5 unreleased RF lenses show up again for certification

degos

EOS RP
Mar 20, 2015
381
320
But I will be getting a R5 or R5s and I strongly assume it will AF just fine with a f7.1 lens with 70.4mm aperture.

Your assumption proceeds from an invalid premise. The AF sensor doesn't care about the physical aperture, just the f-ratio. The image size on the sensor is the same size regardless of the diameter of the objective.

By your reasoning a 2250mm f/32 lens would AF just fine because it has a 70mm aperture...
 
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usern4cr

R5
CR Pro
Sep 2, 2018
1,150
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Kentucky, USA
Your assumption proceeds from an invalid premise. The AF sensor doesn't care about the physical aperture, just the f-ratio. The image size on the sensor is the same size regardless of the diameter of the objective.

By your reasoning a 2250mm f/32 lens would AF just fine because it has a 70mm aperture...
Yes, I did say "But I will be getting a R5 or R5s and I strongly assume it will AF just fine with a f7.1 lens with 70.4mm aperture." But you assume that my premise is that it will AF just fine with any f7.1 lens. That was not my premise.

My premise is that Canon is releasing a next generation camera, sensor and AF technology and it is releasing a new RF 100-500 f4.5-7.1 IS USM lens. The USM means it's electronically focusing with probably their latest USM motors and technology, and almost always (if not always) infers that this lens will AF with their bodies. So I assume that they intend for this lens to AF on their newly released R5 or R5s because(IMHO): it is inferred by their USM designation and it would be an unexpected and major embarrassment otherwise.:cool:

I will revise my post to reflect my premise. I may be right or not, and that's why I mention "assume" and (IMHO). Hope that clears that up. :)
 
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Aregal

EOS M6 Mark II
Oct 3, 2018
96
94
I love focus range of the 100-400mmISii. I use that lens way more than my 70-200/2.8L. My camera bag has consists of the the 24/1.4, 50/102, and the 100-400mmISii most of the time. All my other Canon-Ls sit on the shelf at home.
 

koenkooi

EOS 5D Mark IV
CR Pro
Feb 25, 2015
1,678
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A lot of people will be happy with the 100-500. Eventually, if the IQ checks out, I will probably be one of them.

I wish I knew when it will be in stock at retailers, I'd really like a longer lens critters outside by back yard. In my back yards the 100mm L is enough for most things and the Sigma 150 OS for very skittish things.
But past Sunday I was hiking in actual nature and noticed that I either need waders or a longer lens to capture the dragonflies and frogs in a pond. And since that spot is marked as 'fragile ecosystem', the cheap route of getting waders is a no-go :)

So, it's the 100-400 II or the 100-500 as this years budget item for camera toys. Or neither and just get the RF85 :)
 

Del Paso

M3 Singlestroke
Aug 9, 2018
1,183
1,252
I take sports photography, polo and horseball, and sometimes birds.
An L 500 f: 7.1 lens. I don't see the point, no matter how good the sensors are today
That's why Canon has, for sports photographers and birders, some beautiful 300, 400 ,600 and 800 mm L lenses in the program.
Different (professional) use, different lenses !
 
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jolyonralph

EOS R5 Mark II
CR Pro
Aug 25, 2015
1,419
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London, UK
www.everyothershot.com
Zoom lenses with a lower f# at their wide angle end always (IMHO) seem to quickly have their f# approach the f# of the telephoto end as they go through their range to telephoto. Therefore I'd bet that the f# of the 100-500 f4.5-7.1 at 400mm is in the far upper 6's or even 7.1.

The lens certainly *could* be capable of f/5.6 at 400 based on the design. 400/500 * 7.1 = 5.68 Now, that equation doesn't hold true for all lens designs of course, but it does show that at least it's possible it's f/5.6 at 400mm.

I can't see why Canon would release this class of lens if it DIDN'T do f/5.6 at 400mm - people would buy the EF lens instead.
 

koenkooi

EOS 5D Mark IV
CR Pro
Feb 25, 2015
1,678
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The lens certainly *could* be capable of f/5.6 at 400 based on the design. 400/500 * 7.1 = 5.68 Now, that equation doesn't hold true for all lens designs of course, but it does show that at least it's possible it's f/5.6 at 400mm.

I can't see why Canon would release this class of lens if it DIDN'T do f/5.6 at 400mm - people would buy the EF lens instead.

I was thinking that as well, but I'm slowly coming around to the other side:
  1. With more and more f/7.1 lenses Canon is signalling that small apertures are OK now
  2. With 100mm extra reach, people might forgive 400mm being f/6.3
But there's a counterpoint: there's the actual effective aperture and then there's the aperture that shows up in your EVF. Is anyone really going to notice it being f/6.0 when it reports f/5.6 in the EVF and EXIF?
 

BillB

EOS R
May 11, 2017
1,393
659
I was thinking that as well, but I'm slowly coming around to the other side:
  1. With more and more f/7.1 lenses Canon is signalling that small apertures are OK now
  2. With 100mm extra reach, people might forgive 400mm being f/6.3
But there's a counterpoint: there's the actual effective aperture and then there's the aperture that shows up in your EVF. Is anyone really going to notice it being f/6.0 when it reports f/5.6 in the EVF and EXIF?
So, it would seem possible that the RF 100-500 may be f5.6 at 400mm and quite likely that it is within 1/3 stop of f5.6 at 400mm?
 

usern4cr

R5
CR Pro
Sep 2, 2018
1,150
1,896
Kentucky, USA
The lens certainly *could* be capable of f/5.6 at 400 based on the design. 400/500 * 7.1 = 5.68 Now, that equation doesn't hold true for all lens designs of course, but it does show that at least it's possible it's f/5.6 at 400mm.

I can't see why Canon would release this class of lens if it DIDN'T do f/5.6 at 400mm - people would buy the EF lens instead.
I'm sorry, but you need to rethink your math. By your own assumption, the 100-500 f4.5-7.1 at 100mm should be "able" to have a f# of 100/500 * 7.1 = 1.4. So, do you really think it could be f1.4 at 100mm? That'd be one heck of a lens there! :ROFLMAO:

Now, I know you're trying to get a reasonable estimate of what it could be, so I will mention the math you should have used, which assumes a linear relationship - which it's not, but we'll proceed as if it is. This is the general way to solve simultaneous equations with 2 unknowns (c0 and c1):
f# = c0 + c1 * mm (this will allow a linear relationship if you know (f#1, mm1) and (f#2, mm2) )
f# = 4.5 when mm = 100 and f# = 7.1 when mm = 500
Substitute these to get two equations:
4.5 = c0 + c1 * 100 and 7.1 = c0 + c1 * 500
Solve the first for c0: c0 = 4.5 - c1 * 100
Substitute that c0 into the 2nd equation and solve for c1:
7.1 = 4.5 - c1 * 100 + c1 * 500
7.1 - 4.5 = c1 * (500 - 100)
2.6 / 400 = c1 = .0065
Substitute that c1 into the above c0 equation
c0 = 4.5 - .0065 * 100 = 3.85
Now, find what f# would be at 400mm:
f# = 3.85 + .0065 * 400 = 6.45
So, you could hope that the f# at 400mm could be 6.45. That's fine. But when you look at the data of all the zooms you can find, you will find it's nowhere near linear and that almost all of the change happens quickly at the low mm end, and if I had to guess based on what I've seen I would guess that the f# at 400mm would actually be 7.1 as well since that is what previous zooms have shown to be probable.

If this helps you, great. Either way, it's obvious that I have way too much time on my hands to have written it all out.;) :ROFLMAO:
 
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BillB

EOS R
May 11, 2017
1,393
659
The difference between f5.6 and f7.1 is 2/3 of an f stop. If f5.6 at 400mm and F7.1 at 500mm are ok, how unacceptable can f6.3 or F7.1 at 400mm be?
 
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Pape

EOS RP
Dec 31, 2018
603
365
F7,1 lense could be directed for consumers too ,big white quality but like 2k price.
Dropping 1 stop isnt problem when consumers dont have super computer to remove noise so they use jpg ,what recently got 1 stop gain
 

navastronia

EOS RP + 5D Classic
Aug 31, 2018
713
845
A lot of people will be happy with the 100-500. Eventually, if the IQ checks out, I will probably be one of them.

Unless the lens is just unusable, I plan to get one. I have hope that with high ISO (on a great body, like an R5 or R1) and careful use of shutter speed, I could get away with it for outdoor events and daytime outdoor sports.
 

SecureGSM

2 x 5D IV
Feb 26, 2017
2,376
1,246
Unless the lens is just unusable, I plan to get one. I have hope that with high ISO (on a great body, like an R5 or R1) and careful use of shutter speed, I could get away with it for outdoor events and daytime outdoor sports.
The good news here though is that a F7.1 lens will allow for a metering at 0EV light levels. Here is an example of such an exposure:
ISO100, 1 second, F1.0
So it’s pretty dim lighting.
however , that’s metering. AF and tracking is a different story though.
Canon should have introduced a new naming convention for F7.1 lenses: DLO
Stands for : Daylight Only
:)
 
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justaCanonuser

Grab your camera, go out and shoot!
Feb 12, 2014
815
671
Frankfurt, Germany
As someone who shoots mainly sports and wildlife with Canon at shutter speeds that wouldn't rely on IBIS, I still can't get my head around an L tele zoom with a 7.1 aperture, especially as I already have the 100-400ii. Would it be 6.3 at 400mm?
I agree. Canon obviously must be very bold about the low light performance of their new R series sensors, otherwise such a zoom wouldn't make much sense. On the other hand, many people love the Sigma 150-600mm sports despite the fact that it closes to f = 6.3 already @ about 320mm (maybe the main reason why it is sharper than Sigma's cheaper C zoom).
 
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justaCanonuser

Grab your camera, go out and shoot!
Feb 12, 2014
815
671
Frankfurt, Germany
Pipe dream. You need to try the 400mm DO. No zoom, but you are only going to use it at the long end anyway. With a 1.4x you get to your 560mm at a reasonable f5.6.
In fact, this is one of the most interesting Canon tele lenses for me, too. With the Mk II version they really tackled the softer contrast of the Mk I lens compared with non-DO lenses back then. With that DO optic's tech Canon proves that they were really innovative with lens designs. Nikon tried to follow-up with their smaller 300mm f/4 five years ago, but like so often they struggled with off-centered lenses when they introduced it to the market, they really have issues with production precision: https://www.lensrentals.com/blog/20...-ed-vr-test-or-why-i-dont-test-just-one-copy/
 

usern4cr

R5
CR Pro
Sep 2, 2018
1,150
1,896
Kentucky, USA
In fact, this is one of the most interesting Canon tele lenses for me, too. With the Mk II version they really tackled the softer contrast of the Mk I lens compared with non-DO lenses back then. With that DO optic's tech Canon proves that they were really innovative with lens designs. Nikon tried to follow-up with their smaller 300mm f/4 five years ago, but like so often they struggled with off-centered lenses when they introduced it to the market, they really have issues with production precision: https://www.lensrentals.com/blog/20...-ed-vr-test-or-why-i-dont-test-just-one-copy/
Thanks for the link to the PF (phase fresnel) Nikon lens. I haven't considered fresnel lenses before since they weren't so good long ago (as I remember at least) so I assumed they wouldn't be now. I am very surprised to see that they can be as good. I guess we will see if Canon decides to come out with any RF DO(diffractive optic) lenses. As lens designs get big & heavy it could really make a drastic difference in reducing weight & size.
 

FamilyGuy

EOS RP
Feb 5, 2020
207
374
Saw a couple mallard ducks out back and some deer. Getting close to twilight last night, but not dark by any stretch. I have an RP and an RF 24-240. At 240, I had to be at 6.3 and 1/100th for decent exposure. Pushed the ISO right to 6,400 for the brightness I wanted (just a couple JPEG snaps).

Long way of saying that 7.1 during the so-called “golden hour” could be problematic for people on the 100-500. I’m happy with my pictures, but wouldn’t be if I had paid a couple grand for the lens by itself.