<![CDATA[Abstrak: Penentuan awal waktu Subuh dalam Islam berkaitan erat dengan kemunculan fajar shadiq. Penelitian ini bertujuan menganalisis dampak tingginya intensitas cahaya terhadap visibilitas fajar shadiq di kawasan Masjid Jami’ Manyar Gresik. Metode yang digunakan adalah observasi langsung menggunakan kamera DSLR dengan teknik time-lapse dan pengukuran kecerahan langit menggunakan Sky Quality Meter (SQM). Data dikumpulkan dalam rentang waktu sebelum hingga sesudah prediksi terbitnya fajar shadiq dengan interval pengamatan 60–120 detik. Hasil pengamatan menunjukkan bahwa intensitas polusi cahaya buatan di kawasan industri sangat mempengaruhi keterlambatan dan bias pengamatan fajar shadiq secara visual. Kemunculan fajar shadiq sulit terdeteksi dengan mata telanjang, mengakibatkan ketidakakuratan dalam menentukan waktu Subuh. Faktor atmosferis seperti ketebalan udara, kelembaban, serta sumber cahaya lokal turut memperparah gangguan pengamatan. Penelitian ini menyimpulkan bahwa lokasi dengan polusi cahaya rendah lebih ideal untuk observasi fajar shadiq. Penetapan awal Subuh berdasarkan observasi di kawasan bercahaya tinggi harus mempertimbangkan mitigasi polusi cahaya agar memperoleh hasil yang lebih akurat. Studi ini diharapkan menjadi rujukan untuk pengembangan standar observasi fajar shadiq di Indonesia.Kata Kunci: fajar shadiq, polusi cahaya, observasi astronomi, waktu Subuh. Abstract: The early determination of the time of Fajr in Islam is closely related to the appearance of the dawn of shadiq. This study aims to analyze the impact of high light intensity on the visibility of dawn shadiq in the area of the Jami' Manyar Gresik Mosque. The method used is direct observation using a DSLR camera with a time-lapse technique and measuring sky brightness using a Sky Quality Meter (SQM). Data were collected in the time range before and after the prediction of the dawn of shadiq with an observation interval of 60–120 seconds. The results of the observations showed that the intensity of artificial light pollution in industrial areas greatly affected the delay and visual bias of dawn shadiq observation. The appearance of dawn shadiq is difficult to detect with the naked eye, resulting in inaccuracies in determining the time of Fajr. Atmospheric factors such as air thickness, humidity, and local light sources also aggravate observation interference. This study concluded that locations with low light pollution are more ideal for dawn shadiq observations. The early determination of Fajr based on observations in high-light areas should consider light pollution mitigation in order to obtain more accurate results. This study is expected to be a reference for the development of dawn shadiq observation standards in Indonesia.Keywords: Dawn Shadiq, light pollution, astronomical observations, dawn time. ]]>
