Why the 50 1.4 is NOT a good low light lens.

[bennyboy]

F2 ISO400, not the darkest of situations but my 50 is pretty sharp at f2.

 

http://www.photo.net/photo/4203337

[apdx]

"When you need 1.4, you need 1.4."

 

You need a good 1.4, not the Canon one. One could try competition first. All Canon's fifties are poorly designed and overpriced. Barrel distortion is a signature fature for one.

 

The Canon 85L is a superstar though.. At any f value

 

Lucas, your post is a good service for newbies. Most of them are mislead by raving reviews of 1.4 owners who never owned a better lens.

[edgreene]

Using a body capable of Interchangeable focusing screens helps.<br> So does manual focusing.<br>A body capable of at least ﾖ1EV also helps.<p>There are some circumstances where the <I><b>body is king</b></I>, damn that oft-repeated but still sophomoric ﾓ<I>Itﾒs the lens that makes the shot</I>ﾔ mentality. <p>Get a full ﾓProﾔ body, the ones made to <I>wring the <u>very best</u></i> out of a lens.<br>Anything less is a compromise.<br>Me? In low light, I revert to my old and trusted T-90-multi-spot metering body with a 55mm, f/1:1.2 S.S.C. lens;<br>when I've gotta-gotta-gotta make the shot.<br>*Yeah, it's film, but then, I always use the body/lens combination that works.

[w_t1]

I'm with Ed on this one, I learned on FD lenses, which I still use on the T-90, F-1 and others....and I don't know why folks have such a hard time using manual focus. Perhaps it's the auto-everything Bill Gates-inspired generation. Heck, even on the few EF lenses I use, I use manual focus at least half the time, 20, 50, and 200 2.8, on film and digital. Combine manual focus with a tripod.

[awindsor]

<blockquote>

You need a good 1.4, not the Canon one. One could try competition first. All Canon's fifties are poorly designed and overpriced. Barrel distortion is a signature fature for one.

</blockquote>

The 50/1.8 is definitely not overpriced. The 50/1.4 is poorly designed (the FTM clutch) and overpriced. Both feature designs without a floating group and so will exhibit barrel distortions when focused on a near subject. The 50/2.5 does not exhibit barrel distortion at any distance. <P>

 

Canon could do with updating some of their primes. I have the 50/1.8 and the 35/2. Both have very slow focus motors though I find they focus fairly reliably even in very low light (I got lucky with my 50/1.8). I am waiting for proper USM on a 50. The 85/1.8 (though not a sharp as the "too soft" 50/1.4) is much more pleasant to use.

[lester_wareham]

The low light AF performance is a function of the camera and not the lens, it depends on the AF sensor sensitivity. A 1Dx may do better, cheaper to use manual focus although I don't generally find this problem.

 

Any very fast lens will not be so sharp wide open. With this lens just half a stop closed will make a large differnce. This is part of the teritory with fast lenses. No doubt if you 3-5 times as much you **might** get better performance.

 

The 50/1.4 is probably the sharpest Canon lens but does suffer some CA wide open, some people think this gives portraits a nice glow!

[davidroossien]

Lucas, you're missing my point because I did not explain it very well.

 

You say that you need autofocus because "The viewfinder is so small and the focus so critical."

 

My point: the viewfinder is so small, how do you even know what you're focusing on?

 

The camera/lens may focus quickly, but is it focusing on the right thing? How can you tell? You say the viewfinder is so small.... How does autofocus make this better... It doesn't. With autofocus you must select 1. a point in the scene where you want to focus. 2. Align sensor with that point. 3. Press 1/2 down to focus. 4. Re-frame the shot. 5. Verify visually that you have the correct point in focus. 1-4 are additional steps that can be avoided with manual focus.

 

Forget autofocus speed. I say use manual focus, even on a 20D. With practice your results will become better.

 

I'm guessing that your sharpness issues are not so much related to the lens and f-stop (you should be shooting at f2, not f1.4) and are really: 1. Related to trying to use the 20D's small viewfinder for low light shots and 2. Related to trying to use autofocus (which wastes time and is not more accurate than using manual focus, simply wasting time while the scene is potentially changing)

[awindsor]

<blockquote>

The low light AF performance is a function of the camera and not the lens, it depends on the AF sensor sensitivity. A 1Dx may do better, cheaper to use manual focus although I don't generally find this problem.

</blockquote>

 

No. Low light AF performance is a function of the lens and the body. I depends in a rather complicated way on the lens' maximum aperture, focus motor, and focus throw. The faster the lens is the more light it lets in and hence the more light there is for the AF sensor to work with.

[lucas_jarvis]

If the camera body is using the lens at 1.4 at all times for it's autofocus functionality, isn't it being crippled by it's softness at this aperture? Wouldn't the body have a hard time finding a focus lock because of this? If this EXACT same lens was using f2.2 for focusing, wouldn't it find it easier to lock focus, but lose a little brightness in the viewfinder?

[myrjola]

<P>As everybody has chimed in on this, I'll give my own opinion about the 50mm f/1.4 as well.</P>

 

<P>Personally, I haven't had much trouble with the AF and the 50mm f/1.4 & 20D combo even in very low light (I recently shot some pictures of an acquintance participating in country dance competition in dim nighclub-like environment; in most of the photos, the focus was pretty accurate). It's not as fast as the AF on my other lenses (the difference between Micro USM and Ring USM, I guess...), but accuracy appears to work for me.</P>

 

<P>But my copy of the lens <B>does</B> have significantly degraded sharpness when used wide open; it appears that the jump from f/1.4 to f/1.6 increases sharpness at least as much as going from f/1.6 to f/2.0. It's still good enough at least for the 15x10cm photos (especially as the sharpness difference between the focused area and OOF areas is often quite huge), but I admit that this is something that the lens might need improvements in. The difference between wide open and slightly stopped down is not as big on any of my other lenses.</P>

 

<P>So, it is by far the most useful available light lens I currently have (not perhaps a mean feat, as others are 17-40L f/1.4 and 70-300 DO IS :), but it does have some imperfections. Yeah, a tripod is of course the ultimate solution, but whereas the camera and my three lenses are fairly convenient to carry with me almost all the time, a tripod is not...</P>

[lucas_jarvis]

***My point: the viewfinder is so small, how do you even know what you're focusing on?

 

I can still make out the general subject that I'm focusing on. It's not THAT small of a viewfinder. It's just the small details that are hard to distinguish. Am I focused on the ear, or the eyes? (Just curious, have you tried using a crop camera with manual focus?)

 

***The camera/lens may focus quickly, but is it focusing on the right thing?

 

Yes (using my 24-70L for example)

 

***How can you tell?

 

It makes a little beep confirming lock. I then reconfirm later in post processing. It's very reliable and rarely lets me down.

 

***You say the viewfinder is so small.... How does autofocus make this better... It doesn't. With autofocus you must select 1. a point in the scene where you want to focus. 2. Align sensor with that point. 3. Press 1/2 down to focus. 4. Re-frame the shot. 5. Verify visually that you have the correct point in focus. 1-4 are additional steps that can be avoided with manual focus.

 

I really believe that there would be few who would be able to walk into a live event in a low lit hall (a fast paced test of focus in low light) and be able to maually focus a 50 1.4 on a crop camera and keep up with someone useing a 24-70L in autofocus. And the guy who's there with his 50 1.4 trying to use AUTOFOCUS, he's even MORE doomed.

 

 

Please note: There ARE people that can manual focus in this situation and keep up, but they are an extreme rarety for sure. I had to write this in because I know that person is probobly reading all of this and is like "WHAT!? I'd manual focus your ass all over that hall!"

 

LOL

[lucas_jarvis]

Mika, how 'bout selling me that 17-40L f1.4 you have there :)

[myrjola]

Oops. I suppose it's time to get some sleep when I type something like that (the 17-40L f/1.4, that is). Or perhaps I was already dreaming about that one :)

[digitmstr]

Lucas, the 50 f/1.4 is a GREAT low light lens! But, It's NOT a sports/action lens, obviously.

 

Also, at f/1.4 the DOF is VERY shallow and you can be sure that what some people call the lens "lack of sharpness" is due to the limited DOF, as you know.

 

If you need faster AF in very low light situations get the 85 f/1.8 and you're set.

[desmond_kidman]

Every try a Leica R 50 1.4 wide open? Even if you don't have access or a friend to take a couple of shots, look at the MTF of the lens. Look at a Nikon 1.4 wide open. In MF, look at a Hasselblad/Zeiss 80 2.8 wide open.

 

We're so used to 1.4 normal lenses that we forget, that's a big aperture. The all lose a lot compared to a few stops down.

 

I wish Canon would come out with a 1.4 L and make it a show stopper, or the rumored 1.2 and make it killer at 1.4, but there probably is not much of a market.

[andrew robertson]

I find that if I am careful with selecting an AF target, the 50 f/1.8 II does a damn fine job in

almost any light.

[peza]

Yes - sad truth, 50/1.4 is not sharp @ 1.4. One call it creamy, one dreamy, one soft. Get 85/1.8, 35/2.0 or 24/1.4L and never look back :)

[andrew robertson]

24 f/1.4 L has far worse MTF curves than the 50 f/1.4 wide open.

[lucas_jarvis]

I've just looked up the 24mm L and it doesn't seem to be far worse than 50mm when it comes to MTF charts. It's center loses by just a smidge. Actually, it looks to have a larger area of sharpness in the center of the frame when wide open, while the 50mm drops off faster at the edges. I've never used the 24mm, so I'm not sure how well it focus's in low light. Does it hunt? It seems to me that the 85mm 1.2 L is the 'king' of low light lenses. The MTF shows it to be a great performer even at 1.2. I've also not had the opportunity to use this lens either. Does it hunt? I'm assuming it doesn't. I'm sure if it did the new version just being released would take care of that.

[andrew_c2]

I use a 50/1.4 SMC Takumar on my 350D combined with a Katzeye split prism screen. I find this more effective in lowlight than a USM 50/1.4.