I'm happily shooting Green at 80 . . . .
Printable View
I'm happily shooting Green at 80 . . . .
I don't mean to tell people what to shoot it at, I'm telling you the rated (by the manufacturer) speed of the film, your exposure index is your own business ;)Quote:
Originally Posted by mdarnton
I believe the 100 and 400 speed refers to system speed: The imaging system consisting of the film and the proper intensifying screens that fluoresce under x-rays to expose the film. Place the wrong kind of film into the wrong kind of screens and the resulting system speed drops to around 10 (as I guesstamate from my experience in x-ray). So green x-ray film isn't the same speed when exposed by light in a camera as TMAX 400, nor is blue x-ray film the same speed as Delta 100. I don't believe any ASA/ISO number has been assigned to x-ray film used in-camera and exposed to white light.
Ralph
Quote:
Originally Posted by Ralph Weimer
I did something wrong on the above post, 2161. My comment is in the last two sentences. Thank you, and sorry for the confusion.
a first test to check if it works at all.
http://www.dynamo.de/filmwasters/xray_9x12_001.jpg
Crown Graphic, 6.8/90mm Angulon,
Fuji AD-M, 18x24, cut into 9x12 sheets, iso 100,
Rodinal 1+120, 18°C and 8min. (approx.)
slightly adjusted in Lightroom.
I believe the 100 and 400 speed refers to system speed: The imaging system consisting of the film and the proper intensifying screens that fluoresce under x-rays to expose the film. Place the wrong kind of film into the wrong kind of screens and the resulting system speed drops to around 10 (as I guesstamate from my experience in x-ray). So green x-ray film isn't the same speed when exposed by light in a camera as TMAX 400, nor is blue x-ray film the same speed as Delta 100. I don't believe any ASA/ISO number has been assigned to x-ray film used in-camera and exposed to white light.
Based on a very recent foray into industrial radiography at work, this is correct, except that the "film speed" is the contribution to the "system speed" that is not due to the "screen speed". So a 400-speed film with a matching "fast" screen will have a system speed of 800, for which there is no parallel in the photographic world.
Combining a blue-sensitive film with a green-emitting screen will give lousy results. When I learned this, it suddenly dawned on me why I had to expose CSG at an E.I. of 80 when using strobes, but 64 or less if the exposure was made with only the (tungsten) modeling lights. And when one of the modeling lights was dimmed to match a low flash output, the results were strangely unlike I expected. You might expect that someone who started taking pictures in the 1960s, when film boxes had both "daylight" and "tungsten" ratings marked on them, would remember that even tungsten-halogen lamps aren't the same color temperature as a strobe!
this was shot today using a titan 8x10 pinhole camera, I have a filter on the inside and I forgot to add a bit of exposure for it, green sensitive xray film, f288 6 min. exposure. There was a bit of evening light coming in.
https://farm4.staticflickr.com/3953/...570c212d_z.jpggoforth creek, pinhole 8x10 by goldenimageworks65, on Flickr
Nice! We may as well throw out all our expensive gear.Quote:
Originally Posted by ImSoNegative
yeah. well... just shout when you do ;) i can use some of your lenses ;))))Quote:
Originally Posted by Randy Moe