Cave Nebula, LBN 529, Sh2-155

I've almost finished tweaking my homemade triplet based on a surplus TS115/7 APO Triplet objective lens. I sent it to Fidel's basement workshop to see if anything decent could be made from it. I got plenty of feedback on the lens cell design. But the lens itself turned out to be good—after several attempts, I managed to squeeze a Strehl ratio of 0.990 in red and 0.910 in green from it.

After that, I ordered a metal lens cell and replaced the focuser with a 2.5-inch one. But I couldn't get a flat field with my reducers (TSRed08-72) or flatteners (Takahashi FL-FS-60C 1.04). This image was taken with the Takahashi flattener, but I still had to crop about 20%. All of them are designed for f/6, while mine is f/7. And of course, I need more integration time—it's too noisy. Anyway, first light.