Canon RF 24-300mm f/2.8-5.6L IS USM optical formula patent published

[Czardoom]

You've affirmed what I've said. "More disconcerting is that Canon has overlooked the middle market and appears to be focused on producing entry level lenses or stratospherically priced L ones." The entry level DO lenses are fixed at f/11 and suffer a whole host of limitations from aperture to bokeh. The long primes are heavy, dated, and astronomically expensive. Nikon has successfully targeted the middle and the 800 f 6.3, for example is superb both in terms of size and performance. It is hand holdable, smaller, lighter, and almost a 1/3rd of the price of Canon's RF 800. Also it's sharp wide open (https://cameradecision.com/lenses/img/other/Nikon-Nikkor-Z-800mm-F6.3-VR-S-mtf-chart-1.jpg) and you should compare it against the $18k Canon (https://www.lensrentals.com/product-assets/4e5d812c-4f9c-4022-b1ab-263e16aea902/Table 2.jpeg). Look, I wanted Canon to be producing these kinds of lenses but they've been haphazard, slow to respond, have adopted a strategy which leaves me out. Besides, where is my high MP BSI camera? I'm holding one from Nikon called the Z8 and there is no bet that the R5II will offer a BSI, the range of FPS, fast sensor read out, fully customizable buttons ... The bottom line is Canon left me, I didn't leave Canon.

What you are basically saying is you want Canon to make what Nikon makes, but you would rather whine about it than to switch to Nikon.

 

[EOS 4 Life]

Compared to a Canon 800 f/5.6 at $19,000? I'd say yes. The 800 f/11 is not even a consideration.

You can find a used EF 800 f/5.6 below the price of the Nikon 800 f/6.3

 

[Marphoto]

It's all relative. Probably a large fraction of people who can afford to spend $6500 on a Nikon 800/6.3 can also afford to spend $13500 on a Canon 600/4 + 1.4x, or $17000 on the Canon 800/5.6 (it's $2K less than you state, but that's a quibble at those prices). Of course, since that $6500 Nikon lens won't work on a Canon body, for users on a Canon gear forum the outlay would also need to include a few thousand dollars for a good Nikon MILC.

On the other hand, for the vast majority of ILC users a lens costing $6500 is just as unaffordable as a lens costing $17000, whereas a lens costing only $800 (with the currently available $100 discount) is something within reason for those wanting to reach 800mm with good IQ (which the 800/11 delivers).

Maybe, though the $7-11k difference can buy a lot of other gear including a couple of bodies, a body and some lenses, etc. The 800 f/11 is more of a novelty offering and is impractical for most shooting circumstances. Having shot WL for dozens of years, I can't remember the time that I had enough light to shoot at f/11. I was out shooting some osprey fishing the other morning and was managing a Tv of 1/2000 at ISO 12800, f 5.6. How are you going to do that with an f/11 lens not to mention the bokeh?

 

[Marphoto]

What you are basically saying is you want Canon to make what Nikon makes, but you would rather whine about it than to switch to Nikon.

Nope.

 

[Marphoto]

You can find a used EF 800 f/5.6 below the price of the Nikon 800 f/6.3

You must be Hercules, because I can't handhold a used EF 800 at 9.9 lbs./4,500g nor will it fit into any of my bags. The Nikon Z 800 is a relatively lightweight and balanced lens weighing in at 4 lbs/2385 g, is 5.6"x15". It has become my go to birding lens bar none.

 

[neuroanatomist]

Maybe, though the $7-11k difference can buy a lot of other gear including a couple of bodies, a body and some lenses, etc. The 800 f/11 is more of a novelty offering and is impractical for most shooting circumstances. Having shot WL for dozens of years, I can't remember the time that I had enough light to shoot at f/11. I was out shooting some osprey fishing the other morning and was managing a Tv of 1/2000 at ISO 12800, f 5.6. How are you going to do that with an f/11 lens not to mention the bokeh?

I suggest you look at some of the excellent images @AlanF has posted with the 800/11. Or don’t, because most people don’t like to have their preconceptions challenged.

 

[bbasiaga]

Maybe, though the $7-11k difference can buy a lot of other gear including a couple of bodies, a body and some lenses, etc. The 800 f/11 is more of a novelty offering and is impractical for most shooting circumstances. Having shot WL for dozens of years, I can't remember the time that I had enough light to shoot at f/11. I was out shooting some osprey fishing the other morning and was managing a Tv of 1/2000 at ISO 12800, f 5.6. How are you going to do that with an f/11 lens not to mention the bokeh?

I bought the 800/11 when it was on a refurb sale in 2022. I figured for the price, why not? Its really amazing how usable it is. I've gotten some great long-distance landscapes, whales, birds, other critters. The ability to get usable images with an R6 era body at ISOs up to ~50,000 with noise reduction software helps increase its uses. In broad daylight, NR not necessary with lower ISOs. It collapses down and fits in my regular bag next to my other lenses (100-400, 24-105). Definitely worth it.

If i were a birds only guy, sure the cost of the faster big whites might be worth it, and I might be able to justify the extra weight to drag it around as it would see more use. But the 11 is a great window in to a world previously inaccessible to most photographers. Just because its not for you, doesn't mean its not worth anything.

Backgrounds are still pretty blown at that aperture and focal length, not quite as impressionistic as the big whites but its not like everything is in focus.

-Brian

 

[SwissFrank]

Hey Canon, where are the innovations?

You mentioned DO but I don't think it's laziness or stupidity that has them avoiding a given lens design technique. It's possible they're simply getting better tradeoff between size weight price and image quality via non-DO designs. Unless they have to pay an outside licensor for access to DO (and it's hard to imagine, I think it'd be off-patent at this point??) they'd use it in any lens they could where it gave more attractive tradeoffs.

I think there's a lot of innovations such as AI that tracks people, dogs and cats, birds, cars and motorbikes. Or, say, IBIS. It's not something UNIQUE to Canon, nor are they the first to have it, but these are pretty new technologies to the Canon product line. The sharpness of the 50/1.2 is pretty ground-breaking. The f/2.0 zoom still looks like a typo to me. No-one's had a 14-35/4, 100-300/2.8 or 200-500/4 that I know of (though admittedly some makes have had something pointing in that direction). The 16/2.8, which relies on the camera fixing hellacious distortion and in return offers better resolution for $300 than my old 14/2.8 provided for $2500. Apparently the autofocus tilt-shifts will be coming "real soon now." Also I think the R3 has focus-point-follows-what-you're-looking at, right? I'd love that. Also, you'd be right to point out that it's not available YET, but the 1x/1.4x/2.0x TC is going to be a game-changer I think.

I still expect a lot of things from the R1: I'm guessing it will have electronic ND, no-rolling-shutter, and over 20 stops of DR in a special mode.

 

[neuroanatomist]

Also, you'd be right to point out that it's not available YET, but the 1x/1.4x/2.0x TC is going to be a game-changer I think.

Unless the game being changed is physics, I doubt we'll ever see such a product. I suggest you read the patent on which that rumor is based. If you do so and understand what you read, you'll see that the rumor is a flagrant misinterpretation of the patent. Basically, someone looked at one of the diagrams and jumped to a silly conclusion. The actual patent is for a simple adapter, not a teleconverter.

 

[usern4cr]

If you want higher mag, you can try a 250D or 500D or other closeup lens. It would make the lens EXTREMELY macro at 300mm...

I've never used an add-on closeup lens, for the reason that I typically want a single lens to carry around to take a variety of framed photos with, without having to stop and make changes like adding/removing a TC or additional filter-threaded lens. I just like the simplicity of having the full zoom & focus range available and a good (but not 1x macro) magnification at the far end of a telephoto lens.

However, I'd be curious to know how close the lens would have to be to the subject to get it in focus at 300mm with a closeup lens added? I'm guessing it would be very close, and I normally want to enjoy the more distant subject distances for things like butterflies or other things that could be scared away by getting too close.

 

[Finn]

I hope we see it. Canon needs more innovation in their glass. Tamron has been doing very well with their e-mount lenses (especially their 28-200). I've been wanting a faster, pro level L version of the 24-240 for quite some time for landscapes.

A sharp 24-300 f4-5.6 sounds amazing for a two lens setup for hiking or a do-it-all video lens.

 

[SwissFrank]

I've never used an add-on closeup lens, for the reason that I typically want a single lens to carry around to take a variety of framed photos with, without having to stop and make changes like adding/removing a TC or additional filter-threaded lens. I just like the simplicity of having the full zoom & focus range available and a good (but not 1x macro) magnification at the far end of a telephoto lens.

However, I'd be curious to know how close the lens would have to be to the subject to get it in focus at 300mm with a closeup lens added? I'm guessing it would be very close, and I normally want to enjoy the more distant subject distances for things like butterflies or other things that could be scared away by getting too close.

Thanks for hearing me out.

The Canon 250D gives you infinity focus at 25cm, and closer focus on your lens will be closer yet. 500D is 50cm. They're just like the glasses a jeweler would use to look at a diamond a couple inches away, but they're 2-3 elements to eliminate chromatic aberation and fringing. I know butterflies are skittish at such ranges. I used a 180/3.5 in the 90s, and tried the 90TS+2xTC a couple times (for shots where their wings aren't parallel to the sensor, or at the time, it was film). I've never shot bugs seriously though, just maybe a couple hundred shots over 25 years. That's like a shot every 2 months or something :-D

I will say that screwing in one close-up lens isn't a huge amount of work. These things are thick and thus actually easy to get a grip on. Maybe a pain with a hood though you don't always need a hood.

 

[Rzrsharp]

That myth has been thoroughly debunked by Roger Cicala.

I am not big enough to challenge or trying to challenge him, but even a prime lens may not be internal focusing.

The first or the last, or both of the glass may move to get focusing on some prime lens, or maybe many. The movement changes the volume of the lens barrel and sucks or pushes the air in and out of the lens, together with the dust in the air.

This is the physics, i don't challenge it, neither anyone.

 

[neuroanatomist]

I am not big enough to challenge or trying to challenge him, but even a prime lens may not be internal focusing.

The first or the last, or both of the glass may move to get focusing on some prime lens, or maybe many. The movement changes the volume of the lens barrel and sucks or pushes the air in and out of the lens, together with the dust in the air.

This is the physics, i don't challenge it, neither anyone.

The lenses he found are the, "Biggest dusters: 85 f1.2, 105mm f1.4s, 70-200 f/2.8s, 150-600s." Of those the 85/1.2 is a front focusing lens, but the others are all internal focus and zoom, i.e. no external element movement to change the volume of air in the lens barrel.

Roger sums it up as:

Every lens has air flowing through it, there are no air-tight lenses.​

Air has dust in it.​

Dust in air likes to settle on solid objects.​

His other point is that while all lenses have dust, that dust is much more noticeable on lenses with front and rear elements that magnify strongly...and all of those lenses above fit that description.

But the bottom line is that the contention that a 24-300mm zoom will be a 'dust magnet' because of the extending zoom mechanism is not supported by the observations of someone I'd consider an expert in the field.

 

[Rzrsharp]

The lenses he found are the, "Biggest dusters: 85 f1.2, 105mm f1.4s, 70-200 f/2.8s, 150-600s." Of those the 85/1.2 is a front focusing lens, but the others are all internal focus and zoom, i.e. no external element movement to change the volume of air in the lens barrel.

Roger sums it up as:

Every lens has air flowing through it, there are no air-tight lenses.​

Air has dust in it.​

Dust in air likes to settle on solid objects.​

His other point is that while all lenses have dust, that dust is much more noticeable on lenses with front and rear elements that magnify strongly...and all of those lenses above fit that description.

But the bottom line is that the contention that a 24-300mm zoom will be a 'dust magnet' because of the extending zoom mechanism is not supported by the observations of someone I'd consider an expert in the field.

What makes you think my opinion is because of an “extending zoom mechanism “?

I assume someone had been hurt from the similar argument before and he is sensitive to the topic. LOL

it has not happened yet, let’s wait. No more arguments. We’re not from any manufacturer, right?

 

[neuroanatomist]

What makes you think my opinion is because of an “extending zoom mechanism “?

I assume someone had been hurt from the similar argument before and he is sensitive to the topic. LOL

it has not happened yet, let’s wait. No more arguments. We’re not from any manufacturer, right?

Now I’m curious…why will this lens be a dust magnet?

And hurt? Lol, no. I’m just against the posting of misinformation. And since the lens is only a patent, any statement that it will be a ‘dust magnet’ must be speculation at best.

 

[mb66energy]

Now I’m curious…why will this lens be a dust magnet?

And hurt? Lol, no. I’m just against the posting of misinformation. And since the lens is only a patent, any statement that it will be a ‘dust magnet’ must be speculation at best.

I think there is a difference between internal focusing lenses and those who have extending elements.
The first type pumps air inside the lens which can be kept mostly sealed against the environment.
The second type pumps air between the inside and the outside and is principally prone to suck in dust (and blow it out, but Murphy isn't on our side).
I think Canon uses some filtering elements e.g. in the EF 100-400 which has a larger travel of air volume compared to e.g. a 50 1.8 stm.
Maybe some internally focusing lenses have builtin materials like synthetic felt which might fall apart over time and deliver dust from the inside ...
Generally I havent any bad experience with dust inside lenses which affects my photos (or these aren't good enough to suffer from dust

 

[neuroanatomist]

I think there is a difference between internal focusing lenses and those who have extending elements.
The first type pumps air inside the lens which can be kept mostly sealed against the environment.
The second type pumps air between the inside and the outside and is principally prone to suck in dust (and blow it out, but Murphy isn't on our side).
I think Canon uses some filtering elements e.g. in the EF 100-400 which has a larger travel of air volume compared to e.g. a 50 1.8 stm.
Maybe some internally focusing lenses have builtin materials like synthetic felt which might fall apart over time and deliver dust from the inside ...

I understand the theory – an extending zoom 'sucks air in and pumps it out', a front-focusing lens does the same thing but to a lesser degree, and a lens with internal focus/zoom is 'mostly sealed'. Yes, Canon (and other vendors) use sealing methods (membranes, brushes around the barrel, etc.) to 'filter' out the dust from the air being moved.

But what Roger Cicala is saying is that the theory that extending zooms are dust pumps and therefore the lenses are filled with dust is bogus. The EF 70-200mm zooms seem to collect a lot of dust, but they're internal zoom and focus. The front-focusing EF 85/1.2L is often dusty, but the internal-focusing Nikon 105/1.4 is also dusty.

I think his interpretation of what's really happening is the correct one – there's an ample amount of dust in all lenses (even new ones direct from the factory), it's just that the dust is more easily seen with some lenses, namely the ones that have a high degree of magnification provided by the front or rear elements. That's because when you look through those elements, they magnify the dust on the other elements in the lens. He called that out specifically in a comment, stating anecdotally that looking through the front element of one lens, the second element appeared very dusty but when they removed that front element, the dust on the second element 'disappeared' (which of course it didn't, it was just not nearly as evident without the magnifying glass effect of the first element).

Generally I havent any bad experience with dust inside lenses which affects my photos (or these aren't good enough to suffer from dust

The other important point about lens dust – the reality is that it's just not that big a deal. The reason is pretty simple...for dust in the lens to show up in an image it needs to be in focus, but the only point within the lens at which the light is effectively in focus is at the aperture/iris diaphragm, i.e. a hole where dust can't settle. Dust on any of the element surfaces is going to be out of focus, and as such it can reduce overall contrast and maybe add some veiling glare in harsh light, but those are subtle problems.

Now, having said all of that there's another relevant side to this...the sensor. Even though dust within the lens is not a real problem, dust on the image sensor is. I remember holding my eye up to the back of the EF 24-105/4L at one point and rapidly zooming from tele to wide, and the blowback coming out of the lens made me blink. So to the extent that there's dust in the rear cavity of the lens, i.e. behind the rear element, an extending zoom mechanism can force that dust back toward the sensor. It was less of a problem with a DSLR, since zooming during exposure is not normal and the mirror is there the rest of the time. But with a MILC (or a DLSR in live view), composition is done with the sensor exposed and an extending zoom will have a tendency to push more dust onto the sensor.

Sensor dust is really an unavoidable problem anyway, and IMO the best way to deal with it is to be comfortable cleaning your own sensor or be prepared to send your camera in for frequent cleanings. Personally, I take the former approach (Visible Dust Arctic Butterfly and Sensor Loupe; I have sensor stamps and a LensPen SensorKlear just in case, but so far I've only needed the Arctic Butterfly to do the job). Speaking of which, my R8 needs a cleaning thanks to several lens changes while hiking on Mount Etna in Sicily, with lots of volcanic dust kicked up by fellow hikers.

 

[usern4cr]

I understand the theory – an extending zoom 'sucks air in and pumps it out', a front-focusing lens does the same thing but to a lesser degree, and a lens with internal focus/zoom is 'mostly sealed'. Yes, Canon (and other vendors) use sealing methods (membranes, brushes around the barrel, etc.) to 'filter' out the dust from the air being moved.

But what Roger Cicala is saying is that the theory that extending zooms are dust pumps and therefore the lenses are filled with dust is bogus. The EF 70-200mm zooms seem to collect a lot of dust, but they're internal zoom and focus. The front-focusing EF 85/1.2L is often dusty, but the internal-focusing Nikon 105/1.4 is also dusty.

I think his interpretation of what's really happening is the correct one – there's an ample amount of dust in all lenses (even new ones direct from the factory), it's just that the dust is more easily seen with some lenses, namely the ones that have a high degree of magnification provided by the front or rear elements. That's because when you look through those elements, they magnify the dust on the other elements in the lens. He called that out specifically in a comment, stating anecdotally that looking through the front element of one lens, the second element appeared very dusty but when they removed that front element, the dust on the second element 'disappeared' (which of course it didn't, it was just not nearly as evident without the magnifying glass effect of the first element).


The other important point about lens dust – the reality is that it's just not that big a deal. The reason is pretty simple...for dust in the lens to show up in an image it needs to be in focus, but the only point within the lens at which the light is effectively in focus is at the aperture/iris diaphragm, i.e. a hole where dust can't settle. Dust on any of the element surfaces is going to be out of focus, and as such it can reduce overall contrast and maybe add some veiling glare in harsh light, but those are subtle problems.

Now, having said all of that there's another relevant side to this...the sensor. Even though dust within the lens is not a real problem, dust on the image sensor is. I remember holding my eye up to the back of the EF 24-105/4L at one point and rapidly zooming from tele to wide, and the blowback coming out of the lens made me blink. So to the extent that there's dust in the rear cavity of the lens, i.e. behind the rear element, an extending zoom mechanism can force that dust back toward the sensor. It was less of a problem with a DSLR, since zooming during exposure is not normal and the mirror is there the rest of the time. But with a MILC (or a DLSR in live view), composition is done with the sensor exposed and an extending zoom will have a tendency to push more dust onto the sensor.

Sensor dust is really an unavoidable problem anyway, and IMO the best way to deal with it is to be comfortable cleaning your own sensor or be prepared to send your camera in for frequent cleanings. Personally, I take the former approach (Visible Dust Arctic Butterfly and Sensor Loupe; I have sensor stamps and a LensPen SensorKlear just in case, but so far I've only needed the Arctic Butterfly to do the job). Speaking of which, my R8 needs a cleaning thanks to several lens changes while hiking on Mount Etna in Sicily, with lots of volcanic dust kicked up by fellow hikers.

I agree with the observation that dust in the lens is not a problem. I've kept my lenses clean enough, but I'm not crazy-clean about it. And I've never had a problem with dust with my lenses. Dust on the sensor is another problem, as it is by definition in the exact place to alter the sensor at that location (whether the image is in focus or not). I've heard, often, that Sony cameras have a lot of trouble with dust on the sensor which they don't get rid of well (I don't know how true this was or still is). But I will say that the Canon dust reduction mechanism seems to work really well. And taking raw photos and letting PhotoLab do its cleanup of those images leaves me without any dust issues to notice.

But you mentioned that the diagphram/iris is the place where things are in focus. But that's not true, the iris is not the focus point at all - the sensor is at the focus point (provided the lens is correctly focusing the subject). The iris just reduces the amount of light coming in from the outer edges of the entrance pupil (the circles of light at various angles that pass through the plane of the iris, before that light is blocked by the diaphragm and lens baffling/obstructions). Dust on lens surfaces will become more noticeable the closer to the sensor it is, so that's the most important part of the lens to keep clean, particularly if the rear element travels closer to the sensor.

 

[SwissFrank]

Dust on lens surfaces will become more noticeable the closer to the sensor it is

It depends. If you have large out-of-focus highlights in the shot, dust on the front element is clearly visible in the highlights if you look closely. Of course this requires big dust or really big highlights, but it's certainly noticeable. I made shaped "filters" with black magic marker on CD cases to turn every out-of-focus light into a Chinese character, and did a multiple exposure to make a CNY greeting card.