EF vs RF 50 1.8 STM MTF chart comparison

ctk

Refurb EOS R Kit
Mar 25, 2020
65
66
According to Canon, the RF 50 1.8 is significantly softer than the EF 50 1.8 and RF 35 1.8.

EF vs RF (RF mirrored for comparison):

RFvsEF.png


35 1.8 below:

rf35mm_f18_macro_is_stm_mtf.gif


Admittedly the EF 50's chart seems incredibly optimistic, but if we compare it to the 35 it's basically softer across the entire frame. I will wait for reviews and more sample shots (there are some pretty limited ones here) but the more I see about this lens the less optimistic I am. May still replace my Sigma 50 EX but I've been mulling getting the Samyang 50 XP and I think this just pushed me over since I'm not in the RF 50 1.2's tax bracket. Also still holding out hope for the Samyang 45 1.8 to get ported over but w/e. Thought this would be useful to you guys
 

ctk

Refurb EOS R Kit
Mar 25, 2020
65
66
Update- Canon did update their MTF methodology. Here is an apples to apples comparison:

1604507198421.png


Really really marginal improvement, at least in MTF. Hopefully Canon managed to clean up the LoCA.
 
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Maximilian

The dark side - I've been there
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Update- Canon did update their MTF methodology. Here is an apples to apples comparison:
Thanks for sharing, ctk.
Really really marginal improvement, at least in MTF. Hopefully Canon managed to clean up the LoCA.
I didn't expect much more, so every little bit is welcome.
Esp. when you look a little bit away from the middle (eg. at "10") there is pretty much gained.
Keep in mind that this D. Gauss design is well known and pretty much exhausted in R&D.
That why the modern Sigma and RF and other 50 mm designs are much bigger and complex - and much more expensive ;)
 

Mt Spokane Photography

I post too Much on Here!!
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Mar 25, 2011
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I'd have been disappointed if Canon made a $800 lens with a different design. They went for a very low cost lens that likely costs $40 to manufacture over one costing several times more. Its likely able to make use of the same machinery in Taiwan for making the EF50. They hope to churn out a million of these, and that means every penny is squeezed out of the cost.

Could this be a kit lens for the rumored new very low cost FF R body. It seems unlikely since consumers like the idea of zoom lenses. However, Canon does not yet have a pair of cheap kit lenses just the RF 24-105, no ultra cheap telephoto zoom. If Canon wants their new low cost FF body to end up in stores, they need ultra low cost kit lenses to keep the 2 lens kit price around $1500. So, is there a $400 RF100-300mm low priced zoom coming to put in kits?
 

ctk

Refurb EOS R Kit
Mar 25, 2020
65
66
I'd have been disappointed if Canon made a $800 lens with a different design.
Why do you think this is the only alternative? Canon made a much more complex 35 1.8 "Macro" for $450. A truly new and good 50 1.8 without the macro capability probably could have launched for about $300 (with a sale price of $250 or so), and actually would have been worth buying over an EF 50 STM + adapter.
 

SwissFrank

from EOS 1N to R
Dec 9, 2018
660
371
I'd have been disappointed if Canon made a $800 lens with a different design. They went for a very low cost lens that likely costs $40 to manufacture over one costing several times more. Its likely able to make use of the same machinery in Taiwan for making the EF50. They hope to churn out a million of these, and that means every penny is squeezed out of the cost.

Could this be a kit lens for the rumored new very low cost FF R body. It seems unlikely since consumers like the idea of zoom lenses. However, Canon does not yet have a pair of cheap kit lenses just the RF 24-105, no ultra cheap telephoto zoom. If Canon wants their new low cost FF body to end up in stores, they need ultra low cost kit lenses to keep the 2 lens kit price around $1500. So, is there a $400 RF100-300mm low priced zoom coming to put in kits?

If they could make it for $40, so could third parties, and no-one's done so. So no, I don't think that cost is accurate. Further, the cost of business is hardly simply the marginal manufacturing cost.

I don't know if Canon's offered a prime as the sole kit lens since the 80s. My Canon M did have a 22/2 and 18-55/whatever as kit lenses though.

An $800 design would be fine if it came with the massively-improved resolution that comes hand in hand with the modern designs like the Leica APO APSH 50/2.0, Canon's own RF 50/1.2, the Otus and the like. But why not both--a cheap, super-compact, 50/1.8, and a big, expensive, ultrasharp 50/1.8? I personally would probably own both. I had all four EF pro 50s. (50/1.8 MkI was a pro lens, 50/1.0, 50/1.4, and 50/1.2.)
 

LogicExtremist

Lux pictor
Sep 26, 2021
189
117
I have both of these 50mm F/1.8 lenses. The build quality of the RF lens feels a bit better, but it costs a lot more, and only has one switch for function ring and manual focus selection. Filter thread RF 43mm vs EF 49mm.

From the tests I've seen the image quality of the two is almost the same. The RF is slightly better at the edges, and slightly better in the centre when wide open..

 
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SwissFrank

from EOS 1N to R
Dec 9, 2018
660
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I have both of these 50mm F/1.8 lenses. The build quality of the RF lens feels a bit better, but it costs a lot more, and only has one switch for function ring and manual focus selection. Filter thread RF 43mm vs EF 49mm.

From the tests I've seen the image quality of the two is almost the same. The RF is slightly better at the edges, and slightly better in the centre when wide open..

Many thanks for the link.

I was surprised by his description of the corner sharpness/contrast. I thought his test images showed a VERY notable improvement in the corners in sharpness and in coma, and if anything not quite the improvement in the center he described.

Well, I found this quite depressing. I was really hoping they'd have a considerable improvement here. I do understand they have to choose between a big heavy modern lens design with great sharpness (as the RF 50/1.2, Leica APO-ASPH 50/2, Otus and even Nikon 50/1.8), and the cheap and compact. But I guess if you care about sharpness more than size, you can just mount the 50/1.2 and shoot it at 1.8.

So I'm left wondering which direction they'll jump with a 50/1.4? Will it also be a near-copy of the relatively crap EF, as this 1.8 has shown to be? Will it be a new-school design like the RF 50/1.2 and Nikon 50/1.8? My hope is for a third approach: old-school design but cost-no-object, like the non-APO Leica M 50/2. Keep it light and compact but spend whatever you have to for IQ.

I'd also like to see a halo lens of 50/0.7. It needn't be cheap or common, instead it could be like the old 1200/5.6, almost more a lens to talk about than to own,
 
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LogicExtremist

Lux pictor
Sep 26, 2021
189
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Many thanks for the link.

I was surprised by his description of the corner sharpness/contrast. I thought his test images showed a VERY notable improvement in the corners in sharpness and in coma, and if anything not quite the improvement in the center he described.

Well, I found this quite depressing. I was really hoping they'd have a considerable improvement here. I do understand they have to choose between a big heavy modern lens design with great sharpness (as the RF 50/1.2, Leica APO-ASPH 50/2, Otus and even Nikon 50/1.8), and the cheap and compact. But I guess if you care about sharpness more than size, you can just mount the 50/1.2 and shoot it at 1.8.

So I'm left wondering which direction they'll jump with a 50/1.4? Will it also be a near-copy of the relatively crap EF, as this 1.8 has shown to be? Will it be a new-school design like the RF 50/1.2 and Nikon 50/1.8? My hope is for a third approach: old-school design but cost-no-object, like the non-APO Leica M 50/2. Keep it light and compact but spend whatever you have to for IQ.

I'd also like to see a halo lens of 50/0.7. It needn't be cheap or common, instead it could be like the old 1200/5.6, almost more a lens to talk about than to own,
I think the RF 50 f/1.8 has a slightly different look from its EF counterpart. it seems to have more contrast overall. That's something I believe I also see with the RF 35 f/1.8 and 24-105 f/4 L lenses that I own, but I'm just speculating here. I bought the RF 50 f/1.8 secondhand, barely used, and I'm glad I did, it's good value for money. From f/2.0 and higher the images look excellent.

When it comes to the fancy 50mm lenses, the old EF 50 f/1.2 was expensive, and a big deal at the time, but compared to the RF 50 f/1.2 it's quite soft looking back. I got the Sigma 50mm f/1.4 Art lens way back then, almost as good, and much sharper than the EF 50 1.2, but lacking the 'look' that some want, for less than half the price. The old 50 1.4 was one of Canon's 'misses', hopefully, if we se an RF replacement, they can make it a 'hit' this time round.

Right now, the whole Canon lens range is a bit of a mess, only overpriced top-tier or budget entry-level lens lines, with nothing in the middle. I reckon it will probably pay to wait, to see if Canon will finally fill the missing middle tier, or get out of the way and allow Sigma or another third-party to do so.
 
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SwissFrank

from EOS 1N to R
Dec 9, 2018
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In my experience the RF 24-105 has the image quality of the EF MkII with the size of the far smaller EF MkI. The result is so good (and today's cameras so good in lower light thx to IS and low-noise sensors) that I've gone to using it as my go-to lens after shooting primes, mostly, with my Leica M outfit and EOS-1N/V/Ds Mk I/II/III.

I had all the EF 50's (except for the toy-grade 1.8MkII). The 1.8MkI and 1.4 were borderline acceptable on film, and the 1.0 was of course worse at the only stops you'd ever use it at (1.0-1.4) but the large aperture made it worth having. But the 1.2 was really just crappy. Unless you needed the speed, the 24-70/2.8 actually seemed to be better.

The RF 50/1.2 is finally a Canon lens you will turn to if you absolutely need the highest image quality, and 50mm is at all possible to use. No other lens comes close.

In fact the RF 1.2's 30lp/mm contrast is higher than the EF 1.2's 10lp/mm. Since lp/mm is a linear measure and photos are area, that actually means the RF can deliver something like TEN TIMES the resolution. Or in other words, you can blow it up 3x more (linearly) and still have a higher-quality image.

The Canon RF 50/1.2 isn't alone of course, other manufacturers are also making these 50s that differ completely from the old double-Gauss design. The Leica APO-ASPH 50/2, Otus 50, and maybe a tier down but the same general idea, the new Nikon 50/1.8, are all awesome.

I agree the product line looks like a construction zone.
 
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LogicExtremist

Lux pictor
Sep 26, 2021
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In my experience the RF 24-105 has the image quality of the EF MkII with the size of the far smaller EF MkI. The result is so good (and today's cameras so good in lower light thx to IS and low-noise sensors) that I've gone to using it as my go-to lens after shooting primes
Same here, totally agree, I now use the RF 24-105 F/4 L lens as go-to work lens because it's really sharp and produces great image quality.

From https://www.digitalcameraworld.com/reviews/canon-rf-24-105mm-f4-l-is-usm-review

vMg8XpDNmZFgu87BUA8ccf-970-80.png.webp


"Even wide open the RF 24-105mm is impressively sharp at all focal lengths and stays so up to f/11. The new Nikon Z 24-70mm is still the lens to beat for centre sharpness, but the Canon comes close for edge sharpness, despite its larger focal range."


Here's the RF 50mm f/1.8 for comparison.

From https://www.digitalcameraworld.com/reviews/canon-rf-50mm-f18-stm-review

5rcrWnQ2myRb4MGeP5vhj3-970-80.png.webp

"Centre sharpness is respectable wide open and at f/2, and by f/2.8 it's simply superb. These centre sharpness scores are actually comparable to the far pricier RF 50mm f/1.2! Corner sharpness is nothing special at larger apertures, but it gets much better if you stop down to f/4. A peculiarity with the lens is its mid-frame sharpness (the region surrounding the centre). With most optics, this area is usually softer than the centre, but sharper than the edges of frame. However, our RF 50mm f/1.8 sample was consistently softer in the mid-frame than at the edges, though the difference won't be very noticeable in real-world shooting."


How does the RF 50mm f/1.2 L lens compare?

From https://www.digitalcameraworld.com/reviews/canon-rf-50mm-f12l-usm-review

Uoz2ywxuTpVMEQAGFCopcf-970-80.png.webp

"It's usual for a lens to be this sharp at such a large maximum aperture, but the new RF-mount 50mm delivers great results right up to f/11, and maintains impressive edge sharpness, too."
 
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SwissFrank

from EOS 1N to R
Dec 9, 2018
660
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Between the shorter flange distance and 60% markup, I expected Canon to improve IQ significantly.
flange distance is a godsend wider than 50mm, but for the classic double-gaussian I don't think it helps much. If you look at the comparison of the lens shapes and locations, I think the designers could have easily put the same formula on the EF mount.
 

SwissFrank

from EOS 1N to R
Dec 9, 2018
660
371
LogicExtremist, thx for gathering all the graphs and posting them. I'm surprised it doesn't quite jive with my experiences though.

I love the RF 24-105 but if it's as sharp as my 50/1.2 in the center I had no idea at all. I always ranked the 24-105 as great but the 50/1.2 as superb.

And I found ALL the EF 50s to be only marginally usable*, and the graph of the 50/1.8 doesn't seem much better, so I'm shocked to see the RF 50/1.8 rated so highly,.

*Well I bought most of them when I shot with 1N and 1V and often on 1600 or push-processed 400, and all the 50s were as good as they needed to be for that film.
 
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Antono Refa

EOS R
Mar 26, 2014
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flange distance is a godsend wider than 50mm, but for the classic double-gaussian I don't think it helps much. If you look at the comparison of the lens shapes and locations, I think the designers could have easily put the same formula on the EF mount.
And Canon has to use double gaussian design for the 50mm f/1.8 because...?
 
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LogicExtremist

Lux pictor
Sep 26, 2021
189
117
LogicExtremist, thx for gathering all the graphs and posting them. I'm surprised it doesn't quite jive with my experiences though.

I love the RF 24-105 but if it's as sharp as my 50/1.2 in the center I had no idea at all. I always ranked the 24-105 as great but the 50/1.2 as superb.

And I found ALL the EF 50s to be only marginally usable*, and the graph of the 50/1.8 doesn't seem much better, so I'm shocked to see the RF 50/1.8 rated so highly,.

*Well I bought most of them when I shot with 1N and 1V and often on 1600 or push-processed 400, and all the 50s were as good as they needed to be for that film.
They use software to do the testing, not sure how it compares to real world use. According to the graphs, the RF 50mm f/1.8 is sharper at the centre then the f/1.2 L lens at f/4, and both of them as well as the RF 24-105mm f/4 L are equally sharp at f/5.6!

The TDP test contradicts this, using the R5, the RF 50mm f/1.8 appears less sharp at the centre then the f/1.2 L lens at f/4 and f5.6


On the EOS R, at f/5.6, there seems to be no difference in centre sharpness between the RF 24-105mm f/4 L and the Rf f/1.2 L lens:


It would be nice if tests yielded consistent results! :oops:
 
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