3rd party RF mount lenses, when ?

Fishchris said:

I think a few are already made, but specifically, I'm talking about long zooms for birding and wildlife ?

So here's the thing that kills me, when I was buying my R5, I researched 3rd party zooms a TON.... but apparently, that wasn't enough When I read about the Sigma 150-600c, with an EF to RF mount converter, everything said > it worked great, with basically zero loss in IQ.... which might be somewhat true. But I guess I was not asking the right question Yes > when the focus is spot on < the image quality of the Sigma 150-600c "adapted, to the RF mount" is extremely close to that of the RF 100-500 Canon. But the problem is, the Auto Eye Focus is extremely inconsistent And obviously, it doesn't matter how nice the optics in a lens are, if it is not getting perfect focus.

Duade Paton has done extensive testing of the Sigma 150-600C on the Canon R5. In this video his tests showed that the Sigma was hitting perfectly only about 15% of the time, while the Canon was hitting 80% ! HUGE difference, right ?

{note: this is not the exact video I wanted to show, in which he did a straight across comparison, and posted the % of sharp shots from the Canon, and Sigma, but he does discuss the Auto Eye Focus of the Sigma + R5 issue extensively, here}

AND, after owning this combo for 8 months, I completely agree with this assessment. I'm sorry to say, but 15% sounds about right.

I've ordered, for rent, the Canon RF 100-500 + both TC's.... and I'm afraid of how much I think I will like them ! But my biggest concerns, would be, 1) that I spend another $3K on the Canon lens, and a month later, they come out with a software fix for the Sigma 150-600 (less likely) or 2) that Sigma or another 3rd party manufacturer comes out with an RF mount long zoom lens, for half the price of the Canon.

I'm already completely confident that 3rd party manufacturers can produce fantastic optics, completely comparable to Canon. Its only the compatibility with R series cameras, and Eye Auto Focus which I have not seen yet.

And sorry to be skeptical, but is Canon doing all they can, to make sure this doesn't ever happen ???

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Chris Wolfgram said:

--
Photos are my paintings. The camera is my brush.
Website
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DPreview gallery; http://www.dpreview.com/galleries/5075216809
No time or attention given for negativity or trolls.

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KENTGA said:

Chris, I agree about 3rd party lenses. I did buy a ultra WA for my R5 and I also bought the RF 100-400 because I don't use tele that often and I didn't want to spend the $$$ for the 100-500.

In the past I was a 24-105 user 90% of the time but I use the 24-240 now because I'm both older and lazier.

Kent

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Fishchris said:

I've ordered, for rent, the Canon RF 100-500 + both TC's.... and I'm afraid of how much I think I will like them !

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antonio-salieri said:

I have not had problems with the Sigma 100-400mm on RF. Remember that the two focus setups that Duade tests in the video are not directly comparable. It's not just that the two cameras are different, but the actual focusing mode has changed. As he and a few others note in the comment, they had significantly different experiences in one-shot point AF (which is more directly comparable to what the 5Div is doing), and Sigma apparently responded that this lens in particular is not designed to be used in Servo+Eye Tracking.

I don't have a 1DXiii, but if you tried the lens on that body in live view with eye-tracking servo mode turned on, I imagine that the results would be very similar to the R5's in the test you showed.

On the other hand, many other lenses, including Sigma lenses, work very well in eye-tracking servo AF in my experience. So it's got more to do with this particular lens than EF/RF mount, I think.

In short, while the R5 has a great AF system, it's not necessarily going to work magically with every lens...

But with regards to this...

> Its only the compatibility with R series cameras, and Eye Auto Focus which I have not seen yet.

My Sigma 135mm f/1.8 prime works brilliantly with servo eye AF on the R5. So do a few other Sigma lenses that I have. I don't have the 150-600C or 150-600S.

As for RF-mount lenses from Sigma, the CEO mentioned in a few interviews that they were looking at this. They definitely could try to reverse-engineer support as they did for EF. They may choose not to. There is no legal barrier to actually putting out lenses that use AF on the physical RF mount, but there may be technical barriers which encourage (and Canon indeed would want to encourage this) official licensing --- and it is possible potentially to infringe a Canon patent in one's design, but also certainly possible to create an AF lens that does not infringe any Canon patents. Still, Sigma has a reputation for high quality stuff and probably will not want to put out something that isn't going to work perfectly and keep working. Samyang lenses ran into some issues on the R3 and later models with the differences in firmware. The Viltrox lens that was recently released reported internally that it was a Canon EF lens (which could create issues), etc. Sigma's EF lenses at this point even report the in-camera correction information on Canon cameras, besides generally being of good quality. We're talking about different standards.

Sigma's CEO said in 2019:

"I have a great interest in the Canon R and Nikon Z systems because eventually they will have more and more customers. So we are now investigating these systems. But still it’s too early to make a statement about how we will respond."

In 2021 he said:

"I am aware that there’s a very strong demand from customers for Canon RF and Nikon Z. We believe, too, as a lens manufacturer, that it’s our mission to support as many mounts as possible. We would like to support those mounts, and we’re discussing and researching."

Remember, Canon introduced the EF-M mount in 2012. Sigma only introduced EF-M lenses in 2019, though Tamron did earlier (note that Tamron is now partly owned by Sony). (https://www.dpreview.com/news/26199...unt-conversion-service-now-have-release-dates) The demand for EF-M lenses was not so high at the beginning as the mount as mostly considered secondary to EF. It was only with some of the later EF-M cameras the demand picked up, and still, Sigma does not offer nearly as many EF-M lenses as it does EF lenses. With consumer choice to use RF really picking up with the R5/6 in 2020, and especially with the supply chain issues since then, it's not surprising that Sigma hasn't engineered and released new native lenses for the mount quite yet. This doesn't mean it will never happen. I actually suspect we'll see them in 2023 or 2024.

(As for whether or not they are trying to license specific technology, I don't think that a normal marketing rep could really deliver information of that kind — it would generally violate an NDA if the status of such negotiations were made public, would it not? It's also hardly something to which a regional rep is generally made privy...)

Anyway, in the meantime, there are the Sigma EF lenses on RF cameras, and ... well, I've not heard about any problems with any of them besides the 150-600, at least, and in this case Duade says in the comments that the response from Sigma explains there is a design limitation.

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SNJops said:

The rep I spoke to didn’t say anything about negotiations, there could be some taking place or there might not be any at all. Sony took the approach of licensing emount with a number of 3rd parties which is why Sigma, Tamron, Voigtländer, Tokina and Zeiss (If they ever come back to making photo lenses) can make emount glass work with no issues at all. Fuji previously had a largely closed mount but once they decided to open it up Sigma, Tamron and Voigtländer all made lenses for xmount which has a smaller share of the market than RF I would imagine. There’s also the L mount alliance. So its not a secret that Sigma only release lenses for mirrorless mounts they have a license in which to do. If it was just a Sigma issue then why haven’t Tamron, Voigtländer and Tokina made RF glass either? Samyang and Viltrox did but they stopped.

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antonio-salieri said:

SNJops said:

The rep I spoke to didn’t say anything about negotiations, there could be some taking place or there might not be any at all. Sony took the approach of licensing emount with a number of 3rd parties which is why Sigma, Tamron, Voigtländer, Tokina and Zeiss (If they ever come back to making photo lenses) can make emount glass work with no issues at all. Fuji previously had a largely closed mount but once they decided to open it up Sigma, Tamron and Voigtländer all made lenses for xmount which has a smaller share of the market than RF I would imagine. There’s also the L mount alliance. So its not a secret that Sigma only release lenses for mirrorless mounts they have a license in which to do. If it was just a Sigma issue then why haven’t Tamron, Voigtländer and Tokina made RF glass either? Samyang and Viltrox did but they stopped.

Click to expand...

My point is that a rep of that level has no real authority to speak on any issue of this kind. On the other hand, the Sigma CEO said that they were examining these and that it was part of their future plans. Sigma previously reverse-engineered the AF protocols for EF lenses (and, as far as we know, for EF-M lenses too). But reverse-engineering something to a reliable standard takes time. That's perhaps part of why they didn't release EF-M lenses for five years. Of course, for autofocusing lenses, it's obviously easier to make them when the manufacturer of the camera will send you the AF protocol's specifications. R&D takes time when you have to redo it.

By the way, Canon didn't license the EF mount, and they say so themselves that third-party lenses are reverse-engineered: https://support.usa.canon.com/kb/index?page=content&id=ART126565.

> So its not a secret that Sigma only release lenses for mirrorless mounts they have a license in which to do.

They have sold EF-M lenses since 2019, and there's no evidence they ever licensed any technology from Canon for that. That's also a mirrorless mount. I'm certain the protocols here were reverse-engineered just as they were on EF.

> If it was just a Sigma issue then why haven’t Tamron, Voigtländer and Tokina made RF glass either?

Tamron? I don't know. But most of their offerings have been migrating to Sony only, and they're partly owned by Sony.

Voigtländer only makes manual focus lenses. There are tons of manual focus lenses designed for the RF mount: https://www.canonrumors.com/whats-happening-with-third-party-lenses-for-the-rf-mount/. As for why Voigtländer specifically doesn't make any, I don't know, but there is obviously nothing preventing them from making one. Physically making a manual focus lens fit on a mount isn't hard if the optical design is compatible. Zeiss could do this for their manual lenses ... if they wanted to.

Tokina actually does market one manual focus lens so far for the RF mount: https://tokinausa.com/collections/rf-mount.

Similarly, you can ask why there are relatively few Nikon Z third-party options (though there are a handful more than on Canon RF). The answers are similar too.

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SNJops said:

antonio-salieri said:

SNJops said:

The rep I spoke to didn’t say anything about negotiations, there could be some taking place or there might not be any at all. Sony took the approach of licensing emount with a number of 3rd parties which is why Sigma, Tamron, Voigtländer, Tokina and Zeiss (If they ever come back to making photo lenses) can make emount glass work with no issues at all. Fuji previously had a largely closed mount but once they decided to open it up Sigma, Tamron and Voigtländer all made lenses for xmount which has a smaller share of the market than RF I would imagine. There’s also the L mount alliance. So its not a secret that Sigma only release lenses for mirrorless mounts they have a license in which to do. If it was just a Sigma issue then why haven’t Tamron, Voigtländer and Tokina made RF glass either? Samyang and Viltrox did but they stopped.

Click to expand...

My point is that a rep of that level has no real authority to speak on any issue of this kind. On the other hand, the Sigma CEO said that they were examining these and that it was part of their future plans. Sigma previously reverse-engineered the AF protocols for EF lenses (and, as far as we know, for EF-M lenses too). But reverse-engineering something to a reliable standard takes time. That's perhaps part of why they didn't release EF-M lenses for five years. Of course, for autofocusing lenses, it's obviously easier to make them when the manufacturer of the camera will send you the AF protocol's specifications. R&D takes time when you have to redo it.

By the way, Canon didn't license the EF mount, and they say so themselves that third-party lenses are reverse-engineered: https://support.usa.canon.com/kb/index?page=content&id=ART126565.

> So its not a secret that Sigma only release lenses for mirrorless mounts they have a license in which to do.

They have sold EF-M lenses since 2019, and there's no evidence they ever licensed any technology from Canon for that. That's also a mirrorless mount. I'm certain the protocols here were reverse-engineered just as they were on EF.

> If it was just a Sigma issue then why haven’t Tamron, Voigtländer and Tokina made RF glass either?

Tamron? I don't know. But most of their offerings have been migrating to Sony only, and they're partly owned by Sony.

Voigtländer only makes manual focus lenses. There are tons of manual focus lenses designed for the RF mount: https://www.canonrumors.com/whats-happening-with-third-party-lenses-for-the-rf-mount/. As for why Voigtländer specifically doesn't make any, I don't know, but there is obviously nothing preventing them from making one. Physically making a manual focus lens fit on a mount isn't hard if the optical design is compatible. Zeiss could do this for their manual lenses ... if they wanted to.

Tokina actually does market one manual focus lens so far for the RF mount: https://tokinausa.com/collections/rf-mount.

Similarly, you can ask why there are relatively few Nikon Z third-party options (though there are a handful more than on Canon RF). The answers are similar too.

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Its not speaking with authority if that’s just the company policy, has been briefed to company employees and isn’t classed as sensitive information that they are waiting on licenses from both Canon and Nikon. In terms of reverse engineering as I understand it Sigma will not do this for Canon RF or Nikon Z. Fair enough if they did for EF-M but perhaps that policy has changed since then.

That link you sent from Tokina came back as page not found. The only lens they list for RF is a 400mm f8 that only mounts with a screw on adapter so no electronic contacts. Viltrox and Samyang made AF lenses which were almost certainly reversed engineered in both instances those lenses have disappeared from both manufacturer’s websites. So even others wanted to reverse engineer it seems that isn’t an option anymore. It’s possible doing so infringes on Canon’s IP.

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SNJops said:

I have [had] many questions about it. I know that some [Fujifilm] customers are wishing for us to make lenses for them. It's always a matter of priority. We know there are many good customers of the Fuji system and they're perfectly matched with our ideal customer but [Fujifilm doesn't] really disclose the protocol between the lens and camera, so we need to do the reverse engineering by ourselves.

It's a really time-consuming process so we need to prioritize support for Sony E mount, our L-mount system, existing DSLR mounts and Micro Four Thirds.

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antonio-salieri said:

SNJops said:

antonio-salieri said:

SNJops said:

The rep I spoke to didn’t say anything about negotiations, there could be some taking place or there might not be any at all. Sony took the approach of licensing emount with a number of 3rd parties which is why Sigma, Tamron, Voigtländer, Tokina and Zeiss (If they ever come back to making photo lenses) can make emount glass work with no issues at all. Fuji previously had a largely closed mount but once they decided to open it up Sigma, Tamron and Voigtländer all made lenses for xmount which has a smaller share of the market than RF I would imagine. There’s also the L mount alliance. So its not a secret that Sigma only release lenses for mirrorless mounts they have a license in which to do. If it was just a Sigma issue then why haven’t Tamron, Voigtländer and Tokina made RF glass either? Samyang and Viltrox did but they stopped.

Click to expand...

My point is that a rep of that level has no real authority to speak on any issue of this kind. On the other hand, the Sigma CEO said that they were examining these and that it was part of their future plans. Sigma previously reverse-engineered the AF protocols for EF lenses (and, as far as we know, for EF-M lenses too). But reverse-engineering something to a reliable standard takes time. That's perhaps part of why they didn't release EF-M lenses for five years. Of course, for autofocusing lenses, it's obviously easier to make them when the manufacturer of the camera will send you the AF protocol's specifications. R&D takes time when you have to redo it.

By the way, Canon didn't license the EF mount, and they say so themselves that third-party lenses are reverse-engineered: https://support.usa.canon.com/kb/index?page=content&id=ART126565.

> So its not a secret that Sigma only release lenses for mirrorless mounts they have a license in which to do.

They have sold EF-M lenses since 2019, and there's no evidence they ever licensed any technology from Canon for that. That's also a mirrorless mount. I'm certain the protocols here were reverse-engineered just as they were on EF.

> If it was just a Sigma issue then why haven’t Tamron, Voigtländer and Tokina made RF glass either?

Tamron? I don't know. But most of their offerings have been migrating to Sony only, and they're partly owned by Sony.

Voigtländer only makes manual focus lenses. There are tons of manual focus lenses designed for the RF mount: https://www.canonrumors.com/whats-happening-with-third-party-lenses-for-the-rf-mount/. As for why Voigtländer specifically doesn't make any, I don't know, but there is obviously nothing preventing them from making one. Physically making a manual focus lens fit on a mount isn't hard if the optical design is compatible. Zeiss could do this for their manual lenses ... if they wanted to.

Tokina actually does market one manual focus lens so far for the RF mount: https://tokinausa.com/collections/rf-mount.

Similarly, you can ask why there are relatively few Nikon Z third-party options (though there are a handful more than on Canon RF). The answers are similar too.

Click to expand...

Its not speaking with authority if that’s just the company policy, has been briefed to company employees and isn’t classed as sensitive information that they are waiting on licenses from both Canon and Nikon. In terms of reverse engineering as I understand it Sigma will not do this for Canon RF or Nikon Z. Fair enough if they did for EF-M but perhaps that policy has changed since then.

That link you sent from Tokina came back as page not found. The only lens they list for RF is a 400mm f8 that only mounts with a screw on adapter so no electronic contacts. Viltrox and Samyang made AF lenses which were almost certainly reversed engineered in both instances those lenses have disappeared from both manufacturer’s websites. So even others wanted to reverse engineer it seems that isn’t an option anymore. It’s possible doing so infringes on Canon’s IP.

Click to expand...

All I can say is that they did it for a mirrorless mount for which they began support three years ago, in 2019 (i.e., EF-M). And we know the Sigma CEO has said they are investigating the RF mount (and we also know that reverse engineering these things properly takes some time, as well as that the past two years have not been the best for production of new gear generally). So what I am suggesting is that there is no policy against reverse-engineering at Sigma that has been communicated to marketing reps.

I can actually quote the Sigma CEO on this issue, in 2019: (https://www.dpreview.com/interviews...s-always-a-battle-with-the-design-constraints)

antonio-salieri said:

I have [had] many questions about it. I know that some [Fujifilm] customers are wishing for us to make lenses for them. It's always a matter of priority. We know there are many good customers of the Fuji system and they're perfectly matched with our ideal customer but [Fujifilm doesn't] really disclose the protocol between the lens and camera, so we need to do the reverse engineering by ourselves.

It's a really time-consuming process so we need to prioritize support for Sony E mount, our L-mount system, existing DSLR mounts and Micro Four Thirds.

Click to expand...

Here he says in 2019 that Sigma wasn't reverse engineering Fuji X mount protocols because it was time consuming and not a priority. That's very different from taking a principled stand against the use of the X mount. We know that their use of EF-M was based on reverse engineering — and this was surely helped by the fact that they had already worked on the EF mount for years.

This is consistent with everything else he has said: it's time consuming and not always justified by demand. But that's very different from being against it in principle.

If the RF mount is a potential sales priority for Sigma, they will reverse engineer it. There is probably more money in RF-mount full-frame glass than there is in the Fuji X-mount APS-C contemporary lenses. As they shift towards mirrorless and away from DSLR lenses, RF will probably gain more priority.

On the Tokina link, apologies --- an errant trailing period was added to the link itself there for some reason. Yes, it's just a full-manual lens.

As for patents: Canon has a Japanese patent on the camera body sending a signal to the lens in order to check whether or not it can change autofocus communication speed (https://www.canonrumors.com/patent-new-canon-mount-coming/) and related to changing modes of communication (https://www.canonnews.com/Canon-Pat...e-types-of-lenses-supported-in-a-single-mount).

However, this definitely cannot prevent a manufacturer from making an EF-protocol lens that physically fits the RF mount and uses a mirrorless optical design (this is because of prior art). Nor do the patents seem to cover any of the lens side of the handshake, but rather only the body's method for checking the protocol is the faster one.

Rokinon never stopped listing their lenses on the site, even though they are now shown as sold out. But don't forget that these lenses ran into trouble with new bodies – they required firmware updates with the R5/6 and later ran into more compatibility issues with the R3.

Yongnuo also apparently sells an RF AF lens... I wouldn't buy anything from them myself, but they definitely exist. https://www.bhphotovideo.com/c/prod...yn85mm_f1_8r_df_dsm_yn85mm_f_1_8r_df_dsm.html

As for Viltrox... they dropped the RF lens and also all their RF adapters from their website, apparently – and it's possible they legitimately did copy Canon IP (for example, by copying code from copyrighted firmware).

Legitimately reverse-engineered AF protocol support would be on the basis of re-creating a trade secret (which is kosher to reverse-engineer), and not based on any Canon patent I can find (and patents obviously need to be made public). Anyway, I figure that just like with EF-M (which took 5 years for Sigma to support from initial launch), we will see RF lenses sooner or later, and Sigma surely knows how to do this correctly given their recent track record (btw, 5 years from RF's launch is ... 2023)

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SNJops said:

antonio-salieri said:

SNJops said:

antonio-salieri said:

SNJops said:

The rep I spoke to didn’t say anything about negotiations, there could be some taking place or there might not be any at all. Sony took the approach of licensing emount with a number of 3rd parties which is why Sigma, Tamron, Voigtländer, Tokina and Zeiss (If they ever come back to making photo lenses) can make emount glass work with no issues at all. Fuji previously had a largely closed mount but once they decided to open it up Sigma, Tamron and Voigtländer all made lenses for xmount which has a smaller share of the market than RF I would imagine. There’s also the L mount alliance. So its not a secret that Sigma only release lenses for mirrorless mounts they have a license in which to do. If it was just a Sigma issue then why haven’t Tamron, Voigtländer and Tokina made RF glass either? Samyang and Viltrox did but they stopped.

Click to expand...

My point is that a rep of that level has no real authority to speak on any issue of this kind. On the other hand, the Sigma CEO said that they were examining these and that it was part of their future plans. Sigma previously reverse-engineered the AF protocols for EF lenses (and, as far as we know, for EF-M lenses too). But reverse-engineering something to a reliable standard takes time. That's perhaps part of why they didn't release EF-M lenses for five years. Of course, for autofocusing lenses, it's obviously easier to make them when the manufacturer of the camera will send you the AF protocol's specifications. R&D takes time when you have to redo it.

By the way, Canon didn't license the EF mount, and they say so themselves that third-party lenses are reverse-engineered: https://support.usa.canon.com/kb/index?page=content&id=ART126565.

> So its not a secret that Sigma only release lenses for mirrorless mounts they have a license in which to do.

They have sold EF-M lenses since 2019, and there's no evidence they ever licensed any technology from Canon for that. That's also a mirrorless mount. I'm certain the protocols here were reverse-engineered just as they were on EF.

> If it was just a Sigma issue then why haven’t Tamron, Voigtländer and Tokina made RF glass either?

Tamron? I don't know. But most of their offerings have been migrating to Sony only, and they're partly owned by Sony.

Voigtländer only makes manual focus lenses. There are tons of manual focus lenses designed for the RF mount: https://www.canonrumors.com/whats-happening-with-third-party-lenses-for-the-rf-mount/. As for why Voigtländer specifically doesn't make any, I don't know, but there is obviously nothing preventing them from making one. Physically making a manual focus lens fit on a mount isn't hard if the optical design is compatible. Zeiss could do this for their manual lenses ... if they wanted to.

Tokina actually does market one manual focus lens so far for the RF mount: https://tokinausa.com/collections/rf-mount.

Similarly, you can ask why there are relatively few Nikon Z third-party options (though there are a handful more than on Canon RF). The answers are similar too.

Click to expand...

Its not speaking with authority if that’s just the company policy, has been briefed to company employees and isn’t classed as sensitive information that they are waiting on licenses from both Canon and Nikon. In terms of reverse engineering as I understand it Sigma will not do this for Canon RF or Nikon Z. Fair enough if they did for EF-M but perhaps that policy has changed since then.

That link you sent from Tokina came back as page not found. The only lens they list for RF is a 400mm f8 that only mounts with a screw on adapter so no electronic contacts. Viltrox and Samyang made AF lenses which were almost certainly reversed engineered in both instances those lenses have disappeared from both manufacturer’s websites. So even others wanted to reverse engineer it seems that isn’t an option anymore. It’s possible doing so infringes on Canon’s IP.

Click to expand...

All I can say is that they did it for a mirrorless mount for which they began support three years ago, in 2019 (i.e., EF-M). And we know the Sigma CEO has said they are investigating the RF mount (and we also know that reverse engineering these things properly takes some time, as well as that the past two years have not been the best for production of new gear generally). So what I am suggesting is that there is no policy against reverse-engineering at Sigma that has been communicated to marketing reps.

I can actually quote the Sigma CEO on this issue, in 2019: (https://www.dpreview.com/interviews...s-always-a-battle-with-the-design-constraints)

SNJops said:

I have [had] many questions about it. I know that some [Fujifilm] customers are wishing for us to make lenses for them. It's always a matter of priority. We know there are many good customers of the Fuji system and they're perfectly matched with our ideal customer but [Fujifilm doesn't] really disclose the protocol between the lens and camera, so we need to do the reverse engineering by ourselves.

It's a really time-consuming process so we need to prioritize support for Sony E mount, our L-mount system, existing DSLR mounts and Micro Four Thirds.

Click to expand...

Here he says in 2019 that Sigma wasn't reverse engineering Fuji X mount protocols because it was time consuming and not a priority. That's very different from taking a principled stand against the use of the X mount. We know that their use of EF-M was based on reverse engineering — and this was surely helped by the fact that they had already worked on the EF mount for years.

This is consistent with everything else he has said: it's time consuming and not always justified by demand. But that's very different from being against it in principle.

If the RF mount is a potential sales priority for Sigma, they will reverse engineer it. There is probably more money in RF-mount full-frame glass than there is in the Fuji X-mount APS-C contemporary lenses. As they shift towards mirrorless and away from DSLR lenses, RF will probably gain more priority.

On the Tokina link, apologies --- an errant trailing period was added to the link itself there for some reason. Yes, it's just a full-manual lens.

As for patents: Canon has a Japanese patent on the camera body sending a signal to the lens in order to check whether or not it can change autofocus communication speed (https://www.canonrumors.com/patent-new-canon-mount-coming/) and related to changing modes of communication (https://www.canonnews.com/Canon-Pat...e-types-of-lenses-supported-in-a-single-mount).

However, this definitely cannot prevent a manufacturer from making an EF-protocol lens that physically fits the RF mount and uses a mirrorless optical design (this is because of prior art). Nor do the patents seem to cover any of the lens side of the handshake, but rather only the body's method for checking the protocol is the faster one.

Rokinon never stopped listing their lenses on the site, even though they are now shown as sold out. But don't forget that these lenses ran into trouble with new bodies – they required firmware updates with the R5/6 and later ran into more compatibility issues with the R3.

Yongnuo also apparently sells an RF AF lens... I wouldn't buy anything from them myself, but they definitely exist. https://www.bhphotovideo.com/c/prod...yn85mm_f1_8r_df_dsm_yn85mm_f_1_8r_df_dsm.html

As for Viltrox... they dropped the RF lens and also all their RF adapters from their website, apparently – and it's possible they legitimately did copy Canon IP (for example, by copying code from copyrighted firmware).

Legitimately reverse-engineered AF protocol support would be on the basis of re-creating a trade secret (which is kosher to reverse-engineer), and not based on any Canon patent I can find (and patents obviously need to be made public). Anyway, I figure that just like with EF-M (which took 5 years for Sigma to support from initial launch), we will see RF lenses sooner or later, and Sigma surely knows how to do this correctly given their recent track record (btw, 5 years from RF's launch is ... 2023)

Click to expand...

This is what Fuji rumours reported in 2019 regarding Sigma and xmount lenses https://www.fujirumors.com/sigma-ce...t-fujifilm-does-not-disclose-their-protocols/ its interesting that once Fuji opened up the mount Sigma, Tamron and Voigtländer all released lenses for xmount.

I don’t see a situation where 3rd parties have access to L, E and X mount protocols but then reverse engineer for Canon at the risk of having lenses that work with no issues on 3 mounts but potentially have them on RF. If that was to happen sales of 3rd party lenses on RF would suffer. What was true for EF mount isn’t necessarily true of RF. Even in the case of reverse engineering there’s evidence to suggest that Canon isn’t allowing it so even if Sigma wanted to reverse engineer RF it’s probably not worth doing if suddenly you have to pull your products off the market which is what we have seen with Samyang, Viltrox and Yongnuo. While their products are still available from retailers the manufacturers themselves have no mention of them on their websites. Rokinon being the exception but as has been mentioned their branded RF lenses are out of stock.

As for what the Sigma UK rep told me, the same thing was said to my local camera shop manager last year by another Sigma UK rep.

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Sittatunga said:

It was Michihiro Yamaki's proud boast 40 years ago that Sigma never licenced anything, as they took a pride in their reverse engineering. That's been a Sigma tradition since the start of the company, and I don't think being a founder member of the L mount alliance will have changed it that much. But then, I'm not a Sigma rep.

Making a third party lens for EF-M is very easy, as the cameras basically use EF protocols and there is no performance penalty to port an EF lens to EF-M with EF-M contacts wired up in the same way as the EF - EOS M mount adapter. All it takes is the confidence that the mount will endure...

RF cameras are bilingual; they will control EF lenses to the best of the lenses' abilities, so, again, it's relatively easy to make a functional third-party RF lens, as shown by the downmarket manufacturers who have already done so. But RF lenses also have a high speed communication protocol. So far we know it's used to synchronise the lens and the sensor stabilisation, and we see that RF lenses also show a manual focussing scale in the viewfinder, which makes it obvious which protocol is being used. We don't know what else the RF protocol will be able do in the future, so we know that lenses without it are second-rate but are uncertain how much of a difference that makes. I'm not surprised that Sigma, Tamron, Tokina and Cosina (aka Voigtländer and Zeiss) are still waiting.

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bodeswell said:

I agree with the excellent points made by Salieri and Sittatunga. I would like to mention another factor that may give Sigma and Tamron pause. It is neither technical nor legal. It is a matter of Canon’s marketing strategy.

Consider the RF 100-400. Canon never released anything like it for EF. Not only is it a pretty good lens, but it works with the RF teleconverters. Another clear difference from EF days. The mere presence of this lens in the RF lineup presents Sigma and Tamron with a new problem: Canon is willing to compete head on in the space between the least expensive lenses and the most expensive lenses.

Suppose Canon licensed the RF mount to Sigma but also brought out a line of “arty” f/1.4 primes at competitive prices? Would Sigma still compete?

If Canonm wants to play hardball they can do so even if they offer to license the mount. So will Sigma and Tamron say “game on”? I would like them too, but we shall see.

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