Patent: Canon RF 24-70mm f/4L IS USM

jdavidse

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Sep 13, 2012
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Read Joules' comment on the first page ...

I did.
Canon USA says the EF 24-70 f/4 is 93mm (3.7 inches)
Add the EF->RF adapter and that's 113mm (4.45 inches)

The RF 24-70 f/4 patent says "Total lens length: 145.52mm 135.76mm 160.05mm"

Adjust for the flange distance (subtract 20mm) that's 125.52, 115.76, 140.05

Assume you took the middle measurement of 115.76 (4.56 inches). That's still a touch longer than the EF 24-70 f/4 w/ the adapter on.

The RF 24-105 f/4 is 107.3 (4.22 inches) long

The RF 24-70 f2.8 is 125.7mm (4.95 inches) long

I was off by 10mm in my earlier post because I took the measurement on the left, assuming that was the retracted length. But assuming it's the middle number of 115mm long, why is it 8mm longer than the 24-105 f/4?

Anyways maybe this patent won't prove to be the final version. But so far, this seems DOA if it's this big.
 
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Joules

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Jul 16, 2017
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I did.
Canon USA says the EF 24-70 f/4 is 93mm (3.7 inches)
Add the EF->RF adapter and that's 113mm (4.45 inches)

The RF 24-70 f/4 patent says "Total lens length: 145.52mm 135.76mm 160.05mm"

Adjust for the flange distance (subtract 20mm) that's 125.52, 115.76, 140.05

Assume you took the middle measurement of 115.76 (4.56 inches). That's still a touch longer than the EF 24-70 f/4 w/ the adapter on.

The RF 24-105 f/4 is 107.3 (4.22 inches) long

The RF 24-70 f2.8 is 125.7mm (4.95 inches) long

I was off by 10mm in my earlier post because I took the measurement on the left, assuming that was the retracted length. But assuming it's the middle number of 115mm long, why is it 8mm longer than the 24-105 f/4?

Anyways maybe this patent won't prove to be the final version. But so far, this seems DOA if it's this big.
It took the measured length for the min and max length from TDP:


There is an 8 mm difference in their measurements VS Canon's statement of 93 mm at the short end. That's probably due to differences in what their are measuring, so let's go with Canon statement, since it is the more favorable one.

EF 24-70 4.0: 93 mm + 24 mm (Adapter) = 117 mm
RF 24-70 4.0: 135 mm - 20 mm (RF flange) = 115 mm

You added only 20 mm for the adapter, but as RF flange distance is 20 mm and EF is 44,you have to add 24 mm (also the stated size of the adapter at TDP). So these lenses are very similar in size at their shortest setting. To the point where we have to look closer at the measurement procedures to definitely call one smaller than the other.

Also, I don't think the three numbers in the patent necessarily cover min and max length. I believe they are just the lengths at the before mentioned focal lengths. It is probably fair to assume the lens will be longest at the longest focal length. But there may be a point between the two extremes where it retracts even further than the 115 mm we discussed. That would explain the supposed difference VS the RF 24-105 mm 4.0.

In any case, I would not worry about this lens being DOA. Even if it were bigger, I expect we would see some capability to make up for it.
 
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ctk

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Mar 25, 2020
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I dont understand this lense really.

what is the reason that someone would opt for a 24-70 f4 over the existing 24-105 f4?
Theyre the same category of lens except one has a better reach and is really highly useable.

is the shorter one that much cheaper?
Smaller size. If there's less reliance on software corrections I will trade my 24-105 for one
 
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SteveC

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Sep 3, 2019
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There were two 24-105/4LIS lenses.

The RF24-105 is excellent. I'm used to shooting a 15-lens EF system but I'm just happy with the RF24-105 any more. It's sharp enough I don't seem to need to switch to a prime to be sharper. The camera's high-enough ISO I don't need a special lens just for candle-light dinner mementos. It's wide enough and long enough. I will grant that when I take it off, it's often to mount the 180mm macro, so maybe 0.7x mag would be nice though.

Can't wait to get mine...Right now I have the RF 15-35 f/2.8L and the EF100-400 II L, so there's this big "hole" in my full frame zoom capability, partially plugged by the EF 40 mm pancake, the 50 mm f/1.4 and the 85 mm f/1.8.
 
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Jan 22, 2012
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I dont understand this lense really.

what is the reason that someone would opt for a 24-70 f4 over the existing 24-105 f4?
Theyre the same category of lens except one has a better reach and is really highly useable.

is the shorter one that much cheaper?
I understand your sentiment. It boils down to Image quality. Size/Weight etc are not that much of an issue for me.
 
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YuengLinger

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Dec 20, 2012
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Ive the EF 24-105 f4L MK1, the EF 24-70mm f4L, the EF 24-70mm f2.8L MKII and the RF 24-105 f4L. The present EF 24-70 f4L is very good at 24mm and 70mm but tends to be softer at 50mm. The EF 24-70mm f2.8L MKII is very good throughout the range with a little pin cushion at one end and barrel at the other easily corrected in photoshop. the RF version of the 24-105mm is way better than either the MK1 or MKII version in EF mount. Canon should be able to deliver a pretty good RF 24-70mm f4L hopefully along the lines of the quality found on the EF 16-35mm f4L but including the macro function.

Landscape shooters would lap up the RF 16-35 f4L, RF 24-70 f4L & the RF 70-200 f4L and hopefully not at the crazy prices charged for the f2.8 lenses. Put these together with the R5 or R6 and you've got a winning combination.

This is the only explanation I've read since the original EF version came out that makes sense. I get it! As part of a less costly trinity, it has a place.
 
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Sep 22, 2016
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I dont understand this lense really.

what is the reason that someone would opt for a 24-70 f4 over the existing 24-105 f4?
Theyre the same category of lens except one has a better reach and is really highly useable.

is the shorter one that much cheaper?
It's smaller and lighter, which is good for things like travel and backpacking if those focal lengths work for you. If not, well, that's why there are other lenses out there.
 
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Feb 28, 2013
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I’d be also be extremely interested in this lens; I absolutely love my RF 24-70 2.8, but it pulls my arms off it’s so heavy. Some of my studio shoots can be 10hrs plus and fantastic the 2.8 version is I don’t always need to shoot that wide open.

I did look at the new 24-105 super lightweight and ok as a holiday snapper but I don’t think I would use it for much else other than for light weight travel kit.

Please Canon make the f4 come in at sub 500g if you can and spare our arms
Ive used my RF24-105mm f4L IS USM for quite a few studio shoots now and was really surprised the first time I used it how good it was. Rent one and try yourself.
 
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