Different types of inbuilt flashes modes

[jankcl]

Hi, I'm hoping someone can enlighten me on the different flash modes that I have on my Sony NEX-5 camera.

What's the differences between Rear Sync, Slow Sync, & fill flash? I understand generally why you use fill flash but not sure how you use the other flash modes or when you choose one mode over the other.

any help would be greatly appreciated!

[zona5101]

here's a decent explanation...
Camera Flash Modes Explained

[inkista]

Originally Posted by jankcl

What's the differences between Rear Sync, Slow Sync, & fill flash?...

Rear sync is about changing when the flash burst happens during the exposure. By default, most images have the flash burst go off at the beginning of the exposure period. Rear sync moves the flash burst to just before the end. This is useful for longer shutter speeds, where some sort of "motion trail" is going to happen. Since your subject will be most strongly lit when the burst goes off, if your subject is moving, and the burst happens at the beginning, the motion trails were then fade off in front of your subject. With rear sync, they'll trail behind your subject, which is typically more intuitive/logical to an image viewer.

You don't want to leave rear-sync on by default, though, because if you're taking portraits with TTL, and using a longer shutter speed, there's probably just enough time for your subject to blink their eyes from the "preflash" and you'll only get them with their eyes closed.

Slow sync is about "burning in" the background after the flash burst with a slow shutter speed. This is good for nightscenes, like someone standing in front of a night-time city scape. You light them with the flash burst, then use a longer shutter speed to get the lights in the background to register. This is also called "dragging the shutter".

Fill flash isn't always referring to a flash mode. It's more a general term that means using the flash not as your main illumination source, but rather as a way to decrease the contrast/dynamic range in a scene by "filling in" the shadows with light. In practical lighting terms, it's generally any secondary lighting source you use from an different direction of the main source to keep shadows from obscuring subject detail. A traditional studio three-light setup includes a key (main light), fill, and rim (backlight).

[jankcl]

Originally Posted by inkista

Rear sync is about changing when the flash burst happens during the exposure. By default, most images have the flash burst go off at the beginning of the exposure period. Rear sync moves the flash burst to just before the end. This is useful for longer shutter speeds, where some sort of "motion trail" is going to happen. Since your subject will be most strongly lit when the burst goes off, if your subject is moving, and the burst happens at the beginning, the motion trails were then fade off in front of your subject. With rear sync, they'll trail behind your subject, which is typically more intuitive/logical to an image viewer.

You don't want to leave rear-sync on by default, though, because if you're taking portraits with TTL, and using a longer shutter speed, there's probably just enough time for your subject to blink their eyes from the "preflash" and you'll only get them with their eyes closed.

Slow sync is about "burning in" the background after the flash burst with a slow shutter speed. This is good for nightscenes, like someone standing in front of a night-time city scape. You light them with the flash burst, then use a longer shutter speed to get the lights in the background to register. This is also called "dragging the shutter".

Fill flash isn't always referring to a flash mode. It's more a general term that means using the flash not as your main illumination source, but rather as a way to decrease the contrast/dynamic range in a scene by "filling in" the shadows with light. In practical lighting terms, it's generally any secondary lighting source you use from an different direction of the main source to keep shadows from obscuring subject detail. A traditional studio three-light setup includes a key (main light), fill, and rim (backlight).

Thanks for the detailed explanation!Just want to clarify some things. does this mean in Slow Sync, if the person (subject) moves it will blur? so it's only good for still-ish subjects? as my understanding from your explanation of Rear sync is that you want the flash to go off at the end rather than at the beginning to get the subject in focus?

I also got a little bit lost with the TTL & the blinking bit of the explanation regarding rear sync :s