Canon 50mm f/1.2L

[luckyrwe]

I want one sooooo bad.


http://www.dpreview.com/news/0608/canon/canon_50.jpg

[wxwax]

Well, personally, I want to see how superior it is the 50 1.4.

[truth]

Well, personally, I want to see how superior it is the 50 1.4.

It's exactly 0.2 better. :rofl

[Nikolai]

It's exactly 0.2 better. :rofl
...$1,299 more expensive.
1,300/0.2=$6,500 per an f/stop :wink

[saurora]

...$1,299 more expensive.
1,300/0.2=$6,500 per an f/stop :wink

OUCH! When you break it down in those terms, it sounds less and less appealing!!! :uhoh

[Nikolai]

OUCH! When you break it down in those terms, it sounds less and less appealing!!! :uhoh
I used to be a university math professor for more than 10 years. :):
Math kinda helps you put things into a perspective....:rofl

[gluwater]

I'm guessing this will be like the 85 f/1.2, heavy and slow focusing, being used mostly in the studio. I'm not saying it will be a bad lens, just more of a specialty lens. Plus that price tag is daunting.

[Blurmore]

I think the 85 f1.2 is the penultimate portrait lens for a FF camera. I think the 50 f1.2 will be the ultimate portait lens for a 1.6 crop body. So far as weight and speed go I think you will be suprised. The 85 has a bunch of elements, and the focus travel is long and precise leading to heavy and slow (the MKI more than the MKII) A 50mm f1.2 is not a beastly large manual focus lens, and I doubt it will be a monster akin to the elusive and over zelous f1.0. A 'standard' angle of view lens is the easiest and simplest to build whereas a WA takes many elements to correct distortion and a telephoto many elements to keep sharpness across the frame. I think I read once that for each stop a lens is faster the size of the objective has to double. So by this I think the 50mm f1.2 will be 30% larger than the f1.4 and 60% larger than the plastic fantastic. I think what you can expect from the 50mm f1.2 is a lens with ZERO CA even wide open, perfect field flatness, no distortion, excellent saturation, and unbelievable edge sharpness from f1.8 and smaller. It is also a lens that is just as useable/desireable on a crop body as on a FF body, a lens that will be highly desireable, and comparatively cheap (when compared to the 85 f1.2 or 50 f1.0)

[pathfinder]

I've posted this image before, to demonstrate graphically what Nik expressed mathmatically.

How dramatically bigger f1.2 is than f1.4 .....

Olympus did it 25 years ago.....

http://Pathfinder.smugmug.com/photos/33506239-L.jpg

[Blurmore]

I've posted this image before, to demonstrate graphically what Nik expressed mathmatically.

How dramatically bigger f1.2 is than f1.4 .....

Olympus did it 25 years ago.....



looks like 30% larger

[David_S85]

Olympus did it 25 years ago.....


And Canon did it 30+ years ago. When I was purchasing my AT-1, I had a choice between their 50 1.8, a 1.4, or a 1.2. Even earlier, Canon had a 1.0 lens.

Correction: the 1.2 was 55mm. Source (http://www.canon.com/camera-museum/camera/lens/f_lens.html).

[Nikolai]

I've posted this image before, to demonstrate graphically what Nik expressed mathmatically.

How dramatically bigger f1.2 is than f1.4 .....

Olympus did it 25 years ago.....



"Last 10% cost 90%".
It's universal.
You can't fight it.
Welcome to the Dark Side! :-)

[claudermilk]

Nice to see a much more reasonable thread here. FM is kind of going berzerk over this lens...though it is funny to read.

Considering the 85/1.8 vs 85/1.2 prices, the 50/1.2 price seems about where you'd expect. I probably won't get one since for that money I can get a lot more use out of the 70-200/2.8IS on my wish list. However, I bet blurmore is on the right track here: this might be the holy grail for 1.6 body portraiture. I've played with one of the monster 85/1.2 7 it is a sweet lens, though a little long; knock that back to 50 (or effective 82) and you're right there.

[pathfinder]

looks like 30% larger

Which is what, maybe 1/3 of an fstop?? Whhooo Haa! I can see the appeal.

[rutt]

Let's see if we can think of a way to justify the expense. Might be a good game.

The f/1.4 has a reputation of being soft fully open. The common advice is to stop down to f/2.8 or so and then you'll be happy. Perhaps this lens will perform better stopped down to f/1.4? Perhaps it will perform better at every f stop? For the money it should.

Hey, I'm just saying.

BTW, I love my f/1.2 85mm which I bought used from CMR a couple of years ago. It's a beast in more than one way and took me a while to grow into. But once I got the hang of it, I fell in love with it. It was especially great for those ballet performances.

[Jekyll & Hyde]

J: If I were limited to only 3 lenses, this one would almost certainly make the list. I Loooove using the 50 indoors...


http://www.pbase.com/jekyll_and_hyde/image/63887246.jpg



...$1,299 more expensive.
1,300/0.2=$6,500 per an f/stop :wink
H: Pssst. The math is right on, but the equation is slightly flawed. :wink
J&H

[pathfinder]

Let's see if we can think of a way to justify the expense. Might be a good game.

The f/1.4 has a reputation of being soft fully open. The common advice is to stop down to f/2.8 or so and then you'll be happy. Perhaps this lens will perform better stopped down to f/1.4? Perhaps it will perform better at every f stop? For the money it should.

Hey, I'm just saying.

BTW, I love my f/1.2 85mm which I bought used from CMR a couple of years ago. It's a beast in more than one way and took me a while to grow into. But once I got the hang of it, I fell in love with it. It was especially great for those ballet performances.

I'm just stirring the pot today, John.

You know I love my 85f1.2 also. But ya gotta admit, 99% of the shots can be done with the 85 f1.8 equally as well and focus faster ( unless you are lucky enuff to get the new 85 f1.2 L II ) or have access to the Boston Ballet which I do not:D:D

I am sure I would love the 50mm f1.2, but the reality is that I shoot with the 24-70 or the 24-105 and almost never use my 50 f1.4 now. I doubt that the f1.2 50mm would change that for me.

[wxwax]

Which is what, maybe 1/3 of an fstop?? Whhooo Haa! I can see the appeal.
That's pretty much the tone of the FM thread, only it's taking them 40+ pages to say it.

I'd like to see piccies from the lens. The measurebators are already predicting it will be soft in the corners.

For me, I suspect that this lens will fall into the same category as the 85 1.2 and the 200 1.8 - kinda cool, great results - but too expensive and specialized to belong in my ridiculously large collection of glass.

[claudermilk]

That's pretty much the tone of the FM thread, only it's taking them 40+ pages to say it.

Dont'cha love that thread? Some of them have already passed judgement on it based on little information other than possible price. Pretty amusing reading though.

[I Simonius]

I want one sooooo bad.


http://www.dpreview.com/news/0608/canon/canon_50.jpg

then buy one!:rofl

[I Simonius]

I think the 85 f1.2 is the penultimate portrait lens for a FF camera. I think the 50 f1.2 will be the ultimate portait lens for a 1.6 crop body. So far as weight and speed go I think you will be suprised. The 85 has a bunch of elements, and the focus travel is long and precise leading to heavy and slow (the MKI more than the MKII) A 50mm f1.2 is not a beastly large manual focus lens, and I doubt it will be a monster akin to the elusive and over zelous f1.0. A 'standard' angle of view lens is the easiest and simplest to build whereas a WA takes many elements to correct distortion and a telephoto many elements to keep sharpness across the frame. I think I read once that for each stop a lens is faster the size of the objective has to double. So by this I think the 50mm f1.2 will be 30% larger than the f1.4 and 60% larger than the plastic fantastic. I think what you can expect from the 50mm f1.2 is a lens with ZERO CA even wide open, perfect field flatness, no distortion, excellent saturation, and unbelievable edge sharpness from f1.8 and smaller. It is also a lens that is just as useable/desireable on a crop body as on a FF body, a lens that will be highly desireable, and comparatively cheap (when compared to the 85 f1.2 or 50 f1.0)

:jawdrop Now even I want one - and I am already perfectly happy with the 1.4!

AH no... - hang on it will wheigh a ton, phew - I don't need it after all ( wipes sweat from brow):doh

[I Simonius]

Let's see if we can think of a way to justify the expense. Might be a good game.

The f/1.4 has a reputation of being soft fully open. The common advice is to stop down to f/2.8 or so and then you'll be happy. Perhaps this lens will perform better stopped down to f/1.4? Perhaps it will perform better at every f stop? For the money it should.

Hey, I'm just saying.

yes yes - keep going, Im listening :D

BTW, I love my f/1.2 85mm which I bought used from CMR a couple of years ago. It's a beast in more than one way and took me a while to grow into. But once I got the hang of it, I fell in love with it. It was especially great for those ballet performances.

you taking pictures while doing ballet???:dunno

[Manfr3d]

The old 50mm/1.0 L wasn't exactly alot better than the current
50mm/1.4. It was actually dissapointingly soft wide open. If the
new 1.2 shows the same behaviour, then the high price is really
hard to justify.

duell of the fifties: 1.0 1.4 1.8:
http://wlcastleman.com/equip/reviews/50mm/index.htm

[saurora]

I think the 85 f1.2 is the penultimate portrait lens for a FF camera. I think the 50 f1.2 will be the ultimate portait lens for a 1.6 crop body. So far as weight and speed go I think you will be suprised. The 85 has a bunch of elements, and the focus travel is long and precise leading to heavy and slow (the MKI more than the MKII) A 50mm f1.2 is not a beastly large manual focus lens, and I doubt it will be a monster akin to the elusive and over zelous f1.0. A 'standard' angle of view lens is the easiest and simplest to build whereas a WA takes many elements to correct distortion and a telephoto many elements to keep sharpness across the frame. I think I read once that for each stop a lens is faster the size of the objective has to double. So by this I think the 50mm f1.2 will be 30% larger than the f1.4 and 60% larger than the plastic fantastic. I think what you can expect from the 50mm f1.2 is a lens with ZERO CA even wide open, perfect field flatness, no distortion, excellent saturation, and unbelievable edge sharpness from f1.8 and smaller. It is also a lens that is just as useable/desireable on a crop body as on a FF body, a lens that will be highly desireable, and comparatively cheap (when compared to the 85 f1.2 or 50 f1.0)


Hmmmmm....maybe I do need one! I rarely use my 85..it's just too long indoors. Would a 50 be a good size for group portraits, say 3-5 people?

[Manfr3d]

Hmmmmm....maybe I do need one! I rarely use my 85..it's just too long indoors. Would a 50 be a good size for group portraits, say 3-5 people?

The 50mm has 46° angle of view (diagonal) the 85mm 28,5°, go figure.

[cmr164]

The math and science in this thread has me in stitches... Come on guys what is the diff in f-stops between f/1.2 and f/1.4 and it isn't ".2"

[erich6]

The math and science in this thread has me in stitches... Come on guys what is the diff in f-stops between f/1.2 and f/1.4 and it isn't ".2"

Well, technically a stop would be the difference between f/1.4 to f/2.8 which would make a f-number change of 0.2 equivalent to approximately 0.14 stops (relative to the f/1.4 lens and slightly higher relative to the f/1.2).

The price per stop would then be the difference in cost between the f/1.2L and f/1.4L over 0.14. That is:

($1300 for f/1.2 - $315 for f/1.4)/0.14 = $7035 per stop. Still expensive. :wow

Erich (geeking out)

[pathfinder]

Well, technically a stop would be the difference between f/1.4 to f/2.8 which would make a f-number change of 0.2 equivalent to approximately 0.14 stops (relative to the f/1.4 lens and slightly higher relative to the f/1.2).

The price per stop would then be the difference in cost between the f/1.2L and f/1.4L over 0.14. That is:

($1300 for f/1.2 - $315 for f/1.4)/0.14 = $7035 per stop. Still expensive. :wow

Erich (geeking out)


No No No Nope!! - it is one full f stop from f1.4 to f2.0 and another to f2.8.

From 1.4 to 1.0 is another stop wider, so f1.2 is half a stop faster than f1.4.

My Bad. Thanks for pointing this out CMR.

Glad to see you hanging around to keep us on the straight and narrow:):

[Andy]

Nope - it is one full f stop from f1.4 to f2.0 and another to f2.8.

From 1.4 to 1.0 is another stop wider, so f1.2 is half a stop faster than f1.4.

:nod

[David_S85]

Well, technically a stop would be the difference between f/1.4 to f/2.8

No.

Full stop differences would be (all figures rounded to 0.1):
f/1.0, 1.4, 2.0, 2.8, 4.0, 5.6...

Half stop differences would be:
f/1.0, 1.2, 1.4, 1.7, 2.0, 2.4, 2.8, 3.4, 4.0, 4.8, 5.6...

One third stop differences would be:
f/1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 1.7, 1.8, 2.0, 2.2, 2.4, 2.8, 3.2, 3.4, 3.6, 4.0, 4.5, 4.8, 5.0, 5.6...

The difference from 1.4 to 1.2 is one half stop.

http://www.robert-barrett.com/photo/exposure_calculator.html

[Jeffro]

I hate math....................:huh

[erich6]

No No No Nope!! - it is one full f stop from f1.4 to f2.0 and another to f2.8.

From 1.4 to 1.0 is another stop wider, so f1.2 is half a stop faster than f1.4.

My Bad. Thanks for pointing this out CMR.

Glad to see you hanging around to keep us on the straight and narrow:):

Thanks for keeping me straight guys. Glad to see everyone came out so quickly to correct this!!

So, the revised formulation is:

($1300 for f/1.2 - $315 for f/1.4)/0.5 = $1970 per stop. Still expensive...but more reasonable.

Erich

[erich6]

Thanks for keeping me straight guys. Glad to see everyone came out so quickly to correct this!!

So, the revised formulation is:

($1300 for f/1.2 - $315 for f/1.4)/0.5 = $1970 per stop. Still expensive...but more reasonable.

Erich

From the link:

"f/stop Graph...
The diameter and area values of each f/stop are based on a lens with a focal length of 50mm. Note that an f/stop value is the ratio of the focal length of the lens to the diameter of the aperture. Thus, f/1 has an aperture diameter of 50mm, f/2 a diameter of 25mm, f/8 a diameter of 6.25mm, etc. The percentage value shown next to the aperture area is the aperture area as a percentage of the total f/1 aperture area. The amount of light entering the camera is directly governed by the area of the aperture opening. Thus, f/1.4 is 50% or half the area of f/1 and therefore cuts the light in half -- a "full stop" less light. f/2 is 25% or 1/4 the area of f/1 and is 2 stops less light. "

[ubergeek]

One third stop differences would be:
f/1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 1.7, 1.8, 2.0, 2.2, 2.4, 2.8, 3.2, 3.4, 3.6, 4.0, 4.5, 4.8, 5.0, 5.6...
Actually there should only be two 1/3-stop steps between f/1 and f/1.4, and those would be f/1.1 and f/1.3. Ditto for f/1.4 and f/2 (1.6, 1.8); f/2.8 and f/4 (3.2, 3.5); and f/4 and f/5.6 (4.5, 5.0).

The math isn't hard; each one-stop difference is calculated by multiplying by 2 to the 1/2 power (the square root of 2 or about 1.414). Fractional-stop differences are calculated by multiplying by 2 to the (1/2 * differences in stops); for example, third-stop differences are mutliplied by 2 ^ (1/2 * 1/3) or 2 ^ 1/6 or about 1.122.

I could try to derive the formula to determine how many stops faster (or slower) x is than y for arbitrary values of x and y, but it's getting late and my algebra is rusty. :D

Cheers,
Jeremy

[David_S85]

er.... yes. Did you look at the calculator link (http://www.robert-barrett.com/photo/exposure_calculator.html) I provided?

In my haste, I typed the 1/3 stop increments and accidently also included the 1/2 stop increments. :doh

The graphic is quite good helping to explain the area relationship with the f-stop numbers.

[erich6]

From the link:

"f/stop Graph...
The diameter and area values of each f/stop are based on a lens with a focal length of 50mm. Note that an f/stop value is the ratio of the focal length of the lens to the diameter of the aperture. Thus, f/1 has an aperture diameter of 50mm, f/2 a diameter of 25mm, f/8 a diameter of 6.25mm, etc. The percentage value shown next to the aperture area is the aperture area as a percentage of the total f/1 aperture area. The amount of light entering the camera is directly governed by the area of the aperture opening. Thus, f/1.4 is 50% or half the area of f/1 and therefore cuts the light in half -- a "full stop" less light. f/2 is 25% or 1/4 the area of f/1 and is 2 stops less light. "

It's interesting that given the above definition going from f/1.4 to f/1.0 will give you twice as much light (one full stop) but going from f/1.4 to f/1.2 only gives you 36% more light even though it is technically "half a stop" (and that you get ~75% of the light at f/1.4 that you had at f/1.2).

[ubergeek]

Ahh yes, the graphs are very instructive. I did go to the page the first time, but I didn't see the graphs because they seem to work only in Internet Explorer (I usually use Firefox). Anyway, just thought some of the "math heads" out there might appreciate a more algebraic explanation.

Cheers,
Jeremy

[ubergeek]

It's interesting that given the above definition going from f/1.4 to f/1.0 will give you twice as much light (one full stop) but going from f/1.4 to f/1.2 only gives you 36% more light even though it is technically "half a stop" (and that you get ~75% of the light at f/1.4 that you had at f/1.2).
It's correct, although somewhat inaccurate due to rounding errors.

If we assume that there is a true half stop between the indicated aperture settings, opening up half a stop from f/1.4 to f/1.2 actually lets about 41% more light in, or put another way, we now have 141% of the light we originally had. Opening up another half stop to f/1 gives us 141% of the light we had at f/1.2. If we had opened up from f/1.4 to f/1 we would expect to have twice as much light, or 200% of the original amount of light (let's call that x). Does it work out? Let's see:x * 141% * 141%
= x * 1.41 * 1.41
= x * 1.99~= 2x
36% is close to 41%, but this makes sense when you consider that a half stop faster than f/1.4 is actually ~ f/1.189 (also keep in mind that one stop faster than f/1 is actually ~ f/1.414)--so f/1.2 isn't quite half a stop faster than f/1.4. Of course irrational numbers like the square root of 2 are hard to deal with, so we typically round to nearest tenths for small f/numbers and don't bother to round at all for larger f/numbers.

Cheers,
Jeremy

[saurora]

You know, when I was in school boys didn't like math............what happened??? :dunno

[erich6]

It's correct, although somewhat inaccurate due to rounding errors.


If we assume that there is a true half stop between the indicated aperture settings, opening up half a stop from f/1.4 to f/1.2 actually lets about 41% more light in, or put another way, we now have 141% of the light we originally had. Opening up another half stop to f/1 gives us 141% of the light we had at f/1.2. If we had opened up from f/1.4 to f/1 we would expect to have twice as much light, or 200% of the original amount of light (let's call that x). Does it work out? Let's see:x * 141% * 141%
= x * 1.41 * 1.41
= x * 1.99~= 2x

36% is close to 41%, but this makes sense when you consider that a half stop faster than f/1.4 is actually ~ f/1.189 (also keep in mind that one stop faster than f/1 is actually ~ f/1.414)--so f/1.2 isn't quite half a stop faster than f/1.4. Of course irrational numbers like the square root of 2 are hard to deal with, so we typically round to nearest tenths for small f/numbers and don't bother to round at all for larger f/numbers.

Cheers,
Jeremy

OK. So when a camera/lens reports an aperture of f/1.4 does that really mean f/1.414 and f/1.2 is actually f/1.189? Ziggy also recently posted that the f-stops in camera systems are actually *not* exactly focal length/diameter because the stops are calibrated to ISO standards and therefore dependent on the transmission of the optics and # of elements making up the lens.... :dunno

Erich

[erich6]

By the way, I think the lens sounds and looks like it's going to be a collector's item but will certainly only appeal to a specialized group. I'll stick with my 50mm f/1.4.

Erich

[David_S85]

Please refer to the following graph. The yellow area clearly indicates how much better the 1.2 is (or will be) over the 1.4 lens.

http://users.aol.com/bikedave1/50mm.jpg

[ubergeek]

OK. So when a camera/lens reports an aperture of f/1.4 does that really mean f/1.414 and f/1.2 is actually f/1.189? Ziggy also recently posted that the f-stops in camera systems are actually *not* exactly focal length/diameter because the stops are calibrated to ISO standards and therefore dependent on the transmission of the optics and # of elements making up the lens.... :dunno

All the math is theory--I'd expect actual lenses not to have aperture settings that are so precise. Does f/1.4 mean f/1.400? I doubt it--it could be f/1.41 or f/1.39 or anything else for that matter. Only the lens manufacturer knows for sure (and then there are manufacturing tolerances as well!) :scratch

Then of course there's the optical transmission thing. No optical element, no matter how advanced the coating, will transmit 100% of the light hitting it--there will always be some loss. However, modern coatings are pretty darned good, transmitting (at least according to some manufacturer claims) in the neighborhood of 99.7% of the light. It's not uncommon to see lenses with 12 groups of elements, which if I'm not mistaken means 24 air/glass interfaces (presumably coated). If we have 99.7% transmission at each of these interfaces, then the transmission through the entire lens will be 0.997 ^ 24 or about 93%. 7% loss is a small fraction of a stop--I'd say that's pretty good.

Are aperture settings calibrated to compensate for (in the above case) 7% light loss? In other words, would that lens' f/2.8 setting actually be somewhat larger than f/2.8 to allow an additional 7% light through? My guess is no, but perhaps someone else has a more authoritative answer.

Cheers,
Jeremy

[Manfr3d]

The only confusing thing about all this is that
there are the exact (mathematical) fstop numbers
and the "rounded" fstop numbers.

The mathematical values are needed for example
when creating your hyperfocal distance chart.
Those values can easily be derived by looking
the area of the aperature and dividing it by 2
to reach the next full fstop.

The easiest way to calculate the full fstops is
to take the powers of the suqare root of two:

sqrt(2)/sqrt(2) = 1.0
sqrt(2) = 1.41
sqrt(2)*sqrt(2) = 2.0
sqrt(2)*sqrt(2)*sqrt(2) = 2.83
...

The "rounded" fstops are not always derived
from the mathematical values by rounding them
mathematically. Sometimes they are only "the
next pretty number, close to the exact value".

f/22 for example is mathematically f/22.6274.

It is also incorrect that a f/1.4 lens is two times
brighter than a f/2.0 lens. It only has a opening
twice as large. How much light passes through the
lens though is determined by the number and
characteristics of the glass elements in the lens,
and not (only) on its aperature.

Back in the old days ppl actually tried to give
lenses an additional value for their "light passing
ability". But this wasn't as convenient as using the
fstop scale instead.

[claudermilk]

Please refer to the following graph. The yellow area clearly indicates how much better the 1.2 is (or will be) over the 1.4 lens.

http://users.aol.com/bikedave1/50mm.jpg

:rofl

A nice graphic representation of the law of diminishing returns! I hate to think where a new 1.0L would fall now. :uhoh

[pathfinder]

In my world, an variation of 1/8th of a stop or even 1/6th of a stop is insignificant to the final image.

As for accuracy of aperture reading by manufacturers - they vary all over the map. See below.

Look at some of your telephoto lenses and measure the diameter in millimeters ( or centimeters if you prefer ). Take this diameter in millimeters, and divide it into the focal length of the lens and see how that compares to the labled fstop. You may find more variation than you think. This is more true for long glass than short focal length zooms.

Canon 300mm f2.8 IS L measures approximately 105mm across the front objective lens.

300mm / 105mm = 2.857 That's an honest f2.8

Sigma 120-300 f2.8 measures approximately 97mm across the front objective.

300 / 97 = 3.09 Not f2.8, but more like f3.1, unless the lenses focal length is shorter than 300 which I suspect it is. This is significantly smaller than the Canon 300 f2.8, and they cannot both be 300mm focal length and f2.8. Do the math.

The Tamron 200-500 f5.6-6.3 measures approximately 80mm across the front lens element ( It uses 86mm filters)

500 / 80 = 6.25 pretty close to the spec'd f6.3 I thought it might be less. But it does AF on a 20D so it must be fairly close to f5.6

The Canon 500 f4 measures 122mm across the front element.

500 / 122 = 4.098 Pretty close to f4.

Tamron 180 f3.5 Di macro measures 60mm across the front element.

180 / 60 = 3.0 Better than the stated f3.5, but that may be to allow for the changes that occur when shooting 1:1

Not sure what all this means, but it is worthwhile to measure the front optics diameter to verify the stated aperture.


The measured diameters of the front optics may vary by a millimeter or so, because the optics are recessed, and I cannot get a ruler exactly to the surface, but must measure with the ruler about 1 cm above the surface of the optics due to the curvature of the lens.

The front element of the 50mm f1.2 must be approximately 42mm in diameter then.