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主題: Canon Tele-Converter lens +S30 PRO 作者: peter 於 2026-03-09 08:55:46 https://www.facebook.com/photo/?fbid=10162932838050892&set=pcb.920846667394283
https://www.facebook.com/photo/?fbid=10162932848760892&set=pcb.920846667394283 (https://scontent.ftpe7-4.fna.fbcdn.net/v/t39.30808-6/649516224_10162932848765892_6898164081534309543_n.jpg?_nc_cat=101&ccb=1-7&_nc_sid=e06c5d&_nc_ohc=-Wp68PiZdeYQ7kNvwFPHy8s&_nc_oc=AdnNmNtKJ9GTY-uTUtJ88YAsEbDSk8w4nca-VoLYZDpr1M_C8S0E9HdibaRsCJnl5RQ&_nc_zt=23&_nc_ht=scontent.ftpe7-4.fna&_nc_gid=7Q81u03gRV2j-f6NGAeEzw&_nc_ss=8&oh=00_Afxr-CY3P2pH5iNm5K1GBJQ_qOwVMOYJIdr5vdK3kZSJDQ&oe=69B3F1BE) https://www.facebook.com/photo?fbid=10162932839170892&set=pcb.920846667394283 主題: 回覆： Canon Tele-Converter lens +S30 PRO 作者: peter 於 2026-03-10 08:26:27 https://www.facebook.com/photo/?fbid=10162937615425892&set=pcb.921530480659235
Thanks for everyone's comments on my experiments on fitting an old Canon Tele-Converter to a S30 Pro. The comments on the change in f/ratio was particularly interesting. Somehow I was hoping that the extra aperture would help to balance the "loss" in f-ratio. So I did some measuring (using SAOImage-DS9) of images taken with and without the lens. As can be seen from the screenshots of the results below, a fair amount of light from the 60mm aperture of the Tele-converted was indeed coupled into the Seestar's 30mm aperture, shown in the results. For those not familiar with detector statistics, I highlighted the important numbers to look at, namely Surface Brightness, Mean- and Median count. So, I'm quite happy with these results, showing that I indeed managed to create a S50/60 Pro! |