Are new dream lenses coming for the RF mount? [CR1]

[canonmike]

A 500 f2.8! I'll hapilly hit the gym more to be able to carry it

And rob a bank to be able to pay for it.

 

[canonmike]

I use the 24-105mm F4 L ISand the 16mm F2.8.
Very capable combination for traveling

Concur on the RF24-105 F4L. I have been more than pleased with how capable this lens actually is, far superior to the older EF version and a bargain price for an L lens, I might add. It has been such a pleasure to use, I opted out of the RF70-200, in favor of purchasing the RF100-500. These two lenses cover most of my day to day shooting.

 

[Michael Clark]

Perhaps you need a calculator. 800/5.6 = 143. You should have used the 600/4 as your example, because 600/4 = 150.

In fact, the measured diameter of the 600/4 II front element is around 144mm, because the lens is probably something like 593mm f/4.12. Similar rounding occurs for all lenses (it saves Canon money) and thus the front element of the 800/5.6 would be even smaller than that of the 600/4 (however, I don’t personally have one of the former to measure).

Perhaps you need a calculator with more than three significant digits.

800mm divided by 5.6 is 142.857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142... (with an endlessly repeating 142857) millimeters.

But you'll never admit you're wrong.

 

[neuroanatomist]

Perhaps you need a calculator with more than three significant digits.

800mm divided by 5.6 is 142.857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142... (with and endlessly repeating 142857) millimeters.

But you'll never admit you're wrong.

Rounding numbers is appropriate in mathematics, and does not make use of the equals sign incorrect.

We’ve already established that you don’t know how to properly round numbers or admit your mistakes. Excessive confirmation of your inability to do either of those simple things was unnecessary.

 

[Michael Clark]

Lol. So your justification is that you don’t know the difference between front element diameter and focal length? Or is it that your knowledge of photography is so vast that it has subsumed your knowledge of basic math? Tell me, if I asked you the sum of 3 + 3, would your answer be rounded up to 6.3 or rounded down to 5.6?

I suggested that your attempts to wiggle out of simply admitting you made a mistake would become progressively more pathetic. In that regard, you’ve exceeded expectations.

I know the difference between lens diameter and focal length perfectly well. I also know the difference between dimensionless abstract numbers and numbers that represent physical measurements of actual objects. I also know the common focal lengths above 100mm at which lenses for the 135 format have been offered for about* the last 100 years, I'm sure you do as well, even if you're willing to suspend such awareness when you're intent on making a ridiculous argument.

*Note: "about" = approximately, roughly, more or less, give or take, etc.

If you ask me the sum of 3 + 3 do you honestly believe I would say anything other than 6?

On the other hand, If someone were to ask what f/2 plus three stops would be, I'd answer f/5.6, rather than the more mathematically precise f/5.65685424949238... and so would you.

If someone were to ask "What is three stops darker than f/8?" I'd answer f/22. So would you, even though the actual result of 8 x (√2^3) is 22.627416997969520780827019587355... which rounds to 23, rather than 22.

I will not admit that I made a mistake when I said what I said about a proposed 500mm f/2.8 lens by comparing it to an 800mm f/5.6 lens (which seems to have short-circuited your entire sense of reality) because I didn't make a mistake. I was perfectly aware at the time that 800 divided by 5.6 is not exactly 150, but I chose to round it up to that nice, round number.

You can continue to choose to ignore the obvious if it somehow makes you feel better about yourself by insisting that someone who rounded 142.857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142... mm up to 150mm instead of down to 135mm is completely and utterly wrong.

 

[neuroanatomist]

I know the difference between lens diameter and focal length perfectly well. I also know the difference between dimensionless abstract numbers and numbers that represent physical measurements of actual objects.

The 800mm f/5.5 lens is an actual object with a front element diameter that can be physically measured. A front element that you incorrectly stated is 150mm in diameter.

I know the difference between lens diameter and focal length perfectly well... ...insisting that someone who rounded [143mm] up to 150mm instead of down to 135mm is completely and utterly wrong

So it's just math that you don't know well at all. Someone who rounds 178.6 mm up to 180 mm and also rounds 142.9 mm up to 150 mm while suggesting that the other alternative is to round 142.9 down to 135 mm does not understand basic math.

You say you chose to round 800/5.6 up to the ‘nice, round number’ of 150 instead of correctly rounding 143 down to the equally ‘nice, round number’ of 140. Yet you chose not to round 500/2.8 up to the ‘nice, round number’ of 200, but instead rounded it to 180.

Honestly, I'm certain that you do actually understand basic math, meaning your patently asinine argument about choosing to round 143 up to 150 instead of down to 135 is more of your ongoing and pathetic attempt to avoid admitting you simply made a mistake.

You were correct in one regard, when you stated, “I will not admit that I made a mistake…” You’ve shown us that you are unwilling to do so, no matter how much asinine worm-wiggling you need to do in order to avoid that simple act.

Your efforts, while pathetic and making you appear progressively more foolish, are also mildly amusing. So by all means, feel free to keep wiggling.

 

[SpaceGhost]

To go from f/5.6 to f/4 at 300mm requires a 40% wider diameter front element, from 54mm to 75mm. The lens would need to be a lot bigger, even if it were still 70-300mm.

You're so wrong. In my dream, I also defy the laws of physics.

 

[Michael Clark]

The 800mm f/5.5 lens is an actual object with a front element diameter that can be physically measured. A front element that you incorrectly stated is 150mm in diameter.

I've never come across any commercially produced lens marketed as an 800mm f/5.5 that could actually be measured. Please enlighten me where I may find such a lens? But I'll go out on a limb and assume you meant the EF 800mm f/5.6 L IS and *incorrectly* referred to it as "The" 800mm f/5.5 lens?

Where did I refer to a specific 800mm f/5.6 lens? I don't think I did. When I refer to a specific lens I say something like EF 800mm f/5.6 L IS or AF-S Nikkor 800mm f/5.6 E FL ED VR. If you were half as perceptive as you give yourself credit for being you'd have noticed by now that I usually bother to type out "5D Mark IV" instead of "5D4" in the vast majority of my posts here, though I do occasionally get lazy and succumb to the temptation. But please, keep living in your fantasy world where your biased interpretation of what others did and did not say is the sole basis of reality.

 

[Michael Clark]

So it's just math that you don't know well at all. Someone who rounds 178.6 mm up to 180 mm and also rounds 142.9 mm up to 150 mm while suggesting that the other alternative is to round 142.9 down to 135 mm does not understand basic math.

You say you chose to round 800/5.6 up to the ‘nice, round number’ of 150 instead of correctly rounding 143 down to the equally ‘nice, round number’ of 140. Yet you chose not to round 500/2.8 up to the ‘nice, round number’ of 200, but instead rounded it to 180.

Honestly, I'm certain that you do actually understand basic math, meaning your patently asinine argument about choosing to round 143 up to 150 instead of down to 135 is more of your ongoing and pathetic attempt to avoid admitting you simply made a mistake.

You were correct in one regard, when you stated, “I will not admit that I made a mistake…” You’ve shown us that you are unwilling to do so, no matter how much asinine worm-wiggling you need to do in order to avoid that simple act.

Your efforts, while pathetic and making you appear progressively more foolish, are also mildly amusing. So by all means, feel free to keep wiggling.

Here's a math question for you: which is closer? Rounding 142.9 up to 150 or rounding it down to 135. Because there are no commonly marketed 140mm lenses in the 135 format, that option is out. There are both 150mm and 180mm lenses that have appeared on the 135 format landscape from time to time.

 

[neuroanatomist]

I've never come across any commercially produced lens marketed as an 800mm f/5.5 that could actually be measured. Please enlighten me where I may find such a lens? But I'll go out on a limb and assume you meant the EF 800mm f/5.6 L IS and *incorrectly* referred to it as "The" 800mm f/5.5 lens?

I made a typographical error. I was wrong, and should have stated 800mm f/5.6.

See, that’s how it’s done. You make an incorrect statement, you admit that you were wrong. It’s not difficult. Well, not for me. It seems beyond your capability.

Where did I refer to a specific 800mm f/5.6 lens? I don't think I did.

You referred to ‘the 800/5.6’:

Do you have any idea how much a lens with an 180mm front element would cost? That's larger than the the 150mm front element of the 800/5.6.

Whether or not you were referring to a specific model of 800/5.6 lens by a specific manufacturer is irrelevant, because none of them have a 150mm front element.

 

[neuroanatomist]

Here's a math question for you: which is closer? Rounding 142.9 up to 150 or rounding it down to 135. Because there are no commonly marketed 140mm lenses in the 135 format, that option is out. There are both 150mm and 180mm lenses that have appeared on the 135 format landscape from time to time.

Find me a math textbook where the method for rounding a number involves using commonly marketed 135-format lens focal length values as reference points.

You rounded 178.6mm to the nearest 10’s place number, which is 180mm. Rounding 142.9mm to the nearest 10’s place number is 140mm, not 150mm. That’s how rounding is performed. As I said, my kids could do that correctly in the first grade.

We both know you understand that. We both know you simply made a mistake in stating that an 800/5.6 lens has a 150mm front element. It’s sad that you are mentally and/or emotionally incapable of simply admitting your error. Actually, it’s beyond sad at this point. Beyond pathetic, as well. Words like pitiful and deplorable are more apt, now.

 

[Ph0t0]

I would like to see some high quality lenses for when I'm shooting landscapes while hiking with limited gear. Something light and maybe with a bit more reach so that I wouldn't need to bring the third lens. Maybe a combo of:
20-85mm f4
75-300mm f4

Some bright glass with low vignetting for nightscapes with stars and low ligh photography, portraits etc...
14 or 16mm f1.4
18 or 20mm f1.2
35 or 40mm f1.0
135mm f1.8

Some telephoto lenses like:
400mm f4 small and lightweight (DO?) maybe witha a built in TC?

200-500mm f4 with 1.4TC IS
500mm f5 IS lightweight as possible (DO)
600mm f5.6 IS lightweight as possible (DO)

A bit longer macro lens for RF mount
200mm f4 macro IS

And two specialised lenses for photographing landscapes and architecture like:
24mm TS with AF
16mm or 18mm lens with shift

 

[Del Paso]

I just couldn't wait any longer, so, I just bought an EF 180 F 3,5 macro and I'm happy!
With a stabilized body it's former drawback, compared with the EF 100 L, just vanished.
The day Canon produce a new RF version, I could easily sell it without losing much money (it cost me $650 in mint condition).
But the RF 14mm TSE...gimme quick!