> For the complete documentation index, see [llms.txt](https://guide.cryosparc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://guide.cryosparc.com/processing-data/all-job-types-in-cryosparc/variability/job-3d-variability.md).

# Job: 3D Variability

3DVA

## **Description**

* Compute the principle modes of variability with a dataset of aligned particles. Read a tutorial [here](/processing-data/tutorials-and-case-studies/tutorial-3d-variability-analysis-part-one.md).

## **Input**

* Particles
* Mask

## **Common Parameters**

* `Number of modes to solve`: The number of orthogonal principle modes (i.e. eigenvectors of the 3D covariance) to solve.
* `Filter Resolution (A)`: Resolution at which results are filtered. Typically set between 5 and 10.

{% hint style="info" %}

### Downsampling Particles

Prior to CryoSPARC v5.1, particles were used at their full size in 3DVA. However, the filter resolution is typically coarser than the Nyquist limit for particle images. Downsampling particles before connecting them to a 3D Variability Job such that their Nyquist resolution is slightly finer than the filter resolution can therefore make a 3D Variability job significantly faster.

**In versions of CryoSPARC older than v5.1**, we recommend first using [Downsample Particles](https://guide.cryosparc.com/processing-data/all-job-types-in-cryosparc/extraction/job-downsample-particles) to produce images with a pixel size approximately 0.25 times the filter resolution. For example, for a 5 Å Filter Resolution, the particles should be downsampled such that the pixel size after downsampling is between 1.25 Å, yielding a final Nyquist resolution of 2.5 Å.

**Starting in CryoSPARC v5.1**, particles are automatically downsampled on-the-fly to produce images in which the filter response is 10% at the Nyquist frequency. The exact relationship between this pixel size and the filter resolution is determined by the filter order.
{% endhint %}

## **Output**

* Particles
* Volume

## **Common Next Steps**

* Running a 3D Variability Display job to generate a series of volumes representing frames of motion.