Is there an exposure "rule of thumb"?

divamum

So the other day I wheeled the dial to get some specific settings and suddenly realised... I was shooting in manual. At last. After YEARS of aperture-priority (hey, my first camera was a Pentax ME Super - I was "raised" on Av mode!) More importantly, I knew WHY I needed to switch to manual and had at least some idea of what changes to make to shutter and aperture to precisely control the effects I was trying to get.

But I'm still totally clueless at guessing what exposure might be in the ballpark for a shot. Is there some kind of a listing of rule-of-thumb exposure values, along the lines of the Sunny 16 rule but for other situations? Obviously, each sitch will have its own requirements, but even knowing where to *start* an exposure combination would be a useful guide.

Thanks!

jfriend

When I go to manual, I often use the meter (often set on spot metering) as a guide for a starting point and then learn how much to change it for a specific scene from there. The meter is still active and indicating, even though the camera is set to manual so you can still see what the camera thinks is a good exposure. If you set to spot metering and point at a known neutral mid-tone (like caucassian skin or a green grassy field), you can get a very good starting point for the exposure. If you point it at a snow bank in the sun, you can know that you will need about 2-3 stops more than the meter would indicate on that.

If you search for the "zone system" in Google, you will find lots of articles about how to guage what exposure zone a given subject is in.

The simplest way, is to just take a couple test shots and examine the RGB histogram and then tweak from there. As long as you aren't clipping any channel on the right and aren't leaving a ton of empty space on the right of the histogram, then you are recording a good image and you will be able to fine tune it's brightness in post processing. Any more accurate than that requires some sort of knowledge of a known reference that you can meter off of (either a known item in your scene or a gray card reference). If you shoot in manual a lot, there are probably people who can get within a stop just by examining the scene. I use my tools (meter and histogram) to do it.

Elaine

This probably isn't quite what you're looking for, but I'll share my method.

I usually start with the aperture setting...depending on the lens and the situation, I seem to shoot between f/2-f/5.6 most of the time, unless it's a landscape. Then I dial in the speed and usually start with the meter marker (what is that thing called?) at +1/3 or +2/3, especially when shooting closer portraits. I have the camera set to display the histogram immediately after each shot, so I quickly glance at that to see where I am. If I've got more room to the right, I scroll my dial to the right. I glance at my speed...if it's getting too slow for the situation, I up the ISO. If I'm overexposing, I scroll left and drop ISO if I can. To be honest, it all happens so fast that I'm not completely paying attention to what speed and aperture I'm ending up at. I just start at what looks like it might be on the bright side, check the histogram, scroll right or left, check the histogram, scroll right or left... I should probably pay more attention, to at least my EXIF, so I can plan better for next time, but this method seems to work out for me.

EDIT: When I was shooting soccer this fall, I could have my camera mostly set up before arriving there. I knew the speed I'd need (at least 1/800, preferably faster) and I knew I'd be shooting wide open (f/4 on that lens) so the weather kinda dictated the ISO and resulting speed. It only took a couple shots before the game to get it figured out.

One more edit: I found it very helpful to set up the custom settings on my camera to help me shoot manually in a comfortable way. For example, scrolling right to move my meter marker right (and scrolling left to move it left) was a custom setting. I would set my aperture and then know that using my right/left scroll would only affect the speed, which makes it a quick adjustment for me.

Scott_Quier

This may help:


Then, to make it real...


Does that help?

divamum

GaWOW! That's brilliant, Scott! bow

Thanks to all of you - I have to wrap my mind around this at some point. I suspect it'll just keep happening osmotically as it kind of has already, but it's nice to be able to read up on it, too!

Thanks!!