to use manual focus in the pro-mode, if possible.


Example

The following photo is shot from my roof-deck. Wallet case as holding device. Audio controlled shutter, autofocus set to the streetlight in the center. Shooting mode: Night Short.

Saturday, September 24, 2016

Huawei P9

The Huawei P9 created a lot of controversy in the photographic community.  Yes, indeed, this is a cell phone, one of those being known a smart. With my cheap cell phone causing problems once in a while, I decided to get myself a P9, install Lightroom mobile and Snapseed on it, to not only have a better phone, but also a portable photo studio.

There are many reviews out there, giving a lot of tips and tricks, I don't want to redo any of that. Just a quick-tip for black and white photographers who also want to keep RAW files.

One of the criticism I was reading, and I do fully agree, the present software seems not allow to extract the raw data from the B&W camera. Maybe some firmware update or hack could solve that in the future. It would actually be nice to have both raw files, the RGB and the B&W.


Anyway, for the time being, this is what I can recommend.

  • put the camera in pro-mode (otherwise no RAW file!)
  • swipe from the right side to access the settings menu
  • go to the last menu item "Image adjustments"
  • set saturation to -2 (that turns the JPEG file into a B&W)

The other two sliders could be used in a specific B&W-type way:
  • punchy contrasty low key: contrast +2 and brightness -1
  • soft high key: contrast -1 and brightness +2

You get the idea, I guess.

In the presence of JPEG files, the RAW (DNG) files are not shown directly. However, all you need to do is import the DNGs into Lightroom mobile or open them in Snapseed.

Below, 2 images, one out of camera JPEG, the other converted from the DNG. Both exported to the Lightroom gallery, scaled down to 2048px. Settings for the JPEG: contrast -1 and brightness +1.

JPEG
DNG

Switching between the images, you will also notice the distortion correction, which is applied to the JPEG automatically.

I will certainly experiment with this camera a lot. Hopefully I will find the time to also share my experiences.

Update

The above shown trick recording a B&W-JPEG next to the DNG does not work with flash. When flash is activated, strangely, the desaturation does not happen.
Not all is lost during night-time, the desaturation trick does work with the "Steady on" illumination.