I understand that TTL works using the sensor on the flash. So, unless I have a removable sensor that I can keep on my camera (does such a thing exist), is there any advantage to TTL, at least for off camera use? I guess if I'm just moving the flash above the camera, so it remain in the same plain, the TTL may still work. But what if I want to angle it to the side? If it matters, I use a Nikon N70 and am thinking @ the SB28. Thank you

-- Doug Raymond (fdr@dbr.com), May 10, 2002

Answers

TTL is Through The Lens, not through the flash. Now you should know it has nothing to do with the position or angle of the flash. The camera senses the amount of flash light, and decides when to cut off the flash.

Haishun

-- Haishun Yang (haishunyang@yahoo.com), May 10, 2002.

haishun is right: all of the problems you describe are exactly what TTL was developed to solve. plus, you don't have to tell it what aperture you've set.

:)=

-- rick oleson (rick_oleson@yahoo.com), May 10, 2002.

As already pointed out TTL does not use the sensor of the flash.

But there are advantages of using the flash either sensor-guided or TTL off the camera

It will eg allow bouncing of an umbrella for a basic portrait setup without having to buy monoheads and a flashmeter. Maybe not 100% foolproof, but great wwhen you only starting to experiment.

Or you can place it in such a position that ugly shadows can be avoided, as done by many wedding photographers with special flashbrackets, and the notorious red-eye effect

With a standard non TTL computerflash, there are few very options. Metz has a dedicated sensor for the Metz 60CT1, which ao allows reduction of flashoutput etc (I have one of each gathering dust in a closet) and use (way off) from the camera. Otherwise it's a matter of aiming the sensor of the flah and hoping it doesn't get fooled.

With TTL dedicated flash use off camera on the other hand it is possible with special connection cords (Nikon SU-17 for the SB-28) and even slaves (SU-4 for the SB28, though not recommended by many) to use several flashes hooked up together as eg location units (that's what I did with the 2 Metz 60CT4's I got in addition to my 60CT1; added advantage is I can swap batteries and powerpack) either bounced in umbrella's or for direct (toward the object) but not on the camera/lens axle illumination. No need for a separate flashmeter as the flash is measured TTL by the camera

So yours is not a bad idea

HTH

Paul K

-- Paul K (photopp@wanadoo.nl), May 12, 2002.