TTL Flash Hot Shoe on C 750

[colb]

Doing comparisons on Olympus C740 & 750 I notice apart from mps diffeence the 70 has "TTL Flash Hot Shoe " can some please explain what this is and what it does

[Mike_PEAT]

This allows you to put an external flash on the camera without the need of a proprietary cable and bracket like on previous C-7x0 cameras (C-700/730). TTL means Through The Lens, and if you get a TTL flash that's *compatible* with the camera, the flash and camera can talk with each other to get the correct settings needed for the picture you want to take. A plain flash may be too bright for a particular scene.

The 740 (and 720) have no external flash socket or hotshoe. To use an external flash with those cameras you have to use what's called a "Slave" flash. A slave flash is a unit that fires the flash when it sees the bright light from the camera's internal flash (or the flash from someone else's camera). There's no communication with the camera so your picture may be too bright (most flashes have a light sensor to check the amount of light in a scene so should compensate enough). The thing with Olympus cameras though is they use a preflash, a flash ~100ms before the main flash and the picture is taken...most slaves don't work with preflash cameras, so you have to check if the slave you get is compatible with preflash...a few flashes from Digi-Slave and the Metz 34-CS2 do work properly with preflash cameras.

I should note here that some flashes like the Olympus FL-40 (which is a perfect mate for the C-700/730/750) also has a focus assist lamp which helps the camera focus in low-light situations where the camera wouldn't be able to focus.

[colb]

Thanks Mike for an excellent answer to my question greatly appreciated