# 50mm Primes that don't suck wide open?



## seamonster (Jul 11, 2013)

In preparation for my upgrade to a 5d3 (from a 60D) later this year I'm trying to compile a list of potential prime lenses to get between the 35 and 100mm range. I've already got a 24-105L and will sell my non-L 70-300 to get the L version. Also have a 50mm 1.8 so I'll need to get a 85 1.8 to get my portrait capability back. 

Then the question remains: Do I keep the little plastic toy (which never use wider than 2.8 anyways) or just get a pancake (which is actually pretty usable wide open, vignetting aside)? Do I even need a 50? I know the 50mm 1.4 isn't great wide open either and has fragility issues but at least it'll work with the automatic CA corrections in the 5d3 (I shoot RAW+jpeg). The sigma 50 1.4 is...really big for a 50mm prime, has AF quality control issues and won't work with auto CA corrections. Rumor mill has it that the sigma 50 is due for a rebody to the "art" line they've got going now but probably won't get an optics refresh... Oh yeah, the 50mm 1.2 is a no thanks I'll keep the money. Everything 50mm seems to be a compromise and you'd think after so many decades of people using such a prolific "normal" lens the designers would have perfected the formulas by now. 

Do I even need a 50?


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## neuroanatomist (Jul 11, 2013)

Get the 40/2.8...


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## RLPhoto (Jul 11, 2013)

F/1.2 - 1.4 - 1.8 are compromises. I wouldn't classify them as suck, I only hold the EF 50mm F/1.0 in that category.

All shot @ f/1.2 50mm.


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## dexstrose (Jul 11, 2013)

Just keep what you have until you get the FF. Shoot with the 50 1.8 and see if you like it on the FF. DOF changes when on FF and there is no 1.6 multiplier like crop. So it might change your mind on what you need.


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## Dylan777 (Jul 11, 2013)

I'll take 40pancake if you don't shoot bigger than f2.8 - smaller, lighter and cheaper. It's sharp wide open.

I wouldn't say that about 50L - you just have to own one


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## bholliman (Jul 11, 2013)

dexstrose said:


> Just keep what you have until you get the FF. Shoot with the 50 1.8 and see if you like it on the FF. DOF changes when on FF and there is no 1.6 multiplier like crop. So it might change your mind on what you need.



+1 

I'm happy with my 50 1.4. I normally shot it at f/2.0 - 2.8, but its nice to have the ability to shoot at 1.4 if I need to for really shallow DOF. The lens is a soft at the corners at this aperture, but I'm normally using it for portraits anyway and don't have my subject in a corner of the frame, so that's OK. The 40mm pancake is a nice little lens. I don't see myself buying once since its so close to the 50mm and I now have a 24-70 2.8 II that can take the place of all primes in the range.


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## retina (Jul 11, 2013)

seamonster said:


> Do I even need a 50?



Only you can answer that really.

Personally I like 35mm better than 50mm on FF and I would consider Sigma 35mm f/1.4. All reviews & user feedback suggest that it's an amazing lens for a very reasonable price.


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## Cali_PH (Jul 11, 2013)

seamonster said:


> The sigma 50 1.4 is...really big for a 50mm prime, has AF quality control issues and won't work with auto CA corrections.



Hmmm...are you sure the Sigma doesn't work with CA corrections? Did you mean in-camera or software? Not saying you're wrong, I'd just be surprised if Lightroom didn't have a profile for that lens. Only usuing LR as an example since that's what I use and it's fairly common, but obviously I don't know what you use.


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## noisejammer (Jul 11, 2013)

I've own the Canon 50/1.4, Sigma 50/1.4, OM 55/1.2, Rokkor PG 58/1.2, Zeiss ZE 50/2 MP, OM 50/1.8 and probably a few others that I can't remember.

First, most full frame digital sensors cannot accept light that impinges from a cone outside the f/1.6 region, so it's moot whether a fast lens is of any particular benefit. Still, I expect this will change over the next year or three as new sensor technologies are adopted. _As an aside, some CSC sensors accept light from far wider angles and CAN exploit f/1.2 optics. I have tested this on my Fuji X-E1._

So based on this, the lens with the best sharpness / bokeh trade-off is a converted Rokkor 58/1.2. It can have difficulty reaching infinity focus but this can be dealt with using live view. I've not observed spherochromatism either. Typically $600+ for one in good condition - quite amazing for a 40 year old lens....

The Zeiss ZE 50/2 MP is superb at all apertures, exhibits negligible focus shift on stopping down and is about as sharp as can be had. It can also do 1:2 macro which is sometimes helpful.

The Sigma 50/1.4 has excellent bokeh but suffers from spherochromatism and considerable focus shift. This is fine provided you don't stop it down - but then it becomes a one-trick-pony.

The Canon 50/1.4 is very good. It does have vignetting when wide open (typical of fast lenses) but its biggest drawback was slow autofocus and fragility. It is a very good lens and excellent value for money.

The OM 55/1.2 is soft when wide open and sharp at f/2. I'm not finished with it yet. typically $550+

The OM 50/1.8 is sharp at all apertures but has weird bokeh - probably a result of its rudimentary aperture control. That said, they can be had for about $30 and are compact, well made and robust.


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## ecka (Jul 11, 2013)

seamonster said:


> In preparation for my upgrade to a 5d3 (from a 60D) later this year I'm trying to compile a list of potential prime lenses to get between the 35 and 100mm range. I've already got a 24-105L and will sell my non-L 70-300 to get the L version. Also have a 50mm 1.8 so I'll need to get a 85 1.8 to get my portrait capability back.
> 
> Then the question remains: Do I keep the little plastic toy (which never use wider than 2.8 anyways) or just get a pancake (which is actually pretty usable wide open, vignetting aside)? Do I even need a 50? I know the 50mm 1.4 isn't great wide open either and has fragility issues but at least it'll work with the automatic CA corrections in the 5d3 (I shoot RAW+jpeg). The sigma 50 1.4 is...really big for a 50mm prime, has AF quality control issues and won't work with auto CA corrections. Rumor mill has it that the sigma 50 is due for a rebody to the "art" line they've got going now but probably won't get an optics refresh... Oh yeah, the 50mm 1.2 is a no thanks I'll keep the money. Everything 50mm seems to be a compromise and you'd think after so many decades of people using such a prolific "normal" lens the designers would have perfected the formulas by now.
> 
> Do I even need a 50?



Well, 40mm in comparison is much closer to 35mm than to 50mm prime and if such angle works for you, then you should consider the new Sigma 35/1.4 ART.
Perhaps, at f/1.4, Sigma 50 is the best prime lens at the moment (at least in sharpness and bokeh quality). Canon's 50L has similar AF problems (focus shift), so (IMHO) it is not a much better solution.


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## dtaylor (Jul 11, 2013)

If you want the blur and/or light gathering ability of a fast 50, the Sigma is the best choice for Canon. The bokeh is amazing and the IQ as good as the 1.2L. 

I suspect a large percentage of the AF QC complaints are actually related to the challenge of shooting wide open and nailing/keeping the plane of focus where you want. With a Canon L fast prime the gut reaction is "what am I doing wrong", but with a 3rd party fast prime it's "what did the manufacturer do wrong."

I have about the same difficulty with any of my fast primes, and my success rate has improved as I've learned better technique.


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## tallrob (Jul 11, 2013)

I've owned the Canon EF 50mm 1.4 and the Sigma of the same specs. Hated the Canon, loved the Sigma, especially the color characteristics. Nicknamed the Sigmalux for good reason. But I'd gladly trade the Sigma 50 for the 35/1.4 as I often feel crowded with the 50 lately.


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## tallrob (Jul 11, 2013)

dexstrose said:


> Just keep what you have until you get the FF. Shoot with the 50 1.8 and see if you like it on the FF. DOF changes when on FF and there is no 1.6 multiplier like crop. So it might change your mind on what you need.



Well, dof of the lens doesn't actually change, just the dof at the equivalent angle of view (as with a 35mm lens on a 1.6 crop sensor). So he can just put his 50/1.8 on his existing 1.6 crop and get a sense of the dof, which he's probably already familiar with. The 1.4 will have only slightly shallower dof.


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## Meh (Jul 11, 2013)

seamonster said:


> Do I even need a 50?



Need? No. But want, yes!


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## ecka (Jul 11, 2013)

tallrob said:


> dexstrose said:
> 
> 
> > Just keep what you have until you get the FF. Shoot with the 50 1.8 and see if you like it on the FF. DOF changes when on FF and there is no 1.6 multiplier like crop. So it might change your mind on what you need.
> ...



FF + 50/1.8 is equivalent to APS-C + 30/1.1
APS-C + 50/1.8 is equivalent to FF + 80/2.8
It's a big difference really


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## GmwDarkroom (Jul 11, 2013)

If you like the 50mm view on the crop, how about the 85mm f1.8? It is quite sharp wide open and about the same price as the 50mm f1.4.


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## Harry Muff (Jul 11, 2013)

24-70 2.8L II?


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## bchernicoff (Jul 11, 2013)

I'm very happy with my Sigma compared to the Canon 1.4

It is bigger/heavier for sure though.


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## seamonster (Jul 11, 2013)

GmwDarkroom said:


> If you like the 50mm view on the crop, how about the 85mm f1.8? It is quite sharp wide open and about the same price as the 50mm f1.4.



already said I'd get it.


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## TommyLee (Jul 11, 2013)

seamonster said:


> In preparation for my upgrade to a 5d3 (from a 60D) later this year I'm trying to compile a list of potential prime lenses to get between the 35 and 100mm range. I've already got a 24-105L and will sell my non-L 70-300 to get the L version. Also have a 50mm 1.8 so I'll need to get a 85 1.8 to get my portrait capability back.
> 
> Then the question remains: Do I keep the little plastic toy (which never use wider than 2.8 anyways) or just get a pancake (which is actually pretty usable wide open, vignetting aside)? Do I even need a 50? I know the 50mm 1.4 isn't great wide open either and has fragility issues but at least it'll work with the automatic CA corrections in the 5d3 (I shoot RAW+jpeg). The sigma 50 1.4 is...really big for a 50mm prime, has AF quality control issues and won't work with auto CA corrections. Rumor mill has it that the sigma 50 is due for a rebody to the "art" line they've got going now but probably won't get an optics refresh... Oh yeah, the 50mm 1.2 is a no thanks I'll keep the money. Everything 50mm seems to be a compromise and you'd think after so many decades of people using such a prolific "normal" lens the designers would have perfected the formulas by now.
> 
> Do I even need a 50?



I have the 50 1.8 ...ok in a pinch I suppose...

but.....NO ....skip the 50mm.....I never found one that I liked

get the sigma 35 f1.4 ...
this is a VERY good 'normal' lens..
it is just GREAT wide open 
sharper than most other lenses ...wide open
clean...from most aberrations..

I just went for a walk with what I think is essential......
an ultrawide 14L II (or choose a 16-35 II)
a sigma 35 1.4....really good value and sharp...and it pops the shots....
and a 100mmL macro (or choose the 135 f2)

add a 12mm tube and a 1.4x TC (a tamron fits the macro or the 135L) - especially with the 135L , 

and insert your .... 5D3

love it all 

I have the 24-105 (nice lens) if I only want ONE lens.... it never fails to please....24mm is pretty wide already
...
and....I also have a few specialty lenses ...85L II, 70-200 f4 I.S., 70-200 f2.8 II.... 24L (mk 1)

but the three basic lenses (100L versus 135L ...you decide)
are enough to do the typical stuff...

start there 
I M O

TOM


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## paul13walnut5 (Jul 11, 2013)

It's not what you want and I do know that, but the sigma 50mm f2.8 macro DG is exceptional wide open.

I'm not suggesting you buy one as it's slow focusing, darker than you probably want, but it does tick the boxes if being the right fl, and being sharp eide open. Even if wide open is f2.8.

On the other hand it will be more forgiving than a very shallow lens on full frame.


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## bvukich (Jul 11, 2013)

RLPhoto said:


> F/1.2 - 1.4 - 1.8 are compromises. I wouldn't classify them as suck, I only hold the EF 50mm F/1.0 in that category.



I really wouldn't say the 50/1.0 sucks, but it is a highly specialized use lens. If you're not sure you need the 1.0, you're definitely better off with the 1.2. If you're positive you need the 50/1.0, there's an 80% chance you're wrong, and you'd still be better off the the 1.2.

But... if you need to shoot a candle lit dinner in a coal mine, and don't mind (or like/want) the "dreamy" look the 50/1.0 gives, there really is no substitute.


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## RLPhoto (Jul 11, 2013)

bvukich said:


> RLPhoto said:
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> 
> > F/1.2 - 1.4 - 1.8 are compromises. I wouldn't classify them as suck, I only hold the EF 50mm F/1.0 in that category.
> ...



If you need a 50mm F/1, get the leica... Or at least rent one.


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## Cannon Man (Jul 11, 2013)

You do need a 50 but they don't have one for you. I sold the 50 1.2 in disgust of how soft the pictures were even stopping down.


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## ecka (Jul 11, 2013)

RLPhoto said:


> bvukich said:
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If you can afford Leica 50/1, then you can afford all the fast 50s in question here (as a backup or just for fun) .


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## paulc (Jul 11, 2013)

The fragility of the Canon 50/1.4 focus barrel is mitigated by never taking the hood off it, even when you put it in your bag. The motor and gears are weak, but at least they're replaceable by laymen.

The real question is if you love the results or not.


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## RLPhoto (Jul 11, 2013)

ecka said:


> RLPhoto said:
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Really, I believe don't so but point here is the Leica 50mm doesn't suck.

http://www.ebay.com/itm/LEICA-NOCTILUX-M-50mm-f-1-11821-E60-/121136252503?pt=UK_Lenses_Filters_Lenses&hash=item1c34488657

http://www.ebay.com/itm/Canon-EF-50mm-f-1-0L-f-1-0-L-f-1LLens-Made-in-Japan-Nr-MINT-/181148016924?pt=Camera_Lenses&hash=item2a2d43611c


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## ecka (Jul 11, 2013)

RLPhoto said:


> ecka said:
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Leica M autofocus sucks  and Canon 50/1.0L is just as good optically, if not better.


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## skullyspice (Jul 12, 2013)

How does the old FD 50 1.2 lens compare to todays 50 1.2?


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## Fleetie (Jul 12, 2013)

noisejammer said:


> The OM 55/1.2 is soft when wide open and sharp at f/2. I'm not finished with it yet. typically $550+
> 
> The OM 50/1.8 is sharp at all apertures but has weird bokeh - probably a result of its rudimentary aperture control. That said, they can be had for about $30 and are compact, well made and robust.



Ah! A Zuikophile!

Yes, I have both of the f/1.2 lenses: The 50/1.2 and the 55/1.2. The 55/1.2 is NOT the older one with the radioactive glass element.

They are both pretty terrible wide-open, but pin-sharp at f/2. 

I did a comparison of those 2 lenses with the Canon 50/1.4. I found that the Canon is faster (i.e. brighter in terms of T-stop or light transmittance) than the Zuiko f/1.2 lenses. But there wasn't a lot in it.

https://www.facebook.com/media/set/?set=a.1282664807273.38454.1849695638&type=1&l=33b6f14d3f

I also have a Zuiko 50/1.4 silvernose that I had cleaned internally and it came back in really good nick, nice and clean.

And a 50/1.4 that has SOME fungus inside but not a huge amount.

And a final-version 50/1.8, the final version they did. That is totally 100% clean inside and out.

One day I intend to do a rigorous comparison of all of them. 

I like the 50/1.8 cos it is tiny (short, almost pancake-y) compared to the f/1.4 and f/1.2 versions. So more portable.

When the EOS M II comes out, I intend to get it and use it (sometimes) with the Zuiko 50/1.8 on it.


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## RLPhoto (Jul 12, 2013)

ecka said:


> RLPhoto said:
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Lol you said the canon 50mm 1.0 was good optically. That's cute.


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## callaesthetics (Jul 12, 2013)

The Sigma 50 1.4 is very good on the Canon 5D3 body. Something about the 5D3 focus system that just makes the Sigma work perfectly. I say this because the same Sigma lens on my old 7D had the usual focus shift inconsistency.


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## ecka (Jul 12, 2013)

RLPhoto said:


> ecka said:
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"Good" and "as good" have different meanings, you know ...  , while "as good" and "as bad" are practically the same thing .


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## adhocphotographer (Jul 12, 2013)

Keep the 50 and see how you like it on FF... at 2.8 there is little difference between it and the 40, but you also get the option of opening it up if you really need to, something the 40 can't!

If you did not already have the 50, i would have said get the 40...


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## noisejammer (Jul 12, 2013)

Fleetie said:


> I did a comparison of those 2 lenses with the Canon 50/1.4. I found that the Canon is faster (i.e. brighter in terms of T-stop or light transmittance) than the Zuiko f/1.2 lenses. But there wasn't a lot in it.


So there are people with taste for older glass on this forum too.  I'd turf out your fungus lens before it infects others and recommend you try the Rokkor 58/1.2.... you will like it.

To business - I'm deeply skeptical that the T-stop of the OM 50/1.2 is slower than the EF 50/1.4. Although there should only be 1/3 stop in it, none of your cameras are capable of detecting light that comes from faster than f/1.6. The 7D (iirc used for your test) is not capable of detecting light from a cone faster than f/2. 

Nevertheless, Canon cameras appear to register better sensitivity when coupled to EF lenses. This is because the camera knows that it's connected to a fast lens and silently boosts its ISO. Of course, it has no idea about the OM 50/1.2, so it does nothing and gives you a faithful measure of the detected light. 

I tested this quite carefully - the trick is to partially rotate the lens so that the electrical connection is severed - it's real. Curiously, my ZE 35/1.4 and Sigma 50/1.4 lenses also appear to be faster than they really are...

Others tested the 50L and found it behaves like a 50/1.6 on a 1D4 / 5D2 and a 50/2 on a 7D. I can't speak to a 5D3 - I decided that I'd be upgrading when I got to be better than my camera.

Canon is not the only culprit caught up in this game. Nikon, Sony and Pentax were also caught cheating customers out of large aperture. Per my comments, my Fuji X-E1 doesn't cheat with SLR lenses (but I've no idea whether it does with fast Fuji lenses.)

Now all this returns to the question of which lens is sharpest wide open. Well, the short answer is they're all pretty good at f/1.6 and excellent at f/2. Since the sensor doesn't actually detect light from a fast cone, it can't contribute to the bokeh - but since it's inside the mirror box, it could bounce around and degrade the contrast. Bear in mind that there's more than half a stop between f/1.6 and f/1.2 so 30% of the light intercepted by the lens is bouncing around...


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## canikon (Jul 12, 2013)

noisejammer said:


> Fleetie said:
> 
> 
> > I did a comparison of those 2 lenses with the Canon 50/1.4. I found that the Canon is faster (i.e. brighter in terms of T-stop or light transmittance) than the Zuiko f/1.2 lenses. But there wasn't a lot in it.
> ...



Uhmmm... I'm getting really confused about what you say.
There is something that I don't get at all.
If say a 5DmkIII can "see" only through a f/1.6 lens, so does this mean that everything faster is pretty much useless?
I do believe that the peripheral illumination could be as you say, so not sensitive from a certain relative aperture onward, but the central portion of the sensor should collect light coming from every angle from the lens aperture.
I am in office now, but I hope to be able to do some testing in this regard.
The test I would do is as follows:
- fix the ISO value
- fix the shutter value
- fix the ambient light level with controlled, artificial light
- take pictures at say f/1.4, f/1.6, f/1.8, f/2.0
- compare the brightness of the central pixel of each picture in the three channels (better to use a white paper i the center of the image so the channels would be roughly the same output)
- check if the RGB brightness will vary between the shots
I am pretty sure that it will.
I hope to be able to do so in the incoming week end.
BTW, I like so much you guys in this forum, you are always able to make me learn or at least think about new issues.
Best regards, have a nice day!


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## mrsfotografie (Jul 12, 2013)

canikon said:


> Nevertheless, Canon cameras appear to register better sensitivity when coupled to EF lenses. This is because the camera knows that it's connected to a fast lens and silently boosts its ISO.



I don't think so, that would make pictures taken with fast Canon EF lenses more noisy. It is a fact though that (depending on your camera model) the AF sensor knows it's a fast lens and this the f/2.8 cross points are activated giving you increased AF performance. This has nothing to do with the imaging sensor.


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## Fleetie (Jul 12, 2013)

noisejammer said:


> Fleetie said:
> 
> 
> > I did a comparison of those 2 lenses with the Canon 50/1.4. I found that the Canon is faster (i.e. brighter in terms of T-stop or light transmittance) than the Zuiko f/1.2 lenses. But there wasn't a lot in it.
> ...



I used the 7D in fully-manual mode with 1/50s and the lenses wide-open.

I have a hard time believing the Canon camera is silently boosting its ISO. 

What ISO gets reported in the EXIF data?

The Canon 50/1.4 produced a slightly brighter photograph than the Olympus 50/1.2.

I am not saying you're lying. I am saying I find it hard to believe.


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## noisejammer (Jul 12, 2013)

canikon said:


> Uhmmm... I'm getting really confused about what you say.
> There is something that I don't get at all.
> If say a 5DmkIII can "see" only through a f/1.6 lens, so does this mean that everything faster is pretty much useless?
> I do believe that the peripheral illumination could be as you say, so not sensitive from a certain relative aperture onward, but the central portion of the sensor should collect light coming from every angle from the lens aperture.
> ...


I think you missed the light from outside the f/1.6 cone arrives at the sensor from a steeper angle. Think of each pixel as a short straw with it's active part at the bottom of the straw and all should be clear - in effect the edge of the pixel vignettes each photodiode. I'd expect the cut off to be gradual as the photodiode is shaded.

After reading a recent Panasonic release (http://goo.gl/279uS) I learned that it is typical for current sensors to accept light that impinges between 15 and 20 degrees from the vertical. This corresponds to a light cone of f/1.86 and f/1.37, in general agreement with my measurements.

When you do your test, remember to half-release the lens from the camera so that the camera doesn't know there's an attached lens. Shoot a manual series (raw, full aperture, trade exposure against ISO.) You can then repeat the set with the lens fully mounted and compare images.

The result will then be fairly obvious. If you have software that allows you to compare pixel levels, so much the better.


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## noisejammer (Jul 12, 2013)

mrsfotografie said:


> I don't think so, that would make pictures taken with fast Canon EF lenses more noisy. It is a fact though that (depending on your camera model) the AF sensor knows it's a fast lens and this the f/2.8 cross points are activated giving you increased AF performance. This has nothing to do with the imaging sensor.


Um... AF performance has* absolutely nothing *to do with bokeh or detected light. Perhaps you should try to understand the post and then do the suggested experiment?

Remember, the boost is at most 1/2 to 1 stop. As it happens, the _image noise does increase - albeit slightly_. It takes considerable care to measure changes in the noise floor, particularly below 1600 - 3200 ISO.


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## Steb (Jul 12, 2013)

dtaylor said:


> I suspect a large percentage of the AF QC complaints are actually related to the challenge of shooting wide open and nailing/keeping the plane of focus where you want. With a Canon L fast prime the gut reaction is "what am I doing wrong", but with a 3rd party fast prime it's "what did the manufacturer do wrong."



I'm sure that is not the only reason (but it might contribute to the Sigma's reputation). I own the Sigma myself, bought it with huge focus shift issues, sent it in for calibration, got it back in much better condition. But still the AF is not that reliable. Sometimes it just fucks up, sometimes it is slightly off in one direction, sometimes in the other.

I shot a Canon 1.4 for one afternoon and had a completely different experience. It was always spot on and I could trust the AF much more. Without any AFMA adjustments.

The Sigma is very useable after the calibration, but there is still a difference to the Canon. That said, I don't like the build quality of the Canon 1.4 and the Sigma has great IQ.


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## canikon (Jul 12, 2013)

noisejammer said:


> I think you missed the light from outside the f/1.6 cone arrives at the sensor from a steeper angle. Think of each pixel as a short straw with it's active part at the bottom of the straw and all should be clear - in effect the edge of the pixel vignettes each photodiode. I'd expect the cut off to be gradual as the photodiode is shaded.
> 
> After reading a recent Panasonic release (http://goo.gl/279uS) I learned that it is typical for current sensors to accept light that impinges between 15 and 20 degrees from the vertical. This corresponds to a light cone of f/1.86 and f/1.37, in general agreement with my measurements.
> 
> ...



Thank you very much for further clarifications.
And thank you very much for the sggestion about disconnecting the electronic contacts between lens and camera. From what you say I beleve that you imply that EVEN IN MANUAL MODE with FIXED ISO the camera is cheating with the iso value, and this fact makes me somewhat angry.
Back to technicalities, I am still confused about the above quoted sentences, as I better explain hereby.
You say that "the light from outside the f/1.6 cone arrives at the sensor from a steeper angle".
I have not read the link you provided, I'll do it later, but at moment something comes to my mind.
Given a certain sensor size, the lens is made such as to project a cone of light suitable to cover that particular format. So for EF lenses the cone should cover a bit ove rthe diagonal of a 24x36 frame.
This fact is COMMON to all EF optics, since all of them have to cover tha same sensor format.
So therefore the MAXIMUM angle of incident light cone on the photodiodes is somewhat fixed, and dependent by the values of sensor size and flange to sensos distance.
The only angle that would change with aperture is the angle that say the rightmost ray of light coming from the exit pupil would see when hitting the leftmost pixel on the sensor, and this depends obviously on the exit pupil diameter rather than on the relative aperture.
In this regard as example, the 50mm 1.4 has a fairly "narrow" exit pupil lens, so I don't see any problem at all, while the 85 1.2 has the biggest exit pupil of any lens (they had to fix the contacts on the flass itself!) so therefrore maybe in that case any problem could arise.
This facts leads to the point that I stated above, that the peripheral portion of the sensor is somewhat not sensitive to extremely fast lenses.
I could compute the incident angle for a 50 1.4 and 85 1.2 doing some simple math on the exit pupil diameter, flange to sensor distance, and full frame diameter.
Therefore I don't see what you say, that the maximun angle would depend solely on lens aperture.
Am I thinking the wrong way?


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## RLPhoto (Jul 12, 2013)

ecka said:


> RLPhoto said:
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Lol because you said the EF 50mm f/1 and good in the same sentence. If you've ever rented one, you'd understand.


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## mrsfotografie (Jul 12, 2013)

noisejammer said:


> mrsfotografie said:
> 
> 
> > I don't think so, that would make pictures taken with fast Canon EF lenses more noisy. It is a fact though that (depending on your camera model) the AF sensor knows it's a fast lens and this the f/2.8 cross points are activated giving you increased AF performance. This has nothing to do with the imaging sensor.
> ...



Perhaps this 'iso boost' can be explained by in-camera peripheral illumination correction. Did you do the test with this particular feature switched off?


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## ecka (Jul 12, 2013)

RLPhoto said:


> ecka said:
> 
> 
> > RLPhoto said:
> ...



Nah ... I'm good without it ;D. I just want Canon to get their $#@% together and make a nice EF 50/2 USM Macro.


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## Steb (Jul 12, 2013)

callaesthetics said:


> The Sigma 50 1.4 is very good on the Canon 5D3 body. Something about the 5D3 focus system that just makes the Sigma work perfectly. I say this because the same Sigma lens on my old 7D had the usual focus shift inconsistency.



Naaa, you are just lucky... ;D


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## mrsfotografie (Jul 12, 2013)

Steb said:


> callaesthetics said:
> 
> 
> > The Sigma 50 1.4 is very good on the Canon 5D3 body. Something about the 5D3 focus system that just makes the Sigma work perfectly. I say this because the same Sigma lens on my old 7D had the usual focus shift inconsistency.
> ...



Same luck here, it focuses perfectly on my 5D2, even with the MkII's lame AF system


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## dtaylor (Jul 12, 2013)

_Since the sensor doesn't actually detect light from a fast cone, it can't contribute to the bokeh_

I'm not sure where you read this, but it's demonstrably false. I'm looking at two 7D + Sigma 50mm shots on my screen right now, f/1.4 and f/2, same subject/distance/etc., and the difference in bokeh is quite clear. There are various sites online which demonstrate fast lens bokeh using both FF and crop, and you can confirm the difference. This guy directly addresses the point: 
http://photo.stackexchange.com/questions/4459/do-dslrs-play-games-with-iso-when-used-with-fast-lenses

The idea that DSLRs can't see light cones beyond a certain point became popular with an open letter at Luminous Landscape:
http://www.luminous-landscape.com/essays/an_open_letter_to_the_major_camera_manufacturers.shtml

I remember reading the letter and doing the test where you defocus and shoot at f/1.4, f/2, and then slightly rotate the lens and compare the shots. Yes, the DSLR is playing with ISO at f/1.4. But it's also quite clear that f/1.4 has more exposure then f/2, i.e. the detached lens shot is between the f/2 and f/1.4 attached shots.

I'm not convinced that this is primarily the result of digital sensors and the angle of the light seen on SLRs. Why?

* The same claim was made in relation to vignetting long before the LL article, but 35mm film shot in a SLR vignettes just as much. Most people just never make the comparison to find out.

* Logically the claim leads to the conclusion you made about bokeh, yet bokeh is observably quite different. The camera can't fake that.

What no one has done, to my knowledge, is very, very carefully shoot and develop 35mm film and check the density to determine the t-stop of a lens at f/4, f/2.8, and f/2, and then compare with f/1.4 to see if there's a shift. That's because this would require equipment most do not have along with meticulous work. It's easy to do these kind of tests digitally, and not so easy to do them and do them right with film. (Looking for vignetting is easy, but precisely determining the exposure received by the film to compute t-stop and compare with digital is not.)

It would not surprise me in the least to discover a t-stop shift at fast apertures due to some factor inherent to lens design and the registration distance in a SLR. We treat f-stop as if the resulting change in exposure is absolute, but it's not. T-stop varies between lenses and with subject distance using the same lens. It wouldn't surprise me to learn that it shifts at fast apertures as well.

Nor does it surprise me that camera companies would compensate for this in firmware.


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## sdsr (Jul 12, 2013)

Only you know whether you need or want a 50mm prime. Since you already have one, see how you like that focal length on your 5DIII when you get it. Also, spend a week or two using only your 24-105 L and see where most of your shots are taken. You may prefer 35mm or wider, or 70mm or longer, or may have, say, three most-often-used lengths - if so, and assuming a prime will offer you something the zoom doesn't, get whatever the closest primes are.

I don't have a lot of experience with Canon 50mms. My 50mm 1.8 was sharp enough wide open to create sharp enough photos in very low light, but I didn't like its bokeh and sold it. Bought a 50mm 1.4, but it often front- or back-focused, or just plain missed altogether (as in nothing at all was properly in focus anywhere in the image); I returned it for a replacement, which is excellent - no focusing problems at all and it's certainly useable wide open (superior bokeh to the 1.8 too). After being impressed by the Sigma 35mm I tried their 50mm 1.4 in the hope that I would land a good copy, but mine seemed to combine all the flaws I had read about - not one photo I took while testing it out was in any way acceptable, so I returned it for a refund in the hope that Sigma tries again before too long (or Canon for that matter - I wouldn't object too much if they added one to their line of IS primes). In the world of M43 the 50mm equivalent, the Panasonic/Leica 25mm 1.4, is impressive even wide open, but of course that doesn't help here....


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## GMCPhotographics (Jul 12, 2013)

seamonster said:


> In preparation for my upgrade to a 5d3 (from a 60D) later this year I'm trying to compile a list of potential prime lenses to get between the 35 and 100mm range. I've already got a 24-105L and will sell my non-L 70-300 to get the L version. Also have a 50mm 1.8 so I'll need to get a 85 1.8 to get my portrait capability back.
> 
> Then the question remains: Do I keep the little plastic toy (which never use wider than 2.8 anyways) or just get a pancake (which is actually pretty usable wide open, vignetting aside)? Do I even need a 50? I know the 50mm 1.4 isn't great wide open either and has fragility issues but at least it'll work with the automatic CA corrections in the 5d3 (I shoot RAW+jpeg). The sigma 50 1.4 is...really big for a 50mm prime, has AF quality control issues and won't work with auto CA corrections. Rumor mill has it that the sigma 50 is due for a rebody to the "art" line they've got going now but probably won't get an optics refresh... Oh yeah, the 50mm 1.2 is a no thanks I'll keep the money. Everything 50mm seems to be a compromise and you'd think after so many decades of people using such a prolific "normal" lens the designers would have perfected the formulas by now.
> 
> Do I even need a 50?



Only you can answer your last statement. 
To be fair a 24-70 f2.8 L does so much and so well, a lot of guys don't need the primes in a post high iso world. it can do all the depth of field isolation at the 70mm end or by getting closer and shooting wider. It's MFD is amazing and it's bokeh is first rate. 
I use a 35 f1.4 and 85 f1.2 a lot. But prefer the f2.8 zoom trinity if I can, light permitting. On sunny days, the primes are too bright and my 5DIII bounces off it's 1/8000th max shutter speed....lol!

There isn't a great 50mm, sorry but that' the truth. The best is certainly the 50 f1.2L but it's not that great. It's ok and it does the job best of all. But it's lacking compared to the 35L and 85L. We are all hoping for a 50L which is worthy of the moniker...but that's probably just a fools hope. I think the 50L was a big wake up call for Canon and every lens since has been stellar.


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## noisejammer (Jul 13, 2013)

dtaylor said:


> _Since the sensor doesn't actually detect light from a fast cone, it can't contribute to the bokeh_
> 
> I'm not sure where you read this, but it's demonstrably false. I'm looking at two 7D + Sigma 50mm shots on my screen right now, f/1.4 and f/2, same subject/distance/etc., and the difference in bokeh is quite clear.


Apologies for trimming your post.

First, I'm well aware of the LL open letter and have referred people to it previously - here, on POTN and elsewhere. 

I observed four effects - 
1. Few people bothered to go to read the reference and digest its content. 

2. It refers to a DXO study and there's a rabid hatred of DXO measurements, particularly since they tend to be quite scathing over Canon offerings. 

3. Few people who read the letter did any testing but this did not prevent them from commenting that it was a lie - perhaps a result of point 2. 

4. There was a lot of nastiness - particularly from owners of 50L and 85L lenses - perhaps because they had a lot of dollars sunk in the lenses.

Because of this, I've changed my approach. I invite people to perform the experiments and simply judge for themselves. It cuts through the internet noise quite effectively.

Bokeh
Ok, so let's assume you've now performed the experiment using a 7D. 

If you did it properly, you will have noted that the image is dimmer when the camera could not communicate with the lens. I venture that the same number of photons hit each pixel (within photon noise and your ability to align the tests) so presumably something else gets changed when the camera communicates with the sensor. 

There is simply no way that a photon that is not detected can plausibly contribute to the bokeh. (If you doubt this, please suggest a mechanism.) Therefore, if there's a difference between in the image quality between (say f/1.4 and f/2), it can't be light that's doing it.

_I strongly suspect that there is some image processing going on inside the camera to deliberately soften the image from lenses that have large apertures._ It may be possible to demonstrate this idea by installing an aperture mask on a wide open lens and seeing whether the image quality changes (say between f/1.4 and f/1.8.)

Finally - another reference that may be of interest http://goo.gl/5We9r . Note how the 7D loses 0.65 EV when the sensor is illuminated by a f/1.4 lens. This strongly suggests that the pixels do not respond to light that's coming from a cone which is faster than f/2. Similarly, a 5D2 and 1D4 will lose 0.44 EV at f/1.4. 

regards etc.


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## dtaylor (Jul 13, 2013)

noisejammer said:


> Ok, so let's assume you've now performed the experiment using a 7D.



You don't have to assume. I explicitly stated this.



> If you did it properly, you will have noted that the image is dimmer when the camera could not communicate with the lens.



I noted this. (Honest question: did you read my entire post?) But I also noted that it was brighter then f/2. At least with my Sigma 50mm f/1.4 the detached f/1.4 shot looks about 1/3 of a stop darker then the attached f/1.4 shot, which means it is brighter then the f/2 shot.



> There is simply no way that a photon that is not detected can plausibly contribute to the bokeh.



Agreed. And since bokeh changes, the photons are being detected. Therefore your theory is incorrect.

Please review the link I provided: http://www.canonrumors.com/forum/index.php?topic=15824.45;topicseen
Please also see: http://www.wlcastleman.com/equip/reviews/50mm/bokeh/bokeh.htm
And: http://www.wlcastleman.com/equip/reviews/aps-c_port/bokeh/85mm/index.htm

Note that in every case the bokeh...specifically the defocus of detail outside the plane of focus...changes as one would expect all the way to f/1.0.



> Therefore, if there's a difference between in the image quality between (say f/1.4 and f/2), it can't be light that's doing it.



We're not observing a difference in image quality, but a difference in defocusing which can only happen if the sensor is seeing the entire light cone.



> _I strongly suspect that there is some image processing going on inside the camera to deliberately soften the image from lenses that have large apertures._



Neither my observations nor the observations linked above are related to softness. Defocus ability is not softness and cannot be simulated by the camera firmware.



> _Finally - another reference that may be of interest http://goo.gl/5We9r . _



That's a dead link.



> Note how the 7D loses 0.65 EV when the sensor is illuminated by a f/1.4 lens. This strongly suggests that the pixels do not respond to light that's coming from a cone which is faster than f/2. Similarly, a 5D2 and 1D4 will lose 0.44 EV at f/1.4.



Bokeh / defocus change as expected with the change in aperture. This means the pixels are responding to light from a cone which is faster then f/2.

Either the cause of the shift in t-stop is something unrelated to digital, or the sensors see the full light cone but with some intensity loss at certain angles. Or some combination thereof. But the idea that the sensor cannot see any portion of the light cone beyond f/2 is demonstrably false.


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## skitron (Jul 13, 2013)

mrsfotografie said:


> Steb said:
> 
> 
> > callaesthetics said:
> ...


Ditto, mine works perfectly. Had to send it to Sigma, but it came back spot-on at any distance.

For the price it's very good. I do like the asthetic of the Canon 1.2 better, but then that difference is +$1100...


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## AJ (Jul 14, 2013)

Here's the thing about the 40/2.8, in my humble opinion.

This lens could easily have been speced at f/2. However it isn't. Canon made the diaphragm to open up only to f/2.8 so that it's sharp "wide open". This satisfies the testchart-shooters, and ensures the lens gets good reviews.

Personally I like a lens that opens a little wider, even if that results in a little softness. I like my 50/1.8 and I accept the fact that it's not razor sharp at f/1.8. However it is cracking sharp at f/2.8 so that's what I stop down to when I need more sharpness. It's all about knowing the characteristics of the lens and working with it.

Here's the other bit about fast lenses: it's all about what's not in focus, i.e. bokeh. Sharpness in the center still matters, somewhat, but sharpness in the corners wide-open is completely moot for most purposes (except perhaps astrophotography).


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## Pixelsign (Jul 14, 2013)

there is only one really sharp 50:
Carl Zeiss Distagon T* 1,4/55


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## Sporgon (Jul 14, 2013)

AJ said:


> Here's the thing about the 40/2.8, in my humble opinion.
> 
> This lens could easily have been speced at f/2. However it isn't. Canon made the diaphragm to open up only to f/2.8 so that it's sharp "wide open".




Not so. I think you'll find the Canon 40mm design is identical to the 40mm Pentax M f2.8 of 1975, produced as a budget 'kit' lens for the diminutive ME and MX, although the term 'kit lens' hadn't been coined then. 

The Voightlander 40 is different.


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## mrsfotografie (Jul 14, 2013)

Sporgon said:


> AJ said:
> 
> 
> > Here's the thing about the 40/2.8, in my humble opinion.
> ...



The Voightlander 40 is an interesting lens, I've got one. I only use it on special occasions though, when I like to go MF and portable. It's a great little lens to help boost creativity because I find 40 mm (on full frame) a challenging focal length. Reasoning behind that is that 40 mm is as 'normal' as you can get so it takes extra care to make interesting photo's.


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## paul13walnut5 (Jul 17, 2013)

If you are able, check out this weeks Amateur Photographer magazine (UK) big group test review of 50mm lenses from all the main manufacturers and third parties such as Sigma and Zeiss. The results are quite surprising.
They do a months free trial for the ipad version if thats any use...


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## RGomezPhotos (Jul 17, 2013)

I tried both the Canon 1.2 and Zeiss 1.4. I bought the Zeiss because of it's contrast characteristics. I also like the bokeh compared to the Canon. I think it's also sharper. I remember the Canon being a good deal soft at big apertures. But the Zeiss is MF only. Which is fine for me.

The only 50mm that's going to trump both of these is a Leica with a Canon adapter. And that lens will cost more than both of these combined. But the Zeiss 55mm that's coming out soon will be even pricier than that!


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