# Capture Requirements

For your Capture System to be compatible with Marso Measure, it must:

* Capture images in RAW format, with manual exposure.
* Capture with the flash enabled, and little to no ambient light.
* Capture against a dark background, ideally black.

If you are unsure whether your system will work with Marso Measure, follow the recommendations below, or contact <info@m-xr.com> to discuss the details of your system.

***

* [Camera](#camera)
* [Lens](#lens)
* [Light(s)](#lights)
* [Capture Scene](#capture-scene)
  1. [Ambient Lighting](#ambient-lighting)
  2. [Background](#background)
  3. [Markers](#markers)
* [Framing](#framing)
* [Coverage](#coverage)
* [Files](#files)

## Camera

Marso Measure has been designed and developed with professional & prosumer cameras in mind, such as DSLRs, mirrorless cameras, and some smartphone cameras.

If you are capturing with multiple cameras, they must all be the same model. Marso Measure can only work with one camera model for each capture.

**Key Points**

* Save images in a RAW file format. Supported RAW formats can be found [here](https://docs.m-xr.com/marso-measure/requirements/capture-requirements/supported-raw-formats).
* Set manual exposure (shutter speed / ISO / Aperture).
* Disable any image stabilisation, either on the lens, camera or both.
* A high aperture number will offer better results, by keeping more of the object in focus.

***

## Lens

We suggest use a lens around 28mm (wide). Marso Measure requires the whole object be kept in frame, see [here](#framing).

Ultra-wide and telephoto lenses are not recommended, due to the increased distortion making a photogrammetry solve more difficult.

***

## Lights

Usually the best option for lighting is the on-board flash, either on your DSLR camera or smartphone. If you don’t have an on-board flash, or wish to use an existing light setup, see [here](https://docs.m-xr.com/marso-measure/requirements/capture-requirements/light-sources).

***

## Capture Scene

#### Ambient Lighting

Ideally the scene would have no ambient light at all. Failing this, the flash must be powerful enough to overpower any ambient light. See below for perfect, okay and bad ambient lighting examples.

{% tabs %}
{% tab title="Perfect Lighting" %}

<div><figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/gRL0DQjNCDpmAS5K3Yp2/AmbientLighting_Gooad_FlashOff.png" alt="" width="300"><figcaption><p>Flash Off</p></figcaption></figure> <figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/RL83BgT7jIxTmzGqGDER/AmbientLighting_Gooad_FlashOn.png" alt="" width="300"><figcaption><p>Flash On</p></figcaption></figure></div>
{% endtab %}

{% tab title="Okay Lighting" %}

<div><figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/sj1evtIbEXpbbMn1JFSU/AmbientLighting_Okay_FlashOff.png" alt="" width="300"><figcaption><p>Flash Off</p></figcaption></figure> <figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/2SjGhkFQtv3F6vEofleB/AmbientLighting_Okay_FlashOn.png" alt="" width="300"><figcaption><p>Flash On</p></figcaption></figure></div>
{% endtab %}

{% tab title="Bad Lighting" %}

<div><figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/Pi77fbdFXjSFOfvBPOZ1/AmbientLighting_Bad_Flash_Off.png" alt="" width="300"><figcaption><p>Flash Off</p></figcaption></figure> <figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/G0KZdhuM7ETPp2ueVKSz/AmbientLighting_Bad_Flash_On.png" alt="" width="300"><figcaption><p>Flash On</p></figcaption></figure></div>
{% endtab %}
{% endtabs %}

#### Background

In addition to reducing the ambient lighting, it is also important to reduce any bounced or reflected light. This is quite easy to do by ensuring that you are shooting against black, or by avoiding too much white in your surrounding area. Please see below for good and back background lighting examples.

{% tabs %}
{% tab title="Good Background" %}

<figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/vNPMD7FHwEnteNK7ST67/backdrop0001.jpg" alt="" width="360"><figcaption></figcaption></figure>
{% endtab %}

{% tab title="Bad Background" %}

<figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/EIcXx6rcG4YC6yZgwEzN/backdrop0000.jpg" alt="" width="360"><figcaption></figcaption></figure>
{% endtab %}
{% endtabs %}

#### Markers

Markers are recommended to improve the accuracy of the photogrammetry solve.

Marso Measure also requires the solved scene to be accurately scaled, so it is a good idea to have at least two markers and measure the distance between them, as this can be used to scale the scene.

If the subject is moving, for example on a turntable, it is **crucial** that the markers also move along with the object.

#### Marker Examples

<div align="left"><figure><img src="https://3944730447-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FdSWZvUSEhiy6J2XcG20t%2Fuploads%2FDo2nCeVwIXZrO6lUfGS6%2FRingFlash_Axe_A%201.png?alt=media&#x26;token=0c4d4e83-da28-4196-ae86-2458df7571c8" alt=""><figcaption></figcaption></figure> <figure><img src="https://3944730447-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FdSWZvUSEhiy6J2XcG20t%2Fuploads%2FuyxSQTHGr5q5TDwCD6rt%2FSmartPhone_ArmChair_B%201.png?alt=media&#x26;token=97b50d19-6f02-4b03-b73d-02c73ba1b072" alt=""><figcaption></figcaption></figure> <figure><img src="https://3944730447-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FdSWZvUSEhiy6J2XcG20t%2Fuploads%2Fc8watdPdtfH7Nr2x0XZv%2FArago_CeramicSake_D%201.png?alt=media&#x26;token=ae6c4564-42e6-43d5-9b12-adcd8f582934" alt=""><figcaption></figcaption></figure></div>

#### Framing

It is important to keep as much of the object within the frame where possible.

{% tabs %}
{% tab title="Perfect Framing" %}

<figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/3mlvj6Bf4Uiqi8OAUzgs/ezgif-4-97315d76e3.gif" alt="" width="300"><figcaption></figcaption></figure>
{% endtab %}

{% tab title="Okay Framing" %}

<div><figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/nOkWRRrSfFco77WF9ZrB/ezgif-4-470c43f884.gif" alt="" width="300"><figcaption></figcaption></figure> <figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/kJOpsKdyPzqrtjY1PoL9/ezgif-4-f9597309b9.gif" alt="" width="300"><figcaption></figcaption></figure></div>
{% endtab %}

{% tab title="Bad Framing" %}

<figure><img src="https://content.gitbook.com/content/dSWZvUSEhiy6J2XcG20t/blobs/QfrG5LR40bWlk9htXWW1/ezgif-4-1d73d11d62.gif" alt="" width="300"><figcaption></figcaption></figure>
{% endtab %}
{% endtabs %}

***

## Coverage

Marso requires a high level of coverage, both above and below your asset. See our full coverage documentation [here](https://docs.m-xr.com/marso-measure/requirements/capture-requirements/coverage).

{% hint style="info" %}
Replicating the coverage maps on this linked page will yield optimal results.
{% endhint %}

***

## Files

Marso expects that all captured images for a single subject will be in a single folder. Files must also be named so that they sort alpha-numerically into the order they were captured in. Most cameras do this automatically.

{% tabs %}
{% tab title="Good" %}
`Cam_000, Cam_001, Cam_002, Cam_003, …`

Names are in order

`DSC_1234, DSC_1235, DSC_1236, DSC_1237, …`\
Names don’t start at 0 but are in order
{% endtab %}

{% tab title="Bad" %}
`Cam_0, Cam_1, … , Cam_10, … , Cam_100`\
Numbers are not padded with 0s to the same length

`Cam_000, Image_001, DSC_002, Cam_003, ...`\
Numbers are ordered, but names are not
{% endtab %}
{% endtabs %}

If you are using multiple lights, the captures for each position should be grouped in the order they were captured when sorted.

The simplest way to do this is to name the files with the position first, followed by the light:\
Position\_X\_Light\_Y.dng