diff --git a/conda-recipe/meta.yaml b/conda-recipe/meta.yaml
index dd2b682..6eeec38 100644
--- a/conda-recipe/meta.yaml
+++ b/conda-recipe/meta.yaml
@@ -1,6 +1,6 @@
 package:
   name: aare
-  version: 2025.1.7.dev0 #TODO! how to not duplicate this?
+  version: 2025.1.9.dev0 #TODO! how to not duplicate this?
 
 
 source:
diff --git a/include/aare/ClusterFile.hpp b/include/aare/ClusterFile.hpp
index a484560..8274078 100644
--- a/include/aare/ClusterFile.hpp
+++ b/include/aare/ClusterFile.hpp
@@ -59,10 +59,9 @@ class ClusterFile {
     ClusterFile(const std::filesystem::path &fname, size_t chunk_size = 1000,
                 const std::string &mode = "r");
     ~ClusterFile();
-    std::vector<Cluster3x3> read_clusters(size_t n_clusters);
-    std::vector<Cluster3x3> read_frame(int32_t &out_fnum);
-    void write_frame(int32_t frame_number,
-                     const ClusterVector<int32_t> &clusters);
+    ClusterVector<int32_t> read_clusters(size_t n_clusters);
+    ClusterVector<int32_t> read_frame();
+    void write_frame(const ClusterVector<int32_t> &clusters);
     std::vector<Cluster3x3>
     read_cluster_with_cut(size_t n_clusters, double *noise_map, int nx, int ny);
 
diff --git a/include/aare/ClusterFileSink.hpp b/include/aare/ClusterFileSink.hpp
new file mode 100644
index 0000000..158fdeb
--- /dev/null
+++ b/include/aare/ClusterFileSink.hpp
@@ -0,0 +1,56 @@
+#pragma once
+#include <atomic>
+#include <filesystem>
+#include <thread>
+
+#include "aare/ProducerConsumerQueue.hpp"
+#include "aare/ClusterVector.hpp"
+#include "aare/ClusterFinderMT.hpp"
+
+namespace aare{
+
+class ClusterFileSink{
+    ProducerConsumerQueue<ClusterVector<int>>* m_source;
+    std::atomic<bool> m_stop_requested{false};
+    std::atomic<bool> m_stopped{true};
+    std::chrono::milliseconds m_default_wait{1};
+    std::thread m_thread;
+    std::ofstream m_file;
+
+
+    void process(){
+        m_stopped = false;
+        fmt::print("ClusterFileSink started\n");
+        while (!m_stop_requested || !m_source->isEmpty()) { 
+            if (ClusterVector<int> *clusters = m_source->frontPtr();
+                clusters != nullptr) {
+                // Write clusters to file
+                int32_t frame_number = clusters->frame_number(); //TODO! Should we store frame number already as int?
+                uint32_t num_clusters = clusters->size();
+                m_file.write(reinterpret_cast<const char*>(&frame_number), sizeof(frame_number));
+                m_file.write(reinterpret_cast<const char*>(&num_clusters), sizeof(num_clusters));
+                m_file.write(reinterpret_cast<const char*>(clusters->data()), clusters->size() * clusters->item_size());
+                m_source->popFront();
+            }else{
+                std::this_thread::sleep_for(m_default_wait);
+            }
+        }
+        fmt::print("ClusterFileSink stopped\n");
+        m_stopped = true;
+    }
+
+    public:
+        ClusterFileSink(ClusterFinderMT<uint16_t, double, int32_t>* source, const std::filesystem::path& fname){
+            m_source = source->sink();
+            m_thread = std::thread(&ClusterFileSink::process, this);
+            m_file.open(fname, std::ios::binary);
+        }
+        void stop(){
+            m_stop_requested = true;
+            m_thread.join();
+            m_file.close();
+        }
+};
+
+
+} // namespace aare
\ No newline at end of file
diff --git a/include/aare/ClusterFinder.hpp b/include/aare/ClusterFinder.hpp
index 2fe33a7..4a06c31 100644
--- a/include/aare/ClusterFinder.hpp
+++ b/include/aare/ClusterFinder.hpp
@@ -64,13 +64,13 @@ class ClusterFinder {
             m_clusters = ClusterVector<CT>(m_cluster_sizeX, m_cluster_sizeY);
         return tmp;
     }
-    void find_clusters(NDView<FRAME_TYPE, 2> frame) {
+    void find_clusters(NDView<FRAME_TYPE, 2> frame, uint64_t frame_number = 0) {
         // // TODO! deal with even size clusters
         // // currently 3,3 -> +/- 1
         // //  4,4 -> +/- 2
         int dy = m_cluster_sizeY / 2;
         int dx = m_cluster_sizeX / 2;
-
+        m_clusters.set_frame_number(frame_number);
         std::vector<CT> cluster_data(m_cluster_sizeX * m_cluster_sizeY);
         for (int iy = 0; iy < frame.shape(0); iy++) {
             for (int ix = 0; ix < frame.shape(1); ix++) {
diff --git a/include/aare/ClusterFinderMT.hpp b/include/aare/ClusterFinderMT.hpp
index d3cbaf6..9765512 100644
--- a/include/aare/ClusterFinderMT.hpp
+++ b/include/aare/ClusterFinderMT.hpp
@@ -7,6 +7,7 @@
 
 #include "aare/NDArray.hpp"
 #include "aare/ProducerConsumerQueue.hpp"
+#include "aare/ClusterFinder.hpp"
 
 namespace aare {
 
@@ -21,7 +22,6 @@ struct FrameWrapper {
     NDArray<uint16_t, 2> data;
 };
 
-
 template <typename FRAME_TYPE = uint16_t, typename PEDESTAL_TYPE = double,
           typename CT = int32_t>
 class ClusterFinderMT {
@@ -32,10 +32,8 @@ class ClusterFinderMT {
     using OutputQueue = ProducerConsumerQueue<ClusterVector<int>>;
     std::vector<std::unique_ptr<InputQueue>> m_input_queues;
     std::vector<std::unique_ptr<OutputQueue>> m_output_queues;
-    
-    
-    OutputQueue m_sink{1000}; //All clusters go into this queue
 
+    OutputQueue m_sink{1000}; // All clusters go into this queue
 
     std::vector<std::unique_ptr<Finder>> m_cluster_finders;
     std::vector<std::thread> m_threads;
@@ -43,26 +41,24 @@ class ClusterFinderMT {
     std::chrono::milliseconds m_default_wait{1};
 
     std::atomic<bool> m_stop_requested{false};
-    std::atomic<bool> m_processing_threads_stopped{false};
+    std::atomic<bool> m_processing_threads_stopped{true};
 
     void process(int thread_id) {
         auto cf = m_cluster_finders[thread_id].get();
         auto q = m_input_queues[thread_id].get();
         // TODO! Avoid indexing into the vector every time
         fmt::print("Thread {} started\n", thread_id);
-        //TODO! is this check enough to make sure we process all the frames?
-        while (!m_stop_requested || !q->isEmpty()) { 
-            if (FrameWrapper *frame = q->frontPtr();
-                frame != nullptr) {
+        // TODO! is this check enough to make sure we process all the frames?
+        while (!m_stop_requested || !q->isEmpty()) {
+            if (FrameWrapper *frame = q->frontPtr(); frame != nullptr) {
                 // fmt::print("Thread {} got frame {}, type: {}\n", thread_id,
-                        //    frame->frame_number, static_cast<int>(frame->type));
+                //    frame->frame_number, static_cast<int>(frame->type));
 
                 switch (frame->type) {
                 case FrameType::DATA:
-                    cf->find_clusters(
-                        frame->data.view());
+                    cf->find_clusters(frame->data.view(), frame->frame_number);
                     m_output_queues[thread_id]->write(cf->steal_clusters());
-                    
+
                     break;
 
                 case FrameType::PEDESTAL:
@@ -79,22 +75,22 @@ class ClusterFinderMT {
             } else {
                 std::this_thread::sleep_for(m_default_wait);
             }
-            
         }
         fmt::print("Thread {} stopped\n", thread_id);
     }
 
     /**
-     * @brief Collect all the clusters from the output queues and write them to the sink
+     * @brief Collect all the clusters from the output queues and write them to
+     * the sink
      */
-    void collect(){
+    void collect() {
         bool empty = true;
-        while(!m_stop_requested || !empty || !m_processing_threads_stopped){
+        while (!m_stop_requested || !empty || !m_processing_threads_stopped) {
             empty = true;
             for (auto &queue : m_output_queues) {
                 if (!queue->isEmpty()) {
 
-                    while(!m_sink.write(std::move(*queue->frontPtr()))){
+                    while (!m_sink.write(std::move(*queue->frontPtr()))) {
                         std::this_thread::sleep_for(m_default_wait);
                     }
                     queue->popFront();
@@ -118,7 +114,6 @@ class ClusterFinderMT {
         for (size_t i = 0; i < n_threads; i++) {
             m_input_queues.emplace_back(std::make_unique<InputQueue>(200));
             m_output_queues.emplace_back(std::make_unique<OutputQueue>(200));
-
         }
 
         start();
@@ -126,14 +121,22 @@ class ClusterFinderMT {
 
     ProducerConsumerQueue<ClusterVector<int>> *sink() { return &m_sink; }
 
-    void start(){
+    /**
+     * @brief Start all threads
+     */
+
+    void start() {
         for (size_t i = 0; i < m_n_threads; i++) {
             m_threads.push_back(
                 std::thread(&ClusterFinderMT::process, this, i));
         }
+        m_processing_threads_stopped = false;
         m_collect_thread = std::thread(&ClusterFinderMT::collect, this);
     }
 
+    /**
+     * @brief Stop all threads
+     */
     void stop() {
         m_stop_requested = true;
         for (auto &thread : m_threads) {
@@ -143,42 +146,74 @@ class ClusterFinderMT {
         m_collect_thread.join();
     }
 
-    void sync(){
+    /**
+     * @brief Wait for all the queues to be empty
+     */
+    void sync() {
         for (auto &q : m_input_queues) {
-            while(!q->isEmpty()){
+            while (!q->isEmpty()) {
                 std::this_thread::sleep_for(m_default_wait);
             }
         }
+        for (auto &q : m_output_queues) {
+            while (!q->isEmpty()) {
+                std::this_thread::sleep_for(m_default_wait);
+            }
+        }
+        while (!m_sink.isEmpty()) {
+            std::this_thread::sleep_for(m_default_wait);
+        }
     }
 
+    /**
+     * @brief Push a pedestal frame to all the cluster finders. The frames is
+     * expected to be dark. No photon finding is done. Just pedestal update.
+     */
     void push_pedestal_frame(NDView<FRAME_TYPE, 2> frame) {
-        FrameWrapper fw{FrameType::PEDESTAL, 0, NDArray(frame)};
+        FrameWrapper fw{FrameType::PEDESTAL, 0,
+                        NDArray(frame)}; // TODO! copies the data!
 
         for (auto &queue : m_input_queues) {
             while (!queue->write(fw)) {
-                // fmt::print("push_pedestal_frame: queue full\n");
                 std::this_thread::sleep_for(m_default_wait);
             }
         }
     }
 
-    void find_clusters(NDView<FRAME_TYPE, 2> frame) {
-        FrameWrapper fw{FrameType::DATA, 0, NDArray(frame)};
-        while (!m_input_queues[m_current_thread%m_n_threads]->write(fw)) {
+    /**
+     * @brief Push the frame to the queue of the next available thread. Function
+     * returns once the frame is in a queue.
+     * @note Spin locks with a default wait if the queue is full.
+     */
+    void find_clusters(NDView<FRAME_TYPE, 2> frame, uint64_t frame_number = 0) {
+        FrameWrapper fw{FrameType::DATA, frame_number,
+                        NDArray(frame)}; // TODO! copies the data!
+        while (!m_input_queues[m_current_thread % m_n_threads]->write(fw)) {
             std::this_thread::sleep_for(m_default_wait);
         }
         m_current_thread++;
     }
 
-    ClusterVector<int> steal_clusters(bool realloc_same_capacity = false) {
-        ClusterVector<int> clusters(3,3);
-        for (auto &finder : m_cluster_finders) {
-            clusters += finder->steal_clusters();
+    auto pedestal() { 
+        if (m_cluster_finders.empty()) {
+            throw std::runtime_error("No cluster finders available");
         }
-        return clusters;
+        if(!m_processing_threads_stopped){
+            throw std::runtime_error("ClusterFinderMT is still running");
+        }
+        return m_cluster_finders[0]->pedestal(); 
+    }
+
+    auto noise() { 
+        if (m_cluster_finders.empty()) {
+            throw std::runtime_error("No cluster finders available");
+        }
+        if(!m_processing_threads_stopped){
+            throw std::runtime_error("ClusterFinderMT is still running");
+        }
+        return m_cluster_finders[0]->noise(); 
     }
 
-    
     // void push(FrameWrapper&& frame) {
     //     //TODO! need to loop until we are successful
     //     auto rc = m_input_queue.write(std::move(frame));
diff --git a/include/aare/ClusterVector.hpp b/include/aare/ClusterVector.hpp
index a1b3a62..efad448 100644
--- a/include/aare/ClusterVector.hpp
+++ b/include/aare/ClusterVector.hpp
@@ -41,9 +41,9 @@ template <typename T, typename CoordType=int16_t> class ClusterVector {
      * @param capacity initial capacity of the buffer in number of clusters
      */
     ClusterVector(size_t cluster_size_x = 3, size_t cluster_size_y = 3,
-                  size_t capacity = 1024)
+                  size_t capacity = 1024, uint64_t frame_number = 0)
         : m_cluster_size_x(cluster_size_x), m_cluster_size_y(cluster_size_y),
-          m_capacity(capacity) {
+          m_capacity(capacity), m_frame_number(frame_number) {
         allocate_buffer(capacity);
     }
     ~ClusterVector() {
@@ -55,7 +55,7 @@ template <typename T, typename CoordType=int16_t> class ClusterVector {
     ClusterVector(ClusterVector &&other) noexcept
         : m_cluster_size_x(other.m_cluster_size_x),
           m_cluster_size_y(other.m_cluster_size_y), m_data(other.m_data),
-          m_size(other.m_size), m_capacity(other.m_capacity) {
+          m_size(other.m_size), m_capacity(other.m_capacity), m_frame_number(other.m_frame_number) {
         other.m_data = nullptr;
         other.m_size = 0;
         other.m_capacity = 0;
@@ -70,9 +70,11 @@ template <typename T, typename CoordType=int16_t> class ClusterVector {
             m_data = other.m_data;
             m_size = other.m_size;
             m_capacity = other.m_capacity;
+            m_frame_number = other.m_frame_number;
             other.m_data = nullptr;
             other.m_size = 0;
             other.m_capacity = 0;
+            other.m_frame_number = 0;
         }
         return *this;
     }
@@ -147,6 +149,12 @@ template <typename T, typename CoordType=int16_t> class ClusterVector {
         return 2*sizeof(CoordType)  +
                m_cluster_size_x * m_cluster_size_y * sizeof(T);
     }
+
+    /**
+     * @brief Return the size in bytes of a single cluster
+     */
+    size_t item_size() const { return element_offset(); }
+
     /**
      * @brief Return the offset in bytes for the i-th cluster
      */
@@ -176,6 +184,12 @@ template <typename T, typename CoordType=int16_t> class ClusterVector {
 
     uint64_t frame_number() const { return m_frame_number; }
     void set_frame_number(uint64_t frame_number) { m_frame_number = frame_number; }
+    void resize(size_t new_size) {
+        if (new_size > m_capacity) {
+            allocate_buffer(new_size);
+        }
+        m_size = new_size;
+    }
 
   private:
     void allocate_buffer(size_t new_capacity) {
diff --git a/include/aare/File.hpp b/include/aare/File.hpp
index 7aa30e1..1cef898 100644
--- a/include/aare/File.hpp
+++ b/include/aare/File.hpp
@@ -36,6 +36,8 @@ class File {
     File(File &&other) noexcept;
     File& operator=(File &&other) noexcept;
     ~File() = default;
+
+    // void close();                             //!< close the file
       
     Frame read_frame();                       //!< read one frame from the file at the current position
     Frame read_frame(size_t frame_index);     //!< read one frame at the position given by frame number
diff --git a/pyproject.toml b/pyproject.toml
index 35bdefb..1b75d02 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "scikit_build_core.build"
 
 [project]
 name = "aare"
-version = "2025.1.7.dev0"
+version = "2025.1.9.dev0"
 
 [tool.scikit-build]
 cmake.verbose = true
diff --git a/python/aare/__init__.py b/python/aare/__init__.py
index fb34c7a..b0c9de2 100644
--- a/python/aare/__init__.py
+++ b/python/aare/__init__.py
@@ -8,6 +8,8 @@ from ._aare import DetectorType
 from ._aare import ClusterFile
 from ._aare import hitmap
 
+from ._aare import ClusterFinderMT, ClusterCollector, ClusterFileSink
+
 from .CtbRawFile import CtbRawFile
 from .RawFile import RawFile
 from .ScanParameters import ScanParameters
diff --git a/python/examples/play.py b/python/examples/play.py
index 9c07c99..95da2e5 100644
--- a/python/examples/play.py
+++ b/python/examples/play.py
@@ -8,18 +8,19 @@ import numpy as np
 import boost_histogram as bh
 import time
 
-from aare import File, ClusterFinder, VarClusterFinder
+from aare import File, ClusterFinder, VarClusterFinder, ClusterFile
 
 base = Path('/mnt/sls_det_storage/matterhorn_data/aare_test_data/')
 
 f = File(base/'Moench03new/cu_half_speed_master_4.json')
 
 
-from aare._aare import ClusterFinderMT, ClusterCollector
+from aare._aare import ClusterFinderMT, ClusterCollector, ClusterFileSink
 
 
 cf = ClusterFinderMT((400,400), (3,3), n_threads = 3)
-collector = ClusterCollector(cf)
+# collector = ClusterCollector(cf)
+out_file = ClusterFileSink(cf, "test.clust")
 
 for i in range(1000):
     img = f.read_frame()
@@ -34,13 +35,13 @@ for i in range(100):
 
 # time.sleep(1)
 cf.stop()  
-collector.stop()
-cv = collector.steal_clusters()
-print(f'Processed {len(cv)} frames')
-
+out_file.stop()
 print('Done')
 
 
+cfile = ClusterFile("test.clust")
+
+
 
 
 # cf = ClusterFinder((400,400), (3,3))
diff --git a/python/src/cluster.hpp b/python/src/cluster.hpp
index 90c9f21..459de44 100644
--- a/python/src/cluster.hpp
+++ b/python/src/cluster.hpp
@@ -1,7 +1,8 @@
+#include "aare/ClusterCollector.hpp"
+#include "aare/ClusterFileSink.hpp"
 #include "aare/ClusterFinder.hpp"
 #include "aare/ClusterFinderMT.hpp"
 #include "aare/ClusterVector.hpp"
-#include "aare/ClusterCollector.hpp"
 #include "aare/NDView.hpp"
 #include "aare/Pedestal.hpp"
 #include "np_helper.hpp"
@@ -9,13 +10,12 @@
 #include <cstdint>
 #include <filesystem>
 #include <pybind11/pybind11.h>
-#include <pybind11/stl_bind.h>
 #include <pybind11/stl.h>
+#include <pybind11/stl_bind.h>
 
 namespace py = pybind11;
 using pd_type = double;
 
-
 template <typename T>
 void define_cluster_vector(py::module &m, const std::string &typestr) {
     auto class_name = fmt::format("ClusterVector_{}", typestr);
@@ -64,42 +64,51 @@ void define_cluster_finder_mt_bindings(py::module &m) {
                  auto view = make_view_2d(frame);
                  self.push_pedestal_frame(view);
              })
-        .def("find_clusters",
-             [](ClusterFinderMT<uint16_t, pd_type> &self,
-                py::array_t<uint16_t> frame) {
-                 auto view = make_view_2d(frame);
-                 self.find_clusters(view);
-                 return;
-             })
-        .def("sync", &ClusterFinderMT<uint16_t, pd_type>::sync)
         .def(
-            "steal_clusters",
+            "find_clusters",
             [](ClusterFinderMT<uint16_t, pd_type> &self,
-               bool realloc_same_capacity) {
-                auto v = new ClusterVector<int>(
-                    self.steal_clusters(realloc_same_capacity));
-                return v;
+               py::array_t<uint16_t> frame, uint64_t frame_number) {
+                auto view = make_view_2d(frame);
+                self.find_clusters(view, frame_number);
+                return;
             },
-            py::arg("realloc_same_capacity") = false)
-        .def("stop", &ClusterFinderMT<uint16_t, pd_type>::stop);
+            py::arg(), py::arg("frame_number") = 0)
+        .def("sync", &ClusterFinderMT<uint16_t, pd_type>::sync)
+        .def("stop", &ClusterFinderMT<uint16_t, pd_type>::stop)
+        .def_property_readonly("pedestal",
+                               [](ClusterFinderMT<uint16_t, pd_type> &self) {
+                                   auto pd = new NDArray<pd_type, 2>{};
+                                   *pd = self.pedestal();
+                                   return return_image_data(pd);
+                               })
+        .def_property_readonly("noise",
+                               [](ClusterFinderMT<uint16_t, pd_type> &self) {
+                                   auto arr = new NDArray<pd_type, 2>{};
+                                   *arr = self.noise();
+                                   return return_image_data(arr);
+                               });
 }
 
-
 void define_cluster_collector_bindings(py::module &m) {
     py::class_<ClusterCollector>(m, "ClusterCollector")
-        .def(py::init<ClusterFinderMT<uint16_t, double, int32_t>*>())
+        .def(py::init<ClusterFinderMT<uint16_t, double, int32_t> *>())
         .def("stop", &ClusterCollector::stop)
-        .def("steal_clusters",
-             [](ClusterCollector &self) {
-                 auto v = new std::vector<ClusterVector<int>>(
-                     self.steal_clusters());
-                 return v;
-             }, py::return_value_policy::take_ownership);
-
-
-
+        .def(
+            "steal_clusters",
+            [](ClusterCollector &self) {
+                auto v =
+                    new std::vector<ClusterVector<int>>(self.steal_clusters());
+                return v;
+            },
+            py::return_value_policy::take_ownership);
 }
 
+void define_cluster_file_sink_bindings(py::module &m) {
+    py::class_<ClusterFileSink>(m, "ClusterFileSink")
+        .def(py::init<ClusterFinderMT<uint16_t, double, int32_t> *,
+                      const std::filesystem::path &>())
+        .def("stop", &ClusterFileSink::stop);
+}
 
 void define_cluster_finder_bindings(py::module &m) {
     py::class_<ClusterFinder<uint16_t, pd_type>>(m, "ClusterFinder")
@@ -133,12 +142,15 @@ void define_cluster_finder_bindings(py::module &m) {
                 return v;
             },
             py::arg("realloc_same_capacity") = false)
-        .def("find_clusters", [](ClusterFinder<uint16_t, pd_type> &self,
-                                 py::array_t<uint16_t> frame) {
-            auto view = make_view_2d(frame);
-            self.find_clusters(view);
-            return;
-        });
+        .def(
+            "find_clusters",
+            [](ClusterFinder<uint16_t, pd_type> &self,
+               py::array_t<uint16_t> frame, uint64_t frame_number) {
+                auto view = make_view_2d(frame);
+                self.find_clusters(view);
+                return;
+            },
+            py::arg(), py::arg("frame_number") = 0);
 
     m.def("hitmap",
           [](std::array<size_t, 2> image_size, ClusterVector<int32_t> &cv) {
diff --git a/python/src/cluster_file.hpp b/python/src/cluster_file.hpp
index 82870c4..5280e5f 100644
--- a/python/src/cluster_file.hpp
+++ b/python/src/cluster_file.hpp
@@ -28,16 +28,13 @@ void define_cluster_file_io_bindings(py::module &m) {
              py::arg(), py::arg("chunk_size") = 1000, py::arg("mode") = "r")
         .def("read_clusters",
              [](ClusterFile &self, size_t n_clusters) {
-                 auto *vec =
-                     new std::vector<Cluster3x3>(self.read_clusters(n_clusters));
-                 return return_vector(vec);
+                auto v = new ClusterVector<int32_t>(self.read_clusters(n_clusters));
+                return v;
              })
         .def("read_frame",
              [](ClusterFile &self) {
-                 int32_t frame_number;
-                 auto *vec =
-                     new std::vector<Cluster3x3>(self.read_frame(frame_number));
-                 return py::make_tuple(frame_number, return_vector(vec));
+                auto v = new ClusterVector<int32_t>(self.read_frame());
+                return v;
              })
         .def("write_frame", &ClusterFile::write_frame)
         .def("read_cluster_with_cut",
@@ -59,12 +56,11 @@ void define_cluster_file_io_bindings(py::module &m) {
              })
         .def("__iter__", [](ClusterFile &self) { return &self; })
         .def("__next__", [](ClusterFile &self) {
-            auto vec =
-                new std::vector<Cluster3x3>(self.read_clusters(self.chunk_size()));
-            if (vec->size() == 0) {
+            auto v = new ClusterVector<int32_t>(self.read_clusters(self.chunk_size()));
+            if (v->size() == 0) {
                 throw py::stop_iteration();
             }
-            return return_vector(vec);
+            return v;
         });
 
         m.def("calculate_eta2", []( aare::ClusterVector<int32_t> &clusters) {
diff --git a/python/src/file.hpp b/python/src/file.hpp
index 30fa82f..f20e0ce 100644
--- a/python/src/file.hpp
+++ b/python/src/file.hpp
@@ -124,8 +124,41 @@ void define_file_io_bindings(py::module &m) {
             self.read_into(reinterpret_cast<std::byte *>(image.mutable_data()),
                            n_frames);
             return image;
+        })
+        .def("__enter__", [](File &self) { return &self; })
+        .def("__exit__",
+             [](File &self,
+                const std::optional<pybind11::type> &exc_type,
+                const std::optional<pybind11::object> &exc_value,
+                const std::optional<pybind11::object> &traceback) {
+                //  self.close();
+             })
+        .def("__iter__", [](File &self) { return &self; })
+        .def("__next__", [](File &self) {
+
+            try{
+                const uint8_t item_size = self.bytes_per_pixel();
+                 py::array image;
+                 std::vector<ssize_t> shape;
+                 shape.reserve(2);
+                 shape.push_back(self.rows());
+                 shape.push_back(self.cols());
+                 if (item_size == 1) {
+                     image = py::array_t<uint8_t>(shape);
+                 } else if (item_size == 2) {
+                     image = py::array_t<uint16_t>(shape);
+                 } else if (item_size == 4) {
+                     image = py::array_t<uint32_t>(shape);
+                 }
+                 self.read_into(
+                     reinterpret_cast<std::byte *>(image.mutable_data()));
+                 return image;
+            }catch(std::runtime_error &e){
+                throw py::stop_iteration();
+            }
         });
 
+
     py::class_<FileConfig>(m, "FileConfig")
         .def(py::init<>())
         .def_readwrite("rows", &FileConfig::rows)
diff --git a/python/src/module.cpp b/python/src/module.cpp
index 0ef868b..451a6b8 100644
--- a/python/src/module.cpp
+++ b/python/src/module.cpp
@@ -28,5 +28,6 @@ PYBIND11_MODULE(_aare, m) {
     define_cluster_finder_mt_bindings(m);
     define_cluster_file_io_bindings(m);
     define_cluster_collector_bindings(m);
+    define_cluster_file_sink_bindings(m);
 
 }
\ No newline at end of file
diff --git a/src/ClusterFile.cpp b/src/ClusterFile.cpp
index 0e5b93e..f62b7c9 100644
--- a/src/ClusterFile.cpp
+++ b/src/ClusterFile.cpp
@@ -34,8 +34,7 @@ void ClusterFile::close() {
     }
 }
 
-void ClusterFile::write_frame(int32_t frame_number,
-                              const ClusterVector<int32_t> &clusters) {
+void ClusterFile::write_frame(const ClusterVector<int32_t> &clusters) {
     if (m_mode != "w") {
         throw std::runtime_error("File not opened for writing");
     }
@@ -43,26 +42,27 @@ void ClusterFile::write_frame(int32_t frame_number,
         !(clusters.cluster_size_y() == 3)) {
         throw std::runtime_error("Only 3x3 clusters are supported");
     }
+    int32_t frame_number = clusters.frame_number();
     fwrite(&frame_number, sizeof(frame_number), 1, fp);
     uint32_t n_clusters = clusters.size();
     fwrite(&n_clusters, sizeof(n_clusters), 1, fp);
     fwrite(clusters.data(), clusters.element_offset(), clusters.size(), fp);
-    // write clusters
-    // fwrite(clusters.data(), sizeof(Cluster), clusters.size(), fp);
 }
 
-std::vector<Cluster3x3> ClusterFile::read_clusters(size_t n_clusters) {
+ClusterVector<int32_t> ClusterFile::read_clusters(size_t n_clusters) {
     if (m_mode != "r") {
         throw std::runtime_error("File not opened for reading");
     }
-    std::vector<Cluster3x3> clusters(n_clusters);
+    
+    ClusterVector<int32_t> clusters(3,3, n_clusters);
 
     int32_t iframe = 0; // frame number needs to be 4 bytes!
     size_t nph_read = 0;
     uint32_t nn = m_num_left;
     uint32_t nph = m_num_left; // number of clusters in frame needs to be 4
 
-    auto buf = reinterpret_cast<Cluster3x3 *>(clusters.data());
+    // auto buf = reinterpret_cast<Cluster3x3 *>(clusters.data());
+    auto buf = clusters.data();
     // if there are photons left from previous frame read them first
     if (nph) {
         if (nph > n_clusters) {
@@ -73,7 +73,7 @@ std::vector<Cluster3x3> ClusterFile::read_clusters(size_t n_clusters) {
             nn = nph;
         }
         nph_read += fread(reinterpret_cast<void *>(buf + nph_read),
-                          sizeof(Cluster3x3), nn, fp);
+                          clusters.item_size(), nn, fp);
         m_num_left = nph - nn; // write back the number of photons left
     }
 
@@ -88,7 +88,7 @@ std::vector<Cluster3x3> ClusterFile::read_clusters(size_t n_clusters) {
                     nn = nph;
 
                 nph_read += fread(reinterpret_cast<void *>(buf + nph_read),
-                                  sizeof(Cluster3x3), nn, fp);
+                                  clusters.item_size(), nn, fp);
                 m_num_left = nph - nn;
             }
             if (nph_read >= n_clusters)
@@ -102,7 +102,7 @@ std::vector<Cluster3x3> ClusterFile::read_clusters(size_t n_clusters) {
     return clusters;
 }
 
-std::vector<Cluster3x3> ClusterFile::read_frame(int32_t &out_fnum) {
+ClusterVector<int32_t> ClusterFile::read_frame() {
     if (m_mode != "r") {
         throw std::runtime_error("File not opened for reading");
     }
@@ -110,8 +110,8 @@ std::vector<Cluster3x3> ClusterFile::read_frame(int32_t &out_fnum) {
         throw std::runtime_error(
             "There are still photons left in the last frame");
     }
-
-    if (fread(&out_fnum, sizeof(out_fnum), 1, fp) != 1) {
+    int32_t frame_number;
+    if (fread(&frame_number, sizeof(frame_number), 1, fp) != 1) {
         throw std::runtime_error("Could not read frame number");
     }
 
@@ -119,15 +119,19 @@ std::vector<Cluster3x3> ClusterFile::read_frame(int32_t &out_fnum) {
     if (fread(&n_clusters, sizeof(n_clusters), 1, fp) != 1) {
         throw std::runtime_error("Could not read number of clusters");
     }
-    std::vector<Cluster3x3> clusters(n_clusters);
+    // std::vector<Cluster3x3> clusters(n_clusters);
+    ClusterVector<int32_t> clusters(3, 3, n_clusters);
+    clusters.set_frame_number(frame_number);
 
-    if (fread(clusters.data(), sizeof(Cluster3x3), n_clusters, fp) !=
+    if (fread(clusters.data(), clusters.item_size(), n_clusters, fp) !=
         static_cast<size_t>(n_clusters)) {
         throw std::runtime_error("Could not read clusters");
     }
+    clusters.resize(n_clusters);
     return clusters;
 }
 
+
 std::vector<Cluster3x3> ClusterFile::read_cluster_with_cut(size_t n_clusters,
                                                            double *noise_map,
                                                            int nx, int ny) {
diff --git a/src/File.cpp b/src/File.cpp
index 37e4c57..1180967 100644
--- a/src/File.cpp
+++ b/src/File.cpp
@@ -45,6 +45,8 @@ File& File::operator=(File &&other) noexcept {
     return *this;
 }
 
+// void File::close() { file_impl->close(); }
+
 Frame File::read_frame() { return file_impl->read_frame(); }
 Frame File::read_frame(size_t frame_index) {
     return file_impl->read_frame(frame_index);