FAQ FAQ  Forum Search   Events   Register Register  Login Login

E-mount electronic protocol reverse engineering

Page  <1234 14>
Author
stiuskr View Drop Down
Moderator Group
Moderator Group

Joined: 01 September 2006
Country: United States
Location: West Virginia
Status: Offline
Posts: 11386
Post Options Post Options   Quote stiuskr Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2016 at 22:33
Originally posted by Micholand Micholand wrote:

Keep it up

This definitely is something for our 'Knowledge Base';
still leaving a crumb in the original posted subforum.


I agree Michael, good move. Maybe the OP could also start a discussion topic and leave this one for the tech stuff only.
Rob Suits Jr.
a99M2 a99 a77 a700 KM7D|Min24/2.8 Min35/2 So50/1.4 So50/2.8 Min85/1.4G Tam90/2.8 Tam180/3.5|Tam17-50 CZ24-70G2 KM28-75D So70-200G1 So70-300G So70-400G1| SonyF60 AD200R2
 



Back to Top
Miranda F View Drop Down
Senior Member
Senior Member

Joined: 11 January 2014
Country: United Kingdom
Location: Bristol
Status: Offline
Posts: 3519
Post Options Post Options   Quote Miranda F Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2016 at 23:38
Originally posted by Entropy512 Entropy512 wrote:

Also, we know based on the Sigma MC-11 and Phigment LM-NEX that the lens can report distortion/vignetting profiles to the body so that the camera does not need to maintain a database of lens profiles for correction.


Are you sure about that? I thought the camera look-up table was the only source of correction data, which is why other manufacturers have to pick an existing lens ID before they can auto-focus.
Miranda F & Sensorex, Sony A58, Nex-6, Dynax 4, 5, 60, 500si/600si/700si/800si, various Sony & Minolta lenses, several Tamrons, lots of MF primes and *far* too many old film cameras . . .
Back to Top
Bob J View Drop Down
Admin Group
Admin Group
Dyxum Administrator

Joined: 23 December 2005
Country: United Kingdom
Location: London
Status: Offline
Posts: 26074
Post Options Post Options   Quote Bob J Quote  Post ReplyReply Direct Link To This Post Posted: 06 May 2016 at 23:51
My understanding is that the basic specification for e mount is available as a free licence... would that specification include the information you are trying to gather...
Back to Top
sybersitizen View Drop Down
Senior Member
Senior Member

Joined: 04 August 2006
Country: United States
Location: California
Status: Offline
Posts: 14348
Post Options Post Options   Quote sybersitizen Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 2016 at 00:09
Originally posted by Miranda F Miranda F wrote:

I thought the camera look-up table was the only source of correction data, which is why other manufacturers have to pick an existing lens ID before they can auto-focus.

This was/is true of A-mount. To my knowledge there has been no indication that it's true of E-mount.
Back to Top
sybersitizen View Drop Down
Senior Member
Senior Member

Joined: 04 August 2006
Country: United States
Location: California
Status: Offline
Posts: 14348
Post Options Post Options   Quote sybersitizen Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 2016 at 00:15
Originally posted by Bob J Bob J wrote:

My understanding is that the basic specification for e mount is available as a free licence... would that specification include the information you are trying to gather...

As explained on that page, the specs are not offered to individuals. They are offered to companies that sign a non-disclosure agreement and meet other criteria.
Back to Top
Bob J View Drop Down
Admin Group
Admin Group
Dyxum Administrator

Joined: 23 December 2005
Country: United Kingdom
Location: London
Status: Offline
Posts: 26074
Post Options Post Options   Quote Bob J Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 2016 at 01:32
Originally posted by sybersitizen sybersitizen wrote:

Originally posted by Bob J Bob J wrote:

My understanding is that the basic specification for e mount is available as a free licence... would that specification include the information you are trying to gather...

As explained on that page, the specs are not offered to individuals. They are offered to companies that sign a non-disclosure agreement and meet other criteria.


Granted, but I just wanted to confirm if that specification would include the information being sought...
 



Back to Top
sybersitizen View Drop Down
Senior Member
Senior Member

Joined: 04 August 2006
Country: United States
Location: California
Status: Offline
Posts: 14348
Post Options Post Options   Quote sybersitizen Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 2016 at 02:08
Originally posted by Bob J Bob J wrote:

Granted, but I just wanted to confirm if that specification would include the information being sought...

Only people who have been granted access can give a complete answer - but it must be yes in order for manufacturers to produce properly working lenses and adapters.
Back to Top
Entropy512 View Drop Down
Groupie
Groupie

Joined: 22 July 2015
Country: United States
Status: Offline
Posts: 55
Post Options Post Options   Quote Entropy512 Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 2016 at 13:50
Originally posted by sybersitizen sybersitizen wrote:

Originally posted by Bob J Bob J wrote:

Granted, but I just wanted to confirm if that specification would include the information being sought...

Only people who have been granted access can give a complete answer - but it must be yes in order for manufacturers to produce properly working lenses and adapters.

I would disagree here. Reverse engineering is the way this sort of thing has been done for many years. That announcement was back in 2011, and since then - we've seen no evidence of anyone that does not have an extensive cross-branding agreement with Sony (Zeiss and Tamron) having any sort of documentation.

Techart III is unbelievably buggy.

Metabones IV is the most mature adapter out there, and they explicitly state that they received no assistance from Sony. If there's any company that would be eligible for the specifications, it would be Metabones/Conurus by virtue of being the most well-regarded electronic adapter manufacturer out there.

Sigma's first E-mount autofocus attempt was notably flawed with a bunch of limitations. They didn't even try another E-mount product for another 3-4 years, and I have seen others claim their CEO has been quoted as saying the mount was difficult to work with.

All of the evidence that can be seen in the E-mount product landscape says that the term "basic" in that specifications announcement is much more limiting than people think it is (Perhaps mechanical specifications only?) or the licensing terms are really nasty with non-monetary costs that no one is willing to pay.

On another subject, as to lens vignetting/distortion profiles - for E-mount it's definitely coming from the lens.

For example, from Sigma's MC-11 product description- "MOUNT CONVERTER MC-11 incorporates the digital data necessary to provide fast and smooth AF for compatible lenses as well as OS features and functions of the camera that help control peripheral brightness and correct transverse chromatic aberration, distortion, and more.". Also, Phigment Tech's LM-NEX supported automatic vignetting correction - https://www.phigmenttech.ca/lmnex/index.php?page=config&sensormode=2&model=1.1
Back to Top
sybersitizen View Drop Down
Senior Member
Senior Member

Joined: 04 August 2006
Country: United States
Location: California
Status: Offline
Posts: 14348
Post Options Post Options   Quote sybersitizen Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 2016 at 15:15
Originally posted by Entropy512 Entropy512 wrote:

Originally posted by sybersitizen sybersitizen wrote:

Originally posted by Bob J Bob J wrote:

Granted, but I just wanted to confirm if that specification would include the information being sought...

Only people who have been granted access can give a complete answer - but it must be yes in order for manufacturers to produce properly working lenses and adapters.

I would disagree here. Reverse engineering is the way this sort of thing has been done for many years. That announcement was back in 2011, and since then - we've seen no evidence of anyone that does not have an extensive cross-branding agreement with Sony (Zeiss and Tamron) having any sort of documentation ...

Well, I suppose it remains a matter for speculation. Any company that has the full 'official' specs, whatever they are, would probably have to keep quiet about any details because of the non-disclosure agreement.
Back to Top
Bob J View Drop Down
Admin Group
Admin Group
Dyxum Administrator

Joined: 23 December 2005
Country: United Kingdom
Location: London
Status: Offline
Posts: 26074
Post Options Post Options   Quote Bob J Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 2016 at 18:26
Originally posted by Entropy512 Entropy512 wrote:

Originally posted by sybersitizen sybersitizen wrote:

Originally posted by Bob J Bob J wrote:

Granted, but I just wanted to confirm if that specification would include the information being sought...

Only people who have been granted access can give a complete answer - but it must be yes in order for manufacturers to produce properly working lenses and adapters.

I would disagree here. Reverse engineering is the way this sort of thing has been done for many years. That announcement was back in 2011, and since then - we've seen no evidence of anyone that does not have an extensive cross-branding agreement with Sony (Zeiss and Tamron) having any sort of documentation.

Techart III is unbelievably buggy.

Metabones IV is the most mature adapter out there, and they explicitly state that they received no assistance from Sony. If there's any company that would be eligible for the specifications, it would be Metabones/Conurus by virtue of being the most well-regarded electronic adapter manufacturer out there.

Sigma's first E-mount autofocus attempt was notably flawed with a bunch of limitations. They didn't even try another E-mount product for another 3-4 years, and I have seen others claim their CEO has been quoted as saying the mount was difficult to work with.

All of the evidence that can be seen in the E-mount product landscape says that the term "basic" in that specifications announcement is much more limiting than people think it is (Perhaps mechanical specifications only?) or the licensing terms are really nasty with non-monetary costs that no one is willing to pay.

On another subject, as to lens vignetting/distortion profiles - for E-mount it's definitely coming from the lens.

For example, from Sigma's MC-11 product description- "MOUNT CONVERTER MC-11 incorporates the digital data necessary to provide fast and smooth AF for compatible lenses as well as OS features and functions of the camera that help control peripheral brightness and correct transverse chromatic aberration, distortion, and more.". Also, Phigment Tech's LM-NEX supported automatic vignetting correction - https://www.phigmenttech.ca/lmnex/index.php?page=config&sensormode=2&model=1.1


Those adapters might be buggy, but that may be down to the Canon side - which may well need to be reverse engineered.
Back to Top
Miranda F View Drop Down
Senior Member
Senior Member

Joined: 11 January 2014
Country: United Kingdom
Location: Bristol
Status: Offline
Posts: 3519
Post Options Post Options   Quote Miranda F Quote  Post ReplyReply Direct Link To This Post Posted: 07 May 2016 at 23:27
Originally posted by Entropy512 Entropy512 wrote:

On another subject, as to lens vignetting/distortion profiles - for E-mount it's definitely coming from the lens.

For example, from Sigma's MC-11 product description- "MOUNT CONVERTER MC-11 incorporates the digital data necessary to provide fast and smooth AF for compatible lenses as well as OS features and functions of the camera that help control peripheral brightness and correct transverse chromatic aberration, distortion, and more.". Also, Phigment Tech's LM-NEX supported automatic vignetting correction - https://www.phigmenttech.ca/lmnex/index.php?page=config&sensormode=2&model=1.1


YOu may well be right in your assertion, but to my mind it is not proved by this quote.
Miranda F & Sensorex, Sony A58, Nex-6, Dynax 4, 5, 60, 500si/600si/700si/800si, various Sony & Minolta lenses, several Tamrons, lots of MF primes and *far* too many old film cameras . . .
Back to Top
Entropy512 View Drop Down
Groupie
Groupie

Joined: 22 July 2015
Country: United States
Status: Offline
Posts: 55
Post Options Post Options   Quote Entropy512 Quote  Post ReplyReply Direct Link To This Post Posted: 08 May 2016 at 00:47
Originally posted by Bob J Bob J wrote:


Those adapters might be buggy, but that may be down to the Canon side - which may well need to be reverse engineered.

While it does need to be reverse engineered, the protocols have been around for so long that the results of REing them are, at this point, something you can find with a Google search. https://pickandplace.wordpress.com/2011/10/05/canon-ef-s-protocol-and-electronic-follow-focus/ for example

A number of companies have made products to control EF-mount lenses that work extremely well - see Blackmagic Design's EF-mount cameras for example.

Plus you can see plenty of evidence of problems on the Sony side of things. For example Techart hardcoding the third focus position field (used to calculate subject distance) in message 0x30, and also always reporting the same focus position for both current and predicted motor position in 0x30.

Originally posted by Miranda F Miranda F wrote:


YOu may well be right in your assertion, but to my mind it is not proved by this quote.

I can understand you thinking that for Sigma's quote, but the Phigment LM-NEX vignetting profile feature/capability is unambiguous here.
Back to Top
sympa View Drop Down
Newbie
Newbie

Joined: 09 August 2015
Country: Netherlands
Status: Offline
Posts: 16
Post Options Post Options   Quote sympa Quote  Post ReplyReply Direct Link To This Post Posted: 08 May 2016 at 14:23
True. And Sigma, Tamron and others have been making great Canon compatible lenses for ages.

And if the camera doesn't enable a ceratin feature, it is clearly something in the signalling that is missing. That happens before the EF mount comes into action.
Back to Top
Swede101 View Drop Down
Senior Member
Senior Member

Joined: 03 October 2007
Country: Sweden
Location: Gothenburg
Status: Offline
Posts: 1355
Post Options Post Options   Quote Swede101 Quote  Post ReplyReply Direct Link To This Post Posted: 10 May 2016 at 19:36
Originally posted by sympa sympa wrote:

---
That happens before the EF mount comes into action.



Do you mean Canon EOS fullformat (EF) mount, which was launched 1987? Or
Sony E-mount, where the fullformat lenses (stamped FE) were launched 2013-Oct-16 ? :-)

Edited by Swede101 - 10 May 2016 at 19:45
Gunnar

A77 II; A550; D7D w VC-7D; D7; 500si Super w DB (Unused); NEX-3
20/2,8; 50/1,7 Old; 50/1,8; 28-80 (Unused); 28-80 D; 28-105 RS; 135/2,8; 500/8 Reflex; Tamron 90/2,8 Macro 1:1 (V2); 5600HS(D)
Back to Top
Dyxum main page >  Forum Home > Dyxum Community > Knowledge Base Page  <1234 14>

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.078 seconds.

Monitor calibration strip

Dyxum.com - Home of the alpha system photographer

In memory of Cameron Hill - brettania

Feel free to contact us if needed.