[ayhshum]

I am using Canon 400D and having some trouble taking night portrait photo. Whenever I press the shutter button halfway, I always have difficulty in making the AF points covering the person’s face (i.e. the dot inside the AF points mostly flashes in red in other areas in the photo, but just not on the person). Consequently, most of the photos always turn out blurry on the person and clear in the background. Therefore, I always had to press the shutter button a million times before I can make the AF point to finally detect on the person. This situation happens in all modes of the camera.

If I use manual focus, I could only control one AF point. That would be ok for one person photo, but not for group pictures because only one person would be in focus.

I don’t know if it is because it is at night so the camera couldn’t detect the person and therefore made the AF point to shift its focus on the background instead or if it is because there is something wrong with the camera itself. In daytime, the problem is not as severe and the AF points are more easily focused on the person automatically.

How can I take a night photo (single or group) with both clear on the subject and on the background?

Please advice. Thx Thx!

[tam_dominic]

For group photo you have to set smaller aperture e.g. F5.6, F8, F11
Smaller aperture gives you larger depth of field thus guarantee the whole group are in focus.

In low light situation set higher ISO such as ISO 800.
At ISO 800, 400D still can output nice A4 size photos.

At night there is much less contrast on the face for the camera to focus.
Focusing on the shoulder (with enough depth of field ie smaller aperture) may have a better chance.

Merry X'mas
and
Happy shooting !

[ayhshum]

So if I use a higher f-number (smaller aperture value) for group photo, all people should be in focus even if the AF points does not flash in red directly on the person but on the bright background?

[ediot]

your problem here is two-fold - focus point and depth of field. Let me break them down and make a little explantion here.

1) you're using the 9 point focus at night when the camera fails to recogise the single person's face for focusing. what you SHOULD do, is change the setting to single point focus. set the middle point for focus.

when you take the picture (single person), you aim the middle point (the focus point) at the person's eye (left or right it doesn' matter) and half-press the shutter, the camera will now have focused to that point, now keep your finger half pressed on the shutter, and re-compose your picture. viola! this is how you choose the exact place to focus in your pictures.


2) if you have the aperture wide open (i.e. small F/xx number), only a little will be in focus. this enables more light into the camera so you can take a picture in darker places without flash. for group pictures, you want the F number to be set at a minimum of F/4 or even higher, so more will be in focus. however this means you need more light for the picture, possibly a flash.


when you combine the two factors you notice that given a high enough F number (small aperture) e.g. F11 or above, you don't even have to care about which point the camera uses to focus, as the entire picture would be in focus anyway. the drawback is less light going in, hence the need of longer exposure time or more light. longer exposure time would blur things unless they're steady objects and you use a tripot. more light means, well, flashes etc.

hope that helps