Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,503   Posts: 1,543,421   Online: 851
      
Page 5 of 5 FirstFirst 12345
Results 41 to 42 of 42
  1. #41
    RalphLambrecht's Avatar
    Join Date
    Sep 2003
    Location
    Central florida,USA
    Shooter
    Multi Format
    Posts
    6,532
    Images
    1
    Quote Originally Posted by Kirk Keyes View Post
    Do you mean is there a timer that can be set to 10.1 seconds?

    Yes, several. I've a Gralab 900 and it can do up to 59.9 seconds in tenths of a second. And I've a much beloved Omega CT-40, I think the best darkroom enlarging/process timer yet made (and it came out about 1984), and it can do 9 min 59.9 second exposures (actually, it can do 9 min 99.9 seconds).
    That's useful. Last time I checked into darkroom timers, some did 0.1s intervals but only up to 10s, after that, they switched to 1s steps. 10% increments are too coarse for me. My current timer is from RHDesigns and works in 1/12 stop increments, which is all I need.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  2. #42
    RalphLambrecht's Avatar
    Join Date
    Sep 2003
    Location
    Central florida,USA
    Shooter
    Multi Format
    Posts
    6,532
    Images
    1
    Quote Originally Posted by BetterSense View Post
    I'm a materials scientist and I work with electrical engineers, chemists, and materials scientists on a daily basis, and I read and write technical research papers every day. Regardless of any dictionary definition, I can tell you that in the scientific community, the fact is that it is universally understood that "light" does not necessarily refer to visible light. In technical literature and in person, I hear the word "light" used to refer to radio waves, microwaves, infrared lasers, and xrays and gamma rays, blackbody radiation, and basically any electromagnetic radiation. I opine that the above quoted terminological opinion is quite incorrect and should be abandoned in the interest of understandability. There may be a lay usage of the word 'light' just as there is a lay usage of the word 'work' but in both cases I have to consider the respective definitions currently used uniformly by the scientific community as the ones to be touted about as "most correct".

    The quite distinct concept of 'visible light' is arrived at by integrating the luminance ("light") over one of various well-argued-over luminance functions that supposedly simulate the average human eye's sensitivity curve, to arrive at an artificial picture of "visible light". There is as parallel situation with sound. Scientists refer to everything from infrasonic waves in the earth's crust to far, far ultrasonic lattice vibrations in crystals as 'sound', quite apart from any individual's ability to hear it. If you hang around semiconductor scientists much, you will eventually hear of "phonons" which are quantum "particles" of sound which are shed to crystal lattices during energy transitions! I'm sure that won't fit in the groove of an LP.
    This is all well and good, and we had this conversation a while back, but I stumbled across this by accident:

    The 'SPSE Handbook of Photographic Science and Engineering' published by the Society of Photographic Scientists and Engineers has a different view, which is, however, in line with the Oxford and Webster's Dictionary. On page 4 of my 1973 copy it states:

    quote
    'The term 'light' describes that part of the electromagnetic spectrum to which the human eye is sensitive. It is normally considered to include wavelengths between 400 and 700 nm, although many observers can see wavelengths as short as 380 nm or as long as 760 nm.'
    end quote

    I have also attached a copy of the diagram which this excellent book shows on page 5. I believe to be in pretty good company with 'my' definition of light and stick to the statement that the term 'visible light' is tautological and redundant, since there is no such thing as not visible light.
    Attached Files
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

Page 5 of 5 FirstFirst 12345


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin