Modifying Canon firmware for focus confirmation?

[naplam]

There's a website where some people dump powershot firmwares and modify them with their own custom firmware:
http://chdk.wikia.com/wiki/Main_Page
They haven't done it yet with eos reflex cameras, mainly because all features they add to powershots are already present in high-end cameras. Recently, they have been able to decrypt the 20d, 30d and 400d firmware, and I just realized the number one upgrade we need: focus confirmation without chip!! I'll try to decrypt my 400d firmware and peek into it. Maybe I can do something

[peterqd]

Wow, that would be a great idea! It could make you a fortune Naplam!

[poilu]

thanks napalm
please also add liveview

[LucisPictor]

[patrickh]

Keep us posted - that would open up a whole load more lenses to Canon owners.


patrickh

[Farside]

That would be incredibly useful, but I'm not holding my breath What would be wonderful would be in-body IS, sadly beyond the reach of firmware.

[Juanma]

Another good thing would be a mode in which when shutter was pressed, the camera didn't fire until focus is confirmed. That would be really helpful for MF shooting. I think Pentaxes do both.

[Attila]

One times I updated a dvd player firmware and not worked any more.. so be carefully...

[Orio]

[naplam]

Hehe you all got really excited! I have disassembled the firmware but it will be time consuming to analyze, which means I'll probably be fed up before I do anything actually useful. I've also tried to modify the sensor cleaning animation image but I need to figure out where the file checksum is because it won't accept the modified firmware as is.

[naplam]

[naplam]

I've managed to calculate the file checksum and patch the loader to bypass some other checks, so I can now load in the camera anything I want. Now comes the most complicated/time-consuming work, figuring out how to always confirm focus.

[patrickh]

naplam that's amazing


patrickh

[F16SUNSHINE]

Bravo
I hope you suceed Naplam. Then I hope canon gets wind of it and pisses themselves. These greedy camera companies could treat us all much better. They really hit hard with the prices that are charged. Good of you to hit back

[Attila]

Good luck Naplam! You do a risky business, but if you will be success...That would be wonderful!

[LucisPictor]

[naplam]

I'm still working on it, erm one quick question, to people who may have slow EF-compatible lenses (or canon teleconverters): when you put a slower than f/5.6 lens (EF-compatible and recognised by the body, not MF w/adapter), does the camera body disable autofocus altogether (because it sees the lens max. aperture is above f/5.6) or does it try to focus (successfully focusing if there's plenty of light)? and if you switch the lens to M, does it confirm focus if there's enough light or confirmation is disabled?

[LucisPictor]

I once had an AF Tamron 28-300 that offered only f6.3 at 300mm, but AF worked as usual.

[Juanma]

I think that the AF works just to f6.3. The third party makers as Sigma and Tamron know, so their modern slowest AF lenses are no slower than f6.3. After that AF is disconnected.

For example, I recently bought a 2x Kenko teleconverter. That's the MC 7 model. My f4 lenses are now "transformed" to f8. The camera still autofocuses if there is good light, but that's because the teleconverter doesn't tell the camera that it's there, so the camera thinks that it has a f4 lens attached. If the teleconverter were the Canon model, AF would be disabled, because the Canon one tells the camera that it's there, and doubles the focal lenght and the aperture, and at f8, AF is disconnected.

After my tests, I think that a EOS 30D can focus well at f8 if there is good light, and cannot focus if there isn't. So to avoid problem with the costumers, AF is disabled at f6.3 so there are no complaints.

[Orio]

I am more and more of the opinion that Veijo expressed in the Robot thread.
When there is fast action and not much time to manual focus, AF often fails as it rarely can track optimally moving subjects, especially when there are many subjects moving. In those situation, manual prefocusing (the technique I used for the Carnival for instance) often gives higher useable shots rates.

When shooting still subjects, with no time pressure, well, unless someone has a very weak sight, or uses a very cheap dark camera, the advantage of having an autofocus system escapes my understanding...

-

[Juanma]

Orio, the prefocusing technique works very good with autofocus, as long as the focused object follow a predictible path. One of my passions is the Formula-1. When I go to the track, I prefocus on the zone the car is going to pass, and after that, the focusing process using AF is almost instantaneous. I can follow the car with the AI-Servo in a way that would be much more difficult with manual focusing. And I can tell you that it works.

I enjoy very much MF lenses for the moments that I am not in a hurry, but machines, properly driven (talking about cameras, not cars ) are faster than humans, for the moments that it's needed.

P.D. If you give me your 5D I promise not to shot any still subject with an AF lens anymore

[naplam]

Thanks for the answers so it's safe to assume AF and confirmation are enabled if max Av>0 and <=f/6.3.

[hacksawbob]

I had a peek at the 350D firmware when I got the camera, I didn't get anywhere with it! I am wondering if the firmware that controls the AF confirm is hardcoded onto a ROM chip separate from the OS. Thats what I would do if I was a money grabbing mutinational.

[naplam]

[hacksawbob]

My thought was to have an AF chip permanently mounted to the Eos body I don't know how easy it would be, The AF chip would need to be much thinner and allow mounting of standard AF EOS lenses via some sort of pass through availability. Mounting it may be problematic but it is only a case of physical engineering rather than software. I am sure the AF chips could be reverse engineered easier than the canon software. In some ways you are reinventing the wheel. Although I wonder sometimes whether the AF chip inventors have the secret to the firmware patch, But if theyreleased a firmware patch there would be no way to make a profit from your hard work as you will only sell one copy and it will be all over file sharing sites in 24hours! Do you not think it would be easier to decode the chip?