Can someone please explain the grease spot and juice can thingy?
One of the most common photometers is that of Bunsen, which consists of a screen of white paper with a grease-spot in its center. The lights to be compared are placed on opposite sides of this screen, and their distances are so adjusted that the grease-spot appears neither brighter nor darker than the rest of the paper, from whichever side it is viewed. When the distances have not been correctly adjusted, the grease-spot will appear darker than the rest of the paper when viewed from the side on which the illumination is most intense, and lighter than the rest of the paper when viewed from the other side. The intensities of the two lights are to one another as the squares of the distances from the screen at which they must be placed in order that the grease-spot may appear neither brighter nor darker than the rest of the paper. Quote off
I remember an article in an old photo mag about how to use this principle with a part of a brown paper bag and a juice can. That's all I remember. Perhaps other dinosaurs can help. And they may remember a Leudi, also
News flash: The person who wrote that article is an idiot, a moron, and a dolt. The follow up comments are laughable as well. I will never cease to be amazed how technically inept so many supposed professionals on the Internet are, and by the ways in which they work. Goes to show you that making a living in photography has about 1% to do with technical matters. Good riddance from the world of analog photography!
News flash 2:
Mike Johnston is an informed and generous commentator and photographer who--unlike some around here--covers the analogue and digital worlds with equanimity. He wrote a valuable column for the UK Black & White Photography journal for years without encountering the unsubstantiated hysteria above.
He single handedly runs his site and is trusted by many manufacturers to deliver objective reviews.
As with APUG, Photonet, LF Forum I have learnt from him as well.
The childish display by APUG members on this subject is embarrassing.
Hmmm, I dunno, Ross. There have been more embarrassing displays on APUG than this one...
I don't think Johnston is an idiot, and often what he writes is worth a read. However, he does firmly imply in the article referred to in the OP that even film users should probably just carry around a DSLR rather than a light meter. That is a pretty controversial idea, and bound to excite comment on an analogue forum, even if the article is a couple of years old. For mine, my camera bag is heavy enough already.
You can just call me Ian if you like...
I am not really reading anything into it. I just read the words and drew the obvious implications. But, hey, it is not super-important. It is just an old article stating someone's opinion, to which they are entitled.
what's wrong with this thread is that no one here has gone off on a long winded tangent
"explaining" the history and construction of the light meter, selenium cell and lcd screen
dropping as many names as possible, references to old pre-war german photo manuals and magazines,
and uploading pdf filescans of advertisements in edwardian photo annuals ...
maybe that is coming on page 6 ?
Last edited by jnanian; 10-07-2009 at 10:06 AM. Click to view previous post history.