# Patent: Canon RF 28mm f/1.8 & RF 50mm f/1.8



## Canon Rumors Guy (Apr 18, 2019)

> The Canon RF lens lineup will obviously include more affordable non-L options, and this patent shows Canon is working on such optical formulas.
> The back focus on the RF 28mm f/1.8 is really short, which is quite interesting.
> *Canon RF 28mm f/1.8*
> 
> ...



Continue reading...


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## Josh Leavitt (Apr 18, 2019)

Those will be nice additions to the RF lineup. But I'm hopeful Canon will give us some pancake RF primes eventually. I'd like to see RF versions of the 24mm F/2.8 STM and 40mm F/2.8 STM. I think those along with the upcoming RF 70-200 F/2.8 and an EOS RP would make a perfect light and small travel kit.


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## deletemyaccount (Apr 18, 2019)

> The Canon RF lens lineup will obviously include more affordable non-L options



That's good to know. The RF glass I find very expensive and quite honestly, I find little incentive to even look at it with a large collection of EF L glass.


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## Tom W (Apr 18, 2019)

Very short backfocus distance = Canon taking full advantage of the mirrorless mount system. I would expect the 28/1.8 to be a very good lens.


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## rrcphoto (Apr 18, 2019)

Josh Leavitt said:


> Those will be nice additions to the RF lineup. But I'm hopeful Canon will give us some pancake RF primes eventually. I'd like to see RF versions of the 24mm F/2.8 STM and 40mm F/2.8 STM. I think those along with the upcoming RF 70-200 F/2.8 and an EOS RP would make a perfect light and small travel kit.



24mm may come, but the 40mm will never come for the RF mount.


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## Maximilian (Apr 18, 2019)

R series starts to become more and more interesting 

But when you look at the lens length (incl. 20 mm flange) they are not really small.
Seems Canon takes IQ over size.


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## mb66energy (Apr 18, 2019)

Maximilian said:


> R series starts to become more and more interesting
> 
> But when you look at the lens length (incl. 20 mm flange) they are not really small.
> Seems Canon takes IQ over size.


... without going overboard with size


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## Etienne (Apr 18, 2019)

The 50mm f/1.8 is huge at 3.75 inches. I hope this is not the lens they manufacture


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## Sharlin (Apr 18, 2019)

Etienne said:


> The 50mm f/1.8 is huge at 3.75 inches. I hope this is not the lens they manufacture



The EF 50mm _f_/1.4 is 95mm as well when you include backfocus distance (which lengths mentioned in patents always do).


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## Aaron D (Apr 18, 2019)

If that 28 (or any similar) is as sharp and compact as the RF 35 I'll buy one in a minute. A perfect walking-around lens!


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## Dantana (Apr 18, 2019)

rrcphoto said:


> 24mm may come, but the 40mm will never come for the RF mount.


Is that because of a technical limitation, or something else?


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## LSXPhotog (Apr 18, 2019)

A walk around 50mm RF lens....I hope they target sub $250 with it being a 1.8.


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## jonebize (Apr 18, 2019)

The 28/1.8 is actually not that big. Not bad! I would love a 24/2 in a similar size.


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## Groundhog (Apr 18, 2019)

LSXPhotog said:


> A walk around 50mm RF lens....I hope they target sub $250 with it being a 1.8.



I think there will be a nifty fifty for the RF mount for well under $150 - just like the EF version it will be the inexpesive start for many to shoot with fast primes.


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## jonebize (Apr 18, 2019)

Groundhog said:


> I think there will be a nifty fifty for the RF mount for well under $150 - just like the EF version it will be the inexpesive start for many to shoot with fast primes.



With a 35mm sibling, the pair would be a powerful tool in the market


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## degos (Apr 19, 2019)

Groundhog said:


> I think there will be a nifty fifty for the RF mount for well under $150 - just like the EF version it will be the inexpesive start for many to shoot with fast primes.



Nah, Canon's whole philosophy with RF is to net big juicy margins. Big lenses, big prices, big executive smiles.

EOS M will be the bone thrown to 'enthusiasts' who don't have $1200 to spend on a lens. Go play in the corner with this little toy camera until you earn a decent salary - that's Canon's attitude.

I just hope that Tamron moves into the RF space and starts filling-out the affordable range.


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## canonnews (Apr 19, 2019)

Groundhog said:


> I think there will be a nifty fifty for the RF mount for well under $150 - just like the EF version it will be the inexpesive start for many to shoot with fast primes.


the optics for the 50mm are very similar to that of the RF 35mm. it's most likely going to be, like the 35mm a $500 lens, not a well under $150 one.

also, I made mention of this in our posting on this patent, but it deserves to be mentioned here. as this is the patent application for the RF 35mm 1.8 IS STM, and it does contain a IS element, all these patent embodiments contain the same or similar IS compensation element meaning they probably all have IS.


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## Etienne (Apr 19, 2019)

Sharlin said:


> The EF 50mm _f_/1.4 is 95mm as well when you include backfocus distance (which lengths mentioned in patents always do).



The Canon 50 f/1.4 is listed at 2 inches long, or 50.8 mm


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## Sharlin (Apr 19, 2019)

Etienne said:


> The Canon 50 f/1.4 is listed at 2 inches long, or 50.8 mm



The emphasis was on _when you include backfocus distance_. That 95mm in the patent, like always in patents on optical designs, is measured as the distance from the front element to the image plane. The total length of the EF 50/1.4 is ~95mm when you include the 44mm flange distance of the EF mount. The physical length of this RF lens is about 2cm longer than the EF one, pretty much exactly negating the difference in flange distance (which is 20mm in the RF case). This is likely not a coincidence.


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## Etienne (Apr 19, 2019)

Sharlin said:


> The emphasis was on _when you include backfocus distance_. That 95mm in the patent, like always in patents on optical designs, is measured as the distance from the front element to the image plane. The total length of the EF 50/1.4 is ~95mm when you include the 44mm flange distance of the EF mount. The physical length of this RF lens is about 2cm longer than the EF one, pretty much exactly negating the difference in flange distance (which is 20mm in the RF case). This is likely not a coincidence.



It doesn't negate anything. This lens is nearly twice as long, completely the opposite direction hoped-for with mirrorless tech. And it is not technically necessary as evidenced by the RF 35 f/ 1.8 IS which is slightly faster, includes near macro focusing and is about the same length as its Ef 35 f/2 IS equivalent. So, it is huge for a 50 f/1.8


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## Joules (Apr 20, 2019)

Etienne said:


> It doesn't negate anything. This lens is nearly twice as long, completely the opposite direction hoped-for with mirrorless tech. And it is not technically necessary as evidenced by the RF 35 f/ 1.8 IS which is slightly faster, includes near macro focusing and is about the same length as its Ef 35 f/2 IS equivalent. So, it is huge for a 50 f/1.8


You didn't get the point.

Sharlin's saying that If you want the length of a lens from a patent, you have to subtract the flange distance from it.

So the physical length would be:
total length (from patent) - flange distance
95mm - 20mm = 75mm

If the 50mm 1.4 has a physical length of 50mm, yes the mirrorless version is longer. But that is to be expected. As was said numerous times on this forum, shorter flange distance means all lenses with more than 44mm focal length become longer (by roughly 44mm - 20mm = 24mm), and some with less than that become smaller or cheaper or sharper.

WHich is exaclty what we see here.


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## Etienne (Apr 20, 2019)

Joules said:


> You didn't get the point.
> 
> Sharlin's saying that If you want the length of a lens from a patent, you have to subtract the flange distance from it.
> 
> ...



I did not miss the point
The RF lens is f/1.8, not f/1.4. And it's huge for a 50 f/1.8
The Canon EF 50 f/1.4, a faster lens, is 50mm long


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## canonnews (Apr 20, 2019)

Etienne said:


> I did not miss the point
> The RF lens is f/1.8, not f/1.4. And it's huge for a 50 f/1.8
> The Canon EF 50 f/1.4, a faster lens, is 50mm long



the Nikon 50mm Z 50mm 1.8 is 86.5mm x 76mm. This 50mm would actually be 11mm shorter than the Nikon Z and most likely includes IS. At lens length of 75mm it's only around 6mm larger than the Sony FE mount 50mm 1.8 which also does not include IS.

Canon obviously with these lens designs wants to create a 50mm that is in the same realm of the RF 35mm 1.8 performance wide open, which the Canon EF 50mm 1.8 is not. Just compare the MTF's between the RF 35mm and the EF 50mm 1.4 and the EF 50mm 1.8 .. it's not even close, and the RF 35mm is a much harder lens to design.

I'm pretty excited by this patent. This patent application was really the RF 35mm 1.8 patent application, but all the lenses in here look really legit (except the 28mm looks a bit extended into the mount) and would make a pretty nice 1.8 trinity of IS STM primes of 28,35 and 50mm.


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## canonnews (Apr 20, 2019)

SwissFrank said:


> BTW a quick browse looked like the patent included 28 35 and 50? Was that right? I think the summary might have left off the 35.


that's because this patent application IS for the RF 35mm 1.8 IS STM. the other lenses though were also included in as embodiments.


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## canonnews (Apr 20, 2019)

SwissFrank said:


> OK, so the other designs probably also IS... I can't see a mention of it specifically though.
> 
> That's kind of bad news for me as I'm actually NOT wanting IS. I'd rather the lens be shorter (stick out no farther than the grip) even if they have to do without IS. This is in part for portability, in part because the cameras today do so well at high ISO, and because IBIS is coming in the next few years.



IS in these are only one small element, odds are it's not going to make that much difference in or out of the optical design.

G2F in all the embodiments is the IS element and is mentioned in the patent application.

"G2F, which is arranged closest to the object side of the positive lenses included in the second lens unit L2, is configured to move in a direction having a component that is perpendicular to the optical axis during image stabilization. With this configuration, rapid image stabilization is facilitated. "

Also to be shorter than the grip you're talking a lens around 20-24mm in length, that's probably not going to happen no matter IS or no IS, unless it's around a 18-22mm pancake.


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## canonnews (Apr 20, 2019)

If I recall the Leica has a pretty large floating rear element design, also the RF lenses even without the IS stabilization are just simply much more complicated lenses in terms of elements / groups. IE; Rf 35 is 11/9 groups versus the Leica 1.4 at 8 elements and 6 groups. Canon also has to make these lenses so they can be made by modern mass assembly and manufacturing techniques, with minimal QC problems as the QC checks aren't nearly as extensive of say a Leica. It takes alot to make a good lens, that doesn't require as much human labor, and is QC pass rate.

We also demand far more critical sharpness than the older 35mm film lenses ever had to experience.

Oh !!.. also the RF 35mm (I'll have to read the others) is a 1:2 macro with a MFD of 170mm, versus the leica 35mm 1.4 at a MFD of 701mm

Edit: both the 28 and the 50 are also 1:2 macro lenses.

Sweet.


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## BillB (Apr 20, 2019)

canonnews said:


> If I recall the Leica has a pretty large floating rear element design, also the RF lenses even without the IS stabilization are just simply much more complicated lenses in terms of elements / groups. IE; Rf 35 is 11/9 groups versus the Leica 1.4 at 8 elements and 6 groups. Canon also has to make these lenses so they can be made by modern mass assembly and manufacturing techniques, with minimal QC problems as the QC checks aren't nearly as extensive of say a Leica. It takes alot to make a good lens, that doesn't require as much human labor, and is QC pass rate.
> 
> We also demand far more critical sharpness than the older 35mm film lenses ever had to experience.
> 
> ...


Autofocus may have something to do with the size as well.


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## Josh Leavitt (Apr 21, 2019)

SwissFrank said:


> Hi Josh,
> I have a bit different opinion on two points:
> 
> 1) do you see a benefit of the lens being as short as the pancakes you mention, or would it be "good enough" if the lens stuck out no further than the grip front? I'm leaning towards the later.
> ...



My preference for pancake lenses really just comes down to their diminutive size and weight; and subsequently the advantages those offer for extended outings. I routinely go on 10+ mile hikes on weekends, and so I find myself selecting the smallest and lightest lenses for those treks. Apart from the size/weight benefit of pancake primes for backpacking landscapers like me, another thing I find they're great for is videography. The pancake primes balance effortlessly on even the smallest gimbals. I seldom do video work on my 6D II, but when I do, the 40mm f/2.8 STM is the lens I always reach for.

As for the max aperture of f/2.8? I guess for me it never really mattered - being more inclined towards landscapes and very wide depth-of-field (typically f/8-f/11). I can't dispute the versatility of the holy trinity zooms, however. If the bulk and weight of my gear was a non-issue, I'd probably carry those with me at all times.


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## canonnews (Apr 21, 2019)

SwissFrank said:


> Still, at first glance you'd think an 11/9 lens is going to be harder to engineer, assemble, and QC than a 8/6. But I can believe the opposite might ironically be true in some cases.
> 
> 
> This is utterly true. I don't think anyone was complaining about the EF 50mm 1.8 1.4 and 1.2 when they were all new. And yet they're simply not acceptable now, you almost might as well use a smartphone. (People complained about the 50/1 from day one but in the context of its ability were willing to accept it.)
> ...



Canon uses automated machines to build a lens from scratch. I'm not sure if the RF lenses are automated but I suspect they are. It's certainly something Leica does not do 

If the RF 35mm 1.8 can be used as a measure, the 50mm 1.8 and the 50mm 1.4 MTF's aren't even in the same league wide open. It's not even close.
Comes down to what the lens is designed for. As I mentioned before, the 50mm shown in this patent application is an average size for 50mm's being created for mirrorless these days.

It should also be noted that more modern Leica designs like the Leica Summicron-SL 35mm f/2 ASPH are not small either. Not even Leica has chosen to create a small mirrorless digital lens. (it's MTF's though are excellent).

I assume you are talking about the Leica Summilux-M 35mm f/1.4 ASPH, which really does need to be stopped down according to it's published MTF's which is probably why Leica decided to create a whole new lens design for the SL lens. Here's probably where we get into why it's smaller. Wide open the response it is simply an average lens, it would look good on film because you're not heavily magnifying the images as we do on digital, but it's not up to digital standards.

Here's the rub. We get into a simplistic triangle of lens design we have:


```
SIZE
                COST                QUALITY
```

You can't have all three. Most times you can have 2 out of 3. Sometimes only 1 out of three. Some of the EF-M lenses are the closest I've seen Canon get to actually managing all three to be moderately good to excellent.

A pancake lens designed around a tessar optical design will probably be released by canon sometime - that's the lens you're probably looking for. Odds are it won't be faster than 2.8 (might be 2.0 though), and be around 20mm in focal length. Usually, for Tessar designs, the focal length is approximately the same as the distance from the sensor to the lens.

I should do an article on this. maybe next week.


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## BillB (Apr 21, 2019)

SwissFrank said:


> I decided around 2013 that even if I had the holy trinity on my person, I'd probably mostly use my 24-105/4IS. Like you say, you either are trying to get a conventional picture where everything's sharp (f/5.6-f/11) or you're trying to use DOF (f/2 or below). 70-200 at 2.8 of course has nice subject isolation from DOF, but 16-35 doesn't, and 24-70 not enough to bother with.
> 
> I mean, I'll get the trinity zooms as they come out for RF, I just doubt I'll use them much, not only on size/weight criteria but also just focus range (beaten by the 24-105) and aperture (beaten handily by the 1.2, 1.4 etc. optics I have).


To me, the 16-35 is like having a bag full of (admittedly slowish) wide angle primes. If you are willing to zoom with your feet and crop a little, you can even stretch the effective focal length out around 50mm. One prime can be lighter and smaller than a 16-35, but a couple of primes are going to weigh about as much as a 16-35 f4. I'm not sure what the design sweet spots for light primes are in terms of price, weight and features, or how big the prime lens niches are, but Canon seems to be looking for some those niches in the RF space.


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## BillB (Apr 22, 2019)

SwissFrank said:


> It cuts both ways: a 28mm can kind of almost sort of just about do the job of a 16-35, if not quite a 50. From like 1998 to 2001 my "always in the backpack" outfit was a Contax G2 with 28, 45, and 90 and I never found myself wishing I had something wider than 28, even though I shot with the 14mm a lot on the Canon. Also never needed something between 28 and 45.


I agree about the 28mm, and I still have the EF 28 IS f2.8 that I got the year before the 16-35 f4 came out. Having the 16-35, I have come to really like having the 16mm and 20mm focal lengths there when I want them, along with the 28mm. Often, I'll take along the 85 f1.8 to add some length to the 16-35, and deal with the gap by zooming with my feet, maybe with a little cropping. It's a lot easier to crop than it is to uncrop what comes out of the camera. Of course, it has been quite a while since I carried my camera equipment very far in a back pack.​


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