THE MAKING OF A PHOTOGRAPHIC OBJECTIVE. 



Being a Description of a Course in Applied Optics Offered at the Emerson McMillin 

 Observatory of the Ohio State University. 



H. C. Lord. 



Photography, in its more serious phase, has taken an 

 important place in almost every field of human activity while 

 in its lighter mood, through the development of the "Kodak" 

 and the roll film, is giving us one of our most delightful pastimes. 

 As a condition for the best work, a high grade lens is a necessity 

 and especially so for those extremely short exposures required 

 in the photography of rapidly moving objects. It often happens 

 that some of the most perfect and at the same time most 

 difficult specimens of optical design are found on cameras so 

 small that they can be easily carried in one's coat pocket. 

 These so called anastigmats furnish to the optician a difficult 

 and yet at the same time most fascinating problem for mathe- 

 matical investigation. Thousands of photographic objectives 

 are placed on the market every year, yet though almost every 

 branch of engineering is covered by our technical schools, I 

 know of no place outside of Germany where a student can be 

 instructed in the design and construction of a simple photo- 

 graphic objective. Professor Silvanus P. Thompson in his 

 inaugural address as President of the British Optical Con- 

 vention held in London in 1912, states: "In the Universities 

 and Colleges the only people who are learning Optics are merely 

 taking it as a part of Physics for the sake of passing an exami- 

 nation for a degree, and care nothing for the application of 

 Optics in the industries. They are being taught Optics by 

 men who are not opticians, who never ground a lens or cal- 

 culated even an achromatic doublet, who never worked an 

 opthalmoscope or measured a cylindrical lens." Further on 

 he speaks as follows: "What is wanted is an establishment 

 where the whole atmosphere is one of optical interest; where 

 theory and practice go hand in hand; where the mathematician 

 will himself grind lenses and measure their performance on the 

 test bench ; where braincraf t will be married to handcraft ; where 

 precision, whether in computation or workmanship, will be the 

 dominating ambition." 



