Patent: Canon RF 100mm f/2.8L IS USM Macro

Canon Rumors Guy

Canon EOS 40D
CR Pro
Jul 20, 2010
10,765
3,149
Canada
www.canonrumors.com
It looks like one of the most requested new lenses for the RF mount is getting closer with the latest patent designs from Canon.
Canon News has uncovered a patent showing off two different, yet very similar optical formulas fora Canon RF 100mm f/2.8L IS USM Macro. A lens I expect will be announced in 2021.
Canon Japan Patent Application 2020-204744






Canon RF 100mm f/2.8L IS USM Macro v1





Focal Length...

Continue reading...


 

Joules

doom
CR Pro
Jul 16, 2017
1,801
2,247
Hamburg, Germany
RF mount has a flange distance of 20mm. Both formulas have a slightly shorter ~15.5mm backfocus.

Don't tele lenses have longer backfocus? Why is the last elements so curved?
Canon can use any backfocus they want, it just starts portruding into the body at some point.

Canon also has clearly shown that they consider it advantageous to put the last element close to the sensor even for tele designs, which is why the RF 70-200 mm 2.8 and 100-500 4.5-7.1 for example have no / limited compatibility with TCs.
 
  • Like
Reactions: 1 users
Upvote 0

snappy604

CR Pro
Jan 25, 2017
676
637
wish they'd refresh the 180mm Macro.. I still use the EF 180mm 3.5L and love it, but wish autofocus was useful, its pretty useless, though with the adapter and the R5's manual focus aids... new possibilities ;-).. would also love to see them refresh the MP 65mm Macro.. hear good things but don't want to invest in such an old lens for the R series.
 
  • Like
Reactions: 3 users
Upvote 0
Mar 26, 2014
1,443
536
Canon can use any backfocus they want, it just starts protruding into the body at some point.

Of course it can, question is why. IIRC, it was explained that the closer the last element is to the sensor, the more vignetting the lens would have, due to the angle at which the light rays would hit the sensor.

Canon also has clearly shown that they consider it advantageous to put the last element close to the sensor even for tele designs, which is why the RF 70-200 mm 2.8 and 100-500 4.5-7.1 for example have no / limited compatibility with TCs.

No compatibility with TCs is not an advantage.
 
Upvote 0

Joules

doom
CR Pro
Jul 16, 2017
1,801
2,247
Hamburg, Germany
No compatibility with TCs is not an advantage.
Duh.

But I don't believe Canon compromises on an aspects of their design like this without gaining an advantage by doing so. I won't pretend to understand what that advantage may be. Most likely, it isn't something as cut and dry like 'reduced vignetting by x amount'. I could see it beeing more likely that it is one of many aspects of these designs that allow Canon to produce these lenses which are optically excellent, while reducing the size and / or weight compared to previous version. Maybe it is just about saving costs or making manufacturing easier, but I doubt it.
 
  • Like
Reactions: 1 user
Upvote 0
RF mount has a flange distance of 20mm. Both formulas have a slightly shorter ~15.5mm backfocus.

Don't tele lenses have longer backfocus? Why is the last elements so curved?

From the original patents drawings I see that this lens is focusing internally (2nd and 4th of 5 groups are moved) so maybe they need the space to shift the moving groups and set the last element closer to the sensor. These macros aren't classical tele lenses - they bend the light to do 100mm 1:1 macro which needs 400mm length if you use a single thin lens in a compact package.

I think the last elements try to bend the light that it hits the sensor under an optimized angle to avoid vignetting.
 
Upvote 0

SteveC

R5
CR Pro
Sep 3, 2019
2,678
2,592
Great! I'm finally getting into R world and found my 100mm L macro adapted to R5 being too long/heavy/inconvenient. It could be 150 or 180mm that long and heavy, but it is still 100mm. BTW, I hope to see a longer macro from canon too.

The lens might feel a bit long iwth that adapter on it, but then, the camera is shorter.

Unless you double-count the adapter!
 
Upvote 0
Mar 26, 2014
1,443
536
Duh.

But I don't believe Canon compromises on an aspects of their design like this without gaining an advantage by doing so. I won't pretend to understand what that advantage may be.

The "I know what I'm losing, I don't know what I gain, but it must be worth it" has the scent of fanboyism. At the very least, Canon's PR should have published what the gain is that they've compromised on no TC.
 
Upvote 0
This is a lens I was initially very excited for but not so much now. The reason is due to the RF 85mm f/2 which I’m really enjoying.

I always used the 100L for still life and product photography so never really needed full 1:1 so the current 85mm suits me well!
Good to hear - maybe I will buy the RF 85 macro because of its f/2, compactness, low weight and macro functionality to replace my f/2 100.
While the EF 100 macro (usm version w/o IS) will be used adapted for those 1:1 situations which are - as you said - rare for me too.
 
  • Like
Reactions: 1 user
Upvote 0

dlee13

Canon EOS R6
May 13, 2014
325
227
Australia
Good to hear - maybe I will buy the RF 85 macro because of its f/2, compactness, low weight and macro functionality to replace my f/2 100.
While the EF 100 macro (usm version w/o IS) will be used adapted for those 1:1 situations which are - as you said - rare for me too.

Well if you do I’m sure you’ll be impressed with it! Although I love the RF 35mm, I find the 85mm a bit more unique and just can’t stop using it!
 
  • Like
Reactions: 1 user
Upvote 0

Joules

doom
CR Pro
Jul 16, 2017
1,801
2,247
Hamburg, Germany
The "I know what I'm losing, I don't know what I gain, but it must be worth it" has the scent of fanboyism. At the very least, Canon's PR should have published what the gain is that they've compromised on no TC.
And the idea "the market leader dropped features from their new products for absolutely no reason" has a scent of cynicism. What's your point?

As I said, I won't pretend to understand enough about Optics to challenge Canon's claims. Canon has actually already published a number of marketing and white paper documents that touch on these subjects. From page 9 on the R system white paper, they highlight a big advantage of the new system:

"Large diameter rear lens elements that are much closer to the full frame image sensor —enhancing overall optical performance (in particular, tighter control over optical aberrations at image extremities)"

TThey go on to show how this is handled in the EF Mount and contrast it with RF on the subsequent pages, if you want to have a look. Here is the link if you haven't downloaded it yet:

 
Upvote 0
Mar 20, 2015
428
372
TThey go on to show how this is handled in the EF Mount and contrast it with RF on the subsequent pages, if you want to have a look. Here is the link if you haven't downloaded it yet

They don't actually compare it to an EF lens, just a simulation of a lens using a configuration similar to EF...

Canon have been very careful not to directly compare lenses across the two mounts. The 70-200 2.8 and 50 1.8 certainly don't perform better than heir EF predecessors.
 
Upvote 0