We’ve done another of the Photocast Network Roundtable discussions. This week , John Arnold (Photo Walkthrough), Chris Marquardt (Tips from the Top Floor), Ibarionex Perello (The Candid Frame) and Jeff Curto discuss the importance of printing, lens selection, metering & exposure and self assignments.
We’ve set up a separate subscription feed for these Roundtable (email me with suggestions for a better name) discussions so if you’re subscribed to more than one of the podcasts that participate in the discussions, you won’t get multiple downloads of the show.
Here are the ways you can get the podcast:
- Photocast Network – You can download the show directly from the Photocast Network page
- Standard RSS Feed – A feed you can use in any feed reader
- iTunes “One-Click” subscription – Subscribe via iTunes using this link
Since this is a new venture for us, let us know what you think and what you’d like to see on future episodes of the Roundtable. And… please… help us find a better name for this thing!
I was listening to the second roundtable and the question came up about how 18% gray was chosen as a standard. I heard many years that some folks at Kodak took over a thousand photographic prints cut them into small squares and then measured each of the squares and then averaged all the readings, and the average was 18%. Now I’m not sure if this is true, but knowing a bit about the history of Kodak it makes sense.
Actually, it’s not quite that. I couldn’t come up with it off the top of my head while we were chatting during the recording session. I’ll be clear up front that I’m not a “math guy” (that’s why I’m a photographer!) but here’s the skinny:
Photographic exposure is a logarithmic situation. This is another way of saying that exposure functions in an exponential fashion, not a linear one. So, when we move from one aperture to the next larger one, we double the amount of light. Moving one more aperture larger doesn’t make 4 times the amount of exposure than the first situation; rather it makes 8 times the amount of exposure. This ratio continues on up (or down) the scale.
So, since light is being handled in an exponential way, we end up with a reflectance value of 18% being in the middle. Another way of saying it is that half of all the reflected light in the world is darker than 18% reflectance and the other half of all the reflected light in the world is lighter than 18% reflectance.
Kind of a neat story about Kodak, though… might help explain how they got into their current-day situation!
Jeff,
I have not yet listened to the 2nd roundtable yet, ( my suggestion for a name would be something todo with knights – the photoknights podcat or something like that) I listened to the first episode which I thoroughly enjoyed. I liked the mixture of the creative and technical. So I look forward to many more roundtables.
The parts that I think are great are when everyone has something to say on a topic and you have a dialog. The parts where someone just gives a monolog seem out of place in this format.
To this end talking more on non-technical subjects would be great in future, as these are the ones where everyone has something to say.
Thanks for the feedback, Adam… I’ll send that on to the group. I agree that it feels more like a “roundtable” when we are able to interject, etc.
-Jeff
Hey,
I love what you’e doing!
Don’t ever change and best of luck.
Raymon W.