diff --git a/dx2/CMakeLists.txt b/dx2/CMakeLists.txt
index ca7b921..bf28b2e 100644
--- a/dx2/CMakeLists.txt
+++ b/dx2/CMakeLists.txt
@@ -1,5 +1,6 @@
 add_library(
     dx2
+    utils.cxx
     reflection.cxx
     h5/h5read_processed.cxx
     h5/h5write.cxx
@@ -9,6 +10,7 @@ add_library(
     goniometer.cxx
     scan.cxx
     detector_attenuations.cxx
+    imagesequence.cxx
 )
 target_link_libraries(
     dx2
diff --git a/dx2/detector.cxx b/dx2/detector.cxx
index 6dde3f4..cb8737e 100644
--- a/dx2/detector.cxx
+++ b/dx2/detector.cxx
@@ -255,6 +255,12 @@ Detector::Detector(json detector_data) {
   }
 }
 
+Detector::Detector(std::vector<Panel> panels) {
+  for (auto it = panels.begin(); it != panels.end(); ++it) {
+    _panels.push_back(*it);
+  }
+}
+
 json Detector::to_json() const {
   json detector_data;
   std::vector<json> panels_array;
diff --git a/dx2/imagesequence.cxx b/dx2/imagesequence.cxx
new file mode 100644
index 0000000..3205a56
--- /dev/null
+++ b/dx2/imagesequence.cxx
@@ -0,0 +1,68 @@
+#include "dx2/imagesequence.hpp"
+
+using json = nlohmann::json;
+
+// Constructor for MultiImage formats e.g. h5.
+ImageSequence::ImageSequence(std::string filename, int n_images)
+    : filename_(filename), n_images_(n_images) {
+  single_file_indices_.reserve(n_images_);
+  for (std::size_t i = 0; i < n_images_; ++i) {
+    single_file_indices_.push_back(i);
+  }
+}
+
+// Constructor for non-MultiImage formats e.g. cbf.
+ImageSequence::ImageSequence(std::string filename) : filename_(filename) {}
+
+ImageSequence::ImageSequence(json imagesequence_data) {
+  std::vector<std::string> required_keys = {"template", "__id__"};
+  for (const auto &key : required_keys) {
+    if (imagesequence_data.find(key) == imagesequence_data.end()) {
+      throw std::invalid_argument("Key " + key +
+                                  " is missing from the input imageset JSON");
+    }
+  }
+  if (imagesequence_data["__id__"] != std::string("ImageSequence")) {
+    throw std::runtime_error("Only ImageSequences are supported");
+  }
+  filename_ = imagesequence_data["template"];
+  if (imagesequence_data.find("single_file_indices") !=
+      imagesequence_data.end()) {
+    // for non-multimage formats (e.g. non-h5), allow parsing.
+    json indices = imagesequence_data["single_file_indices"];
+    single_file_indices_ = {};
+    if (*(indices.begin()) < 0) {
+      throw std::runtime_error("Starting file index <0");
+    }
+    for (json::iterator it = indices.begin(); it != indices.end(); ++it) {
+      single_file_indices_.push_back(*it);
+    }
+    n_images_ = single_file_indices_.size();
+  }
+  imagesequence_data_ =
+      imagesequence_data; // To propagate during serialization/deserialization.
+}
+
+json ImageSequence::to_json() const {
+  json imageset_data = imagesequence_data_;
+  imageset_data["__id__"] = "ImageSequence";
+  imageset_data["template"] = filename_;
+  if (single_file_indices_.size() > 0) { // i.e. MultiImage formats (h5).
+    imageset_data["single_file_indices"] = single_file_indices_;
+  }
+  // Set defaults and null for now.
+  std::vector<std::string> optional_keys = {"mask", "gain", "pedestal", "dx",
+                                            "dy"};
+  for (const auto &key : optional_keys) {
+    if (imagesequence_data_.find(key) == imagesequence_data_.end()) {
+      imageset_data[key] = nullptr;
+    }
+  }
+  if (imagesequence_data_.find("params") == imagesequence_data_.end()) {
+    json params;
+    params["dynamic_shadowing"] = "Auto";
+    params["multi_panel"] = false;
+    imageset_data["params"] = params;
+  }
+  return imageset_data;
+}
\ No newline at end of file
diff --git a/dx2/reflection.cxx b/dx2/reflection.cxx
index df0cc01..369efcc 100644
--- a/dx2/reflection.cxx
+++ b/dx2/reflection.cxx
@@ -4,6 +4,7 @@
  */
 
 #include "dx2/reflection.hpp"
+#include "dx2/utils.hpp"
 #include <algorithm>
 #include <chrono>
 #include <unordered_set>
@@ -142,32 +143,6 @@ void ReflectionTable::merge_into_set(std::unordered_set<size_t> &set,
                                      const std::vector<size_t> &rows) const {
   set.insert(rows.begin(), rows.end());
 }
-
-std::string ReflectionTable::ersatz_uuid4() const {
-  // Generate 16 random bytes
-  std::array<unsigned char, 16> bytes;
-  std::random_device rd;
-  std::uniform_int_distribution<int> dist(0, 255);
-  for (auto &b : bytes) {
-    b = static_cast<unsigned char>(dist(rd));
-  }
-
-  // Convert bytes to a single 128-bit hex string (little endian)
-  std::ostringstream oss;
-  for (auto it = bytes.rbegin(); it != bytes.rend(); ++it) {
-    oss << std::hex << std::setw(2) << std::setfill('0')
-        << static_cast<int>(*it);
-  }
-  std::string hex = oss.str();
-
-  // Format as UUID: 8-4-4-4-12
-  std::ostringstream uuid;
-  uuid << hex.substr(0, 8) << "-" << hex.substr(8, 4) << "-"
-       << hex.substr(12, 4) << "-" << hex.substr(16, 4) << "-"
-       << hex.substr(20, 12);
-
-  return uuid.str();
-}
 #pragma endregion
 
 #pragma region Selection Methods
diff --git a/dx2/utils.cxx b/dx2/utils.cxx
new file mode 100644
index 0000000..48c12f0
--- /dev/null
+++ b/dx2/utils.cxx
@@ -0,0 +1,68 @@
+#include "dx2/utils.hpp"
+#include <Eigen/Dense>
+#include <iomanip>
+#include <math.h>
+#include <random>
+#include <sstream>
+
+using Eigen::Vector3d;
+
+double angle_between_vectors_degrees(Vector3d v1, Vector3d v2) {
+  double l1 = v1.norm();
+  double l2 = v2.norm();
+  double dot = v1.dot(v2);
+  double normdot = dot / (l1 * l2);
+  if (std::abs(normdot - 1.0) < 1E-6) {
+    return 0.0;
+  }
+  if (std::abs(normdot + 1.0) < 1E-6) {
+    return 180.0;
+  }
+  double angle = std::acos(normdot) * 180.0 / M_PI;
+  return angle;
+}
+
+/**
+ * @brief Generate a pseudo-random UUID-like identifier.
+ *
+ * This function replicates the behaviour of the Python function
+ * `ersatz_uuid4` from the dxtbx library. It generates a 128-bit
+ * random value and formats it as a UUID-style string using
+ * little-endian byte order, without enforcing RFC 4122 compliance.
+ *
+ * The output is a 36-character string in the format:
+ * `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`, where each `x` is a
+ * hexadecimal digit.
+ *
+ * @return A string representing the generated UUID-like identifier.
+ *
+ * @note This function does not set the version or variant bits as
+ *       specified in RFC 4122. It is intended for internal use where
+ *       uniqueness is sufficient, and compliance with UUID standards
+ *       is unnecessary.
+ */
+std::string ersatz_uuid4() {
+  // Generate 16 random bytes
+  std::array<unsigned char, 16> bytes;
+  std::random_device rd;
+  std::uniform_int_distribution<int> dist(0, 255);
+  for (auto &b : bytes) {
+    b = static_cast<unsigned char>(dist(rd));
+  }
+
+  // Convert bytes to a single 128-bit hex string (little endian)
+  std::ostringstream oss;
+  for (auto it = bytes.rbegin(); it != bytes.rend(); ++it) {
+    oss << std::hex << std::setw(2) << std::setfill('0')
+        << static_cast<int>(*it);
+  }
+  std::string hex = oss.str();
+
+  // Format as UUID: 8-4-4-4-12
+  std::ostringstream uuid;
+  uuid << hex.substr(0, 8) << "-" << hex.substr(8, 4) << "-"
+       << hex.substr(12, 4) << "-" << hex.substr(16, 4) << "-"
+       << hex.substr(20, 12);
+
+  return uuid.str();
+}
\ No newline at end of file
diff --git a/include/dx2/detector.hpp b/include/dx2/detector.hpp
index af8fd11..0fea7b4 100644
--- a/include/dx2/detector.hpp
+++ b/include/dx2/detector.hpp
@@ -106,6 +106,7 @@ class Detector {
 public:
   Detector() = default;
   Detector(json detector_data);
+  Detector(std::vector<Panel> panels);
   json to_json() const;
   std::vector<Panel> panels() const;
   std::optional<intersection> get_ray_intersection(const Vector3d &s1) const;
diff --git a/include/dx2/experiment.hpp b/include/dx2/experiment.hpp
index d19cc70..8d9bd91 100644
--- a/include/dx2/experiment.hpp
+++ b/include/dx2/experiment.hpp
@@ -4,7 +4,9 @@
 #include <dx2/crystal.hpp>
 #include <dx2/detector.hpp>
 #include <dx2/goniometer.hpp>
+#include <dx2/imagesequence.hpp>
 #include <dx2/scan.hpp>
+#include <dx2/utils.hpp>
 #include <nlohmann/json.hpp>
 
 using Eigen::Vector3d;
@@ -22,7 +24,13 @@ template <class BeamType> class Experiment {
   Detector &detector();
   const Crystal &crystal() const;
   void set_crystal(Crystal crystal);
+  void set_beam(BeamType beam);
+  void set_scan(Scan scan);
+  void set_detector(Detector detector);
+  void set_goniometer(Goniometer goniometer);
+  void set_imagesequence(ImageSequence imagesequence);
   void set_identifier(std::string identifier);
+  void generate_identifier();
 
 protected:
   BeamType _beam{};
@@ -30,7 +38,7 @@ template <class BeamType> class Experiment {
   Goniometer _goniometer{};
   Detector _detector{};
   Crystal _crystal{};
-  json _imageset_json{};
+  ImageSequence _imagesequence{};
   std::string _identifier{};
 };
 
@@ -51,8 +59,9 @@ Experiment<BeamType>::Experiment(json experiment_data) {
   this->_goniometer = gonio;
   this->_detector = detector;
   // Save the imageset json to propagate when saving to file.
-  json imageset_data = experiment_data["imageset"][0];
-  this->_imageset_json = imageset_data;
+  json imagesequence_data = experiment_data["imageset"][0];
+  ImageSequence imagesequence(imagesequence_data);
+  this->_imagesequence = imagesequence;
   try { // We don't always have a crystal model e.g. before indexing.
     json crystal_data = experiment_data["crystal"][0];
     Crystal crystal(crystal_data);
@@ -67,7 +76,6 @@ template <class BeamType> json Experiment<BeamType>::to_json() const {
   json elist_out; // a list of potentially multiple experiments
   elist_out["__id__"] = "ExperimentList";
   json expt_out; // our single experiment
-  // no imageset (for now?).
   expt_out["__id__"] = "Experiment";
   expt_out["identifier"] = _identifier;
   expt_out["beam"] =
@@ -82,7 +90,7 @@ template <class BeamType> json Experiment<BeamType>::to_json() const {
   elist_out["goniometer"] = std::array<json, 1>{_goniometer.to_json()};
   elist_out["beam"] = std::array<json, 1>{_beam.to_json()};
   elist_out["detector"] = std::array<json, 1>{_detector.to_json()};
-  elist_out["imageset"] = std::array<json, 1>{_imageset_json};
+  elist_out["imageset"] = std::array<json, 1>{_imagesequence.to_json()};
 
   if (_crystal.get_U_matrix().determinant()) {
     expt_out["crystal"] = 0;
@@ -115,10 +123,33 @@ void Experiment<BeamType>::set_crystal(Crystal crystal) {
   _crystal = crystal;
 }
 
+template <class BeamType> void Experiment<BeamType>::set_beam(BeamType beam) {
+  _beam = beam;
+}
+
 template <class BeamType> BeamType &Experiment<BeamType>::beam() {
   return _beam;
 }
 
+template <class BeamType> void Experiment<BeamType>::set_scan(Scan scan) {
+  _scan = scan;
+}
+
+template <class BeamType>
+void Experiment<BeamType>::set_detector(Detector detector) {
+  _detector = detector;
+}
+
+template <class BeamType>
+void Experiment<BeamType>::set_goniometer(Goniometer goniometer) {
+  _goniometer = goniometer;
+}
+
+template <class BeamType>
+void Experiment<BeamType>::set_imagesequence(ImageSequence imagesequence) {
+  _imagesequence = imagesequence;
+}
+
 template <class BeamType>
 const std::string &Experiment<BeamType>::identifier() const {
   return _identifier;
@@ -126,4 +157,8 @@ const std::string &Experiment<BeamType>::identifier() const {
 template <class BeamType>
 void Experiment<BeamType>::set_identifier(std::string identifier) {
   _identifier = identifier;
+}
+
+template <class BeamType> void Experiment<BeamType>::generate_identifier() {
+  _identifier = ersatz_uuid4();
 }
\ No newline at end of file
diff --git a/include/dx2/imagesequence.hpp b/include/dx2/imagesequence.hpp
new file mode 100644
index 0000000..a386472
--- /dev/null
+++ b/include/dx2/imagesequence.hpp
@@ -0,0 +1,22 @@
+#pragma once
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+class ImageSequence {
+public:
+  ImageSequence() = default;
+  ImageSequence(std::string filename,
+                int n_images); // Constructor for MultiImage formats e.g. h5.
+  ImageSequence(
+      std::string filename); // Constructor for non-MultiImage formats e.g. cbf.
+  ImageSequence(json imagesequence_data);
+  json to_json() const;
+
+protected:
+  int n_images_{};
+  std::string filename_{};
+  std::vector<std::size_t> single_file_indices_{};
+  json imagesequence_data_{}; // For propagating additional metadata during
+                              // serialization/deserialization.
+};
\ No newline at end of file
diff --git a/include/dx2/reflection.hpp b/include/dx2/reflection.hpp
index 5563f76..4a9c468 100644
--- a/include/dx2/reflection.hpp
+++ b/include/dx2/reflection.hpp
@@ -316,27 +316,6 @@ class ReflectionTable {
   template <typename T>
   struct is_column_predicate<ColumnPredicate<T>> : std::true_type {};
 
-  /**
-   * @brief Generate a pseudo-random UUID-like identifier.
-   *
-   * This function replicates the behaviour of the Python function
-   * `ersatz_uuid4` from the dxtbx library. It generates a 128-bit
-   * random value and formats it as a UUID-style string using
-   * little-endian byte order, without enforcing RFC 4122 compliance.
-   *
-   * The output is a 36-character string in the format:
-   * `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`, where each `x` is a
-   * hexadecimal digit.
-   *
-   * @return A string representing the generated UUID-like identifier.
-   *
-   * @note This function does not set the version or variant bits as
-   *       specified in RFC 4122. It is intended for internal use where
-   *       uniqueness is sufficient, and compliance with UUID standards
-   *       is unnecessary.
-   */
-  std::string ersatz_uuid4() const;
-
 public:
 #pragma region Constructors
   /// Re-exported type aliase for convenience
diff --git a/include/dx2/utils.hpp b/include/dx2/utils.hpp
index 65079b4..a0ea002 100644
--- a/include/dx2/utils.hpp
+++ b/include/dx2/utils.hpp
@@ -1,20 +1,8 @@
 #pragma once
 #include <Eigen/Dense>
-#include <math.h>
 
 using Eigen::Vector3d;
 
-double angle_between_vectors_degrees(Vector3d v1, Vector3d v2) {
-  double l1 = v1.norm();
-  double l2 = v2.norm();
-  double dot = v1.dot(v2);
-  double normdot = dot / (l1 * l2);
-  if (std::abs(normdot - 1.0) < 1E-6) {
-    return 0.0;
-  }
-  if (std::abs(normdot + 1.0) < 1E-6) {
-    return 180.0;
-  }
-  double angle = std::acos(normdot) * 180.0 / M_PI;
-  return angle;
-}
+double angle_between_vectors_degrees(Vector3d v1, Vector3d v2);
+
+std::string ersatz_uuid4();
\ No newline at end of file