Exposure Question

[dwdallam]

I'm wondering since the 20D isn't the same as a 35MM, would a regular exposure meter work, or do you have to use the in camera meter? In the same way, could you use another camera's exposure meter for the same ISO, or are the digital meters camera and lens specific? I know other things affect exposure, such as lens lenght and its light capturing ability, but not sure how this all works. I would assume you need to tell the meter what stop your lens is, and the focal lenght. If so, and that is all, then I guess you could use another cameras exposure meter if, for example, they were both 2.8 lenses and at the same focal length?

[howard smith]

An external meter works fine.  You may have to trial and error an ISO on the meter that corresponds to one on the 20D.

Most meters today will give either an f/stop for a given shutter speed, vice versa or an EV value that couples an f/stop and shutter speed.  The meter need not know the focal length of the lens.

I think it is important to learn how an exposure meter works, what it is telling you and how to apply it.  It is pretty basic to repaetable results.

[dwdallam]

An external meter works fine.  You may have to trial and error an ISO on the meter that corresponds to one on the 20D.

Most meters today will give either an f/stop for a given shutter speed, vice versa or an EV value that couples an f/stop and shutter speed.  The meter need not know the focal length of the lens.

I think it is important to learn how an exposure meter works, what it is telling you and how to apply it.  It is pretty basic to repaetable results.

What about the 20D's internal exposure meter? I ahve a good idea about what exposure is all about. It's been easier for me to pick up than DoF issues. However, I could figure it out pretty well if I set down with a pencil and paper and wrote all the pertinent information down and really thught about it on paper in front of me.

So, I'm willing to buy an exposure meter if I need one for the extra information it gives. I know I could put that to use quickly, if the internal meter is not adequate.

[Anon E. Mouse]

Why do you want a separate meter? Where is your camera meter failing you?

BTW, focal length is not required to calculate exposure. Just aperture and shutter speed.

[howard smith]

The 20D's internal meter should do you fine as long as you understand how it works and what it is doing (and not doing) for you.  I see no need for an external meter save a flash meter perhaps.

[dwdallam]

The 20D's internal meter should do you fine as long as you understand how it works and what it is doing (and not doing) for you.  I see no need for an external meter save a flash meter perhaps.

That sounds good then, and yes, I have an understanding of what the meter tells me and how to use it. I've been shooting manually with my F828 for months now. I usually bracket shots I think are important, up to -3 stops and +1 stop, which seems to cover all of the F828 useable ranges for a specific image and location.

However, sometimes I would over expose to get an effect I wanted, such as in night shots.

Thanks for both your replies.

20D in 3 days, 12 hors 13 minutes and 24 seconds!

[Jonathan Wienke]

Read Digital Exposure And Metering Strategies.

[dwdallam]

Jonathan,

Gonna have a look at that right now.