SIGMA RF mount lens information finally coming in February 2024? [CR1]

[Dragon]

For me that would only be attractive if there’s an M6II or M200 sized body to mount them on.

There isn't that much difference https://www.the-digital-picture.com/Reviews/Camera-Specifications.aspx?Camera=1446&CameraComp=1651 . The difference in thickness is due to a deeper grip but that doesn't make the camera any thicker once you put even a pancake lens on it, and the M6 II is much taller with the EVF attached. Maybe a more realistic M vs. R comparison would be this https://www.the-digital-picture.com/Reviews/Camera-Specifications.aspx?CameraComp=1641&Camera=1523 . Mighty close there. In any of these cases (including the M100/M200), the lens is always the obstacle to pocketability, so the next step is a fixed lens camera with a collapsible lens. Ricoh/Pentax GR series comes to mind and there is a market there.

 

[EOS 4 Life]

Are there any that would not have gone L glass if they could have gotten 3rd party glass?

I have mostly 3rd party EF lenses.
Being better is not enough for me to replace them with RF lenses.
My EF lenses have obviously been good enough.
There currently is only one third-party lens that I wish was on RF, the Sigma 14 f/1.4 but I am hoping for a Canon version.
Canon has a patent for one with IS.

 

[EOS 4 Life]

OT: I'm not a lens expert hence I've been wondering: would Tamron be able to directly transfer their lenses to RF mount given that the E mount has the shorter flange distance?

Like do you know if they targeted 18mm? If so would it be problematic to extend the lens elements the extra 2mm behind the mount?

They have talked about it.
It is not as simple as people think it is but it is what they do.
Sigma designs for the L mount and E mount at the same time.

 

[EOS 4 Life]

105mm f/1.4

Nikon has made one but Canon never has.
Canon should either make one or let Sigma bring theirs over.

 

[EOS 4 Life]

Sorry, I must be a little slow tonight. I don't understand the "10 years after ef" part of that comment.

The EF mount came out in 1987. I don't know exactly when the first EF Sigma AF lenses came out, but I know they were pretty widely available by about 1990-1991.

Software patents did not become really strict until 1994.
Before that, cleanroom reverse engineering was possible.

 

[neuroanatomist]

Primes at 16, 22, 28, 32, and 50 make for a decent crop frame setup and none of those are or would be all that expensive.

We already have an RF 16/2.8, RF 28/2.8 and RF 50/1.8, all under $300. Plus an RF 24/1.8 and Rf 35/1.8 with (semi) macro capability typically selling for less than $500. I'm not sure we'll see any RF-S prime lenses at all, because I'm not sure there'a a need.

The last bit needed would be a fast zoom harking back to the EF-s 17-55 f/2.8 or the Sigma 17-50 f/2.8.

Canon showed no inclination to update the EF-S 17-55/2.8 or launch a fast, constant aperture EF-M zoom. I really doubt we'll see one in the RF-S mount.

 

[koenkooi]

There isn't that much difference https://www.the-digital-picture.com/Reviews/Camera-Specifications.aspx?Camera=1446&CameraComp=1651 . The difference in thickness is due to a deeper grip but that doesn't make the camera any thicker once you put even a pancake lens on it, and the M6 II is much taller with the EVF attached. Maybe a more realistic M vs. R comparison would be this https://www.the-digital-picture.com/Reviews/Camera-Specifications.aspx?CameraComp=1641&Camera=1523 . Mighty close there. In any of these cases (including the M100/M200), the lens is always the obstacle to pocketability, so the next step is a fixed lens camera with a collapsible lens. Ricoh/Pentax GR series comes to mind and there is a market there.

I had an M50 and absolutely loathed the waste-of-space EVF on that. And I haven’t used the add-on EVF for the m6II in years. So those small bodies with EVF are not for me. I was very tempted by the R7, but it overlapped to much with my R5.

Now that I sold my R5, an aps-c body needs to be better than my R8 in some way. And that combination of size and features is hard to beat.

 

[Dragon]

We already have an RF 16/2.8, RF 28/2.8 and RF 50/1.8, all under $300. Plus an RF 24/1.8 and Rf 35/1.8 with (semi) macro capability typically selling for less than $500. I'm not sure we'll see any RF-S prime lenses at all, because I'm not sure there's a need.

Yes, I noted the 16 and 28. My point was that the EF-M 22 and 32 would be nice to see in RF mount (because the 22 is tiny and the 32 is optically excellent). The RF 24 and 35 are certainly workable for APS-c, but they are a bit bigger than needed and also a little pricier. You may well be correct, though, in that Canon seems to be trying to make FF lenses that are attractive to crop frame users so they will have no obstacle to upgrading to FF in the future. The RF 28 is a perfect example in that it is optically excellent on either body and very svelte, not to mention that both 28 and 45 are nice walkabout focal lengths. The immensely aspheric elements in that lens surpass the performance of the EF 40mm pancake and that is significant.

 

[David - Sydney]

Software patents did not become really strict until 1994.
Before that, cleanroom reverse engineering was possible.

Can you provide more information? Reverse engineering continues to be an option although encrypted communication protocols make it extremely difficult.

 

[dloop]

I am hoping for the SIGMA 14mm F1.4 in an RF mount for astro. Recent rumors have Canon perhaps offering their own 14mm next year, but today there is nothing.

 

[Walrus]

Can you provide more information? Reverse engineering continues to be an option although encrypted communication protocols make it extremely difficult.

I really don't see, talking about third party RF, any reverse engineering needed, if they want to do a "simple" port; the R bodies "talk EF", and has already been proven that third party can manufacture bits of kit (EF-RF adapters, and the two Samyang RF AF lenses that were retired from sale) with RF contacts that work on R cameras flawlessly.

So I don't see (practically; not talking about patents and authorizations of course) any difficulty in realizing (or adapting an existing e-mount or l-mount) a lens with optics optimized for mirrorless flange, with a RF mount and contacts, and an integrated electronics that translate EF instructions into the RF contacts (which is what any 50$ Meike or Viltrox adapter is already doing).

They just need to manufacture a lens which is EF electronically and mirrorless optically, and integrate the electronics of an EF to RF converter.

EF third party protocols are pretty honed right now, let's face it, the last stuff from Sigma works on DSLR as good as any other Canon lens; if they're not doing it already for ML it's because of Canon patents and authorization, but I'm sure they don't have any tech barrier with it, they can release tomorrow practically any e-mount lens in RF mount, with EF protocols.

 

[Dragon]

I really don't see, talking about third party RF, any reverse engineering needed, if they want to do a "simple" port; the R bodies "talk EF", and has already been proven that third party can manufacture bits of kit (EF-RF adapters, and the two Samyang RF AF lenses that were retired from sale) with RF contacts that work on R cameras flawlessly.

So I don't see (practically; not talking about patents and authorizations of course) any difficulty in realizing (or adapting an existing e-mount or l-mount) a lens with optics optimized for mirrorless flange, with a RF mount and contacts, and an integrated electronics that translate EF instructions into the RF contacts (which is what any 50$ Meike or Viltrox adapter is already doing).

They just need to manufacture a lens which is EF electronically and mirrorless optically, and integrate the electronics of an EF to RF converter.

EF third party protocols are pretty honed right now, let's face it, the last stuff from Sigma works on DSLR as good as any other Canon lens; if they're not doing it already for ML it's because of Canon patents and authorization, but I'm sure they don't have any tech barrier with it, they can release tomorrow practically any e-mount lens in RF mount, with EF protocols.

I don't think any EF-RF translation is needed. R bodies speak EF protocol when one of the additional lines is terminated in a particular way. The catch is that such a lens could not take advantage of any of the new RF features like faster communications and cooperative IS and that would put a third party lens at a serious disadvantage relative to a Canon lens. In order to get all the way to an RF protocol, a lot needs to be learned, much of which may not have yet even been visibly implemented on existing Canon lenses (that is to say there may be future features on cameras that the existing lenses will support, but no snooping of communications between current cameras and those lenses will reveal those features). Lens electronics were pretty simple in 1984, but today, it is not unlikely to have a billion transistor FPGA buried in a lens, so now things are not so simple. Reprogrammable hardware is on a different planet from software on a fixed machine and far less decipherable, particularly when future capabilities have not even been programmed into the hardware yet. (EDIT) One of the features that has been added is the lens parameter table for DLO being in the lens rather than the camera which is the way EF protocol works. For a Zoom lens, that can be a really big table.

 

[neuroanatomist]

Lens electronics were pretty simple in 1984, but today, it is not unlikely to have a billion transistor FPGA buried in a lens, so now things are not so simple.

As an example that I learned from recently venturing into UV/IR photography, some RF lenses have a low-intensity IR light that shines back toward the sensor to interrogate the status of the shutter. I have no idea what the camera uses that information for, but evidently something.

 

[Dragon]

As an example that I learned from recently venturing into UV/IR photography, some RF lenses have a low-intensity IR light that shines back toward the sensor to interrogate the status of the shutter. I have no idea what the camera uses that information for, but evidently something.

Yep, modern protocols are just like Shrek and onions - lots of layers. Even EF protocol clearly had a lot of features that weren't used for years and likely some that were added in ways that didn't screw up the earlier products along with a few that specifically were not supported by some existing products. Sony has clearly shared some part of their protocol with third parties and Nikon was very slow to adapt to true electronic control of lenses (look at how long screw drive Nikon lenses were around). The consequence may be that RF protocol is much more complex and layered than Z protocol, so even if Nikon is not sharing too much, building lenses for Z may be easier than for RF. All that is aside from how aggressive a particular manufacturer may be with respect to patents. BTW, Roger from Lens Rentals ran into that IR light in one of his teardowns and he didn't know what it was for either.

 

[David - Sydney]

I really don't see, talking about third party RF, any reverse engineering needed, if they want to do a "simple" port; the R bodies "talk EF", and has already been proven that third party can manufacture bits of kit (EF-RF adapters, and the two Samyang RF AF lenses that were retired from sale) with RF contacts that work on R cameras flawlessly.

So I don't see (practically; not talking about patents and authorizations of course) any difficulty in realizing (or adapting an existing e-mount or l-mount) a lens with optics optimized for mirrorless flange, with a RF mount and contacts, and an integrated electronics that translate EF instructions into the RF contacts (which is what any 50$ Meike or Viltrox adapter is already doing).

They just need to manufacture a lens which is EF electronically and mirrorless optically, and integrate the electronics of an EF to RF converter.

@EOS 4 Life was saying that cleanroom reverse engineering isn't possible after 1994 which seems strange to me.

You are of course correct and any lens released for EF will work on R mount. Even manual focus lenses with basic aperture control would be fine for astro purposes - just like my Samyang 14/2.8.

What is unusual is that Sigma and Tamron have not released any manual focus lenses for EF or R mount or of course any R mount lenses with EF protocols. IMHO, that would indicate that they are negotiating with Canon and not wanting to complicate those negotiations.

EF third party protocols are pretty honed right now, let's face it, the last stuff from Sigma works on DSLR as good as any other Canon lens

Are you sure that Sigma AF for DLSRs are as good as Canon native EF lenses released relatively recently??

 

[DhlcadR6]

Are you sure that Sigma AF for DLSRs are as good as Canon native EF lenses released relatively recently??

For Stills Single shot AF, I would say so, its limiting factor is the AF motor. However for video AF and Stills Servo AF, yes it's not close to latest generation of EFs, let alone RF. RF kit lens like the 24-105STM will be faster and much more reliable than old 3rd party EF

 

[Dragon]

For Stills Single shot AF, I would say so, its limiting factor is the AF motor. However for video AF and Stills Servo AF, yes it's not close to latest generation of EFs, let alone RF. RF kit lens like the 24-105STM will be faster and much more reliable than old 3rd party EF

In my experience, many of both Sigma and Tamron lenses focus less consistently than native EF lenses even for single shot. I also have one Tamron lens that insists on back-focusing at distance. On a DSLR it can be adjusted with the Tap-In console, but the adjustments have no effect in DPAF mode, so no way to adjust it on a mirrorless body and even on a DSLR, it will be off in live view. Tamron's response was "send the lens and the camera body and we will tune the lens to the camera". Not workable in that I have several bodies I would like to use the lens on. The one body that it does focus correctly on is the 5DSR, which uses CDAF in live view. The only conclusion I can draw is that Tamron doesn't fully understand the dynamics of the DPAF process. I have a half dozen Sigmas and they all focus correctly the majority of the time, but most also randomly mis-focus far more often than Canon lenses and that behavior has been observed by many reviewers. I agree the RF lenses are in another league in that even the low end ones are decently fast and very consistent. The RF 24-240 is remarkably quick for a relatively inexpensive lens and it gives the EF 100-400 II a run for its money in the focus department which is impressive.

 

[DhlcadR6]

In my experience, many of both Sigma and Tamron lenses focus less consistently than native EF lenses even for single shot. I also have one Tamron lens that insists on back-focusing at distance. On a DSLR it can be adjusted with the Tap-In console, but the adjustments have no effect in DPAF mode, so no way to adjust it on a mirrorless body and even on a DSLR, it will be off in live view. Tamron's response was "send the lens and the camera body and we will tune the lens to the camera". Not workable in that I have several bodies I would like to use the lens on. The one body that it does focus correctly on is the 5DSR, which uses CDAF in live view. The only conclusion I can draw is that Tamron doesn't fully understand the dynamics of the DPAF process. I have a half dozen Sigmas and they all focus correctly the majority of the time, but most also randomly mis-focus far more often than Canon lenses and that behavior has been observed by many reviewers. I agree the RF lenses are in another league in that even the low end ones are decently fast and very consistent. The RF 24-240 is remarkably quick for a relatively inexpensive lens and it gives the EF 100-400 II a run for its money in the focus department which is impressive.

Tbh is the problem for all the 3rd parties, the protocol they have is not entirly compatible with late EF era DSLR or RF MILC.. With eyeAF/subject detecti AF on it solves 70~80% of the problem.

 

[Dragon]

Tbh is the problem for all the 3rd parties, the protocol they have is not entirly compatible with late EF era DSLR or RF MILC.. With eyeAF/subject detecti AF on it solves 70~80% of the problem.

Are you suggesting that eye detect has a pinch of CDAF on top of DPAF to get more precise focus and thus is sending fine tuning commands to the lens rather than a simple "go to command" that is typical of PDAF systems or just that the repetitive nature of servo AF gives better odds? For reference, the CDAF on the 5DSR in live view seems to make almost all 3rd party lenses behave, probably due to the iterative behavior of CDAF.

 

[koenkooi]

[…]
Are you sure that Sigma AF for DLSRs are as good as Canon native EF lenses released relatively recently??

The EF-M sigma 56mm focuses just like Canon EF-M lenses. That’s the only datapoint I have for recent Sigma lenses.