Two quick tests with the home-made F:6,7/400mm singlet lens. After sending the previous post I quickly realized that the other lens that I made of two elements was not correctly contstructed – it could not cover the 8 by 10 inches image area. So, I will need to build it again… I think what I’m going to do is make another tube to put the lens elements in, and bring them closer to each other. The fine thing about a cardboard tube is that I can easily try different lens combinations…

An 8×10″ photo paper was rated ISO 6 and exposed in camera for one second. The paper was Ilford MGIV RC, developed in Dektol. The resulting negative was then scanned and inverted to positive in Photoshop.

Another shot with a four second exposure (ISO 6).

I’m quite pleased with this primitive lens, at least the price-quality ratio is nice 😉 . In the test pictures the geometric distortions are surprisingly low, and there’s not too much light fall or blurriness to the corners.

Other tests that I made showed that my wooden plate holder (see the previous post) should work ok, it won’t leak light! Now I can’t wait for the real wet plate tests…