It's a July 4th tradition in my neighborhood for the firemen at the local station to use the ladder on their truck to suspend themselves over a crowd of eager kids and toss handfuls of peanuts and candy down below. Thanks to the light clouds and overcast, I didn't have to worry about overexposing the background or underexposing their black uniforms.
Yes, I know. No photographer worthy of the name shoots JPEGs these days. RAW is superior, it’s the only way to go, blah, blah, blah. All that aside, let’s suppose someone did want to shoot JPEGs for whatever reason—say, for example, because JPEGs take up so much less space on an already overcrowded hard drive, because your camera’s RAW format is so new your favorite raw converter doesn’t support it yet, or maybe just because you simply want to shoot without having to later spend time in front of a computer monitor, tweaking file after file. It might even be that you like shooting video with your DSLR, in which case there is no RAW option; the camera applies whatever JPEG rendering style you've set your camera to. If you fall into this iconoclastic group, here are a few tips to help you get the most out of this valid and often necessary file format.
When you shoot JPEGs, what you see is pretty much what you’re going to get. Exposure, white balance, contrast, and sharpening are baked into the file. Anything other than minor tweaks can therefore cause the image to degrade noticeably. That means you need to make sure the settings you’re using are the ones you really want and appropriate to the light source. The upside to applying this much care and attention up-front is that you won’t have to do it later.
Shoot at maximum quality.
You’re saving so much file space by shooting JPEGs that there’s no point going overboard. Shoot at maximum resolution and minimum compression. If need be, you can always reduce the pixel dimensions and/or increase the compression later, and you won’t need sophisticated or expensive software to do it.
Get the white balance right.
This is a follow-up to my first tip. You really have to have a feel for how well your camera’s white balance settings handle various lighting conditions. When you’re shooting under tungsten lights is the tungsten setting too warm? If the lights are fluorescents is the fluorescent setting too green, magenta, or blue? Are the “cloudy” or “shade” settings too warm? Do you know how to perform a custom white balance to correct for this? The minute of extra effort you put into getting the white balance right from the start can save you hours of regret later.
In contrast to RAW files, which allow you to adjust the sharpening in post-production according to your preference, JPEG sharpening is applied in-camera and can’t be reduced if it’s too high. How can you can tell if it’s too high? Look for a halo effect between high-contrast edges when you view the file at 100%. If it’s obvious it’s too high. Turn it down. If it’s barely noticeable you’re probably okay. If in doubt, set it to the minimum.
Reduce the contrast setting in high-contrast situations.
The default for most JPEG renderings is for “snappy” contrast because that’s what most people like—that is, until they notice that most of the photos they shoot on bright sunny days have bleached highlights and blocked shadows. If you notice your camera doing this and it’s set to Standard, Vivid, Bright, or something similar, try either reducing the contrast setting for your rendering of choice or switching to a lower-contrast rendering such as “neutral” or “faithful.” A couple of clicks is usually all it takes to tone things down a bit.
Develop a tolerance for slight over-exposure.
There’s no getting around the fact that JPEG is an 8-bit file format. That means it simply can’t record as wide a dynamic range of tones as a 14-bit RAW file. If you shoot a scene that has a brightness range that exceeds what the JPEG format can record then something has to give, either the shadows or the highlights. If I’m shooting a scene that has bright but small highlights with not much useful image detail then I let them clip. As you can see from the accompanying photo example, the alternative is a photograph that looks underexposed.
So there you have it. I think I’ve covered all the most useful tips but if you’ve got anything of value to contribute please feel free. And if you feel obliged to preface your suggestion with “I never shoot JPEGs myself, but…” trust me, I will understand.