diff --git a/RELEASE.md b/RELEASE.md
index 9e50145..c9f5e49 100644
--- a/RELEASE.md
+++ b/RELEASE.md
@@ -7,7 +7,8 @@
 
 - Added a new Minuit2-based fitting framework for ``Gaussian``, ``RisingScurve``, ``FallingScurve``, ``Pol1`` and ``Pol2`` models.
 - setter and getter for nSigma for ClusterFinder ``aare.ClusterFinder().nSigma = 2``, ``aare.ClusterFinderMT().set_nSigma(2)`` 
-- mask opeartor for ClusterVector ``masked_clustervector = aare.ClusterVector()(mask)`` 
+- ``aare.Interpolator.transform_eta_values(np.ndarray)`` can take an array of ``Eta`` structs
+- passing pre computed eta values to ``aare.Interpolator.interpolate`` alongside clusters
 
 ### Bugfixes:
 
diff --git a/include/aare/Interpolator.hpp b/include/aare/Interpolator.hpp
index 548aa91..0fd9fbd 100644
--- a/include/aare/Interpolator.hpp
+++ b/include/aare/Interpolator.hpp
@@ -93,6 +93,26 @@ class Interpolator {
     std::vector<Photon>
     interpolate(const ClusterVector<ClusterType> &clusters) const;
 
+    /**
+     * @brief interpolates the cluster centers for all clusters to a better
+     * precision
+     * @param clusters clusters of photon hits to interpolate
+     * @param etas precomputed eta values for each cluster (must be in the same
+     * order as the clusters)
+     * @return interpolated photons (photon positions are given as double but
+     * following row column format e.g. x=0, y=0 means top row and first column
+     * of frame) (An interpolated photon position of (1.5, 2.5) corresponds to
+     * an estimated photon hit at the pixel center of pixel (1,2))
+     */
+    template <typename T, uint8_t ClusterSizeX, uint8_t ClusterSizeY,
+              typename CoordType = uint16_t,
+              typename Enable = std::enable_if_t<is_cluster_v<
+                  Cluster<T, ClusterSizeX, ClusterSizeY, CoordType>>>>
+    std::vector<Photon> interpolate(
+        const ClusterVector<Cluster<T, ClusterSizeX, ClusterSizeY, CoordType>>
+            &clusters,
+        const std::vector<Eta2<T>> &etas) const;
+
     /**
      * @brief transforms the eta values to uniform coordinates based on the CDF
      * ieta_x and ieta_y
@@ -102,6 +122,17 @@ class Interpolator {
     template <typename T>
     Coordinate2D transform_eta_values(const Eta2<T> &eta) const;
 
+    /**
+     * @brief transforms the eta values to uniform coordinates based on the CDF
+     * ieta_x and ieta_y for a vector of eta values
+     * @tparam T type of eta values
+     * @param etas vector of eta values to transform
+     * @return vector of uniform coordinates {x,y}
+     */
+    template <typename T>
+    std::vector<Coordinate2D>
+    transform_eta_values(const std::vector<Eta2<T>> &etas) const;
+
   private:
     /**
      * @brief bilinear interpolation of the transformed eta values
@@ -190,6 +221,19 @@ Coordinate2D Interpolator::transform_eta_values(const Eta2<T> &eta) const {
     return Coordinate2D{m_ietax(ix, iy, ie), m_ietay(ix, iy, ie)};
 }
 
+template <typename T>
+std::vector<Coordinate2D>
+Interpolator::transform_eta_values(const std::vector<Eta2<T>> &etas) const {
+    std::vector<Coordinate2D> uniform_coordinates;
+    uniform_coordinates.reserve(etas.size());
+
+    for (const auto &eta : etas) {
+        uniform_coordinates.push_back(transform_eta_values(eta));
+    }
+
+    return uniform_coordinates;
+}
+
 template <auto EtaFunction, typename ClusterType, typename Enable>
 std::vector<Photon>
 Interpolator::interpolate(const ClusterVector<ClusterType> &clusters) const {
@@ -265,4 +309,49 @@ Interpolator::interpolate(const ClusterVector<ClusterType> &clusters) const {
     return photons;
 }
 
+template <typename T, uint8_t ClusterSizeX, uint8_t ClusterSizeY,
+          typename CoordType, typename Enable>
+std::vector<Photon> Interpolator::interpolate(
+    const ClusterVector<Cluster<T, ClusterSizeX, ClusterSizeY, CoordType>>
+        &clusters,
+    const std::vector<Eta2<T>> &etas) const {
+
+    if (clusters.size() != etas.size()) {
+        throw std::runtime_error(
+            fmt::format("Size of clusters and precomputed etas must be the "
+                        "same, but got {} clusters and {} etas",
+                        clusters.size(), etas.size()));
+    }
+
+    std::vector<Photon> photons;
+    photons.reserve(clusters.size());
+
+    for (size_t i = 0; i < clusters.size(); ++i) {
+        const auto &cluster = clusters[i];
+        const auto &eta = etas[i];
+
+        Photon photon;
+        photon.x = cluster.x;
+        photon.y = cluster.y;
+        photon.energy = static_cast<decltype(photon.energy)>(eta.sum);
+
+        try {
+            // check if eta values are within bounds
+            transform_eta_values(eta);
+        } catch (const std::runtime_error &e) {
+            throw std::runtime_error(
+                fmt::format("{} for cluster: {}", e.what(), i));
+        }
+
+        auto uniform_coordinates = transform_eta_values(eta);
+
+        photon.x += uniform_coordinates.x;
+        photon.y += uniform_coordinates.y;
+
+        photons.push_back(photon);
+    }
+
+    return photons;
+}
+
 } // namespace aare
\ No newline at end of file
diff --git a/python/aare/__init__.py b/python/aare/__init__.py
index 7684df8..0145f37 100644
--- a/python/aare/__init__.py
+++ b/python/aare/__init__.py
@@ -26,6 +26,8 @@ from ._aare import reduce_to_2x2, reduce_to_3x3
 
 from ._aare import apply_custom_weights
 
+from ._aare import Etai, Etad, Etaf
+
 from .CtbRawFile import CtbRawFile
 from .RawFile import RawFile
 from .ScanParameters import ScanParameters
diff --git a/python/src/bind_Eta.hpp b/python/src/bind_Eta.hpp
index e2f9835..c27012f 100644
--- a/python/src/bind_Eta.hpp
+++ b/python/src/bind_Eta.hpp
@@ -13,12 +13,12 @@ void define_eta(py::module &m, const std::string &typestr) {
 
     py::class_<Eta2<T>>(m, class_name.c_str())
         .def(py::init<>())
-        .def_readonly("x", &Eta2<T>::x, "eta x value")
-        .def_readonly("y", &Eta2<T>::y, "eta y value")
-        .def_readonly("c", &Eta2<T>::c,
-                      "eta corner value cTopLeft, cTopRight, "
-                      "cBottomLeft, cBottomRight")
-        .def_readonly("sum", &Eta2<T>::sum, "photon energy of cluster");
+        .def_readwrite("x", &Eta2<T>::x, "eta x value")
+        .def_readwrite("y", &Eta2<T>::y, "eta y value")
+        .def_readwrite("c", &Eta2<T>::c,
+                       "eta corner value cTopLeft, cTopRight, "
+                       "cBottomLeft, cBottomRight")
+        .def_readwrite("sum", &Eta2<T>::sum, "photon energy of cluster");
 }
 
 void define_corner_enum(py::module &m) {
diff --git a/python/src/bind_Interpolator.hpp b/python/src/bind_Interpolator.hpp
index 8bc5ebf..8ee87eb 100644
--- a/python/src/bind_Interpolator.hpp
+++ b/python/src/bind_Interpolator.hpp
@@ -11,17 +11,20 @@
 
 namespace py = pybind11;
 
+// clang-format off
 #define REGISTER_INTERPOLATOR_ETA2(T, N, M, U)                                 \
     register_interpolate<T, N, M, U, aare::calculate_full_eta2<T, N, M, U>>(   \
         interpolator, "_full_eta2", "full eta2");                              \
     register_interpolate<T, N, M, U, aare::calculate_eta2<T, N, M, U>>(        \
-        interpolator, "", "eta2");
+        interpolator, "", "eta2");                                             \
+    register_interpolate_costum_eta<T, N, M, U>(interpolator);
 
 #define REGISTER_INTERPOLATOR_ETA3(T, N, M, U)                                 \
     register_interpolate<T, N, M, U, aare::calculate_eta3<T, N, M, U>>(        \
         interpolator, "_eta3", "full eta3");                                   \
     register_interpolate<T, N, M, U, aare::calculate_cross_eta3<T, N, M, U>>(  \
         interpolator, "_cross_eta3", "cross eta3");
+// clang-format on 
 
 template <typename Type, uint8_t CoordSizeX, uint8_t CoordSizeY,
           typename CoordType = uint16_t, auto EtaFunction>
@@ -48,6 +51,34 @@ void register_interpolate(py::class_<aare::Interpolator> &interpolator,
         docstring.c_str(), py::arg("cluster_vector"));
 }
 
+template <typename Type, uint8_t ClusterSizeX, uint8_t ClusterSizeY,
+          typename CoordType = uint16_t>
+void register_interpolate_costum_eta(
+    py::class_<aare::Interpolator> &interpolator) {
+
+    using ClusterType = Cluster<Type, ClusterSizeX, ClusterSizeY, CoordType>;
+
+    interpolator.def(
+        "interpolate",
+        [](aare::Interpolator &self, const ClusterVector<ClusterType> &clusters,
+           const std::vector<Eta2<Type>> &etas) {
+            auto photons = self.interpolate<Type, ClusterSizeX, ClusterSizeY, CoordType>(clusters, etas);
+            auto *ptr = new std::vector<Photon>{photons};
+            return return_vector(ptr);
+        },
+        R"(
+        Interpolation based on custom eta values provided by the user. 
+
+        Args:
+        cluster_vector: vector of clusters to interpolate
+        etas: vector of eta values for each cluster (must be in the same order as the clusters)
+
+        Returns:
+        interpolated photons
+        )",
+        py::arg("cluster_vector"), py::arg("etas"));
+}
+
 template <typename Type>
 void register_transform_eta_values(
     py::class_<aare::Interpolator> &interpolator) {
@@ -61,10 +92,27 @@ void register_transform_eta_values(
         py::arg("Eta"));
 }
 
+template <typename Type>
+void register_transform_eta_values_vector(
+    py::class_<aare::Interpolator> &interpolator) {
+    interpolator.def(
+        "transform_eta_values",
+        [](Interpolator &self, const std::vector<Eta2<Type>> &etas) {
+            auto uniform_coords = self.transform_eta_values(etas);
+
+           auto* ptr = new std::vector<Coordinate2D>{uniform_coords};
+           return return_vector(ptr);
+        },
+        R"(vector of eta values transformed to uniform coordinates based on CDF ietax, ietay)",
+        py::arg("Etas"));
+}
+
 void define_interpolation_bindings(py::module &m) {
 
     PYBIND11_NUMPY_DTYPE(aare::Photon, x, y, energy);
 
+    PYBIND11_NUMPY_DTYPE(aare::Coordinate2D, x, y);
+
     auto interpolator =
         py::class_<aare::Interpolator>(m, "Interpolator")
             .def(py::init(
@@ -157,6 +205,10 @@ void define_interpolation_bindings(py::module &m) {
     register_transform_eta_values<float>(interpolator);
     register_transform_eta_values<double>(interpolator);
 
+    register_transform_eta_values_vector<int>(interpolator);
+    register_transform_eta_values_vector<float>(interpolator);
+    register_transform_eta_values_vector<double>(interpolator);
+
     // TODO! Evaluate without converting to double
     m.def(
         "hej",
diff --git a/python/tests/test_InterpolationAPI.py b/python/tests/test_InterpolationAPI.py
new file mode 100644
index 0000000..77bef50
--- /dev/null
+++ b/python/tests/test_InterpolationAPI.py
@@ -0,0 +1,31 @@
+import pytest 
+
+from aare import Interpolator, ClusterVector, Etai, Cluster
+
+import numpy as np 
+
+
+def test_interpolation_api():
+    eta_distribution = np.zeros((10, 10, 1)) # dummy eta distribution 
+    etax_bins = np.linspace(0, 1.0, 11) 
+    etay_bins = np.linspace(0, 1.0, 11)
+    e_bins = np.array([0., 10.]) # dummy energy bins
+    interpolator = Interpolator(eta_distribution, etax_bins, etay_bins, e_bins)
+
+    cluster_vector = ClusterVector()
+    cluster_vector.push_back(Cluster(10, 5, np.ones(shape=9, dtype=np.int32)))
+    cluster_vector.push_back(Cluster(20, 10, np.ones(shape=9, dtype=np.int32)))
+
+    eta1 = Etai()
+    eta1.x = 0.1
+    eta1.y = 0.1
+    eta1.sum = 5
+    eta2 = Etai()
+    eta2.x = 0.1
+    eta2.y = 0.9
+    eta2.sum = 6
+    etas = np.array([eta1, eta2]) # dummy etas for the clusters
+
+    photons = interpolator.interpolate(cluster_vector, etas)
+
+    assert photons.size == 2
\ No newline at end of file