On our recent trip around the national parks of Arizona and Utah, we explored some new photographic challenges and solutions. One involved the use of "slow synchro" flash. Read on if you're not familiar with how to use that particular camera setting.
Slow synchro. Sounds intimidating, doesn't it? Do you need to be an expert on shutter speeds and flash strength to use it? Not at all.
This flash setting is the one to use if the flash isn't strong enough to light up the whole area of your picture. That's it. Slow synchro keeps the shutter open a little longer than normal, so whatever's in the background comes through more brightly than in the typical flash picture. There might be a little bit of blur from camera shaking, but you can't have everything.
We ran into this problem in two contexts. Sometimes in a restaurant, taking pictures of food, the light was dim enough that the flash from a point-and-shoot camera would only light up the closest part of a dish. Slow synchro evened out the lighting. Outdoors, a picture of a person in front of a landscape might also call for slow synchro. In the evening, the person might need a flash to be exposed properly, but normally the background would go all dark. At mid-day, harsh light might cast big shadows on the person, again calling for flash, again possibly underexposing the background (such as a mountain slope not in the sun).
Slow synchro isn't consistently placed or labelled across cameras. On smaller point and shoots (e.g. the Canon SD700), it's a distinct flash setting alongside red-eye reduction or auto/on/off. On bigger point and shoots and SLRs, it's typically a setting on the mode dial, often labelled Night Scene.