Back to Basics Photography: Shooting Manual – How to Get Proper Exposure
In the upcoming months John J. Pacetti, CPP, AFP, will be writing a series of basic photography lessons. To find them all just search “Back to Basics” on our blog. This is the eighth article in this series. John is a frequent visitor to the MCP Facebook Community Group. Make sure to join – it’s free and has so much great information.
We’ve looked at ISO, F-Stop and Shutter Speed. We looked at how each one effects the exposure triangle. We looked at what a stop of light is. Now that you have a better grasp of what each individual aspect does, we’re going to put them together in detail which is how you get proper exposure.
Where to start:
My preference is to decide on my ISO first. Since ISO is the sensitivity of the sensor to light, in bright light scenes, like outdoors in sun light, on a beach or park I would choose a low ISO, 100. If it’s an overcast or very cloud covered day possibly 200. There is almost no reason to be at a higher ISO in day light scenes, in my opinion. There may be exceptions, however, as a general rule 100 or 200 should do just fine out door in most situations. In low light settings, evening approaching dusk, I may choose 400, possibly 800, depending on the amount of light available. Indoors I would choose 400 with flash possibly 800 if I wanted to see more of the room light, possibly 1600, even higher if I’m working with available light, like in a church that does not allow flash photography.
Aperture/F-Stop/Depth of Field:
Once I have set my ISO, I decide on the Depth of Field (DOF) I want. Do I want a shallow DOF, (F-2.8) or deep DOF (F-8 or higher).
Once I make that decision, all I need to do is set my Shutter Speed based on the two settings, my DOF and ISO. Once I have set my SS, I’ll do a few test images to be sure my exposure is correct, if not, I’ll make adjustments to get a good exposure.
Now we have our exposure set. We can get creative with those settings. Let’s assume an exposure setting of:
SS 125 – F8 – ISO 400. For this exercise this is our good exposure setting.
- If you decide to change your F-Stop to gain a shallower DOF you’ll need to make an adjustment to ISO or SS (or both) to maintain your good exposure. So, you move out F-Stop to F4. That’s a 2 stop move to a wider aperture. Going from F8 to F5.6 to F4, two stops. So far you haven’t adjusted anything else. Right now, you are two stop over exposed. To get back to your good exposure with your new F-Stop of F4, you can adjust your SS by 2 stops to 500, from 125 to 250 to 500, a total of two stops. You are now back to your good exposure with a shallower DOF.
Your new settings are now: SS 500 – F4 – ISO 400.
- You could have made a slightly different adjustment. Instead of changing your SS we could have changed your ISO to get back to the same exposure. You would need to move from 400 to 200 to 100, a total of two stops.
Your new settings are now: SS 125 – F4 – ISO 100.
- You could have made a slightly different adjustment. You could have made a change to both SS and ISO one stop each. You would need to move from 400 to 200 on your ISO, one stop, AND one stop on your SS, from 125 to 250. A total of two stops, just that you adjust both by one stop each instead of two stops for either SS or ISO.
Our new settings are now: SS 250 – F4 – ISO 200.
Keep in mind, once you have you good exposure setting and make an adjustment in any one of your settings, in order to maintain your exposure, you’ll need to change one or both of your other two by a total of the same number of stops you had changed in your initial adjustment.
John J. Pacetti, CPP, AFP – South Street Studios www.southstreetstudios.com
2013 Instructor at MARS School- Photography 101, The Basics of Photography www.marschool.com
If you have question, feel free to contact me at [email protected] This email goes to my phone so am able to answer quickly. I’ll be glad to help in any way I can.