View Full Version : Stepped Greyscale test

03-03-2011, 10:38 PM
I'm wondering how you take a metered reading off of a grey card in manual mode? I have a Canon EOS Rebel 1000D and I'm new to photography. The course I'm taking asks me to perform a stepped greyscale test and this is one of the steps.

Wicked Dark
03-04-2011, 08:14 AM
basically point the camera at the gray card and get a reading through the lens. make sure the field of view entirely covers the card and that it's neutrally lit. every camera meter is
calibrated to 18% gray. meaning it is calibrated to render every shade of color as 18% gray. obviously not every color is 18% gray, some are more or less dense. this is why you then have to alter your exposure to get the color to render properly. overexposing or underexposing depending on the shade(s) in your scene.

but, back to your card. the exposure the camera chooses (with EV off) will produce a realistic photo of that card. it will look just as it does in real life. that's your base meter reading. the one you use to calculate your over or under exposure based on what you really want to photograph. the materials about exposure in your course will cover this more exactly and you can also check out some books on the subject. I'm told the Petersen book is pretty good.

03-04-2011, 10:17 AM
Thanks so much, I just needed the clarification. I've actually just bought the Peterson book on exposure and it's amazing! I started reading it last night and can't put it down! Thanks again!

Wicked Dark
03-04-2011, 10:23 AM
no problem breezy. glad to be of help.

03-04-2011, 12:06 PM
An article that goes into a bit more detail about metering:

How light meters work (http://www.scantips.com/lights/metering.html)

There are many such articles on the web because it is a difficult thing to understand at first but crucial to getting good exposure in your photos. Good luck!

03-05-2011, 02:16 AM
Saw this at the Toronto Star yesterday as part of their new camera club and this short video is about grey cards, not the best but have a look it only takes a couple of minutes to watch.

Thestar.com - VideoZone (http://www.thestar.com/videozone/936632--grey-snow-get-it-white-use-a-grey-card)

03-05-2011, 10:55 AM
Okay so my next question is: I have my camera set to manual mode and I begin with my aperture set at f/8. I adjust my shutter so that the exposure is correct. Then I'm asked to increase my aperture by one full stop and repeat this 6 times, then do the same while decreasing the aperture. Do I need to readjust my shutter speed each time? I'm sorry, I know these are probably stupid questions but I'm so new to this! Thanks again :)