英语翻译BARRON上的一段话,没看明白As with a single slit,the light going th

英语翻译
BARRON上的一段话,没看明白
As with a single slit,the light going through a lens is diffracted.The amount of diffraction is usually negligible,but one effect is that parallellight entering the lens is brought,not to a point focus,but to a disk focus.The fact that with a lens we get a disk diffraction pattern instead of a point focus sets a practical limit on the magnification obtainale with a lens.
不仅仅要翻译,
打错一个字，最后是obtainable