Modifying Canon firmware for focus confirmation?

[Stan]

Naplam,

As a Russian software engineer (into straight, not reverse engineering though ), I would suggest to find a path in the firmware, when camera fails to communicate with the lens and feed the camera some redefined "lens data", so camera would use is data as if the lens was there.
I, personally, have no experience of reverse engineering or hacking firmware, so I can only support your efforts and cross my fingers for your success. Especially as a 400D owner, sick and tired of buying and glueing AF-confirm chips.
_________________
Canon 400D
Canon FD 50/1.8 S.C.(converted to M42)
Auto-Topcor 35/2.8(converted to M42)
Mamiya/Sekor 55/1.4
Mamiya/Sekor 135/2.8
Konica AR 40/1.8 (converted to EOS)

[naplam]

Hi Stan,
I tried more or less that, but after a couple of tries I decided to stop risking turning my 400D into a brick and only make modifications if 99% sure -which didn't happen since then. I think the firmware we can update is for the main "computer", so we can modify the user interface, send commands to the DIGiC processor, things like that. I think the AF sensor has its own controller and the main processor can just get info from it. The AF controller/processor/circuits probably decide themselves whether to offer AF confirm and that can't be tampered with from the "main computer".
_________________
Gear: Canon EOS 400D, Yashica FX-70, Contax 139Q, Canon EF-M,
Carl Zeiss Planar T* 50mm f/1.7, MIR-1V 37mm f/2.8, Carl Zeiss Jena Flektogon 35mm f/2.4, Yashica ML 28mm f/2.8,
Sigma 17-70 f/2.8-4.5 DC macro, Canon EF 100-300 f/4.5-5.6, Canon EF-S 18-55,
my flickr

[Schnauzer]

Good luck with your project. Sounds interesting.

I have always been irritated by the way canon disables things in their lower priced camera in firmware so it won't cut into their profits on the more expensive ones. With nikon giving them a big kick in the a$$ things are going to have to change or else.
_________________
Ron

[Stan]

I found an interesting approach to address the autoconfirm functionality in Canons. The idea is to solder the AF chip inside the camera body (not in the lens compartment) permanently and have a switch to turn this AF chip when real AF lens is used.

http://www.hackaday.com/2008/06/29/on-board-focus-confirmation-for-the-canon-digital-rebel-xt/
_________________
Canon 400D
Canon FD 50/1.8 S.C.(converted to M42)
Auto-Topcor 35/2.8(converted to M42)
Mamiya/Sekor 55/1.4
Mamiya/Sekor 135/2.8
Konica AR 40/1.8 (converted to EOS)

[lulalake]

[Stan]

IMO, this should be either the same or very similar on 40D. I am about to try this on my 400D, may be next week. It is not clear for me how the switch is connected though...
_________________
Canon 400D
Canon FD 50/1.8 S.C.(converted to M42)
Auto-Topcor 35/2.8(converted to M42)
Mamiya/Sekor 55/1.4
Mamiya/Sekor 135/2.8
Konica AR 40/1.8 (converted to EOS)

[naplam]

[tanheis]

I'm also thinking of doing it by myself.
I do soldering quite a lot at work too while fixing computer parts
like motherboards, psu's ect.. and other electronic equipments...

This whole modification is very simple... Just check from any EOS camera
the pinouts for the lens contacts... Then just sholder those 6 wires to the
rights pins

This works for any brand like Olympus, Nikon or any which uses chips...
It IS easy... The bigger work is to open the camera and close it after finding and sholdering the chip...

About the switch... We should check which pin gives the current for the chip.
Then put switch to that wire...
Maybe making some hole somewhere like inside battery cover and put small switch there to not make any holes outside of the camera?
_________________
Camera:EOS 20D
Lenses: Nikkor 24mm 2.8, Canon 28 2.8 "FD", Pentacon 30 3.5, SMC Takumar 50 1.4, Nikkor 50mm 1.4,Olympus 50 1.8,Pentacon 50 1.8, EF 80-200 2.8L(the only AF lens), Tamron SP 90mm 2.5, Tokina 28-85 4, Tamron SP 35-80 2.8-3.8, Zeiss Planar 85/1.4,Nikon 105mm 1.8,Seimar 135 2.8, Tamron SP 300mm 5.6, Tamron SP 60-300 3.8-5.4, Tamron SP 500mm 8.0 Mirror

[tanheis]

[tanheis]

Friend of mine has Nikon D80... Maybe I should try to get a chip
for it and sholder it inside of it... Then we would have metering on
manual lenses with cheaper Nikon
_________________
Camera:EOS 20D
Lenses: Nikkor 24mm 2.8, Canon 28 2.8 "FD", Pentacon 30 3.5, SMC Takumar 50 1.4, Nikkor 50mm 1.4,Olympus 50 1.8,Pentacon 50 1.8, EF 80-200 2.8L(the only AF lens), Tamron SP 90mm 2.5, Tokina 28-85 4, Tamron SP 35-80 2.8-3.8, Zeiss Planar 85/1.4,Nikon 105mm 1.8,Seimar 135 2.8, Tamron SP 300mm 5.6, Tamron SP 60-300 3.8-5.4, Tamron SP 500mm 8.0 Mirror

[Stan]

tanheis,

Well, the best way to activate chip when MF lens installed and deactivate it when EF lens installed is to connect/disconnect all wires, so that chip does not interfere with electronics in the lens. It is not clear how the chip behaves with no power applied. However, 6-pole switch is gonna be moderately large to hide it inside the camera.

Also, the battery compartment is the simpliest way to mount the switch, more convenient from the user prospective would be somewhere behind the lens (in the mirror chamber).

The best solution is to have the swich detect AF lens installed (say, mechanically) and turn off built in chip. This makes the camera operation completely transparent, but sounds like science fiction.
_________________
Canon 400D
Canon FD 50/1.8 S.C.(converted to M42)
Auto-Topcor 35/2.8(converted to M42)
Mamiya/Sekor 55/1.4
Mamiya/Sekor 135/2.8
Konica AR 40/1.8 (converted to EOS)