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kautsu / 400plus

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Older Lens communication error fix #287

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago 
I have an older sigma lens (AF 28- 200 f/3.8-5.6)  about 8-10 years old.  

The AF of the lens works and the camera can also read the EXIF data (to a point 
it thinks it is a canon 28-70 lens, everything else it can read).  After using 
the lens once you go to step down the aperture past the camera instantly locks 
up with err99.  It works just fine with a wide open aperture and does not cause 
any issues after that.  

I did some research it appears when the lens made canon used a different binary 
pattern to communicate with the lens.  They then changed that pattern as time 
went on even though I don't think the how the protocol executes hasn't changed 
much.  This causes the err99 issue, when the camera tries to communicate with 
the lens it gets an error then fails because it can not communicate correctly 
on the aperture to the lens.  Sigma does know about this and has re-chipped 
lenses in the past but they are running out of or out of chips to do this with.

My thought is, can we modify the firmware to try different binary commands or 
adapt what ones it uses by default to communicate correctly with older great 
lenses.  They are much cheaper and give great results!  The older Canon Digital 
Film Cameras worked just fine with this sigma lens, possibly we can replicate 
that and have two communication modes for the camera to use.  Is this possible 
or a feature that we can possibly look into? I am willing to help, I am a 
system engineer I do know advanced scripting and programing but never 
programmed on the machine (firmware) level.  I can pick stuff up quickly though 
so if I can help in anyway please let me know. 

Any advice in this would help a ton!

Research
http://www.flickr.com/groups/eos-manual-lenses/discuss/72157629683387582/
You can also search Canon XTI older Sigma lens or Sigma Lens Canon rechip and 
several posts about issues will appear.

Original issue reported on code.google.com by brett...@gmail.com on 8 Oct 2012 at 1:07

GoogleCodeExporter commented 9 years ago 
" The only fix is to fit a new chip into these lenses, which Sigma will usually 
do for free, however they usually will tell you they don't have the parts, and 
therefore most lenses of this type are useless. Therefore older Sigma AF lenses 
are ones that I try to avoid, they're more trouble than they're worth."

Have you tried to call them ? Otherwise, I saw some lenses references in the 
firmware file of the XTI, you may check that file

Original comment by tiboun...@gmail.com on 8 Oct 2012 at 4:08

GoogleCodeExporter commented 9 years ago 
I have reached out to them just waiting for a response, I plan to continue that 
path to get more information to see if they are still re-chipping lenses.  

Where can I check that file(sorry new to this project)?  My thought is that 
re-chipping the lens only fixes one lens.  Adapting the camera will allow all 
lenses of this type to work.

Thank you for your input.

Original comment by brett...@gmail.com on 8 Oct 2012 at 4:15

GoogleCodeExporter commented 9 years ago 
I did see that the funclist.S had a lot of funtions capabilities of the lens.  

The main issue with older sigma lenses is the aperture control.  

If you go to this link and go to the conversations from "panabiker"
http://www.flickr.com/groups/eos-manual-lenses/discuss/72157629683387582/
While I am not sure this information is 100% accurate as I have no found more 
posts or website with this information.  I think the concept is correct, is 
possibly modifying the firmware to detect a non standard camera lens and try to 
communicate with a different binary command to control the lens.  

Thoughts?

Original comment by brett...@gmail.com on 8 Oct 2012 at 4:23

GoogleCodeExporter commented 9 years ago 
What we know now is that: There is companion chip "Tx19a" which handles the 
communication with   the lenses, some of the buttons, the view-finder display 
and perhaps some other stuff... We barely know the communication between the 
Digic processor and this companion Tx19a chip. We know nothing about the code 
in this chip, neither how we can change it.

IMO it's impossible to do what you want, at least for now. If we find a way to 
interpret or change the lens communication/data it may be possible, but not for 
now, at least IDK how.

More info: http://code.google.com/p/400plus/issues/detail?id=249

Original comment by fired...@gmail.com on 8 Oct 2012 at 4:28

GoogleCodeExporter commented 9 years ago 
You'll need to compile this file using your favorite C compiler : 
http://pastebin.com/YmJRbcUu
Then download the firmware update file (download the Mac version, and then use 
something like MacDrive under Windows to open the .dmg file, or borrow a Mac 
from a friend :P) : 
http://web.canon.jp/imaging/eosdigital3/e4kr3_firmware-e.html

Then, run the program that you had compiled using this command : ./decrypter30d 
e4kr3111.fir output.bin

You'll have a file with the firmware decrypted. Then execute this command : 
strings output.bin >> strings_XTI.txt
You'll have a new file with all the strings that was in the firmware.

I saw some references of lenses in the text file, like :
EF400mm f/5.6L USM
EF400mm f/5.6L USM +1.4x
EF400mm f/5.6L USM +2.0x

I'm not sure that you'll be able to do something with theses references of 
lens, I think it's used to provide information in the EXIF, altough I may be 
wrong ;)

Sorry for my bad English, I'm 14 and English is not my native language :)

PS : It may be good to make a page on the wiki explaining how to decrypt the 
firmware, that would be great for the new contributors

Original comment by tiboun...@gmail.com on 8 Oct 2012 at 4:31

GoogleCodeExporter commented 9 years ago 
@tibounise:
the decrypted firmware can be found somewhere on the web, but cant remember the 
links...
the strings are for the EXIF info (you're right).
there is information how to decrypt the firmware on the ML wiki pages 
(http://magiclantern.wikia.com/wiki/Firmware_file for a start).

Original comment by fired...@gmail.com on 8 Oct 2012 at 4:37

GoogleCodeExporter commented 9 years ago 
Never saw that page, thanks for the link !

Original comment by tiboun...@gmail.com on 8 Oct 2012 at 4:49

GoogleCodeExporter commented 9 years ago 
you may find many useful links there on the wiki. check them out.

Original comment by fired...@gmail.com on 8 Oct 2012 at 4:51

GoogleCodeExporter commented 9 years ago 
Thank you very much everyone for your input.  I will chase down sigma and some 
sigma service centers for more information on re-chipping.

Original comment by brett...@gmail.com on 8 Oct 2012 at 5:02