On-board focus confirmation for the Canon Digital Rebel

We’ve seen plenty of lens hacks, but [Koray] took things in a new direction. Rather than buy lens chips for modding all of his manual lenses, he added a lens chip inside his Digital Rebel 300D (aka XT). Most of us might cringe at gutting their Rebel, but he performed this bit of soldering surgery on a unit he picked up for £40 and repaired. Excellent work!

Update: yeah yeah, the 300D is the original Digital Rebel.

11 thoughts on “On-board focus confirmation for the Canon Digital Rebel

  1. Hi rasz, I don’t know what type it is, but all it does is to communicate with the camera through a serial connection and report a lens focal length and maximum aperture value. It is basically simulating the original controller chips inside EF lenses. There is not much documentation on this, but there is one commercial website with some info, you may be interested:

    Cheers. K.

  2. thanks for the info, the one you linked is reprogrammable
    the one you used looks just like a 6 pin SOT-23 serial eprom (34VL02 ?).
    Do those chips talk to camera (two way) or just inform the camera what is connected (like SPD on RAM chips in PCs)?

  3. hi rasz, I think it just informs the camera what is connected (i.e., focal length: 50mm maximum aperture:f/2.0). You can order these chips on ebay and even ask for a specific focal length and aperture value pre-programmed for you. even more, there is this dandelion type for olympus cameras, which can be reprogrammed by the user on the go (i don’t know how). Before the proliferation of these chips/adapters, manual lenses (i.e. M42, Zuiko, Nikon ones) were cheap as peanuts. Now the prices are going up and up… Amazing. Cheers, K.

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