16-35mm f2.8 L or 17-40mm L fast focusing...

[Discreet]

woops, i made a mistable. You can turn off the AF assist but not the main gun...

I mean if you are really hard core, you can tilt the main flash backwards or try some way to reduce the power by FEC or putting a black paper on it perhaps? When i was using a 420 EX, i just tilted the head backwards... but after a while people were complaining that they were getting blind....

 

[Snoweagle]

the 2 post does not make sense.

first post 18, you said barrel size makes focusing slower because being a 50mm 1.4, the barrel is larger

now post 22, you said large barrel size + large aperture + USM = aperture by your accounts 50mm 1.4 should focus faster than 16-35 because by your OWN theroy 50mm barrel size is larger, has a larger aperture size with USM.

so have you own the 16-35mm or 50mm 1.4?

which is faster?

Why are you so contridicting?
:devil:

I'm not contradicting, it's a fact. I've tried both lens before and the 16-35 does focus faster than the 50 1.4 but not a lot. 50 1.4's barrel size is not larger by the way.

 

[Snoweagle]

I try not to take portraits with wides as the distortion on the face can be quite pronounced. With longer lenses it looks nicer plus the bokeh is really sweet ..

Correct, but the distortion is not so bad at the wide end for canon lenses.

 

[Belle&Sebastain]

I'm not contradicting, it's a fact. I've tried both lens before and the 16-35 does focus faster than the 50 1.4 but not a lot. 50 1.4's barrel size is not larger by the way.

Your this post just contridicts post 22.

Larger barrel size + large aperture + USM = faster AF

 

[Belle&Sebastain]

Correct, but the distortion is not so bad at the wide end for canon lenses.

what is the distortion percentage and compared to what is the distortion 'not so bad'?

 

[Snoweagle]

Your this post just contridicts post 22.

Haiz nvm, think u dun get what i mean.

 

[sehsuan]

One of the reasons for slow AF on 85/1.2L is because of the sheer weight of the focussing group(s) involved. The "long throw" is possibly because of Canon's desire to make sure during manual focussing, the change is minute and more precise - but do not forget one thing - this lens was probably made to focus-by-wire to work during manual focussing by means of being electronic-powered, not actual MF (meaning, you have to power on the camera to even shift the focus).

For the other lens, the USM systems may be holding on to the lighter groups for AF; hence the fast speed. Of course, other factors such as the maximum aperture would be a difference. The only way to test, is probably to use the same camera with all the different lenses mentioned, to make an educated guess.

 

[Snoweagle]

what is the distortion percentage and compared to what is the distortion 'not so bad'?

How would i know the percentage? If a person who's buying a lens, he won't go find out the technical details on this. It's only when you see it with your own eyes then decide whether to get or not.

 

[Belle&Sebastain]

Haiz nvm, think u dun get what i mean.

because your posts contridicts one another.

 

[Snoweagle]

because your posts contridicts one another.

It ain't contradicting, i'm just trying to state one point. Maybe i explained too cheem.

 

[Belle&Sebastain]

It ain't contradicting, i'm just trying to state one point. Maybe i explained too cheem.

oh please, others have point out your posts have little creditbilty. dun say too cheem, just explain post 18 and 22, which is opposite of each other.

 

[Snoweagle]

oh please, others have point out your posts have little creditbilty. dun say too cheem, just explain post 18 and 22, which is opposite of each other.

Then oh please also....dun wish to create anymore conflicts, say whatever u want, i'm staying put.

 

[Belle&Sebastain]

Then oh please also....dun wish to create anymore conflicts, say whatever u want, i'm staying put.

all i wish for you is to think though and write to inform others, by misinforming people with the little information you know, you create lots of mistakes.

If you still take your stand that you are correct, then i have nothing to say but your post hold very little value to others that read your mistakes.

 

[Snoweagle]

all i wish for you is to think though and write to inform others, by misinforming people with the little information you know, you create lots of mistakes.

If you still take your stand that you are correct, then i have nothing to say but your post hold very little value to others that read your mistakes.

Suit yrself, i've nothing to say too but if u want more info abt fast lens, read the article link i posted earlier on.

 

[Belle&Sebastain]

Suit yrself, i've nothing to say too but if u want more info abt fast lens, read the article link i posted earlier on.

i want to know HOW BARREL SIZE affects focusing SPEED?

bigger slower or faster?
too chiem to understand, please explain in simple english.

what has barrel size got to do with focusing speed as you claim, EXPLAIN!

stop walking around in circles

 

[drumma]

all i wish for you is to think though and write to inform others, by misinforming people with the little information you know, you create lots of mistakes.

If you still take your stand that you are correct, then i have nothing to say but your post hold very little value to others that read your mistakes.

u've got a supporter here. i've been reading most of your replies and found it quite amusing to a certain extent.

i'm still very interested how a bigger barrel size can have fast focusing?

I'm not contradicting, it's a fact. I've tried both lens before and the 16-35 does focus faster than the 50 1.4 but not a lot. 50 1.4's barrel size is not larger by the way.

and i guess why it's contradicting, is because of the way you phrased it.

50 1.4's barrel size is not larger by the way. gives ppl an impression that it's the same.

 

[Snoweagle]

Go read one by one folks. I've done my time, no point continuing saying again n again!

 

[Zack]

Suit yrself, i've nothing to say too but if u want more info abt fast lens, read the article link i posted earlier on.

Actually I read the article link that you posted earlier ler.... I can't find any info on how barrel size affects focussing speed, other than one sentence stating it without giving any further explanation :dunno:

Mebbe you can elaborate more?

 

[Splutter]

I think having a bigger barrel allows more light to enter, and hence easier for the sensors to focus, but how fast it focus will be determined by many other factors mentioned.

 

[sehsuan]

Oddly enough, I've read through every post, and still end up as lost.

My personal view: in really low light, the 50/1.4 should focus a LOT more accurately than the 16-35. SHOULD, but not MUST. In daylight etc, the 16-35 MAY focus a lot faster, knowing that the USM is Ring type, and not MicroUSM type.