Trap Focus on 400D

[Shoot]

Just wondering if anyone knows if the 400D has a trap focus feature?

Eg, select focal length that you want to use and hold shutter button down all the way, then when object comes into focus the shutter is activated. Obviously for this the camera needs to be set in Manual Focus mode. Does anyone know how to do this or if it can be done on the 400D?

[DaveB]

Nope: not possible.

If you switch the lens to MF the camera will take photos regardless of focus confirmation (even if you switch to MF while the shutter button is depressed). No combination of drive mode, AF mode, or custom function will give you trap focus on the 400D (or in fact most of the EOS bodies).

Trap focus is only available (via Personal Function 16) on 1-series bodies (1v, 1D, 1Ds, 1D Mk.II, 1D Mk.IIn, 1Ds Mk.II).

[Shoot]

Grrrrrr thanks Dave.

[gstark]

Rob,

I'm biting my tongue here.

[DaveB]

So why did you post Gary?

I must admit I hadn't missed it in the 6+ years I've been using EOS. There is a close relative of trap focus that I've used in hand-held macro every now and then: single drive, one-shot AF, and when the AF locks on the shot is taken. You can't guarantee what focus position that will be though, which is the difference between that and Trap Focus proper.

[Shoot]

Dave,

Yep, just tried it... works on one shot AF, and AI focus AF. You can set to use an individual focus point also and both modes still work which helps a lot to isolate what your focusing on... but as soon as its put into manual its kaput.... Hmmmm

I'm biting my tongue here.

Now now, knives away Gary.