Spherical lenses charts

The very 1st sharpness charts specially made for 8K cameras ... and more.

The very 1st sharpness charts specially made for 8K cameras and more.

Prêt À Tourner offers the world's first range of optical charts with an unrivaled, very high definition printing for this type of product and designed to offer you maximum comfort and speed of execution, thanks to its numerous adjustment tools.

YOTTA Chart by Prêt À Tourner
YOTTA Chart 92x158 cm by Prêt À Tourner
Sharpness calibration chart
Loca Images - Paris - France

RVZ - Paris - France

Time saving

Each P.A.T. camera sharpness chart has the indispensable tools and aid to realize the best camera test. Cameras that have grown increasingly sophisticated and sensitive literally shorten the length of your day in test. Our charts are made to make you gain time, comfort, and efficiency. You don’t have to take the chart off the wall; everything you need is here.

Comfort and aesthetics

In addition, P.A.T. charts have a sleek and elegant design. All the tools are based on technology but the materials and designs that make up the charts have been thought to highlight your business. Above all, your printed logo on each chart makes them fully yours on your company premises. They are useful and beautiful charts to create beauty. Our main concern is ultimately the same as yours: creating beautiful pictures to make beautiful movies.

Technological advance

But that does not end what makes the Prêt à Tourner Charts so unique. We offer you the possibility to get a real technological head start on the test of your cameras and lenses. As a matter of fact, we found the way to print the very small to allow you printing 250 pairs of lines per millimeter on your sensor, filming the entire chart in full frame. We are the first one to reach that impressive high level of printing on formats 150 cm width. Today, no sensor is accurate enough to reach this definition.

Otto Nemenz International - Los Angeles - USA
Otto Nemenz International - Los Angeles - USA

They trust us...

" Last year we needed a big change within our chart testing room, we needed the best for the best Camera teams that usually test our equipment.  So we started looking around and visiting some rental houses around europe to get some ideas.

It was during our visit to IBC in Amsterdam when we met Stéphane and his company PRET A TOURNER.  We finally found what we where looking for, what we think are the best CHARTS in the market.

But the best was to come. We bought 3 x EXA charts, 1 x YOTTA chart + 1 Anamorphic Chart and... we thought Stephane was going to send the charts by Courier... but we were so glad to discover that he, himself was going to drive the charts to us directly from Marseille to EPC in Madrid.  He wanted to bring the charts and explain to us how to use them properly, he also wanted to know our company and meet our team.

So we not only discovered his company, we had the chance to get to know Stéphane as a person, and we became friends. He is so involved with what he has created, and we love it!!!  We like that passion he puts in his company, he really believes he has the best charts in the market,  and so we do !!!!!!!!! Early this year,  EPC TENERIFE ( Canary Islands ) decided to buy 2 more EXA charts. "

Oscar Perez Medina, head manager, EPC (Equipos Profesionales Cinematograficos) - Spain
PAT harts at EPC Madrid
EPC Panavision - Madrid - Spain

Yotta chart 92x158 cm
EPC Panavision - Madrid - Spain


All our workshop charts have the following technical characteristics. All these characteristics - incredible fineness of printing, different targets, circular, linear or star, integral magnetic support helped by the aluminium corner - have been thought out and brought together with a single aim : the optimization of your calibration test.  

250 pairs-of-lines

250 pairs of lines per millimeter

The unrivaled printing quality for such kind of large format offers, for the very first time, the opportunity to print up to 250 line pairs on the sensor, filming the entire chart in full-frame (Yotta chart). No other sensor has been able to reach that definition so far!


Circular Targets

Find circular targets with different sizes all over the chart. The numbers in the circular targets, in twentieths of a millimeter, stand for the number of line pairs printed on 1 millimeter. Numbers go from 4 up to 55.


Linear Targets

Find linear targets with different sizes all over the chart. The numbers in the linear targets, in twentieths of a millimeter, stand for the number of line pairs printed on 1 millimeter. Numbers go from 4 up to 55.


Siemens Targets

Find many Siemens charts all over the board to manage an easy and quick sharpness calibration.


Frames Leaders

No need to take the chart off the wall to make the frame leader test! The mainframe leaders are on the chart: 1.33 – 1.78 – 1.89 – 2.00 – 2.39.

Magnetic Support

The entire support of the chart is magnetized to facilitate the manipulation, using a metallic wall and even magnetic paint. This magnetic support at the back is your assurance of the immediate flatness of the chart.

Aluminium corner

Aluminium Corner

Our charts are fully protected by an aluminum frame. Light and rigid, it helps the manipulation during the tests and prevents bending over time.


Mat Coating

The mat coating of the charts protects the printed ink and avoids any light reflection that could disturb the test. Most of all, you can write on it!

Exa chart 73x125 cm at FD Times (1)
Exa chart 73x125 cm at Film & Digital Times - New York - USA

Exa chart 73x125 cm at FD Times (2)
Exa chart 73x125 cm at Film & Digital Times - New York - USA


We have developed 3 sizes of charts for you to calibrate your spherical optics:

  • YOTTA Chart 92x158cm : The Yotta chart is more suitable for large 8K full-frame sensors with a diagonal greater than 40 mm, as it will cover the entire image at an optimal test distance.
  • EXA Chart 73x125cm : The Exa chart, an excellent compromise, is perfect for 4K/6K cameras with a diagonal sensor of about 30/35 mm.
  • TERA Chart 55x90cm : The Tera is perfect for smaller cameras and smaller test spaces while benefiting from the same technical features and options as its 2 big sisters.

YOTTA Chart 92×158 cm


EXA Chart 73×125 cm


TERA Chart 55×90 cm

EMIT-Paris-France Prêt À Tourner sharpness chart EXA

Indie Locations-Lyon-France Prêt À Tourner sharpness chart EXA
Indie Locations-Lyon-France


 YOTTA ChartEXA ChartTERA Chart
Dimensions (cm)158 x 92 x 1.3125 x 73 x 1.390 x 55 x 1.3
Dimensions (inches)62 x 36 x 0.549 x 28 x 0.536 x 20 x 0.5
Weight5.5 kg / 12.1 lbs4.5 kg / 9.9 lbs3.5 kg / 7.7 lbs
Optimum printing definition5 pairs of lines / mm5 pairs of lines / mm5 pairs of lines / mm
Circular targetsYesYesYes
Dimensions of the central circular target 45 x 45 cm 35 x 35 cm 25 x 25 cm
Linear TargetsYesYesYes
Siemens TargetsYesYesYes
Frame leadersYesYesYes
Magnetic supportYesYesYes
Anti-bending aluminium cornerYesYesYes
Mat coatingYesYesYes
Magnetic customization area (option)YesYesYes
Magnetic annotation areas (option) 5 4 3
Magnetic neutral grey (option)YesYesYes
Magnetic grey scale and grey gradation (option)YesNoNo
Level bubble (option)YesYesYes
Mirror centering aid (option)YesYesYes
ColorChecker® (option)YesYesYes
Vocas - The Netherlands - Prêt À Tourner (2)
Vocas - The Netherlands
Vocas - The Netherlands - Prêt À Tourner (1)
Vocas - The Netherlands


You have the opportunity to complement your charts with many options. These options are designed to save you precious time and provide comfort during your optical tests, while reinforcing the identification and image of your company.

We propose the entirety of these options in 2 kits that you can find in the shop when ordering your chart:

  • A complete kit including all the options: customization on all the annotation areas by adding your company logo, magnetic annotation areas (technical information, neutral grey, grey scales for the Yotta, optical calibration scale), bubble level, centering mirror, ColorChecker® Classic.
  • A kit including all options except the ColorChecker® Classic. This choice can be financially interesting if you wish to order several charts. Colorimetry tests take a short time in a test day and one color chart can be enough for several test units.


You have the possibility to personalize your chart thanks to the magnetic annotation area provided for this purpose.


Magnetic Annotation Areas

Write down useful and indispensable technical information on the magnetic writable and erasable annotations areas. This tool shields the entire chart against time.


Optical Wedge Scale

The optical wedge scale enables you to evaluate and quantify the sharpness of spherical and anamorphic lenses. It gives mathematical data of the sharpness to facilitate technical exchanges between users, such as camera assistants and camera technicians.


Magnetic Neutral Grey

Add a 18% neutral grey using the dedicated magnetic area.


Magnetic grey scale and grey gradation

2 cross grey scales with 21 steps and 2 cross grey gradation can also be added as magnets on the chart.


ColorChecker® Classic

Digital cameras may require some color test. You have the possibility to add a ColorChecker Classic® using the Velcro® pads in the middle of the chart without removing it from the wall.


Magnetic Mirror Centering Aid

Here is a very smart and useful aid to win time on your camera test! The mirror is handy when it comes to placing the chart perfectly parallel to the image plane in a matter of seconds.


Level Bubble

You have the possibility to add a very useful bubble level on the top of the chart.

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