Tag Archive for: colorchecker

Calibrations demystified

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Calibrations are essential and easy

Let’s first take a look at what a calibration is.
I’m writing this blogpost in English.
I chose English because I know that most people in the world understand English better than Dutch. And the fact I don’t speak any languages as good as Dutch and English.

So because I’m writing this in English everyone reading this understands me.
And this is because we use rules and letters in combinations that we agreed upon as the English language.

And with calibrations it’s the same.
We have many different devices ranging from your camera, to your printer, monitor and scanner.
Some devices are capture devices, some are output devices, but they all use different techniques, and still you want your images to look exactly the same on all devices right?

Luckily there is a solution for this.

Home Theater

When we look at the home theater market calibrations are done to get the optimal image quality out of your tv or projector setup. During these calibrations high-end calibration devices and software are used costing thousands of dollars, and in most cases there is no auto-mode 😀

Now you might wonder, “what is optimal image quality?”
Is this “max light output?”, “the best colors?”
And what is best, or max?

Well luckily there are rules for this.
For most TVs and projectors we use the REC709 colourspace for SDR material (normal HD material) and BT2020 or P3 for the new HDR material.
For the correct colors in the ISF (Imaging Science Foundation) setup we use the D6500 standard.

During a calibration for a tv or projector we look at the following settings.
User settings like Contrast and Brightness to set the perfect dynamic range.
Grayscale for the correct color temperature
CMS (Color Management System) for the correct colors per colourspace.
Gamma for the brightness curve
Extra features like sharpness, iris, motion flow etc.

Because the same rules the calibration follows is also followed by everyone that makes professional movies we can now see the movie exactly as the director intended on our projectors or TVs. And we all know that color evokes emotion, so seeing the correct colors and colortone can have a huge impact on the movie experience.

For Photography and video

Now for Home Theater the process can be complicated and you need to know what you’re doing (I’ve been doing it since 2001 and still have to learn every new format and display) but the workflow is very basic and simple. We just follow what the movie industry follows. For photography it’s the other way around almost.

For photography the process itself is super simple but we have a lot of different devices and things we have to take care off to get it all working together.
So lets take a look at what we can encounter.

First off we have the input devices

Cameras, scanners etc are input devices. This means we have a file that has to be used as our reference file.
One of the tools that’s essential for a fast calibration is the Calibrate Colorchecker passport.
The process is very simple, you just shoot the colorchecker with proper lighting (use a lightmeter) and you can use the included Lightroom plugin or the standalone version.

Now we have to make sure we follow the workflow
After you restart Lightroom you select the colorchecker profile you created from the custom profiles and sync this to the rest of the images you shot with this setup. And indeed when you use the colorchecker with your camera it’s highly recommended to shoot a new colorchecker image with every change in your setup. If you are not incredibly critical you can also create one profile for your camera/strobe combination. It will not be 100% correct but it will be close.

One thing I always do is when I select the profile from the menu you see here, just before syncing I’ll do a quick colorbalance with the colorbalance tool in Lightroom.

Now lets look at the output devices

Output devices can be for example a monitor or printer.
Now we already looked at the colorchecker for the input devices and believe it or not for the output devices we use a similar technique with one difference, now we need a device to meter what the monitor or printer outputs.

I personally really like the Calibrite products due to their ease of use and quality, plus they work with the hardware calibrations on the BenQ monitors I use.
But you can also use other brands of course, just make sure you replace your analyser every few years because they will deteriorate over time.

For the printer we need a so called spectroradiometer and for the monitor we can use the same technique but also a much cheaper solution like for example tristimuls meters. But without getting to technical.

The calibration is very simple.
I’ll walk you through the more advanced version.

You start the software.
Use the following settings:
Color Temp D6500 (some setups depend on D54 but you will know if that’s you)
Gamma 2.2 (2.4) depending on your preference and room.
Lightoutput 110-130cdm depending on your ambient light conditions.
Profile V2

These are the settings you will find in almost all software, and will give you a perfectly calibrated screen.
Now the software will ask you to activate this profile and send you a reminder after X weeks, please don’t ignore that because calibrations do change over time. After you activate the calibration you’re done.

Different profiles, so now what?

By now we have created several profiles.
The colorchecker creates both DCP (Adobe) and ICC profiles.
The monitor calibration creates an ICC profile etc.
But luckily we don’t have to worry about them anymore. The profiles are now exactly where they should be. In the operating system for the monitor and in Lightroom for your camera where you can now select it and sync to the photos shot with that combination.

Why do I mention this?
A lot of people ask me which profile to use when opening files in Photoshop from Lightroom, the monitor profile or the camera profile?
Well both are wrong, how weird it might sound, you can’t use any of them.

When you open up a file in Photoshop you should always select the colourspace that you want to work in, being sRGB, AdobeRGB or ProphotoRGB.
If your monitor is capable of showing 99% AdobeRGB, thanks to the calibration you will now see all the colors as close to accurate as possible, but also when you have to work in another colourspace the monitor and calibration will make sure you are still seeing the correct colors.

Some things to make sure are in place

For a correct and easy workflow there are some things you have to take care off.
When using HDMI make sure your monitor is setup for 0-255 as dynamic range. (16-235 is for video)
Make sure there is no light hitting your monitor, BenQ delivers a nice hood with most of their photography monitors and these can make a huge difference.
As mentioned before a color analyser deteriorates over time, so make sure to replace it every once in a while. The same goes for the colorchecker, and for the colorchecker you can extend it’s life a lot by keeping it out of the sun when not using.

 

This is one part in the series on calibration and colorprofiles, make sure to check the blog for much more.
If you’re in the market for a new monitor, we have some 10% discount codes for BenQ monitors for European customers, mail us for more information.

 

 

Colorspaces explained

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Today I’m sharing a video where I answer some of the questions about colourspaces and calibrations that are often asked during workshops and can really confuse people. I hope this video makes it a bit more clear.

Register for the free webinar about capturing stunning colours and achieve a accurate workflow

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Register for the free webinar about capturing stunning colours and achieving an accurate workflow

One of the most important things about photography and a reliable workflow is calibration.
In essence, by calibrating your workflow, you make sure you get the results you need. Not just colours but also black/shadow and white/highlights detail. So register now for the free webinar about capturing stunning colours and mor. And if you cannot attend live, you will receive a recording.

In all the workshops I teach it always shocks me how many people don’t use ColorCheckers, white balance tools, or even take the time to calibrate their monitor. And it’s not hard, it’s in fact such an important part of the workflow that the software/hardware is designed to be fast and easy to use.

In this free webinar in cooperation with our friends from Calibrite I talk about :
Calibration of the monitor
Using the ColorChecker Duo
The differences between the ColorCheckers

How colours interact
Why we use light meters
Using calibration when working with gels

You also get to see 2 “live” photoshoots where I talk about lens flares, filling in shadows with color, and using gels for extra impact to your shots.

And that’s not all.
We end the broadcast with several color manipulation tips and tricks in Lightroom and Photoshop.

Register via the link below.
You don’t want to miss this one.

free webinar about capturing stunning colours and achieve an accurate workflow

click on the image to register for the free webinar

Solving the P30 Pro color problems

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Let me start out by saying that I’m horrified by the fact that no-one saw this in reviews. It goes without saying that I always have my doubts with reviewers that review smartphones for photography. I strongly have the opinion that those reviewers hardly take any time to shoot serious stuff with the cameras, maybe it’s because of time constraints or it’s simply because they don’t know about DNG.

Long story short (because I could really rant about this), it’s the reviewers we trust, they often get cameras or other devices before the general public and let’s be honest we often determine our spending on their advice. In the past reviews with the P20 Pro I already had my doubts because according to most reviews the images were not more than ok, and only slightly above for example Samsung and Apple….. from the start I suspected them to use the P20Pro on JPG and 10MP because when I shot the P20Pro I was over the moon with the DNG/RAW files on 40MP, but the 10MP JPGs…… mawh not that much, over processed and not color accurate, actually exactly what the reviewers said. Now when you bring a phone like the P20Pro and now the P30Pro on the market aimed so strongly at photographers I really and I mean REALLY can’t figure out why they don’t give the cameras to real photographers that do real work with it. As soon as the P30Pro was announced I was ready, ready to be amazed, come on this is Huawei a brand 2 years ago I would not think about buying but ever since the P20Pro I’ve been a Huawei fanboy, and no I’m NOT affiliated with them, I paid full retail for my phone and they didn’t even a funky color so I ended up with black.

My p30Pro arrived and I couldn’t wait to test it out, to my horror this was not what I expected, images were horrendous. Not in sharpness or noise, not on JPG those rock, and even the video is A LOT better, but my beloved DNG/RAW files on 40MP with all due respect I have no other name for it than…. not accurate at all, not by a mile. At that point also my frustration started to build, all those reviews, all those people that have millions of views and claim to be professionals in their trade…. is it my device? is it me? so i started asking around online, now not a lot of people owned the P30Pro but the once that did to my surprise ALL confirmed that reds were indeed funky, and trust me it’s not just the reds.

Ok so what’s going on?

In essence it’s not that hard to figure out.
The P30Pro is using a new sensor, let’s keep it simple.
A normal sensor captures RGB (often in a Bayer pattern), but this new sensor captures RYYB, meaning not Red, Green and Blue but Red, Yellow, Yellow, Blue. In essence this means more light capture but it also brings a problem. In a balanced colorspace we work with a blackbody curve on which our white point sits (often revered as D65, or 65K or 6500) When you draw a line through these points you end up with a balanced system where Red connects with Cyan, Blue connects with Yellow and Green connects with Magenta. let’s visualize this, this is a REC709 colorspace rendered in 2D. Just ignore the dots, it’s a report from one of my ISF calibrations.

As you can see, the primaries colors are RGB and the secondary colors are CMY.
Normally a colorspace is 3 dimensional. This means that every color has a fixed coordinate, for red REC 709 for example this is

RGB color space parameters[2]
Color space White point Primaries
xW yW xR yR xG yG xB yB
ITU-R BT.709 0.3127 0.3290 0.64 0.33 0.30 0.60 0.15 0.06

And this goes for everything. So Adobe RGB, ProPhoto RGB, REC709, BT2020, P3 etc. all colorspaces that have fixed coordinates for the colors, this way we always know where the colors should be. Now we can manipulate these colors actually pretty simple. Because it’s a 3 Dimensional colorspace we use the so called HSL settings to get the colors in their position. (Hue, Saturation, Luminance) Now this is not the complete story, because there is also something called Gamma but let’s keep it “simple” for now.

Ok so the first images I took with the P30 Pro looked like this.
First the RAW file without any adjustments and after that the JPG and although the JPG is slightly over saturated it’s actually pretty accurate, that thing is really really red.

Ok so you don’t have to be a genius to see that this is not right, and again I really can’t understand why no “professional”  reviewer did not see this.
In essence what’s probably going wrong is that by creating green out of the yellow they shift red towards orange (which is what you see) however when you look closely you see that also blues and cyans are affected, which is to be expected seeing a colorspace is a “balance” thing, if the balance is not 100% ALL colors shift.

Now this got me thinking.
Some people said it must be a problem with the sensor, but that doesn’t make any sense at all. Think about it, the RAW file is captured, and from there the JPG is created, not the other way around, so why would the RAW file be wrong and the JPG correct. The weird thing however is that both in the native app on the P30Pro as in Lightroom CC as in Capture One the P30Pro files just are wrong.

At first of course you panic and you think the worst.
But let’s be honest, what is the first thing I learn you guys when you visit my channel/workshops etc.?
right always calibrate your screen and use the colorcheckers. So I decided to do the same thing but now with my P30Pro.

This is shot with the Xrite colorchecker SG
This is a really nice colorchecker with plenty of patches so you can create nice smooth correction files.

Now this is a HUGE mess, reds, skintones, blues… well let’s be fair almost every color is totally wrong, and not for a small amount.
Luckily Xrite delivers some really nice software to create custom profiles. And it’s not hard, just export from Lightroom, or Capture One and the software does it’s magic. And indeed… voila.
same Raw file

And there we go, now this is something I recognize.

So what do we do?
Well until Huawei somehow fixes their RAW/DNG files (and that shouldn’t be hard seeing it’s only a wrong profiling) you will have to use a separate profile for your DNGs. And again its really easy to build and in all honesty if you’re serious about photography you probably already own a colorchecker.

So is this it?
no I wish, there still is a huge problem for P30Pro owners. Although the files are not lost and you can easily correct them you do have to realize that this is a problem that is very serious, all the apps on your phone that are able to work with RAW files like for example Snapseed, Lightroom CC etc. will all suffer from problems when you open the files directly, meaning editing the RAWs on your phone is NOT possible (if you want accurate colors), so Huawei really has to change this in software and create a proper ICC profile for their DNG files. Luckily this is solvable with software, it’s simply put creating a correct correction file and it’s done. So let’s hope that this maybe helps a bit.

Now what do I think of the phone?
It’s awesome. Love the new screen and look, it’s blazingly fast, it’s even able to decode 1080P .ts streams on the fly to cast to chromecast without any hickups, video looks really nice and smooth in 4K and stunning stabilization in 1080. Fingerprint sensor just works and the camera…. oh man really don’t start about the cameras.

Having a wide angle, standard and 5-10x zoom is just plain awesome.
I would love to have the wide and standard on 40MP but let’s be honest 20MP wide and 40MP is pretty cool too. Oh and the selfie camera is also great (finally)

Just fix the colors on your main MAJOR selling point sensor.
Oh and next time…. maybe first send a device to people that know how to shoot RAW 🙂 (hint hint)

As always feel free to leave comments below. I’ll post some images soon which I took with the camera, but trust me…. run to the store and get one.